This month, the British Medical Journal published research which calls into question the widely held belief that taking an aspirin each day is good for us. While aspirin may reduce the risk of heart disease and stroke, it also increases the risk of bleeding in the gut, and this may have serious and even fatal consequences. This new research suggests that aspirin’s side effects are more common than previously thought, and occur at even the lowest dosages. In an accompanying editorial, Dr Martin Tramèr from Geneva University Hospitals in Switzerland suggests that “it may be more appropriate for some people to eat an apple a day rather than an aspirin a day”. While Dr Tramèr’s comments are not necessarily to be taken too literally, they do at least raise the issue of what real alternatives exist for individuals who end up stopping their daily dose of aspirin. The clear front-runner in this debate is vitamin E. Over the last decade there has been mounting evidence that vitamin E may significantly reduce the risk of heart disease. What is more, this nutrient has been shown to be extremely safe and well tolerated. So, what do we really know about vitamin E’s effects in the body, and what promise does it hold in the prevention and treatment of heart disease and stroke?
Heart disease, and the other ‘cardiovascular’ diseases such as stroke and peripheral vascular disease (hardening of the arteries in the legs) are related to a process known as ‘atherosclerosis’. Here, the arteries in the body become increasingly clogged with a waxy, fat-like substance composed mainly of cholesterol. In recent years, much attention has been focused on the need to control cholesterol levels in the bloodstream. However, studies suggest that cholesterol per se is not the problem. It is when cholesterol becomes damaged through a process known as ‘oxidation’ that it then has the propensity to settle on the inside of the body’s arteries. One of vitamin E’s chief effects is to protect cholesterol from oxidation, thereby reducing its damaging effects in the body.
This isn’t the only way vitamins can help prevent disease. Heart attacks and strokes are very often triggered by the formation of tiny blood clots called ‘thrombi’. Once formed, thrombi can lodge in an artery, blocking it completely. When the body’s tissues are starved of blood in this way for more than a few minutes, they die. Death of heart tissue is known as a ‘heart attack’ while brain tissue death is commonly referred to as ‘stroke’. Thrombi are themselves formed from tiny blood components called platelets. Vitamin E reduces the tendency for platelets to stick together, helping further to reduce risk of heart attack and stroke.
In theory, vitamin E undoubtedly has benefits for the body, but how well does it work in practice? One study, published in the American Journal of Clinical Nutrition, analysed data from 26 countries and found that individuals with the lowest levels of vitamin E in their bodies have the greatest risk of heart disease and stroke. Other studies published in the New England Journal of Medicine in 1993 show that men and women supplementing with 100 IU (international units) or more of vitamin E each day reduced their risk of suffering from a fatal or non-fatal heart attack by about a third. In another study conducted in Cambridge and published in the Lancet in 1996, individuals with diagnosed heart disease were given either vitamin E (400 or 800 IU) or placebo. This study showed no change in the risk of dying due to heart disease, but did show a massive 77 p.c. reduction in risk of non-fatal heart attack in individuals taking vitamin E. The authors of this study went on to explore why vitamin E appeared not to reduce the risk of death due to heart attack. They found that not all individuals scheduled to take vitamin E complied with instructions. On closer analysis it turned out that of the 59 deaths due to heart disease in this study, only six were in individuals actually taking vitamin E.
Vitamin E’s blood thinning effects theoretically increase the risk of stroke due to bleeding in the brain – a condition known as ‘haemorrhagic stroke’. However, even in studies where relatively large doses of vitamin E have been used, there is no evidence of increased risk of haemorrhagic stroke. Indeed, one American study showed that vitamin E supplementation reduced the overall risk of stroke by almost 30 p.c. Vitamin E may have side-effects such as digestive discomfort and reduced blood clotting, but the dose needed to produce significant problems is likely to be 1500 IU or higher. However, because vitamin E can thin the blood at doses of 400 IU or more each day, individuals on anti-clotting medication such as warfarin are advised to use vitamin E with some caution and under medical supervision. While vitamin E can be found in the diet in sunflower seeds, hazelnuts, almonds, avocado and vegetable oils such as olive oil and safflower oil, the average daily intake is probably only between 10 and 20 IU. For individuals wanting to reduce their risk of developing heart disease, I generally recommend that they supplement with 100 – 200 IU of vitamin E each day. For those with a history of heart disease, I usually advise higher doses be taken (about 800 IU per day). Vitamin E comes in two forms; d-alpha-tocopherol (natural) and dl-alpha-tocopherol (synthetic). The natural form of vitamin E appears to work better in the body and is therefore preferred.