In some of the countries people have better longevity with low incidence of degenerative health problems such as Diabetes, CVD and Cancer. The Kuna people of the San Bias islands, off the coast of Panama, have a rate of heart disease that is nine times less than that of mainland Panamanians and is thought to be due to the cocoa drink, which is unusually rich in flavanols that help preserve the healthy function of blood vessels.
The Japanese diet includes foods with very low cholesterol content and abounds in fishes rich in polyunsaturated fats (in particular, eicosopentanoic acid), and the seaweeds Kombu (from warm waters) and Nori (from cold waters) in addition to rice, miso (paste from fermented soybeans used as seasoning in soups), tofu, mushroom and specially cultivated seaweeds. Among the Japanese, Okinawan people live about 7 years longer than Americans and have 80 per cent fewer cases of cancer and heart attacks.
Extremely low death-rates in Okinawa could be due to the specific features of the Okinawan diet. In Okinawa, the consumption of sugar and salt constitutes only 25 per cent and 20 per cent (respectively) of the average amount consumed in Japan, the vegetable consumption is 3 times more, and fish is twice that of other Japanese while the energy consumption is 20 per cent lower. They also believe in eating from small plates and stop eating when they are about 80 per cent full. In Okinawa, it is believed that the diet of soya, sweet potato, green leafy vegetables and turmeric tea are some of the contributors of natives’ longevity beyond 90’s.
Even though Japan continues to have the highest life expectancy in the world, it is expected to be overtaken by other high longevity countries, like Sweden (which has high male and female life expectancy), Italy and Australia (with high male life expectancy).
The lowered life expectancy of Japanese is believed to be due to the high amount of tobacco usage and dietary changes that have elevated the body mass index. Recently, young Japanese, particularly young men in Okinawa, have shown a tendency to avoid the traditional dishes of stewed meat and champuru.
Studies among the elderly in Greece, Denmark, Australia, Spain and China have shown that the overall Mediterranean dietary pattern is more important for longevity than single nutrients thus proving that a Mediterranean diet is associated with longer survival. The Mediterranean diet consists of Olive oil, large quantities of vegetables and legumes in the form of salads and of cooked foods along with wheat, grapes and their derived products.
Antioxidants represent a common element in these foods which provides a plausible explanation for the apparent health benefits. Total lipid consumption of Mediterranean’s may be high, around 40 per cent of total energy intake as in Greece, or moderate, around 30 per cent of total energy intake as in Italy. But the ratio of monounsaturated to saturated dietary lipids is much higher than that in other places of the world, including northern Europe and North America thus making a positive contribution to their health status.
Besides reducing the cardiovascular events, the risk of mortality due to myocardial infarction, and peripheral arterial disease, etc., there is some evidence that Mediterranean diet is also beneficial in relation to bone metabolism, rheumatoid arthritis, neurodegenerative age-related diseases (cognitive deficit, Alzheimer’s disease, Parkinson’s disease).
A Healthy Traditional Dutch diet appears more beneficial for longevity and feasible for health promotion in older Dutch women than a Mediterranean diet. This diet is comparable with other reported healthy or prudent diets which are protective against morbidity or mortality.
In Korean diet, some traditional soybean-fermented foods such as Doenjang, Chunggukjang, kimchi and seaweeds were found to contain considerable amounts of vitamin B12 contributing significantly to good vitamin B12 status in very old elderly Koreans.
Several dietary practices were examined for their influence on ageing process such as modification in the total energy consumption, fat and protein content in the diet. Caloric restriction by 20-30 per cent was first shown to extend life in rats nearly 80 years ago. As early as 1979, Young has reported on the basis of his review on the subject that feeding ad-libitum throughout life does not promote maximal survival and food restriction increases mean life span.
Composition of energy restricted diet for its benefits on longevity was further explored. Although energy restriction provides significant influence on longevity, very high fat diets do not give the same protection as high carbohydrate diets do. Caloric restriction has many positive effects on health and longevity. But quality of life on a restricted diet as well as the ability to maintain that diet long term is a great concern. The possible importance of total energy, carbohydrate, and protein intake as well as the influence of mode of feeding need to be considered.
Recent data indicate that the decrease in mitochondrial ROS generation is due to protein restriction rather than calorie restriction, and more specifically to dietary methionine restriction. Greater longevity would be partly achieved not only by a low rate of endogenous oxidative degeneration, but also by a macromolecular composition highly resistant to oxidative modification, as is the case for lipids and proteins.
In recent years there is growing interest in the role of specific nutrients, whole foods, and also phytochemicals in the process of ageing.