Oxidative damage to such biomolecules as DNA, lipids and proteins is involved in the process of aging and various diseases. In particular, DNA damage has strong influence on various cell functions, thereby being involved in aging and cancer. Oxidative DNA damage seems to be produced by oxidative stress in the body due to the increased production of oxygen radicals and decreased level of antioxidants. This paper reports the relationship between oxidative DNA damage and antioxidants in foods, and present information about the relationship, including analytical methods for assessing DNA damage and antioxidants in human samples. Among the antioxidants in foods, vitamin C, vitamin E, carotenoids, and flavonoids have received considerable attention in studies which evaluated their antioxidative effects in in vitro and in vivo. There have also been some clinical studies reporting the efficacy of these antioxidants against oxidative stress-induced DNA damage, although the results have been inconsistent, even in the case of vitamin C, a well-known antioxidant. The application of antioxidants to our practical eating habits for preventing oxidative DNA damage will therefore require further scientific findings on both their efficacy and safety.
Purpose: We conducted an 8-year longitudinal study to investigate aging-related changes in food and nutrient intake in a cohort of elderly subjects living in an urban community, and attempted to relate the food intake with vital prognosis. Procedures: The first (baseline) nutrition survey was conducted in 1991 on 161 subjects (72 males and 89 females; aged from 65 to 79) living in Koganei City. The second nutrition survey was conducted 8 years later in 1999. Excluding death or illness, 98 subjects (86%) were available for the follow-up study. A nutrition survey was conducted by the three-day dietary record method with daily home visits by dieticians. Aging-related changes in the physical attributes, food intake, nutrient intake, and intake adequacy were analyzed. The relationship between the nutritional intake and mortality was analyzed by the Cox proportional hazard model. Results: The mean of the adequacy of energy intake was 113%, while 13% of the subjects had an energy intake adequacy of less than 90%. The education level and self-rated health were positively correlated with the adequacy of energy intake, as was eyesight. A multiple logistic regression analysis revealed that the education level was significantly associated with the adequacy of energy intake. Among all the food groups considered, the consumption of fruit had declined in both the males and females. A significantly decreased intake of protein, fats, carbohydrate, iron and sodium was observed in the females. There was no change in the protein-fat-carbohydrate energy ratio. The nutrient intake was greater than the recommended dietary allowances during the baseline survey and also eight years later. A significant correlation was observed between the vegetable protein intake and vital prognosis in the males. Conclusion: The results from this cohort indicate that, although the nutrient and food intake changed with aging, the nutrient intake was still higher than the recommended dietary allowances. These results show that a “diet for healthy longevity” can be achieved by continuing to maintain the recommended dietary allowances despite advancing age.
The textural properties of different forms of food, classified on the basis of eating effort by the elderly, were measured at Sugenosato Nursing Home for the elderly. The results demonstrate that the forms of food that require little mastication effort and with a texture most easily lumped together within the oral cavity were all soft and high in both adhesiveness and cohesiveness. It was also indicated that a consistent jellied food texture, which is a property helpful for people with swallowing difficulties, was soft and low in both adhesiveness and cohesiveness, and that it took a form that required neither mastication nor lumping together in the oral cavity. Among the various forms of food studied, thin rice gruel and gruel prepared with a blender, which constitute staple food at the nursing home, were found to be the softest and the highest in adhesiveness and cohesiveness. These findings imply that eating the main and side dishes (meat, fish, vegetables, etc.) simultaneously with the staple food (thin rice gruel and gruel prepared with a blender) makes it easier for the elderly to lump the food together in the oral cavity to form a bolus. A commercially developed and marketed boil-in-the-bag meal series, classified according to the Food Category Table for the Elderly drawn up by Japan Care Food Conference, was demonstrated to have textural properties similar to those of the meals served at the nursing home, where the food is prepared according to the eating ability of each elderly person. These results indicate the importance of measuring the textural parameters of the food served at hospitals and nursing homes for the elderly to identify whether or not an individual with deteriorated eating ability will be able to take in food in a safe manner.
Bittern is mainly used as a magnesium source at present. In this study, we used a bittern solution containing magnesium (Mg2+) at 10.2g/100ml. We assessed the effects of bittern on the activity of pancreatic lipase in assay systems using triolein emulsified with phosphatidylcholine and on the elevation of plasma triacylglycerol levels by the oral administration of a lipid emulsion to rats. Bittern inhibited the hydrolysis of triolein emulsified with phosphatidylcholine by pancreatic lipase in vitro. It also reduced the elevation of rat plasma triacylglycerol levels after the oral administration of a lipid emulsion containing corn oil at doses of 0.0435ml/kg and 4.75ml/kg. In addition, we examined the effects of an MgCl2 solution, which is the primary component of bittern, on the activity of pancreatic lipase and on the plasma triacylglycerol elevation in rats administered the oral lipid emulsion. The MgCl2 solution inhibited the pancreatic lipase activity in a dose-dependent manner in vitro, and at doses of 37.6mg/kg and 4.1g/kg, significantly reduced the elevation of plasma triacylglycerol levels. The anti-hyperlipidemic action of the bittern solution suggests that it is the MgCl2 content that inhibits the intestinal absorption of dietary fat.
Variation in the dietary practice and nutritional intake among different generations of ethnic Koreans in Yanbian Korean Self-governing Province (Jilin, China) were examined in May 2001 in comparison with those of ethnic Chinese in the same Province. A total of 158 junior high school students, 106 high school students in dormitories and 25 elderly people in a welfare Institution, each group including ethnic Koreans and Chinese, were surveyed by questionnaire and interview. Both the Koreans and Chinese consumed rice, fried vegetables and salad most frequently as their staple foods. Considering the fact that salad and fried vegetables are respectively of Korean and Chinese origins, both the ethnic groups are incorporating each other's diet. However, the older group in the welfare institution, whether ethnic Korean or Chinese, depended more heavily on their own traditional dishes than the younger generation of the junior high and high school groups. The major contrast between the ethnic Koreans and Chinese was the relatively high energy intake from carbohydrate and low energy intake from fat by the former than by the latter. We conclude that ethnic Koreans have developed food diversity by incorporating Chinese food, while moderately sustaining their own traditional food.
We investigated the food and nutrient intakes during pregnancy and lactation by Japanese women. One hundred ninety-six pregnant women were divided into two groups: one in the first half of pregnancy (<20 weeks of gestation) and the other in the latter half of pregnancy (≥20 weeks of gestation). In addition, 97 lactating women (≤16 weeks after delivery, excepting those on complete formula feeding) were incorporated into the lactating group. Nutrient intake was calculated according to the Standard Tables of Food Composition in Japan, 5th revised edition. Almost all food and nutrient intakes were higher in the lactating group than in the first half of pregnancy group. The consumption of fish was markedly higher in the lactating group, and the intakes of long-chain polyunsaturated fatty acids, EPA and DHA, were also higher. The pregnant and the lactating groups made efforts to increase the intake of calcium, iron and dietary fiber. We provisionally calculated that the calcium, iron and dietary fiber intakes by 85% of the subjects were less than the levels in the Recommended Dietary Allowances in Japan, 6th revised edition (6th RDA). However, the pregnant and the lactating groups made efforts to decrease the salt, fat and energy intakes such that the levels in the 6th RDA were met.