Everyone is obsessed with protein nowadays. From Khloe Kardashian’s protein popcorn to Ranveer Singh’s protein wafer bars, you might find ‘protein’ claims in almost everything you eat and drink. One of the benefits many think it offers is increased muscle mass and strength.
New Study Challenges Protein Craze
A new study published in the American Journal of Clinical Nutrition, however, suggests that older adults can probably skip the protein-boosted milk in their next Starbucks latte. Why? Because protein alone does not equate to muscle strength.
The Protein Craze Falls Short
While getting adequate amounts of protein in your diet is crucial, the growing obsession is concerning. Giant food companies are adding fuel to protein campaigns by incorporating protein into almost every meal. Walk into a grocery aisle, and you will find protein-fortified everything—cereals, pasta, energy bars—all promising to build strength and slow age-related muscle decline. But does this protein boost help older adults?
According to Lisa Ceglia, lead author, endocrinologist, and associate professor at Tufts University School of Medicine, consuming the normally recommended amounts of protein in the diet, along with adequate exercise, can help older adults keep their muscles youthful.
Around the age of 40, a slow decline in muscle strength begins. At this point, the kidneys start to lose the ability to excrete acid from the body effectively. As a result, the body begins breaking down muscle to release basic substances that neutralise the acid. Previous studies have shown that adding protein to an older adult’s diet can prevent muscle loss. They found it boosts growth factors and works best when combined with exercise. However, until recently, scientists had not tested whether extra protein alone can limit muscle loss in a healthy and well-nourished person.
“So, then you start to say, yes, in theory this makes a lot of sense, but let’s look at the reality,” Ceglia, also a postdoctoral fellow at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA), said.
The Study
To understand the benefits of protein alone, Ceglia and her team, including HNRCA Senior Scientist and School of Medicine Professor Bess Dawson-Hughes, conducted a study. They recruited 141 adults over 65 to test whether extra protein could preserve muscle strength. Half of the participants received whey powder supplements rich in leucine, an amino acid known to trigger muscle-building processes. The other half received a placebo. Some participants also received potassium bicarbonate, a compound that neutralises acid build-up, a potential culprit in age-related muscle loss.
After 24 weeks, the participants’ strength was tested with a range of exercises—from leg presses to balance tests. The results were unexpected. The participants’ strength remained unchanged by the extra protein, with or without potassium bicarbonate. The results were the same regardless of the participants’ sex.
“We were surprised,” Ceglia said, especially as the tests revealed that the participants’ bodies were ready to make more muscle. They excreted more acid, as a younger person would, and had elevated levels of a muscle-building hormone called IGF-1.
Why Didn’t They Build More Muscle?
The researchers had the same question. Why didn’t the participants build muscle strength despite taking the protein supplements? “This is an excellent question, and one that I’ve been asking myself,” Ceglia said. According to the researchers, the participants may have undergone subtle changes that the strength tests were not sensitive enough to detect. It is also possible that, without added exercise, the participants’ bodies did not know what to do with the extra protein.
They also explained that people who add more exercise to their routines might benefit from protein supplementation. Other groups, such as those malnourished after serious injuries like hip fractures, may benefit too. That is why protein-rich drinks are sometimes prescribed to people who have a poor appetite after surgery.
“But if you’re just a healthy individual living in the community and eating protein at the recommended daily amount, there’s no evidence that protein supplementation alone will have a huge impact on your strength and function,” Ceglia said.
Ceglia and the team are planning to investigate whether the combination of exercise and protein supplementation is more effective than exercise alone. Until then, the researchers recommend that older people use resistance training to maintain their strength. “It’s the most consistently effective option we have for improving strength and function,” she added.
