Vitamin E

Vitamin E – what you need to know!

Vitamin E is a group of micronutrients that are essential for human health and vitality. Vitamin E, or tocochromanols, are eight similar compounds naturally found in plants and primarily exhibit important anti-oxidative activities in humans and animals.

In human health and disease, the primary function of vitamin E is its involvement as an antioxidant and an anti-inflammatory substance. Vitamin E is also immune-enhancing and has been shown to be very effective in preventing and treating various chronic diseases.

Vitamin E can be sourced form nuts, seeds and vegetable oils as well as green leafy vegetables and cereals. Although vitamin E is an essential dietary nutrient it does not have to be consumed everyday as it can be stored in fatty tissues in the body.

The vitamin E group is divided into tocopherols and tocotrienols with the two major forms being alpha-tocopherol and gamma-tocopherol. However, only alpha-tocopherol is considered as the vital form of vitamin E that is necessary for human requirements.

Tocopherols

There are four tocopherols compounds: alpha-, beta-, gamma-, and delta-tocopherol.

Tocopherols are lipids (fats) that are distinguishable by their saturated side chains. Alpha- and gamma-tocopherol are found in the serum and in the red blood cells, whereas beta- and delta-tocopherol are found in the plasma.

Tocopherols can react with reactive oxygen species (ROS) and thereby can protect important unsaturated fatty acids from oxidation. Because of this strong antioxidant activity, they have been suggested to be hugely beneficial in a range of diseases including inflammation, cancer, and degenerative diseases.

Research suggests that alpha-tocopherol could be beneficial in the prevention and treatment of cardiovascular disease (CVD). Alpha-tocopherols protect low-density lipoproteins (LDLs), which are used by the body to transport cholesterol through the bloodstream. If LDL oxidizes, it can contribute to the development of CVD.

Furthermore, natural mixtures of tocopherols that are enriched in gamma-tocopherol are suggested to show more anticancer benefits over those that are alpha-tocopherol enriched.

Tocotrienols

There are four tocotrienol compounds: alpha-, beta-, gamma-, and delta-tocotrienol.

Tocotrienols have the same basic structure as tocopherols and differ only by their unsaturated side chain. This gives them a greater ability to access the brain and liver, where they have unique and important physiological functions in both of these tissues.

Tocotrienols possess potent antioxidant, anticancer, and cholesterol-lowering abilities. Researchers have shown that they can suppress pro-inflammatory signaling and are therefore very useful against multiple inflammatory disorders.

Tocotrienols have also been shown to be neuroprotective against a number of different toxins in the brain. In particular, research suggests that tocotrienols are key molecules that protect brain cells from stroke-induced degeneration.

Vitamin E and Vitamin C

Vitamin E and vitamin C are complementary vitamins that together have a cooperative antioxidant action. In addition, the body requires adequate amounts of vitamin C to get all the benefits of vitamin E. This is because vitamin C can also regenerate oxidized vitamin E.

In particular, the combination of these two vitamins has been shown to decrease exercise-induced oxidative stress, which is associated with skeletal muscle damage. In addition, the combination can inhibit UV damage and sunburn and thus reduce the risk of photoageing and skin cancer.

Vitamin E Supplement Health Benefits

Vitamin E is a major antioxidant in the body that protects cells from oxidative stress and lipid peroxidation.

  • Attenuates inflammation
  • Anti-oxidant activity
  • Anti-cancer properties
  • Lowers cholesterol
  • Hypoglycaemic ability
  • Protects against cardiovascular disease
  • Protects brain cells
  • Anti-diabetic
  • Enhances the immune system

Vitamin E protects the heart

Atherosclerosis is a vascular disease that is characterized by plaque formation in the arteries. The presence of high cholesterol and high blood pressure contribute to plaque formation, which causes hardening and narrowing of the arteries. Atherosclerosis is usually the cause of heart attacks and stroke.

A key step in the initiation and progression of atherosclerosis is oxidative stress. Reactive oxygen species underlie the beginning of the inflammatory process that mediates plaque formation and ultimately leads to the clinical complications associated with atherosclerosis.

Oxidation is a key step in atherosclerosis for which vitamin E has been shown to increase oxidative resistance and prevent plaque formation. This is supported by research on people from the Mediterranean, here they are known to consume a vitamin E enriched diet.

Supplemental vitamin E has also been shown to reduce risk factors for arterial plaque formation. Studies show that firstly, tocopherols were shown to have an inhibitory effect on lipid peroxidation and secondly, tocotrienols inhibit cholesterol synthesis. Both of these are known risk factors for CVD.

However, some clinical trials have shown that although supplemental vitamin E may decrease the risk of ischemic stroke it can increase the risk of a hemorrhagic stroke. This is particularly true in the elderly, where the inclusion of vitamin E may reduce their blood clotting ability, which increases the risk of hemorrhagic stroke.

Vitamin E protects the nerves

Vitamin E is classified as a lipophilic compound, which means that it can be dissolved in fats. This lipophilic ability means that it is readily absorbed and taken up by brain cells where it is sequestered into membranes. Here, vitamin E acts as a protective shield against oxidative damage.

Brain cells are highly susceptible to oxidative stress and the damage caused is pathologically related to multiple neurodegenerative disorders. Vitamin E is a highly effective antioxidant that can protect neurons from oxidative stress-related damage and the onset of neurodegenerative conditions.

Tocotrienol and tocopherols are potent neuroprotective compounds that can protect brain cells through their anti-oxidative properties. Many studies have shown that supplementation with vitamin E can enhance the anti-oxidative capacity of brain cells and helps to prevent oxidative damage.

Vitamin E prevents age-related cataracts

Long-term use of supplemental vitamin E may improve outcomes of age-related vision loss such as during cataract formation. Age-related cataracts are the opacification, or clouding over, of the lens and are generally caused by accumulative damage over time.

In a long-term population study, there were observations that individuals, who supplemented with vitamin E for at least 10 years, had clearer eye lens. In comparison with those, who did not take vitamin E supplements, the opacification of the lens and the subsequent development of cataracts were significantly reduced.

Vitamin E and its anti-cancer properties

For many years, researchers have known that vitamin E has potential anti-cancer activities. This is because there is evidence that vitamin E deficiencies are associated with increased risk of cancer. In addition, it is the combination of vitamin C with vitamin E that appears to offer significant protection.

Furthermore, researchers have shown that gamma- and delta-tocopherols may even help prevent lung, breast, colon and prostate cancer. In these studies, daily supplementation with vitamin E caused a reduction in the incidence of these cancers as well as delays in the progression of other types of cancers.

Tocotrienols on the other hand were also believed to suppress cancer-cell proliferation and induce apoptosis in cancer cells. Of the four tocotrienols, delta- and gamma-tocotrienols have the greater anti-cancer activity compared to alpha- and beta-tocotrienols.

Vitamin E optimizes aerobic exercise

In the human body, the brain, heart and skeletal muscles are known to consume the highest amount of energy, nutrients and oxygen. Inside the cells of the brain and the muscles, energy metabolism generates ROS that can cause significant damage if the cells do not protect themselves.

Vitamin E is found enriched in the membranes of cells of the brain and the muscles right in the place where these ROS are generated. Alongside key anti-oxidative enzymes and other anti-oxidative molecules, vitamin E acts as part of the anti-oxidative shield that protects cells from oxidative damage.

Exercise is known to exacerbate the generation of ROS particularly in muscle cells due to the enhanced requirement for generating energy. These reactive species induce oxidative damage and muscle injury and are possibly responsible for the delayed onset of muscle soreness in these tissues.

Vitamin E supplementation can help prevent exercise-induced oxidative damage through the demonstration of its anti-oxidative properties. In addition, vitamin E supplementation has been shown to increase circulating creatine kinase, which is a biomarker for increased muscle repair activity.

Who should use Vitamin E supplements?

  • People who have a vitamin E deficiency
  • Individuals who need to prevent or treat cardiovascular disease
  • Marathon runners

Vitamin E Interactions

  • Vitamin E interacts with cyclosporine and increases its absorption, which may result in increased side-effects
  • Vitamin E supplementation improves liver function, which may increase the breakdown of medications that are metabolized by the liver, including: lovastatin, ketoconazole, itraconazole, and many others

Why take Vitamin E?

Vitamin E is a vitamin that is essential for health and wellbeing. A vitamin E deficiency can result in severe neurological damage that is associated with muscle weakness, degeneration of the retina resulting in vision problems. There are also detrimental effects to the immune system and cardiovascular health.

Vitamin E can also be taken to ensure the following healthy functions:

  • Protects brain cells from damage
  • Healthy heart and blood vessels
  • Improved night vision
  • Healthy ageing
  • Anti-cancer properties

References


  1. Behl C. Vitamin E and other antioxidants in neuroprotection. Int J Vitamin Nutr Res. 1999; 69(3): 213-219
  2. Evans W. Vitamin E, vitamin C, and exercise. Am J Clin Nutr. 2000; 72(2): 647S-652S
  3. Jiang Q, Wong J, Fyrst H, et al. Gamma-tocopherol or combinations of vitamin E forms induce cell death in human prostate cancer cells by interrupting sphingolipid synthesis. Proc Natl Acad Sci USA. 2004; 101: 17825–17830
  4. Singh U and Jialal I. Anti-inflammatory effects of alpha-tocopherol. Annals of the NY Academy of Sci. 2004; 1031: 195-203
  5. Sen C, Khanna S and Roy S. Tocotrienol: the natural vitamin E to defend the nervous system? Annals of the NY Academy of Sci. 2004: 1031: 127-142
  6. Jacques P, Taylor A, Moeller S. Long-term nutrient intake and 5-year change in nuclear lens opacities. JAMA Ophthalmol. 2005; 123(4): 517-526
  7. Yoshida Y, Saito Y, Jones L, et al. Chemical reactivities and physical effects in comparison between tocopherols and tocotrienols: physiological significance and prospects as antioxidants. J of Biosci and Bioeng. 2007; 104(6): 439-445
  8. Constantinou C, Papas A, and Constantinou A. Vitamin E and cancer: An insight into the anticancer activities of vitamin E isomers and analogs. Int J of Cancer. 2008; 123(4): 739-752
  9. Schurks M, Glynn R, Rist P, et al. Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials. BMJ. 2010; 341: c5702
  10. Traber M and Stevens J. Vitamins C and E: beneficial effects from a mechanistic perspective. Free Radic Biol Med. 2012; 51(5): 1000-1013
  11. Ahsan H, Ahad A, Iqbal J, et al. Pharmacological potential of tocotrienols: a review. Nutr Metab. 2014; 11: 52
  12. Trpkovic A, Resanovic I, Stanimirovic J, et al. Oxidized low-density lipoprotein as a biomarker of cardiovascular diseases. Crit Rev Clin Lab Sci. 2014: 1-16