Effects of a high monounsaturated fat, tomato-rich diet on serum levels of lycopene

Objective: To compare the effect of a modified fat, monounsaturated-fat-enriched diet and a high-carbohydrate low-fat diet with high lycopene content on the serum concentration of lycopene and other carotenoids. Design: A randomised crossover dietary intervention study. Setting: Melbourne, Australia - Healthy free-living men. Subjects: A total of 13 healthy males between the age of 20 and 70y, recruited via advertisements in newspapers and university newsletter. Intervention: A randomised dietary intervention with two diets of 14 days each. The two diets were - (1) high-fat monounsaturated-fat-enriched (MUFA) and (2) high-carbohydrate low-fat (HCLF). Both the diets contained the same basic foods and a controlled carotenoid content high in lycopene. Results: A significant increase in serum total lycopene occurred, by 126% on the MUFA diet (P < 0.001) and 108% on the HCLF diet (P = 0.001). A reduction in serum cryptoxanthin (27% on MUFA diet and 25% on HCLF) and alpha-carotene (43% on the MUFA diet and 25% on the HCLF diet) was observed. No change was observed for the other carotenoids. Comparing the end of the two diets, no statistically significant difference was observed for lycopene or the other carotenoids. Conclusion: In all, 15% of energy from fat or 38% of energy from fat (predominantly monounsaturated fat) in the diet does not have a significant differential effect on serum lycopene.