Japanese diet and prevention of cancer: Some sushi for thought..
Japanese and Mediterranean people who still eat in the traditional manner have the highest life expectancy in the world - and their longevity has much to do with their diet. The two diets seem very different, but they have in common a relative absence of saturated fats and margarines, and an emphasis on fish, vegetables and fruit.
This month, researchers from the Aichi Cancer Center in Nagoya, published a study in the International Journal of Cancer about the influence of Japanese diet over breast cancer.
They studied 2,385 women with breast cancer and 19,013 women confirmed as free of cancer and found that the reduction in breast cancer risk was associated with a high consumption of milk and green-yellow vegetables (green leafy vegetables, carrots and pumpkins) among both pre- and postmenopausal women. These protective effects of Japanese diet were more predominant among postmenopausal women. Furthermore, women who ate fish 5 or more times per week had less risk of having breast cancer than women eating fish only 3 times per month. This benefit was also related to amount of fruit in the diet.
Low fat content - especially in saturated fat.
Twice as much fish as meat.
Lots of vegetables, which play an important role - the more popular include bamboo shoots, eggplant, various mushrooms, sweet potato, and Chinese cabbage.
Many natural flavour additives in the form of herbs, spices and condiments such as ginger, lemon, sesame seed and mustard.
A high variety of foods, especially plant foods. A recent Japanese survey of the diets of 200 elderly women revealed they consumed a variety of over 100 biologically different foods per week. By contrast, in most western countries the recommended minimum is only 30. Research shows that the higher the variety, the less risk of many diseases including cardiovascular disease, diabetes and many cancers.
A high intake of soy products - approximately forty times more than the Western intake.
Green tea - this is particularly rich in antioxidants. Our own black tea is also antioxidant-rich, but the effect is destroyed with the addition of milk, which prevents their absorption.
Fruit is served at the end of a meal.
The manner of eating, as much as the food content, is also very important. A traditional Japanese celebratory meal may include a dozen miniature courses served in strict, artistic sequence.
With beauty and ingeniousness, food is displayed to reflect the seasons, with aesthetics, tradition, religion, history, ritual and symbolism involved in every meal - a lesson in relaxation. It is instructive to contrast this with the rushed meal in front of the television which has become a familiar feature of Western dietary routine.
The lesson from all of this - as from the Mediterranean diet - is to recognise the benefits of a high food variety, with minimal saturated fat, more fish, less meat, and especially more fruit, vegetables and grains, not only for postmenopausal women but for everyone in general.
Still not convinced? There is also clear evidence that Japanese people who move overseas and adopt a Western-style diet end up having an increased risk of breast cancer, coronary heart disease and diabetes. No doubt about it: what really motivated the British to colonize so much of the world is that they were just looking for a decent meal. Thanks God they never made it as far as Japan !
Reference: Dietary factors protective against breast cancer in Japanese premenopausal and postmenopausal women.
Hirose K, Takezaki T, Hamajima N, Miura S, Tajima K.