Seasonal differences in total antioxidant capacity intake from foods consumed by a Japanese population

This cross-sectional study aimed to estimate total antioxidant capacity (TAC) intake from food and beverages in a Japanese population from 7-day seasonal dietary records.

The 7-day weighed dietary records of 390 subjects over four seasons between 1996 and 1998 were used. The TAC values (μmol trolox equivalents (μmol TE)/g) of various foods and beverages were defined, as reported in previous studies for weighed dietary records, using several different methods. TAC values of foods were estimated in 242 food and beverage items: 86.5% of vegetables, 99.1% of fruits, 71.5% of potatoes, 96.7% of beans, and 100% of chocolates. Differences in TAC intake per day and intake (g) per day among seasons in each of the food and beverage group were compared using a general linear model for repeated measures. The TAC intake/day were calculated for each food and beverage item in the four seasons.

TAC intake/day (μmol TE/day) varied from 10 189 (summer) to 12 292 (winter). TAC intake/day from fruits (2696) and potatoes (395) was highest in autumn, from vegetables (2827) it was highest in summer and from beans (4151) and tea (2331) it was highest in winter.

The dietary habits of the studied Japanese population showed the highest antioxidant capacity in winter and the lowest in summer.