• Treatment with vitamin E homologs called tocotrienols (T3s) attenuated body weight gain in mice fed high-fat diets.
  • T3s also blocked blood cholesterol elevation and white adipose tissue accumulation in high-fat diet-treated mice.
  • Additionally, T3s also inhibited liver damage from obesity. 

Obesity kills, as over four million people die each year due to obesity-related disorders. This condition affects rich and developing countries, becoming a major worldwide medical and societal issue. While obesity can be prevented by a healthy diet (limiting fat and sugar intake, increasing fruit and vegetable consumption), not everyone can just get up and fight it off with the proper diet. While people have tried to sell all sorts of “get skinny quick” solutions in pill or powder form, a tried and true medical treatment for obesity has been elusive.

Japanese researchers show that ​​tocotrienols (T3s), vitamin E homologs, added to food can attenuate obesity by stopping the buildup of body fat and bad cholesterol. “Overall, our results suggest that a higher intake of tocotrienols from daily foods may be effective to prevent obesity,” said Professor Koji Fukui from Shibaura Institute of Technology (SIT), Japan. The study was published in the journal Molecules.

T3s Treat Obesity by Reducing Fat Accumulation and Bad Cholesterol Levels

To find new materials with anti-obesity effects, understanding the mechanism of obesity is important. Increasing oxidation due to obesity may be one reason to raise the risk of developing various diseases. To find new substances that prevent obesity and severe secondary diseases caused by obesity, such as neurodegenerative diseases, the substance needs to have not only anti-obesity effects but also strong antioxidant functions. ​​Tocotrienols (T3s), which are vitamin E homologs, not only have antioxidant functions but also can limit liver fat droplet accumulation.

Kato and colleagues fed mice a high-fat diet for over 13 weeks, putting on a lot more weight than the control group. But the mice on a high-fat diet supplemented with T3s had a significantly lower body weight. Food supplemented with T3s significantly inhibited the accumulation of perirenal fat – a fat pad surrounding the kidneys – in mice treated with a high-fat diet. However, T3s treatment did not change abdominal (epididymal) fat weight.

While T3s did not modulate the final body weight of mice fed a control diet, T3s inhibited the body weight gain in obese mice compared to the untreated group. However, the final body weight of the T3s-treated obese mice was still higher than that of the T3s-treated control mice. The inhibitory effect of body weight gain of T3s did not completely arrest the high-fat diet-induced body weight gain.

(Kato et al., 2022 | Molecules) Tocotrienols inhibited body and fat (adipose) tissue weight gain. Mice were fed a regular (Ctrl) or high-fat diet (HFD) for 13 weeks. Some mice from each group were also treated with tocotrienols (T3s). The researchers compared each group’s initial and final body (left) and adipose tissue (right) weights. Two kinds of adipose tissue were measured: epididymal (abdominal fat) and perirenal (fat around the kidney). T3s reduced overall body weight and perirenal but not epididymal adipose tissue.

Mice fed high-fat diets had increased blood cholesterol across the board; both LDL (bad) and HDL (good) cholesterol were increased. While T3s did not affect HDL levels, the vitamin E homologs reduced LDL levels. The high-fat diet also caused increased liver damage, which T3s protected against. So, the past research showing that T3s reduce liver lipid droplets may be mediated by their blood cholesterol-lowering effect.

(Kato et al., 2022 | Molecules) Tocotrienols improved serum cholesterol levels. Mice were fed a regular (Ctrl) and high-fat diet (HFD) for 13 weeks. Some mice from each group were also treated with tocotrienols (T3s). The high-fat diet led to increases in LDL (bad cholesterol) and HDL (good cholesterol). T3 only reduced levels of LDL. There were no effects on triglycerides (TG).

Because previous research has linked obesity to cognitive impairment, the researchers undertook a series of tests to see if T3s may help prevent brain oxidation and lessen the cognitive and behavioral abnormalities associated with a high-fat diet. In general, the researchers found no significant changes in behavioral assessments between mice on a high-fat diet plus T3s and animals on a control plus T3s diet.

Kato and colleagues also looked at the levels of a few biomarkers that signify brain oxidation and the production of brain-derived neurotrophic factor – a protein that is important for the growth of neurons and cognitive function- to figure out why a high-fat diet had this impact. However, no significant changes were detected between the high-fat diet and control groups.
Dr. Fukui said, “We hope our research stimulates further studies on anti-obesity substances such as tocotrienols and similar compounds. Our ultimate goal is to lower the amount of people suffering from obesity-related illnesses.”