An Australian woman with a genetic disorder died from consuming too many protein supplements, it was recently reported. The woman in question, Meegan Hefford, a 25-year-old bodybuilder, suffered from a rare, undiagnosed disorder that caused a fatal build-up of ammonia in her body (ammonia is produced when the body breaks down protein). This raises the question: are exercise supplements safe?
In healthy people, most commonly used supplements intended to enhance the body – often referred to in the scientific literature as “nutraceuticals” or “functional foods” – are harmless. Nonetheless, there are rare cases where underlying health conditions or excessive consumption could cause ill health.
By far the most common supplement taken by gym goers are those containing amino acids in the form of protein, protein hydrolysates (such as whey protein), or individual branched chain amino acids (BCAA), containing leucine, isoleucine and valine. People take these supplements to support muscle building on the premise that amino acids are the building blocks of muscle tissue. Aside from the rare genetic disorder suffered by Meegan Hefford, are there any dangers to consuming these protein supplements?
There are a number of other very rare genetic disorders where handling of certain amino acids is compromised. For example, maple syrup urine disease (MSUD) leads to a toxic build-up of the BCAA making their over consumption dangerous. Nonetheless, sufferers of MSUD are typically diagnosed at an early age, so this is unlikely to manifest through excessive protein intake in adulthood.
As well as genetic disorders of amino acid handling, people with kidney disease are often told to avoid high protein diets, since excess intake can strain failing kidneys. It is this that led to the premise that high protein diets and, by extension, protein supplements are “bad for the kidneys”.
But this has now largely been debunked, since athletes consuming nearly 3g per kilogram of bodyweight per day (about three-and-a-half times the recommended daily allowance of 0.8g/kg/day) and healthy adults consuming up to 1.25g/kg/day of leucine show very few negative health effects, at least in the medium term. So, apart from in extremely rare cases, taking protein supplements is generally safe.