Vitamin E may boost immune function: Mouse study

Scientists from Tufts University report that mice fed dietary supplements of alpha-tocotrienols experienced improvements in the function of T cell function. The findings are published in the Journal of Nutrition​.

If the results can be repeated in future studies it may see tocotrienols added to the burgeoning immune health market. In 2008, nine per cent of nutraceutical claims were reportedly for immune health. The area is growing, but science is key to supporting the claims.

The new study investigated the effects of tocotrienols on immune function in old and young mice. The animals were fed 0.1 per cent Tocomin 50 per cent (Carotech), which is a mixture of tocotrienols and alpha-tocopherols, or a control diet containing only tocopherol, for six weeks.

At the beginning of the study the researchers noted that the immune function of the older mice was reduced, compared with the younger mice, as evidenced by the lower levels of the cytokines, interleukin-4 (IL-4), IL-6, and IL-10.

Older mice fed the tocotrienol supplement displayed a greater level of lymphocyte proliferation, a marker of how quickly white blood cells can reproduce in response to infection, than old mice fed the control.

Furthermore, mice of both ages fed the tocotrienol supplement had higher levels of the interleukin-1beta, a cytokine released by immune cells (macrophages).

“These results suggest a beneficial effect of tocotrienols in improving the age-related decline in T cell function,” ​wrote the researchers.

The vitamin E​

There are eight forms of vitamin E: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). Alpha-tocopherol (alpha-Toc) is the main source found in supplements and in the European diet, while gamma-tocopherol (gamma-Toc) is the most common form in the American diet.

Tocotrienols are only minor components in plants, although several sources with relatively high levels include palm oil, cereal grains and rice bran.

While the majority of research on vitamin E has focused on alpha-Toc, studies into tocotrienols account for less than one per cent of all research into vitamin E.

Source: Journal of Nutrition​
Published online ahead of print, doi: 10.3945/jn.110.121434
“Dietary Supplementation with Tocotrienols Enhances Immune Function in C57BL/6 Mice”​
Authors: Z. Ren, M. Pae, M.C. Dao, D. Smith, S.N. Meydani, D. Wu