Effect of coenzyme Q₁₀ supplementation on weight loss in obese female zucker rats

Coenzyme Q10 (CoQ10) is a well known constituent of the mitochondrial respiratory chain. It also acts as an antioxidant and a membrane stabilizer, and it enhances membrane fluidity. CoQ10 has been used to treat various cardiovascular disorders and other potential therapeutic benefits are currently being investigated. When we began our study, only one research group had investigated the use of CoQ10 in the treatment of obesity. Van Gaal et al. divided nine obese patients into a group with low blood levels of CoQ10 (n = 5) and a group with high levels (n = 4). Both groups were placed on a 650 calorie diet, supplemented with 100 mg of CoQ10 daily. By the end of 3 months, the group with low blood levels of CoQ10 had lost significantly more weight than the group with high blood levels of CoQ10. The researchers speculated that CoQ10 may have increased nonshivering thermogenesis. The main objective of our study was to determine if obese female Zucker rats placed on food restricted diets would lose more weight when supplemented with CoQ10. We chose obese Zucker rats because these animals have been shown to have blunted brown fat thermogenesis. Fasting plasma samples were collected from 7 lean (Fa/-) and 14 obese (fa/fa) female Zucker rats (age 4 months) to rule out any initial differences in the plasma CoQ levels (measured by HPLC) between lean and obese rats. There was no difference in the average ± SD baseline plasma CoQ (9+10) level between lean (.157 ± .056 umol/L) and obese (.807 ± .904) rats. The obese rats were then fed 14 grams (60% of their normal intake) of rat chow (Dyets, Inc.) daily for 4 weeks. Half (n=7) were supplemented with 7 mg of CoQ10 daily. Body weight was measured every 3 days and at the end of 4 weeks a second fasting plasma sample was collected. After 4 weeks of supplementation, the plasma CoQ level was significantly (p<0.0001) higher in the rats supplemented with CoQ10 (2.384 ± .732 vs 1.122 ± .297). However, we found no evidence that CoQ10 supplementation had any effect on weight loss over the 4 week study as shown in the table below.