Friday 4 April 2008

HEALTHY AGEING


“Aging is not 'lost youth' but a new stage of opportunity and strength.” – Betty Friedan

If you have been reading this blog, you’ll know I recently attended an international conference on research in Complementary Medicine. This was very interesting and numerous delegates from many well-known universities worldwide were there, presenting papers of great interest. Several presentations focussed on nutrition and especially nutrition and old age. The research is showing that if we take care of our diet, not only do we live longer, but we age in better health. But firstly, what is ageing?

The ageing process is the progressive deterioration of bodily functions over the lifespan. In Australia, life expectancy currently averages 78.5 years for males and 83.3 years for females. From 1901 to 2000, life expectancy at birth increased by 21.4 years for males and 23.3 years for females. The ageing process is destructive, progressive and intrinsically determined, universal amongst all complex living organisms. Is it a disease to be cured or a natural process that can be better managed? These two concepts are united by “anti-ageing strategies” in humans which involve life extension to the maximal limits, currently thought to be about 120 years, but also health extension, staying well until a short decline and death.

Most researchers seem to think that ageing is a multi-factorial process and relies on genetic factors, cumulative damage of body structures by many interactions with environmental stressors, oxidative stress, non-renewal of permanent cells, etc. Although there is no general consensus on the cause of ageing, most researchers would regard cellular damage as a key component. Many anti-ageing approaches involve boosting antioxidant defences against free radical damage and attempting to minimise protein glycation. Other approaches are focussed on gene therapy techniques to restore cell and organ function.

Recent studies in American populations showed that five factors seemed to be associated with a reduced lifespan:
1) Cigarette smoking 2) Diabetes mellitus 3) Obesity 4) Hypertension 5) Sedentary lifestyle.

The obvious thing to do then to extend lifespan, would be to eliminate these five factors from our life. The study referred to above showed that when these factors were eliminated, lifespan easily reached 90 years, other things being equal.

Many other studies around the world show that a low calorie diet is compatible with a longer lifespan. A famous study was set in Japan. Okinawa is a group of islands in southern Japan. Okinawans have up to 4-5 times the number of centenarians as the rest of Japan. Low calorie intake is common at younger ages and body mass index remains low throughout life. Adult energy intake is 20% less than the Japanese national average. Death rates from heart disease, cancer and cerebral vascular disease are 60 to 70% of the rest of Japan and they have half the number of deaths in the 60-64 year age range. Their diet is based around the Satsamu sweet potato, seaweed, leafy vegetables, fish, pork, tofu, green tea and kohencha tea. Mixed food broths are commonly eaten. Food is viewed as medicine and a common practice is to only eat 80% of the amount of food required to fill the stomach.

But what about anti-ageing nutrients? Nutrients impact on metabolism in a variety of ways and can function as gene regulators, free radical scavengers, cell membrane protectors, repair enhancers, anti-inflammatories, immune regulators and hormone modulators. Research has shown that there are many components in foods that can act as anti-ageing compounds and can promote health. Some of these are:

Resveratrol: This is an anti-fungal chemical naturally present in peanuts, mulberries, grapes (particularly those varieties more prone to fungal disease such as Pinot Noir), and in Giant Knotweed, a herb popular in Asian herbal medicine. It is believed to be responsible for the health-promoting effects of red wine.

Curcumin: This is the principal active ingredient in the spice turmeric, a member of the ginger family commonly used in curry powder. Turmeric is a well-known anti-inflammatory herb used for centuries in Ayurvedic medicine and traditional Chinese medicine. It has anti-inflammatory, antioxidant, antiviral, antibacterial, antifungal, and anticancer activities.

Grape seed: This is a superior antioxidant, it maintains capillary integrity, is anti-inflammatory, anticancer, and neuroprotective. Grape seeds contain phenolic acids, polyphenols and flavonoids. About 60-70% of the polyphenols in grapes are found in the seed and these have powerful antioxidant activity, estimated to be twenty times more potent than vitamin C and 50 times more potent than vitamin E and superior to pine bark bioflavonoids. They can scavenge superoxide and hydroxyl radicals, inhibit oxidation of LDL cholesterol, protect against DNA damage in the brain and liver in mice and protect the skin from sun damage.

Mushrooms, especially polypore varieties such as reishi, shiitake and maitake, contain polysaccharides, particularly beta-glucans, that have anti-inflammatory and immuno-modulating properties, including activation of lymphocytes, macrophages, natural killer cells and production of cytokines, tumour necrosis factor alpha and interferon 46. Mushrooms may suppress autoimmune responses, modulate NF-kappa B activity and have anti-cancer effects.

Ginseng is a traditional Asian herb used as an adaptogen and tonic and to restore homeostasis. It has antioxidant, anti-inflammatory, anti-apoptotic and immune-stimulatory activity and has been shown to be useful for CVD, cancer, immune deficiency and liver toxicity. Ginseng's active components have beneficial effects on ageing, CNS disorders and neurodegenerative diseases.

Brahmi is a herb used in Ayurvedic medicine for the treatment of cognitive deficits. It has antioxidant activity in the brain and is a potent adaptogen. Brahmi prevents depletion of acetylcholine in the hippocampus, increases glutathione peroxidase levels and boosts the synthesis of new protein in brain tissue.

The general consensus about food and healthy ageing is, that we should develop good dietary habits while still young. Have a low body mass index and eat less calories, with a low saturated fat diet. Complex carbohydrates supplemented by a variety of seasonal fresh fruits and vegetables, good calcium intake, moderate sun exposure, lots of grapes (eaten with seeds!), some red wine with meals, nuts, some herbs and spices. Certain Asian diets and many Mediterranean diets adhere to these guidelines.

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