Nutrition, Exercise, and Mental Health: an Interconnected Analysis

Introduction

In today’s world of sport and physical activity, many individuals are looking for products to give them an anabolic edge, reduce fatigue, or assist with recovery after exercise, practice, and competition. For these purposes, one of the most popular supplements on the market includes that of branched-chain amino acids (BCAAs) that are taken in hopes to improve performance as an intra- or post-workout supplement. After investigating the purity and reliability of the choice supplement brand, athletes use approximately 10 grams of powdered BCAAs mixed with liquid to create a drink. Depending on what is actually consumed versus the recommended dosage and blend of ingredients, individuals may see a variety of results including muscle gain, fatigue resistance, or nothing at all. Due to these differences, the major question that lies within this practice concerns how well branched-chain amino acids actually work compared to how much of the performance increases are due to a placebo effect. In order to investigate the issue, this assignment will focus first on the general background of BCAAs, will then discuss what the research has to say regarding the subject, and finally will give some ideas as to how we can better research and recommend these products, especially to those who may consume diets with low protein content.

What Are Branched-Chain Amino Acids?

To begin, amino acids are a group of twenty protein building blocks that can be further divided into non-essential and essential classes. Non-essential amino acids are readily synthesized in the body, and support tissue growth/repair, strengthen the immune system, help to form red blood cells and synthesize hormones. Opposing these, essential amino acids must be taken in through the diet and are abundantly found in foods such as chicken, beef, tuna, soybeans, nuts, and quinoa. Of the essential amino, three (leucine, isoleucine, and valine) have been taken and turned into a product called branched-chain amino acids or BCAAs. At their lowest level, BCAAs are formed by a non-continuous link of carbon bonds, meaning there is a central carbon linked around at least three others in a non-linear pattern. The structure becomes significant as it affects how well the molecules are broken down and transported throughout the body. Though most amino acids can easily be broken down by the liver, branched-chain amino acids are indirectly disjoined and must be oxidized. For this process, the enzyme branched-chain keto acid dehydrogenase is needed to convert the supplement into acetyl-CoA derivatives called oxy-Keto acids. Once broken down, the oxy-Keto acids can then be used directly by muscle for the Krebs’s cycle, or they may be transported to the liver for additional oxidation.

Recently, it was found that due to the ability of branched-chain amino acids to absorb directly into the bloodstream, there was a possibility for these molecules to enhance mitochondrial metabolism. In addition, many amino has the ability to signal various tissues to synthesize and hormones to activate in the post-absorptive state. When branched-chain amino are taken into the body by themselves they begin to help the recycling of essential amino acids from protein breakdown into protein synthesis. In the cases where the supplement is ingested with other foods or nutrients, the anabolic signaling significantly decreases. Leucine, isoleucine, and valine all contribute differently to the mixture that goes into the body, but of the three, leucine becomes the most important. This is the only branched amino that on its own has proven to obtain an anabolic response from ingestion and activates the metabolic pathways. Leucine also oxidizes both isoleucine and valine, therefore decreasing their overall concentration in the blood.

Uses for BCAAs in Physically Active Individuals

Recently, supplementation with branched-chain amino acids has been considered to be a plausible nutrition strategy to help physically active individuals avoid or lessen the effects of exercise-related muscle damage. When we exercise we induce both a mechanical strain and intra-muscular inflammation, especially when using an eccentric mode of training. Without proper aftercare, delayed onset muscle soreness or DOMS will peak at the 24 to 48-hour mark and has a strong effect on a range of motion, strength, power, and technique. In addition, there is evidence that we begin a process of muscle protein breakdown and glycogen store depletion. With this in mind, it has been considered that BCAAs could assist with controlling structural and metabolic adjustments seen in the studies, and the anabolic effect of leucine in the product could be used to promote the repair of tissues in the hours of recovery following training. As muscles with a low to moderate bout of damage heal, the addition of BCAAs to the diet can actually allow for benefits to occur when daily intake is high and the products are used for a long period of time overall. In cases when BCAAS are used before high-intensity exercise, there is a higher likelihood that noted attributes will help individuals to feel more prepared for upcoming training as muscles will be able to better retain their abilities between sessions.

To continue with the effects of exercise, those who are physically active also become fatigued due to the use of ATP and the accumulation of by-products in the muscles. The more fatigued a person becomes over the duration of a competition or training session, the more performance will decline. As a performance decrease takes place, individuals then open themselves up to an increased risk of injury, muscle soreness, and bouts of chronic inflammation that cause weakness and injury long-term. As we discussed earlier in this inquiry, branched-chained is the only amino readily available to the bloodstream and oxidation, which allows them the opportunity to trigger a decrease in the TCA cycle which often is a contributor to fatigue as it exhausts energy stores. As the TCA cycles release energy for muscle use, glutamine levels are also at their lowest after exhausting exercise. By taking in BCAAs, they will act as a precursor for lost glutamine which is important for metabolism, immune health, and other chemical processes in the body. While supplementing glutamine on its own has not proven very effective in sustaining overall endurance capacity, a dosage mixed with a branched-chain amino acid allows for the preservation of ATP as the combination acts as an intermediate variable for the TCA cycle.

BCAAs in Low Protein Diets

The macronutrient of protein is a very important aspect of an individual’s overall diet and should comprise approximately 10-15 percent of the daily caloric intake. Though there is some evidence that the standard American diet overconsumes proteins throughout the day, there are also studies that show that some individuals have trouble reaching the minimum requirement due to high carbohydrate intake. At a minimum, 50 grams per day is necessary to retain muscle mass and upkeep other bodily functions, but when taken in at lower levels there is missed opportunity to obtain the necessary essential amino acids not formed in the body. As three of the essential amino (leucine, isoleucine, and valine) are found in BCAA supplement products, it is noted in emerging studies that use can assist with the maintenance of muscle mass and can help reduce the chance of other serious side effects from the lacking diet including fatty liver and a predisposition to obesity.

As many Americans take part in physical activity for the purpose of weight loss, they also engage in a “cutting” type of diet that is highly restrictive in what can and cannot be eaten. By making this behavior a habit, you negate the body’s ability to put on the lean mass needed to naturally boost the body’s resting metabolic rate and you also receive a decrease in performance as an energy deficit comes from not consuming enough of each type of nutrient. Especially after bouts of high-intensity training, insufficient dietary protein intake in any form (protein powder, lean meat, etc.), can cause an increased rate of protein catabolism, therefore resulting in a negative protein balance and slower muscle recovery. In some cases, branched-chain amino supplementation can take individuals from a negative to positive state of protein balance after exercise. This means the use of a BCAA product in addition to a well-planned and executed resistance training program may actually improve the sought-after training adaptations in athletes of all levels. Though, one must consider that as exercise also helps to oxidize BCAAs for their use throughout the body, a significant increase in training volume, duration, or intensity may also increase the need for additional branched-chain amino acid consumption on a day to day basis.

Future Research for Deficient Diets and Fat Loss

Up to this day, BCAA supplementation for general fat loss has not been thoroughly tested in individuals who consume a low protein diet. However, in the past fifteen years, there has been researching on the potential thermogenic effects of additional branched-chain amino acid consumption, but many studies were found to be incomplete. In these instances, a hypothesis was offered for what results may have appeared if variables could have been better controlled or if researchers had a longer period of time to observe and survey subjects. It was also found that most BCAA mixtures seem to agree on a 2:1:1 ratio of leucine, isoleucine, and valine. Leucine has the highest concentration in the product as it comes with the greatest amount of individual benefits as well as its ability to oxidize the other amino it works with. To fully understand the effects of consumption, research must take into account that molecules will work differently depending on a variety of factors including nutrient timing, training age, and training intensity.

Furthermore, it has been indicated that by using an intro or post-exercise serving with 10-15 grams of the branched-chain amino acid mix, muscle performance does increase enough to help with adding lean body mass and decreasing some fat inadequately trained male subjects. For the purpose of improving research, the first question that needs to be addressed would be one that asks what the optimal ratio of the three involved amino needs to be in a combination product. Secondly, a new study would need to determine what, if any, could be the differences be in fat loss when groups follow both a controlled diet and exercise program in a set time frame. To give an idea of how science can proceed, the following paragraphs will work to formulate a hypothesis for a new study and give the parameters for participant selection and experiment conduction.

As we know that leucine is the most important of the branched-chain amino acids, I would like to hypothesize that increasing the amount of this ingredient to a 4:1:1 ratio in comparison to the standard 2:1:1 will lead to a higher amount of body fat that is lost when protein is consumed sparingly during a set physical activity schedule. In addition to the two determined products, a placebo should also be given to a portion of selected participants to note if BCAA consumption had as much control as hoped over the changes in body composition. The study itself should last around ten weeks, as eight weeks is about average to see changes in the body and we should ensure that some time has passed so we can obtain a more accurate representation.

In order to select participants, our study should focus on those who are previously trained and consume 50 grams or less of protein a day. As it is not yet known whether gender has an effect on how well BCAAs are used in the body, choosing a single group of either male or female is ideal in order to prevent possible outliers in the data. Once the gender is set, age group is also a variable that can be controlled. In this case, I would like to focus on those between the ages of 21 and 30 as individuals in this range have higher rates of supplement consumption and fitness levels than others. Approximately 30 individuals should be taken from those who volunteer as it would allow for three even groups in which we disperse the placebo, 2:1:1, and 4:1:1 mixtures. Once chosen, each participant should undergo a dual-energy x-ray absorptiometry (DEXA) to test the amount of fat mass and lean mass they have prior to the forthcoming 10 weeks. In addition, each should also set up a macronutrient tracking application to ensure they do not go above the allowed range of protein in their daily consumption of food. Once baseline measurements have been gathered and all accounts have been confirmed, the experiment may commence.

During the discussed ten weeks, groups will be brought in and given their predetermined BCAA mixture after not having eaten for at least an hour prior. The mixture given should be consumed with no other beverage except for plain water while undergoing a controlled exercise session. Sessions will take place four to five days per week for 45 minutes at a time. I have decided to control the type, duration, and intensity of the training session in order to ensure that all participants are doing the same type of workout, rather than the data assuming that each person did relatively the same amount of work. Upon completion of the workout, diet and exercise should proceed as normal with at least 10 grams of protein being added to the post-training meal. Within 24 hours after the ten weeks of the set, the schedule comes to a close, we will bring all participants back together and have them undergo a dual-energy x-ray absorptiometry or DEXA, test again, and will compare results to gain end sight and build a discussion.

Concluding Remarks and Discussion

Though supplementing the diet with additional branched-chain amino acids may sound simple, it is important for the consumer to weigh all of the potential benefits or risks, and consider talking to a professional before making a purchase. In today’s world, there are many product brands out there willing to promise the buyer results, however, most production laboratories are not well controlled and you may not be getting what you pay for. All of the research up to this point suggest that there is likely an optimal balance of each ingredient in the product, but how well that is managed during creation is truly unknown. This is not to say that all supplements are faulty as there are some very high-quality brands that have been tested, evaluated, and re-formulated overtime to ensure the safety of all users.

Clearly, there are some benefits to branched-chain amino when used in addition to a well-balanced or low caloric diet, however, these should not be used to replace adequate nutrition and exercise if one looking to gain muscle mass and lose body fat. When taking BCAAs it is important to follow dosing instructions and ensure that they are properly consumed during exercise or before other meals so they may be taken in the post-absorptive state. It is important to remember that during these times the digestive tract is empty and the fuel being used comes from the decomposition of stored energy. In order to prevent too much breakdown of the body’s nutrient reserves and musculature, amino acids will signal the metabolism and other anabolic processes to slow how fast systems such as the TCA cycle oxidizes proteins, carbohydrates, and fats. By doing so, there will be a slowing of the fatigue rate and an increase in the ability of muscles to recover from daily training that causes body damage.

In conclusion, this area of health and nutrition still needs to further the research on the more specific areas and formulations of branched-chain amino acids for the purpose of fat loss with a low protein diet. Though some studies have shown that leucine, isoleucine, and valine all may have their individual thermogenic properties, science’s main focus has been the aftercare of trained muscles and fatigue prevention. With the little information accumulated so far, we do know that 7 to 12 grams per day is the minimum amount of BCAAs needed to stimulate metabolic processes, regulate beta-oxidation, and help to control the glucose levels when there is an abundance of carbohydrates in the human body. By balancing blood sugar levels and managing the triglyceride accumulation there is potential to control the hunger that stems from a lack of caloric balance and help with the prevention of diseases including type II diabetes. Overall, a small portion of the fat loss effects will come from the preservation and addition of lean mass, but still, we must understand that all involved individuals will react differently to the formulated BCAA mixture used in any study. If subjects were told that this product could help them reach their goals faster sometimes a placebo effect may be all that is needed to motivate one to keep up with semi-adequate nutrition and exercise plan and we must account for those variables as well.

References

1. Du, Y., Meng, Q., Zhang, Q., & Guo, F. (2011). Isoleucine or valine deprivation stimulates fat loss via increasing energy expenditure and regulating lipid metabolism in WAT. Amino Acids, 43(2), 725-734. doi:10.1007/s00726-011-1123-8
2. Dudgeon, W. D., Kelly, E. P., & Scheett, T. P. (2016). In a single-blind, matched group design: Branched-chain amino acid supplementation and resistance training maintains lean body mass during a caloric restricted diet. Journal of the Society of Sports Nutrition, 13(1). doi:10.1186/s12970-015-0112-9
3. Foure, A., & Bendahan, D. (2017). Is Branched-Chain Amino Acids Supplementation an Efficient Nutritional Strategy to Alleviate Skeletal Muscle Damage? A Systematic Review. Nutrients, 9(10), 1-15. doi:10.3390/nu9101047
4. Gannon, Nicholas P., et al. “BCAA Metabolism and Insulin Sensitivity - Dysregulated by Metabolic Status?” Molecular Nutrition & Food Research, vol. 62, no. 6, 2018, p. 1700756., doi:10.1002/mnfr.201700756.
5. Greer, Beau Kjerulf, et al. “Branched-Chain Amino Acid Supplementation and Indicators of Muscle Damage after Endurance Exercise.” International Journal of Sport Nutrition and Exercise Metabolism, vol. 17, no. 6, 2007, pp. 595–607., doi:10.1123/ijsnem.17.6.595
6. Holeček, Milan. “Branched-Chain Amino Acids in Health and Disease: Metabolism, Alterations in Blood Plasma, and as Supplements.” Nutrition & Metabolism, vol. 15, no. 1, 2018, doi:10.1186/s12986-018-0271-1.
7. Koo, Ga Hee, et al. “Effects of Supplementation with BCAA and L-Glutamine on Blood Fatigue Factors and Cytokines in Juvenile Athletes Submitted to Maximal Intensity Rowing Performance.” Journal of Physical Therapy Science, vol. 26, no. 8, 30 Aug. 2014, pp. 1241–1246., doi:10.1589/jpts.26.1241.
8. Pasiakos, S. M., Mcclung, H. L., Mcclung, J. P., Margolis, L. M., Andersen, N. E., Cloutier, G. J., . . . Young, A. J. (2011). Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances postexercise muscle protein synthesis. American Journal of Clinical Nutrition, 94(3), 809-818. doi:10.3945/ajcn.111.017061
9. Pezeshki, A., Zapata, R. C., Singh, A., Yee, N. J., & Chelikani, P. K. (2016). 0476 Low protein diets produce divergent effects on energy balance. Journal of Animal Science, 94(5), 227-240. doi:10.2527/jam2016-0476
10. Shimomura, Y., Murakami, T., Nakai, N., Nagasaki, M., & Harris, R. A. (2004). Exercise Promotes BCAA Catabolism: Effects of BCAA Supplementation on Skeletal Muscle during Exercise. The Journal of Nutrition, 134(6). doi:10.1093/jn/134.6.1583s
11. Sowers, S. (2009). A Primer On Branched Chain Amino Acids [PDF]. Knoxville: Huntington College of Health Sciences.
12. Wolfe R. R. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality?. Journal of the International Society of Sports Nutrition, 14, 30. doi:10.1186/s12970-017-0184-9