The present cross-sectional study assessed the potential relationships of carotenoid intake with lipid and oxidative stress markers in middle-aged men. A total of 296 apparently healthy middle-aged men (mean age 50.5 (SD 5.0) years, BMI 25.8 (SD 3.5) kg/m(2)) were recruited to participate in the study. Dietary intake, anthropometry, blood pressure, lifestyle features, blood and urine biomarkers were assessed using validated procedures. The lipid markers included NEFA, Castelli index, and TAG:HDL ratio; oxidative stress markers included urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-iso-PGF2α and plasma oxidised-LDL (ox-LDL). We observed a significant inverse association (P < 0.05) between NEFA concentrations and consumption of lutein plus zeaxanthin, β-carotene, α-carotene and total carotenoid, while Castelli index was negatively associated with daily intake of lycopene, β-carotene and total carotenoids. Regarding oxidative stress biomarkers, urinary 8-OHdG and ox-LDL concentrations were also inversely associated (P < 0.05) with consumption of lycopene, lutein plus zeaxanthin, β-carotene, α-carotene and total carotenoids, regardless of confounding variables. Moreover, there was a negative association of urinary 8-iso-PGF2α concentration with dietary lutein plus zeaxanthin (β - 0.135, 95% CI - 0.268, - 0.001), β-carotene (β - 0.156, 95% CI - 0.277, - 0.034) and with the sum of all carotenoids (β - 0.189, 95% CI - 0.333, - 0.046). In conclusion, total daily carotenoid intake based on five investigated carotenoid types (β-cryptoxanthin, lycopene, lutein plus zeaxanthin, β-carotene and α-carotene) was inversely associated with relevant lipid and oxidative stress markers in middle-aged men, with emphasis on β-carotene that was negatively associated with five of the six lipid and oxidative stress markers evaluated in the present study.
Keywords: Carotenoids; Food habits; Lipids; Oxidative stress.