Vitamin E is recognised as a powerful antioxidant by the European Food Safety Authority and plays a critical role in supporting brain, eye, cardiovascular, maternal and infant health, as well as protecting the skin. Unlike vitamin C and vitamin D, insufficient intake is not necessarily manifested by a deficiency disease such as scurvy or rickets; but symptoms of deficiency can include muscle weakness, loss of muscle mass, problems with vision and other neurological disorders.
It is estimated that more than 90% of the population in the USA does not meet the dietary intake recommendations for vitamin E
The importance of vitamin E in humans was not recognised until a relatively late stage and it is estimated that more than 90% of the population in the USA does not meet the dietary intake recommendations for vitamin E.1 The outcomes of studies to investigate the possible effect of vitamin E on cardiovascular disease have been inconsistent and the subsequent media coverage has had an impact on levels of vitamin E intake.
In fact, there is a strong body of evidence to demonstrate the benefits that can be gained from vitamin E. But, so-called ‘sensational’ headlines often gain coverage owing to the controversial nature of the content. These conflicting messages can only confuse consumers, so scientists, healthcare professionals and governments must respond collectively to consistently reinforce the wealth of existing safe science. The impact of low vitamin E intake globally should be a serious public health concern and there is an urgent requirement for additional research.
Why vitamin E?
Vitamin E is a generic term for eight fat-soluble compounds found in nature, of which alpha-tocopherol has the highest biological activity and is the most abundant in the human body. The main biological function of vitamin E is as a powerful antioxidant, preventing the propagation of free-radical reactions and playing a critical role in cell signalling, gene expression and the regulation of other cell functions. The damaging effects caused by free radical reactions can lead to various health conditions such as heart disease, cancer and inflammatory conditions.
The role of vitamin E supplementation in the treatment of neurodegenerative diseases such as Alzheimer’s disease is currently under investigation
New research into the role of vitamin E has been limited in the last couple of years. However, in recent months, a number of studies have been published to demonstrate that the benefits of vitamin E span beyond its well-known function as a fat-soluble antioxidant. First, the role of vitamin E supplementation in the treatment of neurodegenerative diseases such as Alzheimer’s disease is currently under investigation. The Journal of the American Medical Association has recently published a major study, which found that vitamin E can slow the progression of Alzheimer’s disease.2
Secondly, there have been a number of published studies on the efficacy of vitamin E to prevent the progression of non-alcoholic fatty liver disease, which is pandemic in societies where more than half of the population is obese. The results of several human studies have demonstrated the benefit of vitamin E compared with a placebo. Vitamin E was found to be effective in reducing the disease activity of non-alcoholic fatty liver disease, was safe in the applied dose and did not lead to side-effects such as weight gain.3
Finally, there are findings on the role of the genotypes related to the benefits of vitamin E. Evidence from various observational human studies indicates that vitamin E has beneficial effects on the cardiovascular system, but results from randomised controlled trials did not detect a consistent benefit of vitamin E supplementation on cardiovascular health. An analysis of the data suggests that the genotype of an individual appears to be an important factor in the effect of vitamin E supplements on cardiovascular endpoints.4 This means that subgroups of the population may be at risk of reduced vitamin E status or increased oxidative stress.
The way forward
There have been a number of exciting new discoveries in the field of vitamin E; but despite these advances there is a requirement for additional research. The intake of vitamin E remains below the current dietary recommendations for the vast majority of consumers and the findings highlight the need for ongoing consumer education on the potential benefits of vitamin E. A new study has also been started to evaluate vitamin E intake recommendations, with the existing guidelines typically based on anecdotal historic data.
References
1. V.L. Fulgoni 3rd, et al., “Foods, Fortificants and Supplements: Where do Americans Get Their Nutrients?” J. Nutr. 141, 1847–1854 (2011).
2. M.W. Dysken, et al., “Effect of Vitamin E and Memantine on Functional Decline in Alzheimer’s Disease: The TEAM-AD VA Cooperative Randomized Trial,” JAMA 311(1), 33–44 (2014).
3. A.J. Sanyal, et al., “Pioglitazone, Vitamin E or Placebo for Nonalcoholic Steatohepatitis,” N. Engl. J. Med. 362(18), 1675–1685 (2010).
4. U. Milman, et al., “Vitamin E Supplementation Reduces Cardiovascular Events in a Subgroup of Middle-Aged Individuals with Both Type 2 Diabetes Mellitus and the Haptoglobin 2–2 Genotype: A Prospective Double-Blinded Clinical Trial,” Arterioscler. Thromb. Vasc. Biol. 28, 341–347 (2008).
