Effects of Nutrition Education Program for the Japan Diet on Serum LDL-Cholesterol Concentration in Patients with Dyslipidemia: A Randomized Controlled Trial

Aim: The Japan Diet (JD) recommended by the Japan Atherosclerosis Society based on the traditional Japanese diet is presumably favorable for preventing atherosclerotic cardiovascular diseases, but few high-quality controlled clinical trials have examined its benefits as compared with other diets. We studied effects of nutrition education for JD intake as compared with partial JD (PJD) intake on serum lipids and inflammatory parameters in subjects with dyslipidemia. Methods: A randomized parallel controlled clinical trial was conducted on outpatients with dyslipidemia. Participants were randomly divided into the JD or the PJD group. Face-to-face nutrition education based on each diet at baseline and at 3 months, as well as monthly counseling by mail during the intervening 3-month period, were provided and participants practiced up to 6 months. Both groups were advised to reduce consumptions of animal fat/ fatty meat/poultry, confections, and alcoholic drinks. Additionally, the JD group participants were recommended to consume more fish, soybean products especially natto, vegetables, and seaweed/mushrooms/konjak, and to switch from refined to unrefined cereals or barley. Results: Mean LDL-cholesterol was 125 +/- 29 mg/dL at baseline, and the JD group ( n =49) showed a greater mean LDL-cholesterol decrease than the PJD group ( n =49) [- 8 mg/dL in JD vs 1 mg/dL in PJD, difference, -9 mg/dL (95%CI, -17 to 0) p =0.043)], and triglyceride ( p =0.023) and insulin ( p =0.033) reductions were larger in the JD group than in the PJD group at 6 months. Conclusion: Nutrition education for JD intake was suggested to improve serum lipid and metabolic parameters in patients with dyslipidemia.