As popular as branched-chain amino acid supplements are, you don’t hear much in the way of side effects of BCAAs.
Is it just clever marketing or are BCAAs free of side effects found in other supplements?
It turns out that BCAAs are one of the lowest risk supplements on the market.
Branched-chain amino acids are the result of protein digestion, which is in most foods that you eat.
When you eat chicken, for example, your body breaks down the protein then absorbs and utilizes the BCAAs within.
With a BCAA supplement, you’re essentially skipping the middle man.
With that said, BCAAs do have a few side effects to watch out for, especially if you have one of the medical conditions listed below.
This reported side effect has no concrete proof but some users do report that taking BCAAs at night disrupts their sleep.
Exercise increases levels of serotonin, a hormone associated with relaxation and fatigue.
This is why you feel tired post-workout.
Studies show that BCAA supplementation in rats decreases serotonin production by competing with tryptophan, a precursor of serotonin.
The result is less fatigue during and after exercise.
Although human studies are pending, the idea is that if BCAAs interfere with serotonin production at night, you won’t be able to sleep.
Oddly enough, you can find people saying the opposite on bodybuilding forums: that BCAAs help them to sleep.
Best way to find out? Try it yourself.
Another side effect that is missing evidence is stomach trouble when using BCAAs.
Some users claim that BCAA supplementation has caused diarrhea, nausea, and irritable bowel syndrome.
One very important thing to consider that is often left out of the discussion: BCAA supplements can contain artificial sweeteners, fillers, and preservatives.
Whereas there is no concrete proof that BCAAs cause stomach distress, there are several studies showing the correlation between the consumption of artificial sweeteners and upset stomach, flatulence, and diarrhea.
While taking BCAA supplements is safe for most people, if you have one of the following serious medical illnesses, BCAAs can cause extreme side effects.
Amyotrophic Lateral Sclerosis (ALS)
Also called Lou Gehrig’s disease, ALS results in a loss of voluntary control of muscle nerves.
While human studies are still pending, some experts believe there is a correlation between long term BCAA use and the onset of ALS in athletes.
At the very least, researchers suggest that BCAA supplements can worsen this condition and increase the risk for lung failure and death.
Branched-Chain Ketoaciduria (Maple Syrup Urine Disease)
When your body isn’t able to metabolize the amino acids leucine, isoleucine, and valine because something is wrong with a process known as branched-chain α-keto acid dehydrogenase (BCKD), you develop Branched-Chain Ketoaciduria.
Taking BCAAs when you have this disease can spell big trouble. Since your body isn’t able to process BCAAs, consuming more is thought to increase your risk for seizures as well as severe mental and physical retardation.
For those battling chronic alcoholism, BCAAs can dramatically worsen your condition.
Studies show that the consumption of BCAAs can lead to liver disease in those with alcoholism as well as non-alcoholic liver disease in obese people. The worst-case scenario is permanent brain damage.
If you have any of these three conditions, do not take a BCAA supplement.
Not sure? Talk with your doctor.
Interactions with Medication
If you’re currently on medication, you must talk with your doctor before beginning to use any dietary supplement, especially BCAAs.
Even though they are seemingly harmless on their own, BCAAs might have a negative interaction with the following medications:
- Proglycem (diazoxide)
- Thyroid hormone
- Diabetes medications
- Parkinson’s medications
It’s Not Your BCAAs Causing Side Effects
Continuing with the point from above, if you’re an otherwise healthy person and you notice some mild side effects, consider the idea that it isn’t the branched-chain amino acids causing the problem – it could be what it’s made with.
Artificial sweeteners and fillers make up the majority of BCAA supplements that you find on the market.
Those bright-colored powders with their over-the-top flavoring have been shown to cause digestive problems including irritable bowel syndrome.
What’s more, artificial sweeteners such as aspartame and high fructose corn syrup have been linked to weight gain and a higher risk for disease.
When looking for a BCAA supplement, try to find one that is naturally sweetened and free of fillers and preservatives.
Read Next: The 3 Best BCAA Powders Money Can Buy!