The mystery about vitamin E, atherosclerosis, and inflammation
Vitamin E is said to be a powerful antioxidant that counteracts wrinkles, reduces the degeneration of joints in rheumatoid arthritis, and even protects against atherosclerosis and cancer. However, studies have shown contradictory results, and the positive effects are most probably a result of luck. Now, a team of international scientists has demonstrated that the effect of vitamin E is not related to the vitamin itself but rather to the effect of a vitamin E-dependent metabolite that is produced in the liver. The researchers see a huge potential in vitamin E therapy that is tailored to fit each person’s individual utilization and metabolism of the nutrient. Vitamin E supplements should contain natural forms of the vitamin to provide the best effect.
For nearly 100 years, scientists have studied the effect of vitamin E, a lipid-soluble vitamin of vegetable origin that is primarily found in foods with a high fat content.
Vitamin E includes eight different compounds classified as tocopherols and tocotrienols. Alpha-tocopherol is considered to be of primary importance to humans, as it is the most abundant and active form. Science has pretty much mapped out the chemical foundation for vitamin E and its functions. Lab studies and animal studies have shown that vitamin E is a powerful antioxidant that counteracts free radicals, which are aggressive molecules that damage cells and tissues. The number of free radicals is increased by factors such as stress, smoking, ageing processes, radiation, and poisoning. Free radicals occur with inflammation and are therefore seen involved in atherosclerosis and all the diseases that involve inflammatory processes. According to Dr. Andreas Koeberle from the Friedrich-Schiller University in Jena, Germany, it has been difficult to demonstrate vitamin E’s antioxidant effect in clinical studies of humans, and scientists have reached different results. Some studies show a positive effect of vitamin E, while others do not. To science, this has been a mystery.
Did you know that vitamin E was isolated from wheat germ oil for the first time in 1936?
Vitamin E is important for the formation of an anti-inflammatory metabolite
Dr. Koeberle has discovered a possible explanation to this mystery in collaboration with scientists from France, Austria, and Italy. It turns out that the effect of vitamin E is not based on the vitamin itself but on the effect of a certain anti-inflammatory metabolite called alpha-carboxy chromanol.
The human liver is very important for our ability to utilize vitamin E
Vitamin E is carried from the intestine to the liver, where the nutrient is involved in the formation of alpha-carboxy chromanol. According to the researchers behind the new study, however, the amount that is produced varies from person to person. If the effect of vitamin E depends on how much alpha-carboxy chromanol the liver produces, this may explain why supplements containing the exact same amount of vitamin E can have such different effects on a case-by-case basis. By determining the patients’ liver metabolism, it would therefore be possible to customize and improve the effect of vitamin E with the potential of increasing the therapeutic outcome. The same goes for other types of medicine, which should be adjusted to each person’s individual metabolism and requirements.
Alpha-carboxy chromanol blocks a key enzyme involved in inflammation
In the new study, the researchers looked at how alpha-carboxy chromanol inhibits a key enzyme involved in inflammatory processes. The enzyme is named 5-lipoxygenase (5-LO) and plays a central role in inflammatory diseases such as asthma and rheumatoid arthritis. There is currently only one authorized drug that is able to block 5-LO, but the use of it is limited due to the risk of severe side effects. The researchers from the Friedrich-Schiller University hope to use their results to develop a new medical drug without side effects that can be used to treat inflammatory conditions. Their work is published in Nature Communications.
Vitamin E deficiency and poor utilization of the nutrient may be caused by
- Low-fat diets and poor lipid uptake
- Metabolic syndrome (an early stage of type 2 diabetes)
- Type 2 diabetes
- Diseases of the liver and pancreas, where the digestive enzymes have difficulty with breaking down vitamin E-containing fats in the diet. Included are also celiac disease (gluten intolerance), cirrhosis, cystic fibrosis, and pancreatitis.
- Diet drugs that inhibit the uptake of fat and lipid-soluble vitamins
Vitamin E is lipid-soluble and therefore found in dietary fats, especially vegetable sources such as plant oils, nuts, kernels, whole grain, avocado, and green vegetables like broccoli and Brussels sprouts. Vitamin E is also found in cod liver oil, cod liver, eggs, high-fat dairy products, and breast milk.
Choose supplements with natural vitamin E and avoid synthetic forms of the nutrient
Natural vitamin E (they have a “d” in front of them) are absorbed far better than synthetic forms (that start with a “dl”). Natural forms of vitamin E are also utilized far better upon absorption, as synthetic vitamin E is broken down and excreted faster than natural forms.
The most common form of natural vitamin E is d-alpha-tocopherol
The most common form of synthetic vitamin E is dl-alpha tocopherol
Other nutrients that inhibit inflammation
The immune system is complicated and depends on other nutrients that vitamin E in order to work optimally. Science has demonstrated that having stable blood sugar levels and enough vitamin D, selenium, zinc, and magnesium also helps control inflammation.
Helmut Pein et al. Endogenous metabolites of vitamin E limit inflammation by targeting 5-lipoxygenase. Nature Communications, 2018
Friedrich-Schiller-Universität Jena. Why vitamin E effect is often a matter of luck until now. ScienceDaily 2018