7) Supplements and vitamins
Much work is still being conducted on the use of vitamins and supplements to protect against Alzheimer’s Disease. Several vitamins are well established to either contribute to dementia if they are lacking or to specifically protect against Alzheimer’s Disease if they are present. Folate and B12 deficiencies are both known to increase risk for Alzheimer’s Disease and other dementias. Thus ensuring that both of this vitamins are present in the blood in appropriate amounts is one reason why yearly routine blood tests are important. Studies of other vitamins has proved much less conclusive. For instance, the use of vitamins C and E have not shown that decline into Alzheimer’s Disease can be prevented. And although low vitamin D levels have been associated with increased risk of Alzheimer’s Disease the use of vitamin D prophylactically has not yet demonstrated benefit in preventing Alzheimer’s Disease. The message about vitamins seems to be – don’t be deficient – but taking excess of any of them is not helpful in the prevention of Alzheimer’s Disease.
Another hot area of research concerns the role of fatty acids in the cause or prevention of Alzheimer’s Disease. Fatty acids are derived directly from our diet and are taken up by the brain by neurons to help build their outer walls. However, certain fatty acids lead to over-excitation and inflammation of neurons leading to their degeneration and death. By manipulating our diets it’s possible to change the composition of fatty acids in the brain. Scientists believe that this is why certain diets protect us from Alzheimer’s Disease [see above] and others do not. A typical western diet can be high in polysaturated fats and those known as omega-6 fatty acids whereas diets known to be protective against Alzheimer’s Disease are low in polysaturated fatty acids, high in unsaturated fatty acids and have high levels of omega-3 fatty acids. Docosahexaenoic acid (DHA) in particular is associated with reduced risk for Alzheimer’s Disease. Again though it is unclear whether taking DHA as a supplement can reduce the risk for Alzheimer’s Disease although it is clear that diets associated with high fish consumption do lower risk for the disease. Fish oil supplements are very popular and are taken to ward off or even treat a wide range of ailments but at this stage it’s not possible to recommend daily supplementation with DHA or other fatty acids contained in fish whereas the substitution of fish for meat dishes can be recommended.
Many other supplements have been investigated in the prevention of AD most noticeably Ginkgo Biloba. Despite several very large scale studies searching for a beneficial effect of Ginkgo there is no evidence that it can fend off Alzheimer’s Disease or inhibit cognitive decline. Many other claims for supplements or mixtures of supplements in the prevention or reversal of memory loss have never been as thoroughly tested as has Ginkgo and therefore the claims remain unproven. Until other supplements are thoroughly investigated it’s recommended that they are not taken in excess.