- Leucine
- Isoleucine
- Valine
BCAA supplements are commonly used to promote muscle growth and enhance athletic performance. They may also help with weight loss and reduce post-exercise fatigue.
What are branched chain amino acids?
Branched chain amino acids are composed of three essential amino acids:
- Leucine
- Isoleucine
- Valine
These amino acids are grouped together because they are the only three amino acids that have chains that branch to one side.
Like all amino acids, branched-chain amino acids are the building blocks your body uses to make protein.
Branched-chain amino acids are considered essential because, unlike non-essential amino acids, your body cannot make them. Therefore, it is crucial to get them from your diet.
How do branched-chain amino acids work?
Branched-chain amino acids make up a large portion of the body's total amino acid pool.
Together they make up about 35-40% of all essential amino acids in your body and 14-18% of all essential amino acids in your muscles.
Contrary to most other amino acids, branched-chain amino acids are primarily broken down in the muscles rather than in the liver. Because of this, they are thought to play a role in energy production during movement.
Branched-chain amino acids play a variety of other roles in your body.
First, your body can use them as building blocks for protein and muscle.
They may also be involved in regulating blood sugar levels by preserving sugar stores in the liver and muscles and stimulating cells to absorb sugar from the blood.
In addition, branched-chain amino acids can help reduce fatigue during exercise by reducing the production of serotonin in the brain.
Of the three substances, leucine is thought to have the greatest impact on the body's ability to build muscle protein.
Meanwhile, isoleucine and valine appear to be more effective at producing energy and regulating blood sugar levels.
The Food and Nutrition Board (FNB) of the Institute of Medicine established the Recommended Dietary Allowances (RDAs) for essential amino acids in 2002. Leucine, adults 19 years and older, 42 mg/kg body weight/day; Isoleucine 19 mg/kg body weight/day; Valine 24 mg/kg body weight/day.
For a 70 kg (154 lb) person, this is equivalent to 2.9, 1.3 and 1.7 g/day. A diet that meets or exceeds the recommended daily intake of total protein (0.8 g/kg/day; 56 g for a person weighing 70 kg) and also meets or exceeds the recommended daily intake of branched-chain amino acids.
Branched-chain amino acids can reduce fatigue during exercise
Consuming branched-chain amino acids may help reduce physical and mental fatigue.
One study reported that consuming 20 grams of branched-chain amino acids dissolved in 400 ml of water and 200 ml of strawberry juice 1 hour before exercise prolonged participants' fatigue time.
Another study found that participants who took branched-chain amino acids during exercise reported a 15% reduction in fatigue compared to participants who took a placebo.
In one study, this increased resistance to fatigue helped the BCAA group exercise longer before reaching exhaustion compared with the placebo group.
However, not all studies find that reduced fatigue improves physical performance.
BCAA supplements may reduce muscle soreness
Branched-chain amino acids can also help reduce muscle soreness after exercise.
One approach they might take is to lower blood levels of creatine kinase and lactate dehydrogenase, enzymes linked to muscle damage. This can improve recovery and provide some protection against muscle damage.
Various studies have asked participants to rate their muscle soreness after performing certain strength training exercises.
Participants who took BCAA supplements rated their muscle soreness as 33% less than those who took a placebo.
In some cases, people who received BCAAs also showed a 20% improvement in performance when they repeated the same strength training test 24-48 hours later.
However, effects may vary based on your gender or the total protein content of your diet.
BCAAs may increase muscle mass
Some people buy branched-chain amino acid supplements to increase muscle mass.
After all, research shows that branched-chain amino acids do activate the enzymes responsible for building muscle.
Some studies also suggest that branched-chain amino acid supplements may be effective in increasing muscle mass, especially if they contain a higher proportion of leucine than isoleucine and valine.
However, there is currently no evidence that getting branched-chain amino acids from supplements is more beneficial than getting them from your diet or from whey or soy protein supplements.
In fact, research shows that, at least in some cases, taking a complete protein supplement may be better for muscle growth than taking a single amino acid supplement.
BCAAs may lower blood sugar levels
BCAAs may also help maintain normal blood sugar levels.
Leucine and isoleucine are thought to increase insulin secretion, allowing muscles to absorb more sugar from the blood, thus lowering blood sugar levels.
In practice, however, not all studies support these effects.
In fact, some people even report that blood sugar levels may rise, depending on the type of diet participants follow. For example, when BCAAs are combined with a high-fat diet, taken in supplement form, they may cause insulin resistance.
That said, many of these studies were performed on animals or cells, which means their results may not fully translate to humans.
In humans, the effects also appeared to vary between participants.
For example, in one recent study, participants with liver disease took 12.5 grams of branched-chain amino acids three times a day. Ten participants experienced a reduction in blood sugar levels, while 17 participants experienced no effects.
BCAAs Can Promote Weight Loss
Branched-chain amino acids may help prevent weight gain and promote fat loss.
In fact, observational studies report that people who consume an average of 15 grams of branched-chain amino acids per day in their diet may have a 30% lower risk of being overweight or obese compared with those who consume an average of 12 grams per day.
However, it's worth noting that people who consumed fewer branched-chain amino acids also consumed about 20 grams less total protein per day, which may have affected the results.
If you're trying to lose weight, branched-chain amino acids may help your body get rid of excess fat more efficiently.
During the 19-day study period, wrestlers who consumed a high-protein, calorie-restricted diet supplemented with BCAAs lost 3.5 pounds (1.6 kg) more than those who took a soy protein supplement.
Despite consuming the same calories and slightly less total protein per day, the BCAA group lost 0.6% more body fat than the soy protein group.
In another study, weightlifters who took 14 grams of branched-chain amino acids per day lost 1 percent more body fat over an eight-week study period than those who took 28 grams of whey protein per day. The BCAA group also gained 4.4 pounds (2 kilograms) of muscle.
That said, both studies have some flaws. For example, they provide little information about supplements and dietary ingredients, which may affect the results.
What's more, research into the effects of branched-chain amino acids on weight loss has shown inconsistent results.
Branched-chain amino acids may reduce liver disease complications
Branched-chain amino acids may help reduce complications associated with liver failure.
One possible complication is hepatic encephalopathy (HE), which can cause confusion, loss of consciousness, and coma.
A 2014 review suggested that BCAA supplements may be more effective than other supplements in reducing the severity of HE in people with liver disease.
However, branched-chain amino acids did not improve overall survival or reduce the risk of other complications, such as infection and stomach bleeding.
Another review of studies in patients undergoing liver surgery reported that BCAA-rich solutions may help improve liver function, reduce the risk of complications and shorten hospital stays.
Branched-chain amino acid supplements are also effective in reducing fatigue and improving weakness, sleep quality, and muscle spasms in people with liver disease.
For liver cancer, taking branched-chain amino acid supplements may help reduce water retention and reduce the risk of premature death.
However, if you have liver disease, discuss using BCAA supplements with your healthcare team before starting.
Dosage instructions
If you want to start supplementing with branched-chain amino acids, you should consult a health care professional to determine if it is right for you and how much you should take.
Additionally, there are no official daily requirements for branched-chain amino acids, although studies have suggested different amounts.
However, people whose diets contain enough protein-rich foods will most likely not need to take supplements.
The best times to take BCAA supplements are before and/or after exercise. Many people who want to build muscle also take them in the morning and before bed.
However, whether the exact timing has a significant impact on this has not been properly studied. But you should follow the manufacturer's instructions and don't exceed the maximum dosage listed.
main food source
There are many foods that contain branched-chain amino acids, such as:
- Meat, poultry and fish
- beans and lentils
- Dairy products, such as cheese and milk
- Tofu and tempeh
- Egg
- Quinoa
- Nuts and seeds
Safety and side effects
For most people, taking branched-chain amino acid supplements is generally safe and has no side effects.
However, people with a rare congenital disease called maple disease should limit their intake of branched-chain amino acids because their bodies cannot break them down properly.
generalize
In some cases, branched-chain amino acid supplements may provide impressive benefits, especially in the area of muscle growth and physical performance.
However, branched-chain amino acids are also found in whole-protein supplements and in a variety of protein-rich foods.
Therefore, it may not be necessary to take BCAA supplements, especially if you get enough BCAAs through diet or protein supplements.
