Vitamin E tocotrienols show endurance benefits: Rat study

Supplements of vitamin E tocotrienols may prolong running times in obese rats to the same extent as whey protein alone, says a new study.

Ten weeks of supplementation with either whey protein isolate (WPI) or full spectrum palm tocotrienols were associated with 50% increases in running times, according to results published in PLOS One.

However, combining the two didn’t produce any additional effects, wrote researchers from Victoria University (Melbourne, Australia).

“To our knowledge this is the first study demonstrating that animals on a [high fat diet] supplemented with [tocotrienols] and/or WPIs show a remarkable increase in exercise capacity compared with [high fat diet] only animals,” wrote the researchers.

“This novel finding provides new awareness of the potential of these naturally occurring nutrients to increase exercise tolerance in populations at-risk of developing obesity and potentially subsequent insulin-resistance, which in turn could aid in the amelioration or prevention of these diseases.”

The findings add to a 2009 study published in the European Journal of Applied Physiology, which found that tocotrienol supplementation reduced oxidative stress in rats in a swimming test (as a model of strenuous exercise).

“We were surprised by the benefit of tocotrienols + WPI, and when our data combines with that of Lee et al, the benefits on exercise endurance are quite compelling. The mechanisms of this will be very interesting to elucidate,” said Dr Andrew Betik, lead author on the PLOS One paper.

Study details

Vitamin E

Vitamin E is a family of eight separate but related molecules: four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta). While alpha-tocopherol is found in most multivitamins and is supplemented in foods, a growing base of evidence suggests that this popular vitamin E interferes with the uptake and function of tocotrienols. Tocotrienols are derived from three major sources, including rice, palm and annatto.

The researchers randomly divided 35 sedentary, diet-induced obese rats into four groups: (i) high-fat diet, high-fat diet supplemented with (ii) mixed tocotrienols at dosage of 50mg/kg (EVNol, supplied by ExcelVite), (iii) WPI (8% of total energy intake) and (iv) mixed tocotrienols plus WPI for 10 weeks.

Results showed that there were no significant changes in terms of food intake, body composition, glucose tolerance, insulin sensitivity among all the groups. However, both single supplement groups showed significant higher exercise capacity (greater than 50% longer running time), compared to the control group. While the combined supplement group did not further improve exercise endurance, the rats in this group did have higher endurance compared to the control group, said the researchers.

“Exercise generates free radicals such as reactive oxygen species (ROS) and if the level of ROS is left unchecked, it would lead to muscle fatigue or weakness in physical performance such as running, swimming and other sports activities,” said CheeYen Lau, Nutritionist at ExcelVite.

“Tocotrienols’ superior antioxidant activity explained the significant increase in exercise endurance as demonstrated in these two studies. Both animal studies with different physiological performances have shown that supplementation of EVNol helps to improve exercise endurance. These initial results are very promising and encouraging for our future studies, including a potential human clinical study in sport endurance and weight management,” added Lau.

Source: PLOS One

11(4), e0152562, doi:10.1371/journal.pone.0152562

“Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet-Induced Obese Male Sprague-Dawley Rats”

Authors: A. Betik