1. Introduction
Cancer is one of the leading causes of disease and death worldwide. In 2008, an estimated 12.66 million new cases of cancer occurred, excluding nonmelanoma skin cancer, and 7.56 million cancer deaths (approximately 13% of all deaths) [ 1 ]. The most frequent types were lung, prostate, colorectal, stomach, and liver cancer for men, and breast, colorectal, cervix uteri, lung, and stomach cancer for women. However, in the United States in 2011, cancer deaths accounted for 23% of all deaths [ 2 , 3 ].
Although much of the war on cancer emphasizes early detection and treatment, the burden of cancer will remain high unless the primary risk factors for cancer are understood and addressed. A general understanding exists of many of the cancer risk—modifying factors; for example, according to the World Health Organization (WHO) [ 4 ].
About 30% of cancer deaths are due to the five leading behavioral and dietary risks—high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco use, and alcohol use.
Tobacco use is the most important risk factor for cancer, causing 22% of global cancer deaths and 71% of global lung cancer deaths.
Cancer-causing viral infections such as hepatitis B and C viruses and human papillomavirus are responsible for up to 20% of cancer deaths in low- and middle-income countries.
The American Institute for Cancer Research/World Cancer Research Fund [ 5 ] recommends limiting intake of red meat and avoiding processed meat, eating mostly foods of plant origin, and limiting consumption of energy-dense foods, which includes sugary drinks.
Several epidemiological approaches are used to investigate cancer risk-modifying factors. These approaches include case-control studies, nested case-control studies derived from cohort studies, and ecological studies. Multicountry ecological studies have been used to identify and quantify risk factors for cancer. In 1975, examined dietary links to cancer by using incidence data for 27 cancers from 23 countries and mortality rates for 14 cancers from 32 countries [ 6 ]. They found that meat consumption was an important risk factor for colon cancer and that fat consumption was an important risk factor for breast and endometrial cancer. Per capita gross domestic product (GDP) also highly correlated with these cancers.
Both single- and multicountry ecological studies offer evidence that solar ultraviolet-B (UVB) irradiance, through production of vitamin D, reduces cancer risk [ 7 , 8 , 9 , 10 ]. The UVB–vitamin D–cancer hypothesis has received reasonable support in other types of studies, including case-control and nested case-control studies, and the mechanisms whereby vitamin D reduces risk of cancer are well known [ 11 , 12 ]. The UVB–vitamin D–cancer hypothesis is thought to generally satisfy the criteria for causality in a biological system outlined by Hill [ 13 ] for several cancers [ 14 , 15 ].
Using the ecological study approach, this study presents results with cancer incidence data for 87 countries with high-quality mortality rate data and 157 countries total with respect to dietary supply and other factors, including per capita GDP, life expectancy, smoking, and latitude (an index for solar UVB doses). I then compare the results to published results from observational studies.
2. Data and Methods
The hypothesis tested in this study is that various cancer risk-modifying factors affect cancer incidence rates at the national population level and the relative contributions to cancer risk can be determined. The risk-modifying factors considered in this study include alcohol consumption, animal fat consumption, animal product consumption, cereals consumption, gross domestic product, life expectancy, solar UVB and vitamin D production, and sweeteners consumption. Other components of diet, such as eggs, fish, meat, and milk, were considered, but since they are highly correlated with total animal product supply, it was not though that any one of these factors would alone explain the finding for total animal product supply. Other cancer risk-modifying factors were not considered; generally due to the fact that it would be difficult to obtain or develop and index that could be used for all countries. Some of the factors omitted are discussed later.
Cancer incidence data for 2008 came from GLOBOCAN [ 1 ]. I chose countries used in this study according to two criteria. First, the country must have dietary supply data from the Food and Agriculture Organization published in printed form for 1992–1994 [ 16 ]. The reason for this requirement is that diet may affect the risk of cancer 10–30 years before cancer develops [ 17 , 18 ]. Second, the country must have more than 100,000 inhabitants in 1992–1994 since developing robust cancer statistics for countries with fewer inhabitants is difficult. A total of 157 countries met both criteria. Of those, 87 countries have level 1 or 2 quality data (hereafter, high-quality data), on the basis of classifications by WHO for deaths in 2001–2002 [ 19 , 20 ]. Appendix lists countries used in this study.
Dietary supply data came from the Food and Agriculture Organization, both from the book published in 1996 for 3-year averaged data from 1979–1981 to 1992–1994 [ 16 ] and from their website for single-year averaged data for 1995 and 2000 [ 21 ]. I obtained values for alcohol, animal fat, animal product energy, cereals, energy (total), fat, fish, and meat. I used data for various years since a 10- to 30-year lag generally exists between national dietary changes and cancer incidence rate [ 17 , 18 ]. For example, animal product energy supply increased in the 1990s for some countries but decreased in other countries; varying the year of the data serves to help estimate the lag between dietary change and cancer incidence.
I used lung cancer incidence rates as the index of health effects of smoking. Ecological studies of cancer in Nordic countries have used lung cancer incidence rates [ 22 ], and ecological studies in the United States [ 8 ] and Spain [ 23 ] have used lung cancer mortality rates. Lung cancer incidence or mortality rates are ideal since they integrate the effects of smoking over many years [ 24 ]. Also, cigarette consumption data are not available for all countries. A possible downside is that diet and other factors, such as solar UVB doses/vitamin D [ 25 ], can also affect risk of lung cancer. However, as results for various cancers will show, this does not present a problem.
Nonetheless, I obtained data for cigarette consumption per capita for 1990 from WHO, generally of the form used on its data sheet for Poland [ 26 ], with the country name changed for different countries. Some URLs were of a slightly different form and found through additional Internet searches. I chose the year 1990 since lung cancer takes many years to develop and I judged the data for 2000 to be too recent. I could have used data for 1980 although fewer countries have data for 1980, but the data for 1990 serve the intended purpose to show that lung cancer is strongly linked to cigarette consumption. I obtained data for 71 countries, including 54 countries with high-quality cancer incidence data and life expectancy greater than 60 years for males in 1990. I apportioned the cigarette consumption data to males and females in proportion to the male–female balance of lung cancer incidence rates in each country in 2008.
The index used for socioeconomic status is GDP per capita for 1999 from the International Monetary Fund [ 27 ]. Data were available for 143 countries. However, the analyses omitted data for one country, Brunei, since the high per capita GDPs for this country were acquired recently and probably have not been shared with many in the country’s population, such as guest workers. I considered two other sets of data: International Monetary Fund data for 1989 [ 27 ] and CIA values for 2008 [ 28 ]. Among concerns regarding the 1989 data is that many countries were not included, in part since they were not independent countries then, and that 1989 was 19 years before the cancer incidence data. One problem with the 2008 data is that the data are for the same year as for cancer incidence rates. However, GDP per capita for the year of cancer incidence could reflect cancer screening rates for breast, colorectal, and prostate cancer.
The analyses also used latitude of the approximate center of population of each country. This index is considered an index of annual solar UVB doses.
I obtained life expectancy data for males in 1990 for 151 countries from World Health Statistics [ 19 ]. For some cancers, cancer rates correlated with life expectancy for countries with life expectancy greater than 60 years.
I analyzed the countries in three different sets: the entire set (157 countries); that for countries with life expectancy of 60 years or greater for males in 1990 (100 countries); and countries with high-quality data in 2001 and 2002 for causes of death according to [ 15 , 19 ], along with life expectancy greater than 60 years for males in 1990 (87 countries). I estimated cancer incidence rates for the remaining 70 countries from data for countries with high-quality data [ 20 ]. Thus, rates are not entirely independent of rates in countries with high-quality data; however, values for risk-modifying values should be independent. When the incidence rate was zero, I omitted the value. KaleidaGraph [ 29 ] created the graphs.
I ran regression analyses by using IBM SPSS Statistics 20 (Armonk, New York, NY, USA). The analyses included various combinations of risk-modifying factors for each type of cancer and for both sexes. I eliminated those factors with large p values and reran the regression. For factors that had two or more sets of data for various years, such as animal products, cereals, and sweeteners, I used pairs of data to see which had the stronger correlation. This was a useful step since not all countries had values for each year. When multiple linear regression analysis found significantly correlated factors, I ran each factor in a linear regression analysis to see whether each was independently significantly correlated with cancer incidence rates and with the same direction (direct or inverse) since the factors are highly correlated and can interfere with each other. The final analysis omitted those not independently correlated.
Table 1 lists cross-correlation coefficients for various risk-modifying factors for the 87 countries with high-quality data. Most factors are highly correlated with each other, except sweeteners. Latitude is highly correlated with energy from animal products (0.74 < r < 0.79). Cereals are inversely correlated with all other factors.
3. Results
Table 2 gives regression results for the set of 87 high-quality countries. Significant results emerged for 21 cancers as well as all and all less lung cancer for countries with high-quality data. The regression found no significant results for esophageal, gallbladder, and stomach cancer.
Table 3 gives regression results for all 157 countries. The regression results for the 100 countries with male life expectancy greater than 60 years in 1990 were similar to those for the other two sets of countries (data not shown).
Table 4 gives the numbers of cancers significantly correlated with each risk-modifying factor for the two sets of countries. Four factors have significant correlations with a reasonable number of cancer types: lung cancer, energy derived from animal products, latitude, and GDP. Alcohol supply is associated only with colorectal cancer.
The results for animal product energy show that data for 1990 have the most high-significance correlations with cancer incidence, indicating about a 15- to 20-year lag between diet and cancer incidence. Prostate cancer has the longest lag, 28 years.
Life expectancy is significantly associated with several cancers: brain and colorectal cancer, leukemia, and multiple myeloma.
Latitude is directly correlated with several cancers: bladder, brain, kidney, lung (females), melanoma, and Hodgkin’s lymphoma, and inversely correlated with cervical, lip, and thyroid cancer. Latitude is generally not found significantly correlated with cancer incidence rates if animal product energy is; this is the case for 11 cancers. Both animal product energy and latitude were significantly correlated for only two cancers: brain and kidney cancer. Evidently when energy from animal products is significantly correlated with cancer incidence rates, it overwhelms the effect of latitude.
Lung cancer was directly correlated with cigarette consumption per capita for both sexes as well as animal fat in 1993 and latitude.
The regression results for all cancer less lung cancer for both males and females for high-quality countries found a significant correlation between energy derived from animal products and lung cancer. Alcohol and latitude were also directly correlated with all cancer less lung cancer for females, whereas cereals were inversely correlated.
4. Discussion
The lag of 15–20 years between energy derived from animal products is supported from studies of cancer trends in countries undergoing nutrition transitions: 15–27 years for colon cancer mortality rates in Japan [ 30 ], 20–31 years for breast cancer mortality rates in Japan [ 18 ], and 10 years for mortality rates for several cancers in several Southeast Asian countries [ 19 ]. Studies reporting early-life effects on risk of prostate cancer [ 31 , 32 ] support the finding of 28 years for prostate cancer.
Other evidence supporting the role of energy derived from animal products as important risk factors includes the finding that Seventh Day Adventists, who generally are lacto-ovo vegetarians who do not smoke or drink alcohol excessively, have lower cancer rates than do others living in the same region [ 33 , 34 , 35 ].
Table 1
Cross-correlations of factors used in this study for the 87 high-quality countries *.
—: no significant results; *: if p < 0.001, value omitted; F: female; M: male; Animal en, Animal energy. After obtaining results of the regression analyses, I searched the journal literature through PubMed.gov for papers that supported the findings for risk-modifying factors for each type of cancer. The search was not meant to be comprehensive or to provide enough information to conclude whether the support could be considered definitive.
| Factor | Animal Energy, 1980 | Animal Energy, 1985 ( r , r 2 , p ) | Animal Energy, 1990 ( r , r 2 , p ) | Animal Energy, 1993 ( r , r 2 , p ) | Animal Energy, 2000 ( r , r 2 , p ) | Animal Fat, 2000 ( r , r 2 , p ) | Cereals 1993 ( r , r 2 , p ) |
| Alcohol, 1993 | 0.62, 0.37 | 0.66, 0.43 | 0.71, 0.49 | 0.63, 0.38 | 0.65, 0.41 | 0.67, 0.44 | −0.51, 0.24 |
| Animal en, 1980 | 0.99, 0.98 | 0.96, 0.92 | 0.94, 0.87 | 0.94, 0.87 | 0.92, 0.85 | −0.59, 0.34 | |
| Animal en, 1985 | 0.98, 0.96 | 0.96, 0.92 | 0.94, 0.88 | 0.95, 0.90 | −0.61, 0.36 | ||
| Animal en, 1990 | 0.99, 0.97 | 0.95, 0.89 | 0.95, 0.90 | −0.61, 0.36 | |||
| Animal en, 1993 | 0.95, 0.91 | 0.95, 0.90 | −0.58, 0.33 | ||||
| Animal en 2000 | 0.99, 0.98 | −0.60, 0.36 | |||||
| Animal fat, 2000 | −0.60, 0.35 | ||||||
| Factor | Fat, 2000 ( r , r 2 , p ) | GDP 1999 ( r , r 2 , p ) | Latitude ( r , r 2 , p ) | Life Expectancy ( r , r 2 , p ) | Lung Cancer, M ( r , r 2 , p ) | Lung Cancer F ( r , r 2 , p ) | Sweeteners 1990 ( r , r 2 , p ) |
| Alcohol, 1993 | 0.63, 0.39 | 0.57, 0.31 | 0.51, 0.25 | 0.47, 0.21 | 0.53, 0.27 | 0.45, 0.19 | 0.13, 0.001, 0.30 |
| Animal en, 1980 | 0.81, 0.64 | 0.74, 0.54 | 0.79, 0.63 | 0.63, 0.38 | 0.61, 0.36 | 0.73, 0.53 | 0.29, 0.07, 0.02 |
| Animal en, 1985 | 0.84, 0.69 | 0.77, 0.59 | 0.79, 0.61 | 0.66, 0.43 | 0.63, 0.39 | 0.72, 0.51 | 0.28, 0.07, 0.02 |
| Animal en, 1990 | 0.85, 0.72 | 0.76, 0.57 | 0.77, 0.60 | 0.67, 0.43 | 0.65, 0.42 | 070, 0.49 | 0.23, 0.04, 0.06 |
| Animal en, 1993 | 0.85, 0.72 | 0.75, 0.55 | 0.67, 0.44 | 0.65, 0.42 | 0.51, 0.25 | 0.65, 0.41 | 0.17, 0.02, 0.16 |
| Animal en 2000 | 0.89, 0.79 | 0.79, 0.62 | 0.66, 0.43 | 0.66, 0.43 | 0.51, 0.25 | 0.67, 0.45 | 0.17, 0.02, 0.16 |
| Animal fat, 2000 | 0.89, 0.78 | 0.77, 0.59 | 0.66, 0.43 | 0.63, 0.39 | 0.51, 0.25 | 0.67, 0.45 | 0.17, 0.01, 0.18 |
| Cereals, 1993 | −0.53, 0.27 | −0.58, 0.33 | −0.14, 0.008, 0.19 | −0.62, 0.38 | −0.23, 0.04, 0.04 | −0.50, 0.24 | −0.35, 0.11, 0.003 |
| Fat, 2000 | 0.83, 0.68 | 0.53, 0.27 | 0.73, 0.53 | 0.46, 0.20 | 0.65, 0.41 | 0.14, 0.004, 0.27 | |
| GDP, 1999 | 0.41, 0.16 | 0.77, 0.59 | 0.26, 0.06, 0.02 | 0.67, 0.44 | 0.37, 0.12, 0.003 | ||
| Latitude | 0.24, 0.05, 0.02 | 0.63, 0.39 | 0.47, 0.21 | — | |||
| Life expectancy | 0.30, 0.08, 0.005 | 0.55, 0.29 | 0.29, 0.07, 0.02 | ||||
| Lung cancer, M, 2008 | 0.49, 0.23 | — | |||||
| Lung cancer, F, 2008 | 0.32, 0.09, 0.007 |
Table 2
Regression results for 87 high quality countries.
*: p < 0.001; **: omits Australia, Luxembourg, New Zealand; ***: omits Australia, New Zealand; AF93: animal fat, 1993; Alc93: alcohol supply, 1993; Cer: cereals supply; Cer90: cereals supply, 1990; LE: life expectancy; F: female; M: male; CigF: cigarettes consumed by females; CigM: cigarettes consumed by males; Fat00: Fat, 2000.
| Cancer | Sex | Number of Countries | Lung Cancer | Animal Energy | Latitude | GDP 1999 | Miscellaneous | Adjusted |
| (β, p ) | (year; β, p ) | (β, p ) | (β, p ) | (β, p ) | r 2 , F , p | |||
| All | M | 82 | 0.40, * | 2000; 0.44, * | Alc93: 0.23, 0.003 | 0.77, 93, * | ||
| 84 | 0.38, * | 1993; 0.46, * | Alc93: 0.20, 0.997 | 0.77, 91, * | ||||
| F | 87 | 0.49, * | 1993; 0.33, * | Cer93: −0.20, 0.002 | 0.77, 99, * | |||
| 82 | 0.53, * | 1993; 0.30, * | Alc93: 0.30, 0.004 | 0.77, 93, * | ||||
| All Less Lung | M | 62 | 0.23, 0.01 | 1980; 0.54, * | 0.21, 0.04 | 0.74, 58, * | ||
| 87 | 0.28, * | 1993; 0.52, * | Cer93: −0.21, 0.006 | 0.69, 63, * | ||||
| F | 62 | 0.40, * | 1990; 0.44, * | 0.10, 0.38 | 0.72, 52, * | |||
| 82 | 0.43, * | 1993; 0.34, * | Alc93: 0.22, 0.004 | 0.71, 67, * | ||||
| 82 | 0.43, * | 0.22, 0.004 | Alc93: 0.20, 0.013Cer00: −0.25, 0.001 | 0.71, 51, * | ||||
| Bladder | M | 79 | 0.43, * | 0.30, 0.003 | 0.23, 0.006 | 0.58, 37, * | ||
| F | 80 | 0.48, * | 0.26, 0.003 | 0.17, 0.09 | 0.58, 37, * | |||
| Brain | M | 79 | 0.58, * | 0.26, 0.004 | 0.52, 44, * | |||
| 79 | 1993; 0.26, 0.004 | 0.58, * | 0.51, 41, * | |||||
| F | 85 | 0.33, 0.001 | 0.38, * | 0.35, 24, * | ||||
| Breast | F | 80 | 0.23, 0.009 | 1993; 0.41, * | 0.31, 0.002 | 0.72, 67, * | ||
| Cervix | F | 80 | −0.40, * | −0.33, 0.001 | 0.37, 24, * | |||
| Colorectal | M | 77 | 0.40, * | 0.31, * | Alc93: 0.39, * | 0.75, 76, * | ||
| F | 67 | 0.37, * | 1985; 0.17, 0.12 | Alc93: 0.24, 0.003LE: 0.28, 0.001 | 0.77, 56, * | |||
| 82 | 0.33, * | 0.25, 0.001 | Alc93: 0.25, 0.001LE: 0.28, * | 0.74, 58, * | ||||
| Corpus uteri | F | 68 | 1985; 0.67, * | 0.44, 53, * | ||||
| Hodgkin’s Lymphoma | M | 82 | 0.25, 0.02 | Fat00: 0.48, * | 0.40, 28, * | |||
| F | 78 | 0.33, 0.005 | Fat00: 0.29, 0.01 | 0.26, 15, * | ||||
| Kidney | M | 87 | 0.27, 0.004 | 0.50, * | Cer93: −0.25, 0.001 | 0.60, 44, * | ||
| 87 | 0.27, 0.003 | 1993; 0.32, 0.001 | 0.32, 0.003 | 0.60, 43, * | ||||
| 87 | 0.40, * | 1993; 0.47, * | 0.56, 55, * | |||||
| F | 85 | 0.30, 0.001 | 0.52, * | Cer93: −0.17, 0.04 | 0.60, 42, * | |||
| 85 | 0.30, 0.002 | 1993; 0.23, 0.04 | 0.39, * | 0.60, 42, * | ||||
| Laryngeal | M | 85 | 0.86, * | 2000; −0.33, * | 0.55, 52, * | |||
| F | 78 | 0.48, 0.001 | 2000; −0.39, 0.008 | 0.12, 6, * | ||||
| Leukemia | M | 86 | 0.43, * | LE: 0.44, * | 0.47, 39, * | |||
| 80 | 0.46, * | 0.40, * | 0.46, 35, * | |||||
| F | 86 | 0.30, 0.006 | LE: 0.36, 0.001 | 0.32, 21 * | ||||
| Lip, oral | M | 87 | 0.53, * | 0.28, 34, * | ||||
| F | 86 | 0.51, * | −0.31, 0.007 | 0.19, 11, * | ||||
| Liver | M | 67 | 1980; −0.27, 0.03 | 0.06, 5, 0.03 | ||||
| F | 67 | 1980; −0.51, * | 0.25, 23, * | |||||
| Lung | M | 54 | CigM: 0.65, * | AF93; 0.36, * | 0.73, 72, * | |||
| 54 | CigM: 0.63, * | 0.35, * | 0.72, 67, * | |||||
| 54 | CigM: 0.79, * | 0.62, 89, * | ||||||
| 54 | Cig: 0.80, * | 0.62, 86, * | ||||||
| F | 54 | CigF: 0.65,* | AF93; 0.32, * | 0.77, 92, * | ||||
| 54 | CigF: 0.64, * | 010, 0.35 | AF93: 0.26, 0.018 | 0.77, 61, * | ||||
| 54 | CigF: 0.70, * | 0.26, 0.003 | 0.75, 81, * | |||||
| 54 | CigF: 0.85, * | 0.71, 131, * | ||||||
| Lat × Lat | ||||||||
| Melanoma | M | 53 ** | 0.41, * | 0.52, * | 0.72, 68, * | |||
| 54 *** | 0.48, * | 0.43, * | 0.69, 59, * | |||||
| 52 ** | 0.40, * | 0.53, * | 0.72, 67, * | |||||
| 53 *** | 0.45, * | 0.47, * | 0.70, 63, * | |||||
| Multiple myeloma | M | 64 | 85; 0.57, * | LE: 0.27, 0.02 | 0.59, 46, * | |||
| 58 | 85; 0.53, * | 0.29, 0.04 | 0.59, 42, * | |||||
| F | 77 | 0.44, * | LE: 0.37, 0.003 | 0.58, 54, * | ||||
| 77 | 0.74, * | 0.53, 88, * | ||||||
| Non-Hodgkin’s lymphoma | M | 80 | 0.75, * | 0.55, 97, * | ||||
| F | 80 | 0.73, * | 0.54, 91, * | |||||
| Ovarian | F | 68 | 85; 0.70, * | 0.49, 65, * | ||||
| Pancreatic | M | 86 | 0.71, * | 1993; 0.16, 0.04 | 0.64, 78, * | |||
| 86 | 0.80, * | 0.63, 144, * | ||||||
| F | 86 | 0.40, 0.001 | 1993; 0.31, 0.008 | 0.39, 29, * | ||||
| Prostate | M | 68 | −0.26, 0.014 | 80; 0.62, * | Cer93: −0.36, 0.001 | 0.59, 33, * | ||
| Testicular | M | 59 | 85; 0.66, * | 0.25, 0.023 | 0.74, 82, * | |||
| Thyroid | M | 82 | 1993; 0.74, * | −0.29, 0.023 | 0.33, 20, * | |||
| F | 84 | 1993; 0.58, * | −0.25, 0.07 | 0.19, 10, * |
Table 3
Regression results for the 157 countries.
M: male; F: female; *: p < 0.001; sweet90: sweetener supply, 1990; sweet93: sweetener supply, 1993.
| Cancer | Sex | Number of Countries | Lung Cancer | Animal Energy | Latitude | GDP 1999 | Miscellaneous | Miscellaneous | Adjusted |
| (β, p ) | (year; β, p ) | (β, p ) | (β, p ) | (β, p ) | (β, p ) | r 2 , F , p | |||
| Bladder | M | 140 | 0.40, * | 0.36, * | 0.19, 0.002 | 0.66, 91, * | |||
| F | 139 | 0.37, * | 0.25, 0.001 | 0.22, 0.009 | 0.52, 50, * | ||||
| Brain | M | 126 | 1990; 0.26, 0.007 | 0.42, * | LE: 0.27, * | 0.71, 101, * | |||
| 130 | 0.16, 0.036 | 1990; 0.37, * | 0.38, * | 0.68, 91, * | |||||
| 145 | 0.59, * | LE: 0.35, * | 0.67, 149, * | ||||||
| 130 | 1990; 0.44, * | 0.44, * | 0.67, 131, * | ||||||
| 126 | 1090; 0.58, * | LE: 0.27, 0.001 | 0.64, 111, * | ||||||
| F | 147 | 0.30, * | 0.43, * | Sweet93: 0.18, 0.006 | 0.54, 59, * | ||||
| 148 | 0.36, * | 0.47, * | 0.53, 83, * | ||||||
| Breast | F | 142 | 0.22, * | 1993; 0.49, * | 0.26, 0.001 | 0.76, 147, * | |||
| 142 | 0.28, * | 0.17, * | 0.51, * | 0.70, 111, * | |||||
| Cervix | F | 142 | −0.40, * | −0.30, * | 0.38, 44, * | ||||
| Colorectal | M | 122 | 0.38, * | 1985; 0.21, 0.013 | 0.25, * | Alc93: 0.22, * | 0.84, 160, * | ||
| 138 | 0.35, * | 0.17, 0.007 | 0.26, * | Alc93: 0.31, * | 0.80, 141, * | ||||
| F | 131 | 0.36, * | 1985; 0.31, * | LE: 0.14, 0.02 | Alc93: 0.21, * | 0.77, 112, * | |||
| 136 | 0.35, * | 1985; 0.40, * | Alc93: 0.23, * | 0.74, 127, * | |||||
| Corpus uteri | F | 137 | 0.38, * | 1990; 0.37, * | Sweet90: 0.21, 0.001 | 0.68, 97, * | |||
| Hodgkin’s lymphoma | M | 141 | 0.26, 0.003 | Fat00: 0.44, * | 0.41, 49, * | ||||
| F | 132 | 0.33, * | Fat00: 0.36, * | 0.39, 43, * | |||||
| Kidney | M | 153 | 0.32, * | 0.54, * | Cer93: −0.26, * | 0.70, 122, * | |||
| 152 | 0.25, * | 1993; 0.39, * | 0.30, * | 0.70, 119, * | |||||
| 154 | 0.37, * | 1993; 0.53, * | 0.67, 153, * | ||||||
| 153 | 0.36, * | 0.51, * | 0.64, 135, * | ||||||
| F | 153 | 0.24, * | 1993; 0,21, 0.018 | 0.45, * | Cer93: −0.15, 0.007 | 0.69, 84, * | |||
| 153 | 0.30, * | 0.57, * | Cer93: −0.21, * | 0.68, 106, * | |||||
| 153 | 0.24, * | 1993; 0.34, * | 0.35, * | 0.67, 105, * | |||||
| 153 | 0.37, * | 0.53, * | 0.64, 133, * | ||||||
| 154 | 0.28, * | 1993; 0.57, * | 0.62, 123, * | ||||||
| Laryngeal | M | 157 | 0.68, * | 0.46, 131, * | |||||
| F | 139 | 0.31, * | 0.09, 15, * | ||||||
| Leukemia | M | 147 | 0.32, * | 2000; 0.38, * | LE: 0.20, 0.016 | 0.62, 78, * | |||
| F | 151 | 0.37, * | LE: 0.45, * | 0.52, 81, * | |||||
| 146 | 0.32, * | 2000; 0.15, 0.15 | LE: 0.36, * | 0.52, 52, * | |||||
| Lip, oral | M | 157 | 0.45, * | −0.20, 0.06 | 0.11, 10, * | ||||
| F | 156 | 0.29, 0.002 | −0.29, 0.003 | 0.06, 6, 0.003 | |||||
| Liver | M | 136 | 1980; −0.37, * | 0.13, 21, * | |||||
| F | 136 | 1980; −0.44, * | 0.19, 33, * | ||||||
| Lung | M | 68 | CigM; 0.62, * | 0.33, * | 0.68, 72, * | ||||
| 68 | CigM; 0.63, * | AF00: 0.34, * | 0.67, 68, * | ||||||
| 68 | CigM; 0.60, * | 0.23, 0.04 | AF00: 0.14, 0.22 | 0.68, 49, * | |||||
| F | 71 | CigF; 0.69, * | AF93; 0.26, 0.001 | 0.78, 123, * | |||||
| 71 | CigF; 0.74, * | 0.21, 0.004 | 0.77, 118, * | ||||||
| Multiple myeloma | M | 112 | 1985; 0.61, * | 0.22, 0.05 | 0.64, 100, * | ||||
| 122 | 1985; 0.66, * | LE: 0.17, 0.05 | 0.61, 97, * | ||||||
| F | 110 | 1990; 0.33, 0.003 | 0.49, * | 0.61, 88, * | |||||
| 129 | 0.55, * | LE: 0.28, 0.001 | 0.60, 85, * | ||||||
| Non-Hodgkin’s lymphoma | M | 142 | 0.68, * | 0.46, 120, * | |||||
| F | 141 | 0.71, * | 0.50, 140, * | ||||||
| Ovarian | F | 138 | 0.25, 0.002 | 1990; 0.55, * | 0.55, 85, * | ||||
| Sweet90: | |||||||||
| Pancreatic | M | 132 | 0.42, * | 1985; 0.28, 0.001 | Alc93: 0.18, 0.005 | 0.15, 0.013 | 0.74, 93, * | ||
| 132 | 0.45, * | 1990; 0.39, * | 0.15, 0.013 | 0.73, 116, * | |||||
| F | 132 | 0.26, 0.001 | 1990; 0.46, * | 0.20, 0.003 | 0.64, 80, * | ||||
| Prostate | M | 137 | 1980; 0.52, * | Cer93: −0.23, * | Sweet90: 0.18, 0.019 | 0.56, 58, * | |||
| 132 | 0.45, * | 1990; 0.39, * | 0.15, 0.013 | 0.73, 116, * | |||||
| F | 132 | 0.26, 0.001 | 1990; 0.46, * | 0.20, 0.003 | 0.64, 80, * | ||||
| Testicular | M | 123 | 1985; 0.85, * | 0.72, 312, * | |||||
| Thyroid | M | 146 | 1993; 0.78, * | −0.26, 0.009 | 0.36, 42, * | ||||
| F | 152 | 1993; 0.60, * | −0.27, 0.014 | 0.18, 18, * |
Table 4
Numbers of cancer types for which significant direct and inverse correlations were found.
M: male; F: female; HQ: high quality countries.
| Factor | All Countries M | All Countries F | All Countries M/F | HQ Countries M | HQ Countries F | HQ Countries M/F |
| Direct correlation | ||||||
| Alcohol | 1 | 1 | 1 | 1 | 1 | 1 |
| Animal fat | 2 | 1 | 2 | 2 | 1 | 2 |
| Animal product energy | 9 | 7 | 12 | 5 | 6 | 10 |
| Fat | 1 | 1 | 1 | 1 | 1 | 1 |
| GDP | 4 | 4 | 5 | 5 | 3 | 7 |
| Latitude | 6 | 4 | 6 | 5 | 6 | 6 |
| Life expectancy | 1 | 2 | 3 | 2 | 3 | 3 |
| Lung cancer | 8 | 11 | 12 | 8 | 9 | 10 |
| Sweeteners | 1 | 2 | 3 | 0 | 0 | 0 |
| Inverse correlation | ||||||
| Animal product energy | 0 | 0 | 0 | 2 | 2 | 2 |
| Cereals | 2 | 1 | 2 | 2 | 1 | 2 |
| GDP | 0 | 1 | 1 | 0 | 1 | 1 |
| Latitude | 2 | 3 | 3 | 0 | 2 | 2 |
Meat consumption has been recognized as a risk factor for cancer since at least the early 20th century. A study of cancer rates in different ethnic groups in Chicago from 1900 to 1907 found that “heavy meat eaters—Germans, Irish, Scandinavians—apparently had high rates of cancer mortality, but pasta-consuming Italians and rice-eating Chinese had low rates. Though the survey was crude, it was more thorough than many of its kind (it studied some 4600 cases over a seven-year stretch from 1900 to 1907). Its conclusions concerning the potential risk of eating too much meat crudely anticipated those of many experts eighty years later” [ 36 , 37 ].
The present study as well as other ecological studies found dietary animal products associated with increased risk of chronic diseases. McCarty noted that several cancers increased in frequency in Asia, in southern Europe, and among African Americans in the 20th century after the increase in dietary animal products: breast, colon, kidney ovary, pancreas, and prostate [ 38 ]. A recent ecological study of trends of Alzheimer’s disease rates in Japan correlated meat and animal products with a 15- to 25-year lag between dietary changes and prevalence of Alzheimer’s disease [ 39 ]. Iron was also suggested as a link for that finding.
Mechanisms linking animal products to risk of cancer probably include increased production of insulin, insulin-like growth factor 1, and sex hormones: “Epidemiological evidence is accumulating and suggests that the risk of cancers of the colon, pancreas, endometrium, breast and prostate are related to circulating levels of insulin, (insulin-like growth factor 1), or both” [ 40 ]. Also, iron in meat may be a risk factor for cancer through increased production of free radicals and increased oxidative stress and DNA damage [ 41 ].
The correlation of energy from animal products with risk for a number of common cancers observed in this study may meet with some skepticism, inasmuch as, in prospective or case-control studies conducted in Western countries, such a correlation is rarely reported. Correlations with red meat or flesh foods cooked in high heat occasionally emerge (possibly reflecting an impact of heme iron, mutagens, or saturated fat), but animal products per se are rarely incriminated in such studies. A possible explanation may be that a moderate degree of essential amino acid restriction is required for down-regulation of IGF-I, mTORC1 activity, or other yet-unknown factors which act as cancer promoters [ 42 , 43 ]. Such restriction may be achievable with a vegan diet of moderate protein content, but diets that incorporate meaningful quantities of high-quality animal protein would presumably be too high in essential amino acids to down-regulate cancer promotional activities. And even vegans in Western countries often have an ample intake of isolated soy protein, which is of intermediate quality and capable of boosting IGF-I levels [ 44 , 45 ]. So only a tiny fraction of people in Western societies are likely to achieve a degree of essential amino acid restriction capable of modulating cancer risk—and most of these are only vegan for a portion of their life span. Varying protein intake within the range typical of Western societies may have little impact on cancer promotional activities.
4.1. Latitude
Several previous multicountry ecological studies interpreted findings of an index for annual solar UVB dose, which is strongly inversely correlated with latitude, as an index of vitamin D production. Such studies found inverse relations between that index and incidence rates for a number of types of cancer. Those cancers included bladder [ 46 ], brain [ 47 ], breast [ 48 ], colorectal [ 49 ], endometrial [ 50 ], kidney [ 51 ], lung [ 52 ], ovarian [ 53 ], pancreatic cancer [ 54 ], and leukemia [ 55 ]. However, under the Bonferroni principle ( p must be < 0.05/ n , where n is the number of factors for significance to be claimed), the UVB index was significantly correlated with only bladder, brain, kidney, and lung cancer. This study confirmed these findings.
As to why this study did not find more cancers to have significant increases with increasing latitude, it appears that if animal products are significantly correlated with cancer incidence rates, it is less likely that latitude is. This seems to be the case for breast, corpus uteri, ovarian, and pancreatic cancer. For kidney cancer, when energy from animal products is included, the correlation for latitude is lower than when cereals are included.
In single-country studies, latitude is often a good index of solar UVB doses [ 56 , 57 , 58 ]. However, in the United States, considerable asymmetry exists in solar UVB doses owing to the geography [ 59 ]. However, the interpretation of latitude as an index of vitamin D production globally is questionable. The primary reason is that skin pigmentation varies with solar UV doses where people have lived for many generations [ 60 , 61 ] so that serum 25-hydroxyvitamin D [25(OH)D] levels do not vary much globally. Three reviews found that country mean serum 25(OH)D levels are near 50 nmol/L in nearly every country [ 62 , 63 , 64 ]. The nearly constant serum 25(OH)D with respect to latitude is reasonable since if large differences existed, risk of vitamin D—sensitive diseases would vary considerably with respect to latitude. A pronounced increase of multiple sclerosis prevalence occurs with increasing latitude [ 65 ]. One study inversely correlated both solar UV dose and vitamin D with risk of multiple sclerosis [ 66 ].
The inverse correlation for cervical cancer can be understood in terms of higher risk of infections at low latitudes, and that for lip cancer in that UVB is a risk factor for lip cancer [ 22 ].
An alternative interpretation of latitude is that it may be an index of various modeled and/or unmodeled factors such as infection, living in urban regions, and eating processed food. For example, Toxoplasma gondii infection rates increase with latitude, and T. gondii is a risk factor for brain cancer [ 67 ].
4.2. GDP
Studies have often correlated per capita GDP with increased risk of chronic diseases, such as cancer [ 6 ] and diabetes [ 68 ]. Several possible reasons may account for why cancer rates are higher in countries with higher GDP: more time spent indoors, less time engaged in physical exercise [ 69 ], greater consumption of processed foods [ 70 ], greater life expectancy [ 71 ], more chemical pollution exposure, and reduced risk of infectious diseases [ 72 , 73 ].
4.3. Life Expectancy
Cancer risk does increase with life expectancy for most cancers in this study, such as breast and colorectal cancer (see Figure 1 ). However, life expectancy is significantly correlated with only three cancers: brain cancer, leukemia, and multiple myeloma. Why life expectancy is not significantly correlated with other cancers in this study is unclear.

4.4. Individual Cancers
Table 5 lists journal papers supporting the findings in Table 2 and Table 3 . Findings from this ecological study generally agree with the journal literature for most factors for most cancers studied. Some results in the journal literature were not supported in this study, such as alcohol for several cancers, animal products for colorectal cancer, and latitude for many cancers. These failures indicate that such ecological studies can identify only up to three or four cancer risk-modifying factors as having significant correlations with cancer incidence rates in the best model for the particular cancer. Thus, findings by such ecological studies do not offer evidence that nonsignificant risk-modifying factors are not related to cancer risk, just that they seem less important than other factors.
This study found no significant results for esophageal, gallbladder, and stomach cancer. Esophageal and stomach cancer have infections as important risk factors (see Table 5 ).
Studies have inversely correlated white meat [ 74 ] and fish [ 75 ] with risk of liver cancer, whereas other studies directly correlated liver cancer risk with intake of red and processed meat [ 74 , 75 ].
The directly correlation of latitude with melanoma risk is related to skin pigmentation. Melanoma incidence rates for people living in their ancestral homelands below 35° latitude are very low (mean value, ~2 cases/100,000/year) but rise rapidly at higher latitudes (regression mean, ~14 for >60° latitude). The main reason for this latitudinal variation is variation in skin pigmentation, which has adjusted for protection against adverse effects of solar UV while permitting adequate production of vitamin D [ 56 ]. Australia and New Zealand have the highest melanoma incidence rates and are populated primarily by people who can trace their ancestry to northern Europe. GDP’s direct correlation with melanoma incidence rates may be related to increased travel to sunny locations for those living in the wealthiest countries. Studies in Norway and the United States have correlated air travel with risk of melanoma [ 76 , 77 ].
Table 5
Journal literature supporting findings in this study.
UVB: strong support for UVB from single-country studies [ 9 , 56 , 57 , 58 , 125 ]; uvb: moderate support.
| Cancer | Animal Products | Smoking | GDP per Capita | Latitude * | Alcohol | Misccellaneous | Infection |
| Bladder | [ 78 , 79 ] | [ 80 , 81 ] | [ 82 ] | [ 46 ] UVB | |||
| Brain | [ 83 ] | [ 84 ] | [ 47 , 67 ] | [ 67 , 85 ] | |||
| Breast | [ 86 , 87 ] | [ 82 , 88 ] | UVB | ||||
| Cervix | [ 80 ] | [ 89 ] | |||||
| Colorectal | [ 78 , 90 , 91 ] | [ 80 ] | [ 49 , 82 , 88 ] | UVB | [ 92 , 93 ] | Sugar [ 94 ] | [ 89 ] |
| Corpus uteri | [ 78 ] | [ 95 ] | uvb | Sugar [ 96 ] | |||
| Esophageal | [ 90 , 91 , 97 ] | [ 80 , 81 ] | uvb | [ 92 ] | [ 98 ] | ||
| Gallbladder | uvb | ||||||
| Gastric | [ 81 ] | uvb | [ 99 ] | ||||
| Hodgkin’s lymphoma | [ 100 ] | uvb | [ 101 ] | ||||
| Kidney | [ 79 ] | [ 102 ] | [ 82 ] | [ 51 , 103 ] UVB | Cereals [ 104 , 105 ] | ||
| Laryngeal | [ 80 , 81 ] | uvb | [ 92 ] | [ 106 ] | |||
| Leukemia | [ 107 ] | [ 107 ] | [ 55 ] | ||||
| Lip | [ 108 ] | [ 108 ] (direct) | |||||
| Liver | [ 74 , 90 ] | [ 81 , 102 ] | [ 109 ] | ||||
| Lung | [ 87 , 91 , 110 ] | [ 81 ] | [ 88 ] | [ 52 ] uvb | |||
| Mult. Myel. | [ 100 , 111 ] | [ 112 ] | |||||
| Non-Hodgkin’s lymphoma | [ 113 , 114 ] | [ 82 , 88 ] | UVB | [ 115 ] | |||
| Ovarian | [ 78 , 116 , 117 ] | [ 118 ] | [ 82 ] | [ 53 ] UVB | |||
| Pancreatic | [ 78 , 87 , 119 ] | [ 80 , 81 ] | [ 88 ] | [ 54 ] UVB | [ 92 , 120 ] | Sugar [ 94 ] | |
| Prostate | [ 79 ] | [ 121 ] (inverse) | [ 82 , 88 ] | uvb | [ 122 ] | Sugar [ 94 ], rice [ 121 ] | |
| Testicular | [ 79 ] | Fat [ 123 ] | |||||
| Thyroid | [ 124 ] | uvb |
4.5. Strengths and Limitations of This Study
Ecological studies such as those reported here have several strengths and limitations. Strengths include that such ecological studies involve many cases, permitting investigation of many cancers and consideration of many factors. Also, since data exist for several indices of cancer risk-modifying factors over many years, ecological studies can investigate the effect of delay between risk-modifying factor and cancer incidence.
Limitations include that the data are for country populations as a whole, so values for risk-modifying factors may not accurately reflect risk factors on individuals who develop cancer. For example, solar UVB doses vary widely in mid-latitude countries with large latitude ranges. Also, dietary intake varies widely by individual. Further, dietary supply data are based on food that enters the consumer supply and does not account for waste, loss, and spoilage. This study assumes that consumption rates are a similar fraction of consumer supply for each country, probably around 70%. Also, country-averaged data for some cancer risk-modifying factors, such as rates for obesity, physical exercise, and diseases that may compete with risk of cancer (e.g., cardiovascular disease and infectious diseases), are either not available or were not included in the analysis. In addition, there are cancer risk-modifying factors that are particular to a few countries or regions within countries. Examples of such factors include poor sewage disposal, which is a risk for Helicobacter pylori infection and gastric cancer [ 126 ], arsenic in drinking water and risk of renal cancer [ 127 ], industrial pollution, a risk factor for several types of cancer [ 128 ], betel quid chewing and risk of head and neck cancers [ 129 ].
5. Conclusions
This multicountry ecological study of cancer incidence rates in 2008 found that lung cancer incidence rates, supply of energy derived from animal products, latitude (an index for solar UVB doses), and per capita GDP had the largest number of significant correlations with various cancers. Alcoholic beverages, animal fat, life expectancy, and sweeteners had significant correlations with a few cancers. This study found inverse correlations for cereals, per capita GDP, and latitude for one to three cancers each. For all countries, the models explained 9%–84% of the variance, with median values of 62% for males and 54.5% for females. For countries with high-quality data, the models explained 6%–75% of the variance, with median values of 55% for males and 41.5% for females. Since most factors considered are environmental, rather than genetic, one may reasonably conclude that environmental causes of cancer contribute much more to cancer risk than do genetic factors, and thus lifestyle changes could reduce much of the cancer burden.
Conflicts of Interest
The authors declare no conflict of interest.
References
1. Ferlay J. Shin H.R. Bray F. Forman D. Mathers C. Parkin D.M. GLOBOCAN 2008, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 10 Int. J. Cancer. 2010 127 Available online: http://globocan.iarc.fr/factsheet.asp (accessed on 29 August 2013)
2. Siegel R. Ward E. Brawley O. Jemal A. Cancer statistics, 2011: The impact of eliminating socioeconomic and racial disparities on premature cancer deaths CA Cancer J. Clin. 2011 61 212 236 10.3322/caac.20121 21685461
3. Hoyert D.L. Xu J. Deaths: Preliminary data for 2011 Nat. Vital Stat. Rep. 2012 61 8 24984457
4. Cancer Available online: http://www.who.int/mediacentre/factsheets/fs297/en/ (accessed on 4 November 2013)
5. The American Institute for Cancer Research/World Cancer Research Fund Policy and Action for Cancer Prevention. Food, Nutrition and Physical Activity: A Global Perspective AICR Washington, DC, USA 2009
6. Armstrong B. Doll R. Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practices Int. J. Cancer 1975 15 617 631 10.1002/ijc.2910150411 1140864
7. Garland C.F. Garland F.C. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int. J. Epidemiol. 1980 9 227 231 10.1093/ije/9.3.227 7440046
8. Garland C.F. Garland F.C. Gorham E.D. Lipkin M. Newmark H. Mohr S.B. Holick M.F. The role of vitamin D in cancer prevention Am. J. Public Health 2006 96 252 261 10.2105/AJPH.2004.045260 16380576 PMC1470481
9. Grant W.B. Garland C.F. The association of solar ultraviolet B (UVB) with reducing risk of cancer: Multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates Anticancer Res. 2006 26 2687 2699 16886679
10. Grant W.B. Ecological studies of the UVB—Vitamin D—Cancer hypothesis Anticancer Res. 2012 32 223 236 22213311
11. Garland C.F. Gorham E.D. Mohr S.B. Garland F.C. Vitamin D for cancer prevention: Global perspective Ann. Epidemiol. 2009 19 468 483 10.1016/j.annepidem.2009.03.021 19523595
12. Moukayed M. Grant W.B. Molecular link between vitamin D and cancer prevention Nutrients 2013 5 3993 4021 10.3390/nu5103993 24084056 PMC3820056
13. Hill A.B. The environment and disease: Association or causation? Proc. Royal Soc. Med. 1965 58 295 300 10.1177/003591576505800503 PMC1898525 14283879
14. Grant W.B. How strong is the evidence that solar ultraviolet B and vitamin D reduce the risk of cancer? An examination using Hill’s criteria for causality Dermato-Endocrinology 2009 1 17 24 10.4161/derm.1.1.7388 20046584 PMC2715209
15. Mohr S.B. Gorham E.D. Alcaraz J.E. Kane C.I. Macera C.A. Parsons J.K. Wingard D.L. Garland C.F. Does the evidence for an inverse relationship between serum vitamin D status and breast cancer risk satisfy the Hill criteria? Dermato-Endocrinology 2012 4 152 157 10.4161/derm.20449 22928071 PMC3427194
16. Food and Agriculture Organization of the United Nations Food Balance Sheets, 1992–94 Average FAO Rome, Italy 1997
17. Harashima E. Nakagawa Y. Urata G. Tsuji K. Shirataka M. Matsumura Y. Time-lag estimate between dietary intake and breast cancer mortality in Japan Asia Pac. J. Clin. Nutr. 2007 16 193 198 17215198
18. Zhang J. Dhakal I.B. Zhao Z. Li L. Trends in mortality from cancers of the breast, colon, prostate, esophagus, and stomach in East Asia: Role of nutrition transition Eur. J. Cancer Prev. 2012 21 480 489 10.1097/CEJ.0b013e328351c732 22357483
19. World Health Organization Tables of Causes of Death and Disability Adjusted Life Years by Country 2004 Available online: http://www.who.int/healthinfo/statistics/bodgbddeathdalyestimates.xls (accessed on 5 November 2013)
20. Mathers C.D. Bernard C. Iburg K. Inoue M. Ma Fat D. Shibuya K. Stein C. Tomijima N. The Global Burden of Disease in 2002: Data Sources, Methods and Results GPE Discussion Paper No. 54 World Health Organization Geneva, Swizerland 2003
21. Food and Agriculture Organization of the United Nations Food Balance Sheets Available online: http://faostat.fao.org/site/368/default.aspx#ancor (accessed on 4 November 2013)
22. Grant W.B. Role of solar UVB irradiance and smoking in cancer as inferred from cancer incidence rates by occupation in Nordic countries Dermato-Endocrinology 2012 4 203 211 10.4161/derm.20965 22928078 PMC3427201
23. Grant W.B. An ecologic study of cancer mortality rates in Spain with respect to indices of solar UVB irradiance and smoking Int. J. Cancer 2007 120 1123 1128 10.1002/ijc.22386 17149699
24. Bilal U. Fernandez E. Beltran P. Navas-Acien A. Bolumar F. Franco M. Validation of a method for reconstructing historical rates of smoking prevalence Am. J. Epidemiol. 2013 10.1093/aje/kwt224 24077091
25. Afzal S. Bojesen S.E. Nordestgaard B.G. Low plasma 25-hydroxyvitamin D and risk of tobacco-related cancer Clin. Chem. 2013 59 771 780 23503722 10.1373/clinchem.2012.201939
26. Data on Tobacco Consumption Available online: http://www.who.int/tobacco/media/en/Poland.pdf (accessed on 20 December 2013)
27. International Monetary Fund List of Countries by Past and Future GDP (PPP) per Capita Available online: http://en.wikipedia.org/w/index.php?title=List_of_countries_by_pastand_futur_GDP_(PPP)_per_capita&oldid=574426146 (accessed on 4 November 2013)
28. Central Intelligence Agency The CIA World Fact Book 2008 Central Intelligence Agency Washington, DC, USA 2008
29. KaleidaGraph version 4.2 Synergy Software Reading, PA, USA 2005
30. Tsuji K. Harashima E. Nakagawa Y. Urata G. Shirataka M. Time-lag effect of dietary fiber and fat intake ratio on Japanese colon cancer mortality Biomed. Environ. Sci. 1996 9 223 228 8886335
31. Andersson S.O. Baron J. Wolk A. Lindgren C. Bergström R. Adami H.O. Early life risk factors for prostate cancer: A population-based case-control study in Sweden Cancer Epidemiol. Biomark. Prev. 1995 4 187 192 7606192
32. John E.M. Koo J. Schwartz G.G. Sun exposure and prostate cancer risk: Evidence for a protective effect of early-life exposure Cancer Epidemiol. Biomark. Prev. 2007 16 1283 1286 10.1158/1055-9965.EPI-06-1053 17548698
33. Hirayama T. Mortality in Japanese with life-styles similar to Seventh-Day Adventists: Strategy for risk reduction by life-style modification Nat. Cancer Inst. Monogr. 1985 69 143 153 3834324
34. Fraser G.E. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists Am. J. Clin. Nutr. 1999 70 532 538 10.1093/ajcn/70.3.532s 10479227
35. Thygesen L.C. Hvidt N.C. Hansen H.P. Hoff A. Ross L. Johansen C. Cancer incidence among Danish Seventh-day Adventists and Baptists Cancer Epidemiol. 2012 36 513 518 22910035 10.1016/j.canep.2012.08.001
36. Cancer Increasing among Meat Eaters New York Times Sep 24 1907 Available online: http://query.nytimes.com/gst/abstract.html?res=9502E1D81331E733A25757C2A96F9C946697D6CF (accessed on 24 December 2013)
37. Patterson J.T. The Dread Disease; Cancer and Modern Culture Harvard University Press Cambridge, MA, USA 1987 44 45
38. McCarty M.F. Mortality from Western cancers rose dramatically among African-Americans during the 20th century: Are dietary animal products to blame? Med. Hypotheses 2001 57 169 174 10.1054/mehy.2000.1315 11461167
39. Grant W.B. Trends in diet and Alzheimer’s disease during the nutrition transition in Japan and developing countries J. Alzheimerʼs Dis. 2013 38 611 620 24037034 10.3233/JAD-130719
40. Kaaks R. Nutrition, insulin, IGF-1 metabolism and cancer risk: A summary of epidemiological evidence Novartis Found. Symp. 2004 262 247 268 247–260; discussion 260–268 10.1002/0470869976.ch16 15562834
41. Grant W.B. An ecological study of cancer mortality rates including indices for dietary iron and zinc Anticancer Res. 2008 28 1955 1963 18630488
42. McCarty M.F. Insulin and IGF-I as determinants of low “Western” cancer rates in the rural third world Int. J. Epidemiol. 2004 33 908 910 10.1093/ije/dyh265 15256521
43. Fontana L. Weiss E.P. Villareal D.T. Klein S. Holloszy J.O. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans Aging Cell 2008 7 681 687 10.1111/j.1474-9726.2008.00417.x 18843793 PMC2673798
44. Allen N.E. Appleby P.N. Davey G.K. Kaaks R. Rinaldi S. Key T.J. The associations of diet with serum insulin-like growth factor I and its main binding proteins in 292 women meat-eaters, vegetarians, and vegans Cancer Epidemiol. Biomark. Prev. 2002 11 1441 1448 12433724
45. Dewell A. Weidner G. Sumner M.D. Barnard R.J. Marlin R.O. Daubenmier J.J. Chi C. Carroll P.R. Ornish D. Relationship of dietary protein and soy isoflavones to serum IGF-1 and IGF binding proteins in the Prostate Cancer Lifestyle Trial Nutr. Cancer 2007 58 35 42 10.1080/01635580701308034 17571965
46. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Ultraviolet B irradiance and incidence rates of bladder cancer in 174 countries Am. J. Prev. Med. 2010 38 296 302 10.1016/j.amepre.2009.10.044 20171531
47. Mohr S.B. Gorham E.D. Garland C.F. Grant W.B. Garland F.C. Low ultraviolet B and increased risk of brain cancer: an ecological study of 175 countries Neuroepidemiology 2010 35 281 290 10.1159/000314350 20948235
48. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Relationship between low ultraviolet B irradiance and higher breast cancer risk in 107 countries Breast J. 2008 14 255 260 10.1111/j.1524-4741.2008.00571.x 18422861
49. Cuomo R. Mohr S.B. Gorham E.D. Garland C.F. What is the relationship between ultraviolet B and global incidence rates of colorectal cancer? Dermato-Endocrinology 2013 5 181 185 10.4161/derm.23773 24494052 PMC3897587
50. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Is ultraviolet B irradiance inversely associated with incidence rates of endometrial cancer: An ecological study of 107 countries Prev. Med. 2007 45 327 331 17395256 10.1016/j.ypmed.2007.01.012
51. Mohr S.B. Gorham E.D. Garland C.F. Grant W.B. Garland F.C. Are low ultraviolet B and high animal protein intake associated with risk of renal cancer? Int. J. Cancer 2006 119 2705 2709 10.1002/ijc.22213 16981191
52. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Could ultraviolet B irradiance and vitamin D be associated with lower incidence rates of lung cancer? J. Epidemiol. Community Health 2008 62 69 74 10.1136/jech.2006.052571 18079336
53. Garland C.F. Mohr S.B. Gorham E.D. Grant W.B. Garland F.C. Role of ultraviolet B irradiance and vitamin D in prevention of ovarian cancer Am. J. Prev. Med. 2006 31 512 514 10.1016/j.amepre.2006.08.018 17169713
54. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Ultraviolet B irradiance and vitamin D status are inversely associated with incidence rates of pancreatic cancer worldwide Pancreas 2010 39 669 674 10.1097/MPA.0b013e3181ce654d 20442683
55. Mohr S.B. Garland C.F. Gorham E.D. Grant W.B. Garland F.C. Ultraviolet B and incidence rates of leukemia worldwide Am. J. Prev. Med. 2011 41 68 74 10.1016/j.amepre.2011.04.003 21665065
56. Mizoue T. Ecological study of solar radiation and cancer mortality in Japan Health Phys. 2004 87 532 538 15551791 10.1097/01.hp.0000137179.03423.0b
57. Astbury A. Non Uniformity in Cancer Mortality in the USA and Australia Appears to Share a Common Pathway. Triumf Report, TRI-PP-05–01, 2005 Available online: http://www.triumf.ca/publications/pub/arch05/pp-05–01.pdf (accessed on 21 November 2011)
58. Chen W. Clements M. Rahman B. Zhang S. Qiao Y. Armstrong B.K. Relationship between cancer mortality/incidence and ambient ultraviolet B irradiance in China Cancer Causes Control 2010 21 1701 1709 10.1007/s10552-010-9599-1 20552265
59. Fioletov V.E. McArthur L.J. Mathews T.W. Marrett L. Estimated ultraviolet exposure levels for a sufficient vitamin D status in North America J. Photochem. Photobiol. 2010 100 57 66 10.1016/j.jphotobiol.2010.05.002 20554218
60. Jablonski N.G. Chaplin G. The evolution of human skin coloration J. Hum. Evol. 2000 39 57 106 10896812 10.1006/jhev.2000.0403
61. Jablonski N.G. Chaplin G. Colloquium paper: Human skin pigmentation as an adaptation to UV radiation Proc. Natl. Acad. Sci. USA 2010 107 8962 8968 10.1073/pnas.0914628107 20445093 PMC3024016
62. Hagenau T. Vest R. Gissel T.N. Poulsen C.S. Erlandsen M. Mosekilde L. Vestergaard P. Global vitamin D levels in relation to age, gender, skin pigmentation and latitude: An ecologic meta-regression analysis Osteoporos Int. 2009 20 133 140 10.1007/s00198-008-0626-y 18458986
63. Van Schoor N.M. Lips P. Worldwide vitamin D status Best Pract. Res. Clin. Endocrinol. Metab. 2011 25 671 680 10.1016/j.beem.2011.06.007 21872807
64. Hilger J. Friedel A. Herr R. Rausch T. Roos F. Wahl D.A. Pierroz D.D. Weber P. Hoffmann K. A systematic review of vitamin D status in populations worldwide Br. J. Nutr. 2013 10.1017/S0007114513001840 23930771
65. Kurtzke J.F. Epidemiologic evidence for multiple sclerosis as an infection Clin. Microbiol. Rev. 1993 6 382 427 8269393 10.1128/cmr.6.4.382 PMC358295
66. Lucas R.M. Ponsonby A.L. Dear K. Valery P.C. Pender M.P. Taylor B.V. Kilpatrick T.J. Dwyer T. Coulthard A. Chapman C. Sun exposure and vitamin D are independent risk factors for CNS demyelination Neurology 2011 76 540 548 10.1212/WNL.0b013e31820af93d 21300969
67. Thomas F. Lafferty K.D. Brodeur J. Elguero E. Gauthier-Clerc M. Misse D. Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common Biol. Lett. 2012 8 101 103 10.1098/rsbl.2011.0588 21795265 PMC3259962
68. Basu S. Yoffe P. Hills N. Lustig R.H. The relationship of sugar to population-level diabetes prevalence: An econometric analysis of repeated cross-sectional data PLoS One 2013 8 e57873 23460912 10.1371/journal.pone.0057873 PMC3584048
69. Bosdriesz J.R. Witvliet M.I. Visscher T.L. Kunst A.E. The influence of the macro-environment on physical activity: A multilevel analysis of 38 countries worldwide Int. J. Behav. Nutr. Phys. Act. 2012 9 110 10.1186/1479-5868-9-110 22967164 PMC3490943
70. Hawkes C. The role of foreign direct investment in the nutrition transition Public Health Nutr. 2005 8 357 365 10.1079/PHN2004706 15975180
71. Renton A. Wall M. Lintott J. Economic growth and decline in mortality in developing countries: An analysis of the World Bank development datasets Public Health 2012 126 551 560 10.1016/j.puhe.2012.03.011 22640938
72. Huicho L. Trelles M. Gonzales F. Mendoza W. Miranda J. Mortality profiles in a country facing epidemiological transition: An analysis of registered data BMC Public Health 2009 9 47 10.1186/1471-2458-9-47 19187553 PMC2640471
73. Shuman E.K. Global climate change and infectious diseases Int. J. Occup. Environ. Med. 2011 2 11 19 23022814
74. Freedman N.D. Cross A.J. McGlynn K.A. Abnet C.C. Park Y. Hollenbeck A.R. Schatzkin A. Everhart J.E. Sinha R. Association of meat and fat intake with liver disease and hepatocellular carcinoma in the NIH-AARP cohort J. Natl. Cancer Inst. 2010 102 1354 1365 10.1093/jnci/djq301 20729477 PMC2935477
75. Fedirko V. Trichopolou A. Bamia C. Duarte-Salles T. Trepo E. Aleksandrova K. Nothlings U. Lukanova A. Lagiou P. Boffetta P. Consumption of fish and meats and risk of hepatocellular carcinoma: The European Prospective Investigation into Cancer and Nutrition (EPIC) Ann. Oncol. 2013 24 2166 2173 10.1093/annonc/mdt168 23670094 PMC3718509
76. Bentham G. Aase A. Incidence of malignant melanoma of the skin in Norway, 1955–1989: associations with solar ultraviolet radiation, income and holidays abroad Int. J. Epidemiol. 1996 25 1132 1138 10.1093/ije/25.6.1132 9027516
77. Agredano Y.Z. Chan J.L. Kimball R.C. Kimball A.B. Accessibility to air travel correlates strongly with increasing melanoma incidence Melanoma Res. 2006 16 77 81 16432460 10.1097/01.cmr.0000195696.50390.23
78. Tavani A. La Vecchia C. Gallus S. Lagiou P. Trichopoulos D. Levi F. Negri E. Red meat intake and cancer risk: A study in Italy Int. J. Cancer 2000 86 425 428 10.1002/(SICI)1097-0215(20000501)86:3<425::AID-IJC19>3.0.CO;2-S 10760833
79. Oplander C. Volkmar C.M. Paunel-Gorgulu A. van Faassen E.E. Heiss C. Kelm M. Halmer D. Murtz M. Pallua N. Suschek C.V. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates Circ. Res. 2009 105 1031 1040 10.1161/CIRCRESAHA.109.207019 19797169
80. Thun M.J. Henley S.J. Calle E.E. Tobacco use and cancer: An epidemiologic perspective for geneticists Oncogene 2002 21 7307 7325 10.1038/sj.onc.1205807 12379875
81. Yun Y.H. Jung K.W. Bae J.M. Lee J.S. Shin S.A. Min Park S. Yoo T. Yul Huh B. Cigarette smoking and cancer incidence risk in adult men: National Health Insurance Corporation Study Cancer Detect. Prev. 2005 29 15 24 15734213 10.1016/j.cdp.2004.08.006
82. Bray F. Jemal A. Grey N. Ferlay J. Forman D. Global cancer transitions according to the Human Development Index (2008–2030): A population-based study Lancet Oncol. 2012 13 790 801 10.1016/S1470-2045(12)70211-5 22658655
83. Kaplan S. Novikov I. Modan B. Nutritional factors in the etiology of brain tumors: Potential role of nitrosamines, fat, and cholesterol Am. J. Epidemiol. 1997 146 832 841 10.1093/oxfordjournals.aje.a009201 9384204
84. Mandelzweig L. Novikov I. Sadetzki S. Smoking and risk of glioma: A meta-analysis Cancer Causes Control 2009 20 1927 1938 19568697 10.1007/s10552-009-9386-z
85. Alibek K. Kakpenova A. Baiken Y. Role of infectious agents in the carcinogenesis of brain and head and neck cancers Infect. Agents Cancer 2013 8 7 10.1186/1750-9378-8-7 23374258 PMC3573938
86. Ishimoto H. Nakamura H. Miyoshi T. Epidemiological study on relationship between breast cancer mortality and dietary factors Tokushima J. Exp. Med. 1994 41 103 114 7701504
87. Hu J. La Vecchia C. DesMeules M. Negri E. Mery L. Meat and fish consumption and cancer in Canada Nutr. Cancer 2008 60 313 324 10.1080/01635580701759724 18444165
88. Knaul F.M. Adami H.O. Adebamowo C. Arreola-Ornelas H. Berger A.J. Bhadelia A. Cleary J. Hunter D.J. Keating N. Mebewu A. The Global Cancer Divide: An Equity Imperative Closing the Cancer Divide: An Equity Imperative Harvard University Cambridge, MA, USA 2012
89. Zur Hausen H. Papillomaviruses in the causation of human cancers—A brief historical account Virology 2009 384 260 265 10.1016/j.virol.2008.11.046 19135222
90. Cross A.J. Leitzmann M.F. Gail M.H. Hollenbeck A.R. Schatzkin A. Sinha R. A prospective study of red and processed meat intake in relation to cancer risk PLoS Med. 2007 4 e325 10.1371/journal.pmed.0040325 18076279 PMC2121107
91. Aune D. de Stefani E. Ronco A. Boffetta P. Deneo-Pellegrini H. Acosta G. Mendilaharsu M. Meat consumption and cancer risk: A case-control study in Uruguay Asian Pac. J. Cancer Prev. 2009 10 429 436 19640186
92. Haas S.L. Ye W. Lohr J.M. Alcohol consumption and digestive tract cancer Curr. Opin. Clin. Nutr. Metab. Care 2012 15 457 467 10.1097/MCO.0b013e3283566699 22797570
93. Nan H. Lee J.E. Rimm E.B. Fuchs C.S. Giovannucci E.L. Cho E. Prospective study of alcohol consumption and the risk of colorectal cancer before and after folic acid fortification in the United States Ann. Epidemiol. 2013 23 558 563 10.1016/j.annepidem.2013.04.011 23726821 PMC3749268
94. Hu J. La Vecchia C. Augustin L.S. Negri E. de Groh M. Morrison H. Mery L. Canadian Cancer Registries Epidemiology Research Group Glycemic index, glycemic load and cancer risk Ann. Oncol. 2013 24 245 251 10.1093/annonc/mds235 22831983
95. Al-Zoughool M. Dossus L. Kaaks R. Clavel-Chapelon F. Tjonneland A. Olsen A. Overvad K. Boutron-Ruault M.C. Gauthier E. Linseisen J. Risk of endometrial cancer in relationship to cigarette smoking: Results from the EPIC study Int. J. Cancer 2007 121 2741 2747 10.1002/ijc.22990 17657712
96. Zemla B. Guminski S. Franek K. Kolosza Z. Banasik R. Etiological factors in invasive corpus uteri carcinoma Neoplasma 1991 38 157 163 2041575
97. Choi Y. Song S. Song Y. Lee J.E. Consumption of red and processed meat and esophageal cancer risk: Meta-analysis World J. Gastroenterol. 2013 19 1020 1029 10.3748/wjg.v19.i7.1020 23467465 PMC3581989
98. Zheng S. Vuitton L. Sheyhidin I. Vuitton D.A. Zhang Y. Lu X. Northwestern China: A place to learn more on oesophageal cancer. Part one: Behavioural and environmental risk factors Eur. J. Gastroenterol. Hepatol. 2010 22 917 925 10.1097/MEG.0b013e3283313d8b 20520561
99. Crew K.D. Neugut A.I. Epidemiology of gastric cancer World J. Gastroenterol. 2006 12 354 362 16489633 10.3748/wjg.v12.i3.354 PMC4066052
100. Tavani A. Pregnolato A. Negri E. Franceschi S. Serraino D. Carbone A. La Vecchia C. Diet and risk of lymphoid neoplasms and soft tissue sarcomas Nutr. Cancer 1997 27 256 260 10.1080/01635589709514535 9101555
101. Hjalgrim H. On the aetiology of Hodgkin lymphoma Dan. Med. J. 2012 59 B4485 22759852
102. Ray G. Henson D.E. Schwartz A.M. Cigarette smoking as a cause of cancers other than lung cancer: An exploratory study using the Surveillance, Epidemiology, and End Results Program Chest 2010 138 491 499 10.1378/chest.09-1909 20154072
103. Karami S. Boffetta P. Stewart P. Rothman N. Hunting K.L. Dosemeci M. Berndt S.I. Brennan P. Chow W.H. Moore L.E. Occupational sunlight exposure and risk of renal cell carcinoma Cancer 2010 116 2001 2010 10.1002/cncr.24939 20213683 PMC2856708
104. La Vecchia C. Chatenoud L. Negri E. Franceschi S. Session: Whole cereal grains, fibre and human cancer wholegrain cereals and cancer in Italy Proc. Nutr. Soc. 2003 62 45 49 10.1079/PNS2002235 12740056
105. Daniel C.R. Park Y. Chow W.H. Graubard B.I. Hollenbeck A.R. Sinha R. Intake of fiber and fiber-rich plant foods is associated with a lower risk of renal cell carcinoma in a large US cohort Am. J. Clin. Nutr. 2013 97 1036 1043 10.3945/ajcn.112.045351 23515007 PMC3628376
106. Li X. Gao L. Li H. Gao J. Yang Y. Zhou F. Gao C. Li M. Jin Q. Human papillomavirus infection and laryngeal cancer risk: A systematic review and meta-analysis J. Infect. Dis. 2013 207 479 488 10.1093/infdis/jis698 23175764
107. Ma X. Park Y. Mayne S.T. Wang R. Sinha R. Hollenbeck A.R. Schatzkin A. Cross A.J. Diet, lifestyle, and acute myeloid leukemia in the NIH-AARP cohort Am. J. Epidemiol. 2010 171 312 322 10.1093/aje/kwp371 20042434 PMC2842202
108. Maruccia M. Onesti M.G. Parisi P. Cigna E. Troccola A. Scuderi N. Lip cancer: A 10-year retrospective epidemiological study Anticancer Res. 2012 32 1543 1546 22493399
109. Ringelhan M. Heikenwalder M. Protzer U. Direct effects of hepatitis B virus-encoded proteins and chronic infection in liver cancer development Dig. Dis. 2013 31 138 151 10.1159/000347209 23797136
110. Kubik A. Zatloukal P. Tomasek L. Dolezal J. Syllabova L. Kara J. Kopecky P. Plesko I. A case-control study of lifestyle and lung cancer associations by histological types Neoplasma 2008 55 192 199 18348651
111. Vlajinac H.D. Pekmezovic T.D. Adanja B.J. Marinkovic J.M. Kanazir M.S. Suvajdzic N.D. Colovic M.D. Case-control study of multiple myeloma with special reference to diet as risk factor Neoplasma 2003 50 79 83 12687283
112. McShane C.M. Murray L.J. Engels E.A. Landgren O. Anderson L.A. Common community-acquired infections and subsequent risk of multiple myeloma: A population-based study Int. J. Cancer 2013 10.1002/ijc.28479 PMC3947153 24105662
113. Zheng T. Holford T.R. Leaderer B. Zhang Y. Zahm S.H. Flynn S. Tallini G. Zhang B. Zhou K. Owens P.H. Diet and nutrient intakes and risk of non-Hodgkin’s lymphoma in Connecticut women Am. J. Epidemiol. 2004 159 454 466 14977641 10.1093/aje/kwh067
114. Van Leeuwen M.T. Turner J.J. Falster M.O. Meagher N.S. Joske D.J. Grulich A.E. Giles G.G. Vajdic C.M. Latitude gradients for lymphoid neoplasm subtypes in Australia support an association with ultraviolet radiation exposure Int. J. Cancer 2013 133 944 951 10.1002/ijc.28081 23382012
115. Liu Y.C. Yang Y.H. Hsiao H.H. Yang W.C. Liu T.C. Chang C.S. Yang M.Y. Lin P.M. Hsu J.F. Chang P.Y. Herpes zoster is associated with an increased risk of subsequent lymphoid malignancies—A nationwide population-based matched-control study in Taiwan BMC Cancer 2012 12 503 10.1186/1471-2407-12-503 23114019 PMC3531246
116. Risch H.A. Jain M. Marrett L.D. Howe G.R. Dietary fat intake and risk of epithelial ovarian cancer J. Natl. Cancer Inst. 1994 86 1409 1415 10.1093/jnci/86.18.1409 8072035
117. Kolahdooz F. Ibiebele T.I. van der Pols J.C. Webb P.M. Dietary patterns and ovarian cancer risk Am. J. Clin. Nutr. 2009 89 297 304 19056595 10.3945/ajcn.2008.26575
118. Beral V. Gaitskell K. Hermon C. Moser K. Reeves G. Peto R. Ovarian cancer and smoking: Individual participant meta-analysis including 28,114 women with ovarian cancer from 51 epidemiological studies Lancet Oncol. 2012 13 946 956 10.1016/S1470-2045(12)70322-4 22863523 PMC3431503
119. Ghadirian P. Thouez J.P. PetitClerc C. International comparisons of nutrition and mortality from pancreatic cancer Cancer Detect. Prev. 1991 15 357 362 1751946
120. Anderson M.A. Zolotarevsky E. Cooper K.L. Sherman S. Shats O. Whitcomb D.C. Lynch H.T. Ghiorzo P. Rubinstein W.S. Vogel K.J. Alcohol and tobacco lower the age of presentation in sporadic pancreatic cancer in a dose-dependent manner: A multicenter study Am. J. Gastroenterol. 2012 107 1730 1739 10.1038/ajg.2012.288 22929760 PMC3923585
121. Severson R.K. Nomura A.M. Grove J.S. Stemmermann G.N. A prospective study of demographics, diet, and prostate cancer among men of Japanese ancestry in Hawaii Cancer Res. 1989 49 1857 1860 2924323
122. Sawada N. Inoue M. Iwasaki M. Sasazuki S. Yamaji T. Shimazu T. Tsugane S. Alcohol and smoking and subsequent risk of prostate cancer in Japanese men: The Japan Public Health Center—Based prospective study Int. J. Cancer 2014 134 971 978 10.1002/ijc.28423 23929133
123. Sigurdson A.J. Chang S. Annegers J.F. Duphorne C.M. Pillow P.C. Amato R.J. Hutchinson L.P. Sweeney A.M. Strom S.S. A case-control study of diet and testicular carcinoma Nutr. Cancer 1999 34 20 26 10.1207/S15327914NC340103 10453437
124. Markaki I. Linos D. Linos A. The influence of dietary patterns on the development of thyroid cancer Eur. J. Cancer 2003 39 1912 1919 10.1016/S0959-8049(03)00432-5 12932671
125. Grant W.B. Update on evidence that support a role of solar ultraviolet-B irradiance in reducing cancer risk Anti-Cancer Agents Med. Chem. 2013 13 140 146 10.2174/187152013804487425 23094927
126. Bellack N.R. Koehoorn M.W. MacNab Y.C. Morshed M.G. A conceptual model of water’s role as a reservoir in Helicobacter pylori transmission: A review of the evidence Epidemiol. Infect. 2006 134 439 449 10.1017/S0950268806006005 16512966 PMC2870436
127. Ferreccio C. Smith A.H. Duran V. Barlaro T. Benitez H. Valdes R. Aguirre J.J. Moore L.E. Acevedo J. Vasquez M.I. Case-control study of arsenic in drinking water and kidney cancer in uniquely exposed Northern Chile Am. J. Epidemiol. 2013 178 813 818 10.1093/aje/kwt059 23764934 PMC3817454
128. Lopez-Abente G. Garcia-Perez J. Fernandez-Navarro P. Boldo E. Ramis R. Colorectal cancer mortality and industrial pollution in Spain BMC Public Health 2012 12 589 22852770 10.1186/1471-2458-12-589 PMC3490748
129. Petti S. Masood M. Scully C. The magnitude of tobacco smoking-betel quid chewing-alcohol drinking interaction effect on oral cancer in South-East Asia. A meta-analysis of observational studies PLoS One 2013 8 e78999 10.1371/journal.pone.0078999 24260143 PMC3832519
Appendix
The 87 countries with level 1 or 2 quality and life expectancy for males in 1990 >60 years: Albania, Argentina, Armenia, Australia, Austria, Azerbaijan, Bahamas, Barbados, Belarus, Belgium, Belize, Brazil, Brunei, Bulgaria, Canada, Columbia, Costa Rica, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Dominican Republic, Ecuador, Egypt, El Salvador, Estonia, Fiji, Finland, France, Georgia, Germany, Greece, Guatemala, Guyana, Hungary, Iceland, Iran, Ireland, Israel, Italy, Jamaica, Japan, Kazakhstan, Korea (Republic), Kuwait, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Macedonia, Malaysia, Mauritius, Mexico, Mongolia, Netherlands, New Zealand, Nicaragua, Norway, Panama, Paraguay, Peru, Philippines, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, South Africa, Spain, Sri Lanka, Suriname, Swaziland, Sweden, Switzerland, Syria, Tajikistan, Trinidad and Tobago, Turkey, Turkmenistan, Ukraine, United Kingdom, United States, Uruguay, Uzbekistan, Venezuela.
The other 70 countries: Algeria, Angola, Bangladesh, Benin, Bolivia, Botswana, Burkina Faso, Burundi, Cambodia, Cameroon, Cape Verde, Central African Republic, Chad, Chile, China, Comoros, Djibouti, Ethiopia, French Polynesia, Gabon, Gambia, Ghana, Guadeloupe, Guinea, Guinea-Bissau, Honduras, India, Indonesia, Iraq, Ivory Coast, Jordan, Kenya, Laos, Lebanon, Lesotho, Libya, Madagascar, Maldives, Mali, Malta, Martinique, Mauritania, Moldova, Morocco, Mozambique, Myanmar, Namibia, Nepal, New Caledonia, Niger, Nigeria, Pakistan, Papua New Guinea, Reunion, Saudi Arabia, Senegal, Sierra Leon, Solomon Islands, Sudan, Tanzania, Thailand, Togo, Tunisia, Uganda, United Arab Republic, Vanuatu, Viet Nam, Yemen, Zambia, Zimbabwe.