Dietary Quercetin Increases Mitochondrial Biogenesis and Oxygen Consumption

By Robbie Durand, M.A.

Senior Science Editor

            Mitochondrial biogenesis is the process by which new mitochondria are formed in the cell. Mitochondria are key regulators of the metabolic activity of the cell, and are important for fat metabolism. The increase of muscle mitochondria during cardiovascular exercise plays an important role in the increase in maximal oxygen uptake. In addition, there is a shift in substrate utilization toward increased oxidation of fat. The more mitochondria a person has, the more fat can be utilized. In fact, many supplement companies are developing products that can create more mitochondria to prevent obesity. More mitochondria means more fat mobilization, so increasing mitochondria is a good thing for burning fat.

            In addition to doing cardio, which increases mitochondrial biogenesis— the birth of mitochondria— researchers from University of South Carolina found that adding quercetin to your supplement stack may help peel off some fat, improve your exercise stamina, and reduce fatigue. Quercetin is one of the most abundant natural flavonoids, and is present in a wide variety of fruits, vegetables and berries. These compounds have multiple biological properties including antioxidant and anti-inflammatory activity, and perhaps most exciting— the ability to increase mitochondrial biogenesis. 

            Another good thing about quercetin is that it has psychostimulant properties. Quercetin, like caffeine, is an adenosine A1 receptor antagonist, and can cause a delay in fatigue that occurs with caffeine— which results at least in part from its ability to block adenosine receptors in the brain. Quercetin may offer some of the same psychostimulant properties of caffeine, without side effects such as increased heart rate or blood pressure. 

            Researchers assigned 12 volunteers to one of two treatments: (a) 500 mg of quercetin twice daily dissolved in vitamin-enriched Tang or (b) a non-distinguishable placebo (Tang). Baseline oxygen consumption and bike-ride times to fatigue were established. Amazingly, researchers found that dietary supplementation with quercetin (500 mg twice daily for just seven days) increased both oxygen consumption and endurance capacity in healthy participants. The researchers speculated that the increase in oxygen consumption and endurance capacity could be due to quercetin’s ability to increase mitochondrial biogenesis, which causes an increase in mitochondria, which enhance fat oxidation. The findings could also be due to be quercetin’s ability to stimulate the same receptors as caffeine, and delay fatigue.

Reference:

            Davis JM, Carlstedt CJ, Chen S, Carmichael MD, Murphy EA. The dietary flavonoid quercetin increases VO(2max) and endurance capacity. Int J Sport Nutr Exerc Metab, 2010 Feb;20(1):56-62.

BCAAs and Glutamine Prevent Overtraining and Reduce Cortisol

            All bodybuilders walk a fine line when training— you want to stimulate muscle enough for growth, but not train so hard that your body can’t recuperate. It’s very much like the title character in “Fiddler on the Roof” in that you must maintain balance— move too far in either direction, and you are doomed to fail.

            Many bodybuilders eat plenty of protein, but think that taking a few amino acids is not going to help. After reading this, you may want to reconsider that pec-tacular postulation. Prior research has shown that resistance training alone, while it increases skeletal muscle protein synthesis, also results in an increase in protein breakdown. Although the net effect is an increase in protein synthesis, skeletal muscle remains in an overall catabolic state in the absence of adequate nutritional intervention. The ingestion or infusion of amino acids, in conjunction with an acute bout of resistance training, has been shown by numerous studies to significantly increase protein synthesis and yield a net anabolic state. 

            Research published in the Journal of Strength and Conditioning Research shows that taking glutamine and branched-chain amino acids (BCAAs) can reduce the catabolic state caused by heavy resistance exercise. Resistance-trained males were randomly assigned to either a high-BCAA or placebo group. Subjects consumed the supplement for three weeks before commencing a fourth week of supplementation, with concomitant high-intensity total-body resistance training.

            The amino acid supplement contained L-glutamine 2,000 mg; L-leucine 1,800 mg; L-isoleucine 750 mg and L-valine 750 mg. The BCAA group consumed 6 grams (12 capsules, which is the manufacturer’s recommended daily dose). At the end of the study, it could be concluded that if you are not taking BCAAs, you are going to kick yourself in the ass! 

            Compared to the placebo group, the group of men training hard and taking BCAAs had decreased levels of cortisol, higher testosterone levels, and lower markers of muscle damage. After reading Dr. Gwartney’s “Fat Attack” in this issue of MD about the role of dieting and cortisol, you know that consuming a reduced-calorie diet causes an increase in cortisol— so taking BCAAs may reverse this catabolic state. 

            These findings suggest that short-term amino acid supplementation, which is high in BCAAs, may produce a net anabolic hormonal profile— while attenuating training-induced increases in muscle tissue damage.

Reference:

            Sharp CP, Pearson DR. Amino Acid Supplements and Recovery from High-Intensity Resistance Training. J Strength Cond Res, 2010 Mar 17.