An increase in longevity is of much greater value if it is associated with freedom from suffering, pain and disability. Many of the diseases of older age are, fortunately, largely preventable. Reducing the risk of chronic diseases such as cardiovascular disease, certain cancers, diabetes, and some eye diseases is achievable by implementing changes to diet and lifestyle, and can be assisted with nutrient supplementation and herbal medicines. The earlier changes are implemented, the greater the reduction in risk of disease. Extending the length of our lives has its major benefit only if we can balance extended longevity with decent quality of life.
Special Nutritional Needs
Good nutrition is essential for the health of seniors, not just for minimising sickness, but to maintain an independent lifestyle for as long as is possible. The foundation of good nutrition is a diet that contains a wide variety of nutritious foods.
Ageing affects lifestyle and impacts on nutritional needs. For example with ageing, physical activity usually declines, resulting in a decrease in the amount of energy required by the body. Therefore, with lower energy demands, we eat less food; seniors therefore need to ensure that foods consumed are nutrient-dense to maintain adequate nutrient intake. It is difficult to maintain sufficient intake of nutrients without the use of supplements - a good multivitamin contains the RDI (recommended dietary intake) of most vitamins and minerals.
With age, muscle mass also declines - this is called sarcopenia. A decline in strength increases the risk of falls and susceptibility to broken bones. The decline can be slowed by ensuring an adequate intake of protein and amino acids, and by exercising for example 30 minutes of aerobic exercise daily helps maintain muscle mass.
Consumption of pharmaceutical drugs typically increases with age, and some foods can affect the absorption of drugs eg. grapefruit juice can affect liver enzymes that are involved in the metabolism of heart drugs and antihistamines, increasing blood drug levels by as much as 300%, to potentially lethal levels. The heart drug warfarin reacts with vegetables such as Brussels sprouts, cabbage, broccoli and asparagus, that contain vitamin K which hinders the drug's clotting effect.
Substitutes for salt that are based on potassium can lead to dangerously high levels of potassium in people taking certain heart drugs. On the other hand, large amounts of liquorice can deplete potassium levels, which can be dangerous in those taking potassium-reducing diuretics.
Some herbs can also interact with prescription medicines eg. the anti-depressant herb Hypericum (St John's Wort) stimulates certain liver enzymes which may lead to a reduction in blood level of the drugs as the body tries to eliminate them. Herbs such as ginkgo affect blood platelets aggregating and can potentiate the effects of anticoagulant drugs (such as warfarin) - even garlic and ginger can do this, so it is best to check with your healthcare professional when you are taking medicines and supplements together.
More importantly, many medicines can interfere with the absorption and metabolism of vital nutrients. For example, some antidepressants and heart drugs can cause a lack of interest in food, resulting in a reduction in protein and calorie (energy) intake. Mineral oil laxatives can inhibit absorption of the fat-soluble vitamins A, D, E and K, while drugs with a diuretic action may increase excretion of water-soluble minerals including sodium, zinc, magnesium and potassium. Corticosteroids can inhibit calcium absorption, promoting osteoporosis; they also alter sugar metabolism and affect kidney function, leading to potassium deficiency and an increase in sodium.
Ageing brings about certain physiological changes. A reduction in the secretion of stomach acid is common in older people - this decrease can lead to a decrease in the absorption of folate from foods and contribute to a deficiency in vitamin B12. Lowered blood levels of these two vitamins are associated with elevated blood levels of an amino acid called homocysteine which is a risk factor for cardiovascular disease and dementias such as Alzheimer's disease.
Foods rich in calcium such as salmon, sardine, soy, sesame seeds, almonds, figs and dairy. High calcium intake slows rate of bone loss and reduces risk of fractures. Vitamin D is important for calcium absorption. Ensure sufficient exposure to sunlight to allow skin to manufacture vitamin D.
Vegetables, fruit and legumes - population studies show that those who consume large amounts of these foods have decreased risk of degenerative diseases associated with ageing, such as heart disease, stroke, cancer, diabetes, cataract and age-related macular degeneration.
High fibre foods with a lower glycaemic index (GI) eg. whole grain cereals, pastas and bread. Soluble and insoluble fibre are digested slowly, have a lower GI, and help stabilize blood sugar.
Salt - high blood pressure responds to a reduction in sodium (salt) intake.
Fat, particularly saturated fats. Cholesterol is a risk factor for heart disease in the 65-75 year age group.
Variety in the diet will help to supply all the required nutrients as well as maintaining an interest in eating. Focus on fresh nutrient-rich foods which are low in fats and refined sugars.
If living alone do try to cook meals for yourself, or get together with a friend and take turns in preparing meals to share.
A healthy meal plan should include:
- Fresh vegetables which can be stir fried, baked, steamed or made into salads
- Eat at least 1-3 pieces of fresh fruit per day
- Fish, chicken, lean meat and eggs will provide essential protein
- Tofu is another easy was to add protein to the diet
- Whole grain breads; avoid highly refined 'white' breads
- Well cooked rice and pasta Good quality yoghurt
- Juices such as carrot and apple
- Aim to drink at least 6-8 glasses of water per day.
Approximately 7% of seniors live in aged care accommodation and their needs differ to those living independently. For example they are more likely to suffer chronic illnesses, they expend less energy, and they are less exposed to sunlight. Health authorities recommend supplementation with vitamin D in these situations. Also because energy requirements are less, nutrient-dense foods are required, and supplementation with a general multivitamin and mineral preparation may be needed for nutritional insurance.
Preventative Health Care
Many of the diseases associated with the ageing process and with older age appear to be caused by compounds called free radicals. These are highly reactive by-products of oxidation, normal biological processes within the body that use oxygen. Free radicals help fight infection and are involved in many other processes including blood vessel function. The body has mechanisms to deal with excess numbers of these reactive particles. If the body is not functioning properly, however, unchecked free radicals can cause damage.
In addition environmental pollutants such as cigarette smoke, smog, ultraviolet radiation, pesticides, even some food additives, over-exercising and stress can all create extra demands for antioxidants to neutralize the free radicals.
Free radicals can cause damage to:
- The lens of the eye, leading to cataracts, and the macula at the rear of the eye, causing age-related macular degeneration
- Nerves and brain, leading to Parkinson's disease.
- The cardiovascular system.
- Oxidation of LDL cholesterol causes atherosclerosis.
Genetic DNA, leading to mutations within cells that can cause cancers of linings within the body such as the throat, stomach and colon, and skin, lungs and cervix.
Cell mitochonchria, leading to impaired energy production.
The body's natural antioxidant system appears to decline with age. It is not certain whether this decline is associated with reduced intake of natural antioxidant nutrients from the diet, impaired absorption or perhaps increased needs associated with age. Prevention or minimisation of free radical damage can be achieved by:
Avoiding exposure to environmental pollutants.
Introducing antioxidant rich foods into the diet.
Supplementing with antioxidant nutrients including the vitamins A (as beta-carotene, the vegetable form of vitamin A), C and E.
From population and supplementation studies, it appears that the protective benefits of these antioxidant vitamins are at levels that can not be obtained from an average diet. For example the amount of vitamin E required to slow the progression of heart disease appears to be a level greater than 400 iu (compared with the recommended dietary intake of around 15 iu).
Other antioxidants include selenium and glutathione; zinc is involved in antioxidant enzymes systems. Herbs such as milk thistle, ginkgo, bilberry and grapeseed all have plant flavonoid compounds that have a protective antioxidant action within the body.