Effects of Vegetable and Fruit Intakes on Serum Carotenoid and MDA-LDL Concentrations in a Pilot Study of Japan Diet Education for Middle-aged Men

Abstract

  We previously reported a 6-week pilot study demonstrating the effects of Japan Diet education for reducing malondialdehyde modified (MDA)-low density lipoprotein (LDL) in middle-aged men. Herein, we investigated the association of consuming vegetables and fruits, as recommended by the Japan Diet education program, with serum carotenoid and MDA-LDL concentrations. The intake volume of vegetables including green and yellow varieties increased, but was only about 300 g at week 6. Although green and yellow vegetable consumption was only 100 g, it tended to be inversely associated with MDA-LDL at week 6 (p = 0.051). Increased α-carotene and β-carotene intake attributed to elevate those serum concentrations at week 6, which were not associated with MDA-LDL. Intakes of fruits and β-cryptoxanthin did not change with the intervention. Our results suggest that consuming green and yellow vegetables might reduce MDA-LDL in combination with other food comprising the Japan Diet. Further study on vegetable and fruit intakes is thus warranted to determine the protective effects of the Japan Diet on LDL oxidation.