Animal study: octacosanol is an endurance sports supplement

Octacosanol is found in wheat germ oil, but far higher concentrations of the substance are to be found in sports supplements. The ergogenic effect of the compound was demonstrated in studies done decades ago, but there’s a more recent Korean study that confirms this – and shows exactly how octacosanol works.

The chemical structure of octacosanol [shown here] is simple: it’s a long chain of carbon atoms with a hydroxyl group at the one end. Octacosanol and its chemical relatives are often found on the outside of fruit, grains and leafy vegetables. They form Octacosanol the waxy layer that protects plants from the outside world.

In 1972 the swimming champion and sports scientist Thomas Kirk Cureton [who died in 1992] [ 1992/12/24] published The Physiological Effects of Wheat Germ Oil on Humans in Exercise, in which he described the performance-enhancing effects of wheat germ oil on athletes. They gained more stamina, and the muscles in their lower arms and upper body gained strength.

Scientists first thought that these effects were due to the vitamin E analogues in wheat germ oil. But when they tested one of these – alpha tocopherol – on athletes and got disappointing results, mainstream science wrote wheat germ oil off. That might have been a too hasty reaction: later studies have shown that it’s not vitamin E, but the aliphatic alcohols like octacosanol that improve athletes’ performance.

Nutritionists at Yonsei University in Seoul, South Korea, set up this animal study to see whether there is a good reason for athletes to use supplements containing concentrated octacosanol. By the way, the Korean ministry of agriculture financed the study.

The researchers gave a group of rats a diet that contained 0.75 percent octacosanol [EO] for four weeks. A control group got feed with no additives [EC]. The researchers got the animals in both groups to run in a treadmill five times a week for the length of the experiment. The training programme is shown below. A second control group was given no exercise and no octacosanol either [SC]. At the end of the four weeks the researchers made the rats run to the point of exhaustion.

As the figure below shows, the octacosanol supplement enhanced the endurance capacity by a factor of 1.8.


When the Koreans examined the muscle tissue of their animal subjects, they learned how octacosanol works. The compound raised the amount of glycogen in the muscles. This is probably because octacosanol boosts the citric acid cycle.

The citric acid cycle is a complex reaction that converts nutrients into energy for cells. Octacosanol clearly boosts the activity of citrate synthase [CS], an enzyme that kicks in the first step of the citric acid cycle. The Koreans suspect that, via the citric acid cycle, octacosanol induces muscle cells to produce more glycogen, or to use it more sparingly. If it’s the latter mechanism that’s at work, then it would imply that octacosanol enhances fat burning.

Octacosanol supplementation increases running endurance time and improves biochemical parameters after exhaustion in trained rats.


This study evaluated the effects of octacosanol on running performance and related biochemical parameters in exercise-trained rats run to exhaustion on a treadmill. Male Sprague-Dawley rats were randomly assigned to one of three groups – sedentary control group (SC), exercise-trained control group (EC), and exercise-trained, octacosanol-supplemented group (EO) – and raised on either control or octacosanol (0.75%)-supplemented diet with (or without for SC rats) exercise-training for 4 weeks. EC rats ran 184% longer until exhaustion than SC rats (P < .01), while octacosanol-supplemented trained rats ran 46% longer than EC rats (P <.05). Under the exhausted state immediately following the running performance test, EO rats exhibited significantly higher plasma ammonia and lactate concentrations compared with the values for EC rats (P <.05). Although EO rats ran significantly longer until exhausted, their plasma glucose level and gastronecmius muscle glycogen concentration were not significantly different from those of EC rats. Dietary supplementation of octacosanol resulted in significantly higher creatine phosphokinase activity in plasma (44% increase, P <.01) and citrate synthase activity in muscle (16% increase, P<.01) of exercise-trained rats. These results suggest that the ergogenic properties of octacosanol include the sparing of muscle glycogen stores and increases in the oxidative capacity in the muscle of exercise-trained rats. PMID: 14977443 [PubMed - indexed for MEDLINE] Source: