Associations between green tea drinking and body mass index, serum lipid profile and prostate-specific antigen in a Ghanaian population: a cross-sectional study.

BACKGROUND

Prostate cancer (PCa) is a major malignancy that affects men worldwide. Obesity, dyslipidemia and elevated serum PSA are common risk factors. Green tea is a popular beverage in some West African communities with a relatively low incidence of PCa. However, the associations of green tea consumption with these PCa risk factors in that population remain unknown. This study therefore aimed at investigating the associations between green tea intake and the serum lipid profile, body mass index (BMI), and serum PSA.

METHODS

An analytical cross-sectional survey was conducted to compare the serum lipid profile, BMI and serum PSA between green tea drinkers (GTD) and non-tea drinkers (NTD). A total of 415 men, 40 years or older, who gave their consent were assigned to four groups on the basis of age: 40-49 years, 50-59 years, 60-69 years, and 70 + years. BMI, serum lipid profile (total cholesterol, HDL-c, LDL-c, and triglycerides), and serum PSA level were determined and compared between GTD and NTD.

RESULTS

Compared with the NTD group, the GTD with normal BMI were significantly greater across all age groups, and the odds of being overweight (obese) were significantly lower in the GTD group than in the NTD group. Compared with those in the NTD, significantly fewer atherogenic lipids in the GTD were observed across all age categories. Furthermore, the odds of dyslipidemia in GTD groups were lower than those in NTD groups across all age groups. A significantly lower mean serum PSA level was observed in the older GTD age groups (60-69 and 70+) than in the NTD group, and significantly lower odds of elevated serum PSA were detected in the GTD group than in the NTD group. However, there were no differences in the mean PSA between the GTD and NTD groups in the younger age groups. Weak positive correlations between serum PSA and BMI were observed in the NTD group regardless of the age category. However, a significantly strong negative correlation between the serum PSA concentration and BMI was observed in the older age GTD group compared with the NTD group.

CONCLUSIONS

Consumption of green tea was associated with reduced atherogenic serum lipids and improved BMI independent of age. Furthermore, GTD was significantly associated with reduced serum PSA in older men but not in younger adults.