The associations of plasma carotenoids and α -tocopherol concentrations with fasting glucose in Cameroon

Abstract Previous estimations of the associations between fruits and vegetables (F/V) intake with diabetes markers showed mixed results, possibly partly because of the subjective assessment of dietary intake. We aimed to examine the relationship between plasma carotenoids and α -tocopherol (as objective markers of F/V intake) and fasting glucose. This was a population-based cross-sectional study in 592 adults in Cameroon. Self-reported F/V intake was assessed using the WHO STEPS questionnaire, and the biomarkers were analysed by HPLC. The mean age of participants was 38·5 ( sd 8·6) years (63·7 % women). The median (IQR) number of times participants self-reported consuming fruits in a typical week was 2(1–5) and vegetables was 4(2–7) times/week. Plasma total carotenoids was positively correlated with self-reported intake of fruits ( r = 0·13) and vegetables ( r = 0·29), both P -values < 0·01. In unadjusted analysis, the difference in fasting glucose comparing the highest against the lowest tertile of the biomarkers concentrations was −0·28 (95 % CI −0·56, −0·001) mmol/l for total carotenoids and −0·31 (–0·59, −0·03) mmol/l for plasma α -carotene. The associations became stronger after adjusting for sociodemographics, lifesyle factors and cholesterol (–0·36 (–0·73, −0·002) mmol/l for total carotenoids and −0·41 (–0·79, −0·03) mmol/l for α -carotene). There was no evidence of an association between α -tocopherol and fasting glucose. We showed an inverse association of total carotenoids and α -carotene, objective indicators of F/V intake, with fasting glucose; suggesting that higher F/V intake may be beneficial for diabetes prevention in African populations where F/V intake is low.