Effects of oral supplementation with whey protein concentrate and its hydrolysates on blood cholesterol levels and oxidative DNA damage in South Korean male smokers.

OBJECTIVE: Cigarette smoking leads to oxidative stress and high cholesterolemia, which are key drivers of cardiovascular disease (CVD). Whey is known for its antioxidant and hypolipidemic properties. This study investigated whether whey protein concentrate (WPC) and hydrolysate of WPC (HWPC) can alleviate CVD risk in South Korean smokers by lowering oxidative stress and blood lipids.

METHODS: A total of 25 male smokers were screened, of which 18 eligible participants (72.0%), randomly assigned to either the WPC (n=9) or the HWPC (n=9) group, completed the 8-week intervention. Before (week 0, baseline) and after the intervention, participants visited the laboratory for blood collection and anthropometric measurements (body weight, height, waist circumference, body fat mass, nutritional intake). Blood samples were analyzed for plasma lipid profiles, plasma fat-soluble antioxidants, and leukocyte oxidative DNA damage using the comet assay.

RESULTS: There were no significant differences in anthropometric measurements, dietary food intake, plasma conjugated dienes, total radical-trapping antioxidant potential, and erythrocytes' glutathione peroxidase and catalase activities in both WPC and HWPC groups. However, we observed a significant decrease in the tail moments of leukocytes, low-density lipoprotein cholesterol, atherogenic index, and high coenzyme Q10 levels in both groups. In the WPC group, total cholesterol decreased, while plasma retinol, α-tocopherol, lycopene, α-carotene, and β-carotene increased.

CONCLUSION: WPC or HWPC significantly decreases blood cholesterol levels and oxidative DNA damage and increases plasma fat-soluble antioxidant levels. Thus, WPC or HWPC might be used as oral supplementation to lower the risk for CVD in South Korean male smokers.