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Health of Elderly Vegetarians
Maximizing Long-Term Health on a Vegetarian Diet
by Stephen Walsh PhD.
Vegetarian Health and Mortality
All major studies of vegetarians have found vegetarians to live about 5 years longer than the general population in their country and to have good general health. Much of this advantage lies in less smoking, more exercise and characteristics of diet other than just avoiding meat. Heavy smoking can take a decade from your life and lack of exercise can take 2 - 3 years even if not resulting in excess weight.
We need to learn from studies of vegetarians and others about dietary choices promoting health:
» Daily consumption of nuts can add 2 years to your life (more for men);
» Obesity can cost about 2.5 years of life in women and 4 years in men;
» Fruit and vegetables can reduce risk of cancer, heart disease and other illnesses;
» Elevated homocysteine (associated with B12 deficiency) may cost about 4 years in life and may be especially dangerous for diabetics ;
» Blood pressure and risk of stroke and osteoporosis can be lowered by a diet rich in potassium and calcium and low in sodium (common table salt).
Obesity and Diabetes
Obesity (BMI>30) is a primary cause of diabetes through promoting insulin resistance. Increased BMI also reduces good cholesterol and increases bad cholesterol, blood pressure and risk of heart disease, colon cancer and breast cancer. Overall obesity costs about 3years of life expectancy.
The ideal BMI is 20-23 for most people. For a 1.83m(6') person this equals 67 to 73kg or 10.5 to 12 st.
» Risk of obesity is reduced by diets high in fibre and low in calorie density; plenty of fruit, vegetables. Sugary drinks promote obesity.
» High physical activity, low saturated fat intake and high fibre intake reduce the risk of diabetes, whether obese or not.
» Low chromium or magnesium intake may increase risk of diabetes. Plenty of fruit and vegetables and whole grains instead of refined grains will avoid the risk increase.
» Western vegetarians show relatively low levels of obesity and diabetes compared with non-vegetarians.
Cardiovascular health
The magic combination is low LDL (bad) cholesterol, high HDL(good)cholesterol, low blood pressure, high omega-3 fatty acids, high total antioxidant capacity and low homocysteine.
» A low intake of saturated and trans (hydrogenated as found in margarine) fat and moderate intake of unsaturated fat promotes a good cholesterol balance.
» Low blood pressure is promoted by low sodium intake and high potassium and calcium intakes and by low BMI.
» Omega-3 fatty acids can be readily obtained from flaxseed (culinary grade linseed), hempseed, rapeseed (canola) and walnuts.
» Homocysteine is reduced by adequate B vitamins (particularly B12, folate, B2 and B6) and by avoiding coffee and smoking.
» Vegetarians of all types show reduced risk of heart disease, but more attention to increase B12, omega-3 fats and calcium intakes and to reducing trans fats and salt could give substantial improvements.
» Increased calcium, potassium and magnesium intakes are all associated with reduction of stroke mortality.
» Vegetarians are often (but not always) found to have lower blood pressure.
Bone health
At any age a fracture is inconvenient, but a hip fracture can be particularly immobilising with adverse effects on the quality of life. The keys to bone health are:
1. Making it easy to match calcium losses with dietary calcium absorption, and
2. Making it difficult to lose calcium from the bones.
The requirement for (1) is the same as for blood pressure- low sodium, high potassium and high calcium. If sun exposure is limited, e.g. during winter in northern latitudes or restriction to indoors, dietary vitamin D becomes important.
With regards to (2), protein has a U-shaped effect: beneficial up to about 1g per day per Kg of body weight, but adverse thereafter through increasing calcium losses. The most effective way to keep calcium in the bones is to ensure adequate vitamin K from green leafy vegetables or broccoli.
The best foods for bone health are low oxalate leafy greens like spring greens, kale, other vegetables like peppers, potatoes, soy beans and fruit such as bananas, oranges, and almonds, because they reduce calcium loss, provide readily absorbed calcium and provide the vitamin K to keep calcium in the bones where it belongs. Dairy products are not even as effective as a simple calcium carbonate supplement let alone leafy greens!
Preventing Cancer
Evidence for an overall benefit for fruit and vegetables has declined over the past 5 years as more prospective studies have reported. Evidence for benefit now centres on folate (greens and beans) and carotenoids, particularly lycopene (brightly coloured veggies, especially red) and possibly fibre.
» There is modest evidence for a benefit of calcium and vitamin D on colorectal cancer and breast cancer and for vitamin D and selenium on prostate cancer.
» The evidence for adverse effect of cow's milk on prostate cancer and an adverse effect of preserved meat on colorectal cancer is reasonably strong.
» Foods and drinks consumed when very hot increase risk of mouth and throat cancer.
» There is very little evidence for an effect of fat intake on cancer risk, except via increased weight.
Clear mind and eyes
» Poor cardiovascular health and oxidative stress promote dementia and cognitive decline. Oxidative stress is a major factor in macular degeneration and cataracts.
» Elevated homocysteine is strongly associated with dementia (both vascular dementia and Alzheimer's disease).
» Green leafy vegetables including spinach, kale and broccoli are antioxidant powerhouses as well as providing folate to reduce homocysteine and the particular carotenoids that protect eyes from oxidative damage.
» B12 (along with folate) is key to low homocysteine levels in vegetarians.
» Brightly coloured vegetables and fruits are the best source of antioxidants (kale, spinach, tomatoes, carrots, blueberries, strawberries and plums are all excellent sources). Nuts and seeds and olives are also useful sources.
» Brazil nuts are an exceptionally concentrated source of selenium (one a day is enough).
Dietary Iodine
Iodine is required by the thyroid gland which drives the body metabolism. Intake required is 150-400 mg per day. Iodine is an element found in the soil but may not be enough in plants. Seaweeds are a good source of Iodine while iodised salt is not the right source. 15g of Kelp or 1 kg of Nori per year is enough to meet iodine needs. Do not take more than 500mg of kelp per week. Selenium found in Brazil nuts also supports the thyroid function as well.
Fish! And 0mega-3 fatty acids
Trials on fish and fish-oils are estimated to reduce mortality from hearth attack by 15% to 30%. On the other hand trails using plant-centred diets incorporating vegetable oils high in monounsaturated and omega-3 fatty acids show mortality reductions of 50%-70% - a much better performance!
Interesting to note is that studies carried out in Finland show increased mortality from consumption of fish with high mercury contamination.
Omega-3 fatty acids are important in the diets and vegetarians can obtain this from rapeseed oil, flaxseed, walnuts and some green vegetables. One teaspoon flaxseed oil or one tablespoon of ground flaxseed or two tablespoons of rapeseed oil provides an adequate daily intake.
Dairy products
Contrary to propaganda, dairy foods range from being moderately beneficial to bone health to having notable adverse effects. Simply dropping dairy products will not promote health but compensating with adequate calcium intake, B12 and iodine from plant sources, while avoiding the health hazard of saturated fat, will strongly promote better health.
Conclusions and recommendations:
Although a vegetarian diet is an excellent diet, very good for body health, it has some weak points and these have to be watched out.
By observing monkeys and apes in the wild, we learn that they willingly or unwillingly eat insects to boost their B12 intake; their intake of essential nutrients of calcium and omega-3 oils are more abundant in wild fruits consumed by monkeys, than in cultivated fruits available to humans.
Therefore:
» Eat plenty of coloured vegetables (like carrots, pumpkin, etc), fruits and green leafy vegetables. (lettuce, kale, broccoli)
» Eat moderate amount of nuts and seeds, particularly almonds, peanuts, cashew, hazels (filberts), walnuts and flaxseed, and a small amount of Brazil nuts.
» Use monounsaturated oils, (instead of butter and margarine) such as olive, avocado, rapeseed (canola) and peanut (groundnut) oil. Remember that heating during cooking changes unsaturated oils to saturated making them just as bad as saturated fats that promote cholesterol.
» Make whole grains (brown rice, rolled oats, rolled barley and wheat) and fruit the main starchy foods.
» Limit salt intake (get your iodine from sea vegetables, or other fortified foods or take supplements but not more than twice a week)
» Be sure to get at least 3mg of B12 per day from fortified foods, and/or supplements) do not rely on the amounts quoted on packets, overdoses of B12 have no adverse effect but the lack of it is extremely dangerous to health.
» Ensure an adequate intake of calcium and vitamin D. It is most important for older people because the body's absorption capability declines with age.
Mostly reproduced from a talk by Stephen Walsh PhD given during the 35th World Vegetarian Congress held in Edinburgh Scotland July 2002.
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