Comparison of the Health Benefits of Different Eras of Japanese Foods : Lipid and Carbohydrate Metabolism Focused Research

Abstract

Since the Japanese are known for their long life span, Japanese food has potential for health promotion. To identify the era of Japanese food that was beneficial to health, we investigated the health enhancing effects of Japanese foods from different eras, focusing on lipid and carbohydrate metabolic systems. Based on the National Nutrition Survey, representative one-week menus of Japanese foods from 2005, 1990, 1975 and 1960 were prepared, cooked, and powderized. Each mixture of Japanese food was given to normal ICR mice and senescence-accelerated mice (SAM) P8 as a 30 % mixture in standard diet for eight months. As a result, the Japanese food mixture from 1975 suppressed lipid accumulation in white adipose tissues in both mouse strains. To examine the underlying mechanisms, we conducted DNA microarray analysis of the liver, which is responsible for energetic lipid metabolism. As a result, the Japanese food mixture from 1975 promoted gene expression for high-energy expenditure in ICR mice. Additionally, the Japanese food mixture from 1975 promoted gene expression for enhanced degradation of triglycerides, suppression of fatty acid synthesis, and cholesterol catabolism in SAMP8 mice. Overall, it was suggested that components of Japanese foods from around 1975 are more effective than those of modern Japanese foods in preventing metabolic syndrome.

Fermented Soybean Suppresses Visceral Fat Accumulation in Mice

“…In addition, a control (CO) group was fed with normal diet and a high‐fat diet (HFD) group was fed with Western diet containing 5% of the replaced material without addition of Natto or soybeans. Energy was calculated using the modified Atwater method (4 kcal of protein, 9 kcal of lipid, 4 kcal of carbohydrate per g) …”

“…As the Japanese diet has become more westernized in the past 50 years, the prevalence of lifestyle diseases has increased . Therefore, we also examined the contents of Japanese diets from different years to determine which was most effective for maintaining good health . The Japanese diet from 2005 was defined as the modern Japanese diet.…”

“…One characteristic of the 1975 Japanese diet is that it contained a large quantity of soy products . Beneficial effects of soybeans on health have been studied worldwide, and fermented soy products such as Natto and Miso are well known as health foods.…”

Comparison of the Effects of the 1975 Japanese Diet and the Modern Mediterranean Diet on Lipid Metabolism in Mice

“…The nutritional composition fat, protein, moisture, ash, carbohydrate and energy of the prepared diets was determined to confirm the actual values Table 3 . Fat was measured by acid digestion; protein by a modified Dumas method Sumigraph NC analyzer NC-220 F; Sumika Chemical Analysis Service ; moisture by vacuum oven drying; ash by direct ashing; and carbohydrate by subtracting the fat, protein, moisture and ash contents from the total amount 8,19 . The energy content was calculated using modified Atwater factors 4, 9 and 4 kcal/g for protein, fat and carbohydrate, respectively 19 .…”

“…Therefore, the 1975 Japanese diet appears to limit accumulation of visceral fat and is the least likely to cause obesity among Japanese diets from different eras. In subsequent studies, the 1975 Japanese diet has been shown to have beneficial effects on diabetes, fatty liver, dementia and lifespan 8,10 .…”