Too much of the wrong protein could reduce lifespan

May 3, 2019

Branched-chain amino acids (BCAAs) are a group of essential amino acids most commonly found in protein-rich foods such as soy, eggs, dairy, chicken, and red meat. Muscle-building fitness proteins typically contain high levels of BCAA and are much consumed, but have lesser-known side effects.

New research led by Professor Stephen Simpson and Dr. Samantha Solon-Biet from the University of Sydney’s Charles Perkins Centre, Australia, has suggested that excessive consumption of BCAAs may cause weight gain, bad moods and reduced life expectancy.

In the research, mice were fed varying amounts of BCAAs for a time: twice the normal amount (200%), the standard amount (100%), half (50%), or one fifth (20%). Notably, mice which were fed 200% BCAAs increased their food intake, resulting in obesity and a shortened lifespan. The research further examined the impacts other essential amino acids such as tryptophan had on the health and body composition of mice.

Professor Simpson has explained that high levels of BCAAs in the blood compete with tryptophan for transport into the brain – tryptophan is the precursor for the mood-enhancing “happiness chemical” or serotonin. The lowered serotonin levels in the brain then drove increased appetite and massive overeating in the mice, which became hugely obese and lived shorter lives.

Foods rich in tryptophan include seeds and nuts, soy beans, cheese, chicken, turkey and interestingly, crocodile.

Dr. Solon-Biet’s has said that while diets high in protein and low in carbohydrates were beneficial for reproductive function, they had detrimental effects for health in mid-late life. She has advised mixing protein sources to ensure optimum amino acid balance.

Qualified dietitian and public health nutritionist from the University of Sydney, Dr. Rosilene Ribeiro, has also recommended consuming a wide assortment of proteins for health benefits.


Category: Education, Features

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