A Recipe for Abundant Vegan Health
The basic benefits of a vegan diet
by Dr. Stephen Walsh and Dr. Glynis Chapman
Veganism promotes health for animals by ceasing to support the pervasive cruelty of the modern meat and dairy industries. Once someone has recognised the cruelty of tearing the calf from its mother, the ethical case for veganism is clear.
Article continues below
Being vegan minimises direct exposure to animal-borne diseases, both known and unknown. This is no mean advantage. There are already over 100 cases of vCJD caused by eating meat from cattle with BSE and no one knows what the final toll will be. If BSE/vCJD does not emerge as one of the greatest public health disasters of the 21st century this will simply be a matter of luck.
The vegan diet is healthfully low in saturated fat resulting in lower cholesterol levels than meat eaters or vegetarians. Elevated cholesterol is an important risk factor for heart disease and overall mortality up to about the age of 60. Reduced cholesterol levels reduce overall mortality in this age range by reducing heart disease risk. As this removes a major risk of premature death, the likely benefits for overall life expectancy are significant.
Veganism allows humans to use a smaller amount of land for food, freeing up land for trees and energy crops to reduce global warming and providing space for the many other species with whom we share this planet to thrive.
Veganism promotes health for humans, animals and the planet we share. All vegans should take pride in this.
Maximising the health benefits of a vegan diet
An appropriate vegan diet has great potential to support a long, healthy and full life but a poor vegan diet will not promote optimal health. If the benefits of vegan diets are to be recognised and embraced by the majority of the population, they must be demonstrated to be nutritionally complete and advantageous to health. It is not uncommon to find adults who have adopted vegan diets, not felt as well as they hoped, and returned to omnivorous or lacto-ovo dietary patterns. Often these individuals followed a manifestly flawed diet, which could have been easily improved by the addition of appropriate plant-based foods. Thus, it is important that key nutritional issues are clearly identified so that vegans can easily construct diets that best promote health at every stage of life. By providing an example of abundant health, vegans can greatly encourage others to become vegan - the key to eliminating animal abuse.
Much of modern nutritional science is focussed on the health of omnivores, so its results and messages require some interpretation to be useful to vegans. Some messages need no interpretation. Whole grains and nuts promote health. Vitamin C is good for you. Eat more fruits and vegetables. All this is good news for vegans. Other messages don't seem particularly applicable to vegans or even seem to be opposed to veganism. "Folic acid supplements prevent birth defects and promote a healthy heart". Don't vegans get plenty of folic acid from greens and beans? "Eat fish and fish-oils to get healthful omega-3 fats". Are they saying a vegan diet can't be optimally healthy? In both cases there is a positive and useful message for vegans but we need to dig beneath the surface.
Folic acid (or folate) prevents birth defects and may improve heart health. It does this by reducing the levels of a toxic chemical called homocysteine in the body. Vegans usually have better than average folate intake. Vegans eating a predominantly whole-food diet including green vegetables and beans will have excellent folate intake. However, vegans have been found to have higher levels of homocysteine than meat eaters. In omnivores the predominant dietary cause of high homocysteine is low folate intake, with low B12 intake being much less significant. So the health message to the general population is take folic acid supplements and eat your greens. For vegans not taking B12 fortified foods or B12 supplements, low B12 intake is the dominant dietary cause of high homocysteine. So the health message for vegans is take enough B12.
Between 5 and 10 micrograms per day of B12 is sufficient to minimise homocysteine levels and minimise the risk of birth defects and heart disease associated with homocysteine. This is a lot more B12 than is needed to avoid the classic deficiency symptoms of anaemia and nervous system damage. 5 micrograms of B12 can be readily obtained by the use of nutritional yeast and foods fortified with B12 or by the use of B12 supplements. Most B12 tablets contain much more than 10 micrograms and can be broken up to provide the required daily amount at lower cost. Taking a single high potency tablet once per week will have much less effect as less B12 will be absorbed. Intakes up to 1000 micrograms a day are not harmful but are unnecessary.
So what about fish, fish-oils and omega-3 fatty acids? The good news is that there is a plant omega-3 fatty acid, alpha-linolenic acid, from which the body can produce all the other omega-3 fatty acids it needs. Even better news, is that the most successful trial ever on preventing recurrence of heart attacks, in people who had already had one heart attack, used the plant omega-3 and not fish-oils. The amount of omega-3 used was equivalent to half a teaspoon of flaxseed oil. The mortality dropped by 70% mostly due to fewer heart attacks. Incidence of cancers was also reduced, though this may have been due to chance. The bad news is that high intakes of the main plant omega-6 fatty acid, linoleic acid, obstruct the conversion of the plant omega-3 to the other omega-3 fatty acids needed in the body. Vegans eat more of the plant omega-6 than omnivores (two to three times as much). Vegans would benefit from reducing consumption of omega-6 fatty acids by making olive oil, hazelnuts, almonds, cashews and avocadoes the main fatty foods and cutting back on sunflower, safflower, corn and sesame oils. Vegans should increase omega-3 consumption. A teaspoon of flaxseed oil per day provides a good amount of plant omega-3. Green vegetables and beans are also useful sources of omega-3. If you use marge, Vitaquell's omega-3 marge is a good choice. Flaxseed oil and Vitaquell can be obtained from most health-food stores.
There are four other nutrients that deserve specific comment.
Iodine deficiency is the biggest cause of preventable IQ loss in the world and can have particularly severe effects on children up the age of one year, including before birth. Iodine deficiency also promotes abnormal thyroid function, which can give rise to many health problems in later life. North America tries to prevent iodine deficiency through the use of iodised salt. The UK and Ireland rely on iodine in milk, which is boosted by the use of iodine fortification of cattle feed. Because the soil in the British Isles is depleted of iodine due to the last Ice Age, the level of iodine in UK plant foods is low. UK vegans have been found to frequently have intakes bordering between mild and moderate deficiency (about 50 micrograms per day). Recommended intakes are 150 micrograms per day for the general population, with North America recommending higher intakes for pregnant women and breastfeeding mothers. High intakes have adverse effects on a susceptible minority so the optimal intake lies between 150 micrograms and 300 micrograms of iodine per day. Vegans can get iodine from supplements (multiminerals or kelp tablets - watch out for whey in some kelp tablets) or from seaweeds or from iodised salt (only recommended if you use salt anyway). Unfortunately, iodine content in most types of seaweed is very variable so only a few types are reliable sources. About 100g per year of hijiki or 15g per year of kelp (kombu) would provide a suitable amount of iodine. It is very important to spread your iodine intake out by taking small amounts frequently, at least twice a week.
Selenium is also marginal in vegan diets in Britain due to low levels in the soil. Selenium has many benefits for the immune system and reproduction and may have powerful cancer preventing properties. Typical UK vegan intakes are about 40-50 micrograms per day. Cancer preventing properties appear to be strongest at intakes around 200 micrograms per day. Intakes above 400 micrograms per day are undesirable. One Brazil nut contains about 70 micrograms of selenium, so one or two Brazil nuts a day provides an excellent intake. Brazil nuts also contain small amounts of radium and barium. This is unlikely to be harmful but vegan selenium supplements are readily available for those preferring an alternative source.
Vitamin D from sunlight can be stored in the body for several months, but in countries like Britain the sun is too low in the sky to produce vitamin D from about October to February. This has been found to lead to a pronounced winter dip in vitamin-D stores that is more severe in individuals with no dietary vitamin D. This includes all vegans who don't take fortified foods or supplements. There is reason for concern that vegan levels in winter will not sustain optimal bone health, particularly if calcium intake is not high. There is also growing evidence that low vitamin D levels increase risk of auto-immune illness and cancer, though this is not yet conclusive. Vegans should take about 5 micrograms (200IU) of vitamin D2 (ergocalciferol) per day from October to February (D3 is derived from sheep wool) or take a winter holiday further south to boost their vitamin D levels as nature intended. Older vegans or vegans with limited sunlight exposure may need 15 micrograms (600 IU) per day. Vitamin D2 can be obtained from fortified foods, such as plant milks, or supplements, such as multiminerals.
Calcium is a controversial nutrient for vegans due to the dairy industry's strenuous and incorrect attempts to make us believe that dairy products are the best source of calcium to promote healthy bones. In fact, during millions of years of our evolution we appear to have consumed large amounts of calcium from wild plant foods. Most estimates suggest we consumed about 1000mg of calcium per 1000 calories of plant foods, as do many modern monkeys and apes. Unfortunately, grains are particularly poor sources of calcium and many of the wild plants we ate, such as natural gums, are not readily available, so modern plant foods contain much lower levels of calcium. Whole-food vegan diets rich in vegetables and fruit match our ancestral intakes of many other important nutrients such as potassium, magnesium and vitamin C better than the standard western diet does. Vitamin C, potassium and magnesium all appear to improve health in many ways, including the health of our bones. On calcium it seems to be more of a stretch to match the intakes we evolved with, due to the low levels in many modern plant foods.
The human requirement for calcium is still controversial, but optimal intakes are unlikely to be less than about 800mg per day in adults and may be as high as 1300mg per day for adolescents, who add about 300mg/day of calcium to their skeleton during peak growth. There is evidence that calcium intakes above 2000mg/day may have harmful effects on magnesium absorption particularly if the diet is also rich in phosphorus. Processed dairy foods such as cheese are a relatively poor source of calcium compared to green leafy vegetables as they are acid forming and contain high amounts of sodium, increasing losses of calcium from the body. Milk is fortified with retinol in Sweden, the United States and some other countries. There is considerable evidence that retinol acts to accelerate bone loss in older individuals and may contribute to high levels of osteoporosis in Sweden and Norway. Vegans have many excellent sources of calcium lacking these adverse effects. Green leafy calcium-rich vegetables such as spring greens, kale, collards, mustard greens, and Chinese cabbage provide between 100 and 200mg of well-absorbed calcium per 100g, along with many other healthful nutrients. Spinach, Swiss chard, rhubarb and beet greens are poor sources as their calcium is very poorly absorbed. Most fortified soya milks provide about 300mg of calcium per cup. A cup of fortified soya milk and a large portion of calcium-rich green leafy vegetables in a day will take calcium intake above 800mg very pleasantly and healthfully.
None of the recommendations above are difficult to implement. Taken together with the general recommendation of a predominantly wholefood diet with plenty of vegetables and fruit they should promote abundant health for vegans providing an example for the rest of the world to follow. It should not be forgotten that diet is only one aspect of promoting health. Putting your energy into what is important to you, quality time with friends and family, regular physical activity, and adequate rest and relaxation are also key.