Your physically fit patients may be poisoning themselves with protein
Key Takeaways
Protein supplements are growing in popularity, especially plant-based proteins.
Americans already eat enough protein but should focus more on vegetarian and seafood sources.
High protein intake can be harmful for people with kidney damage and may contribute to lesser-known health issues related to protein fermentation in the gut.
Protein has long been associated with strength and vitality. While its essential role in human nutrition is generally undisputed, the ideal daily dosage remains highly debated.
Despite different opinions on the ideal amount and source of protein, everyday consumers turn to increasing their protein intake via supplements or specially formulated food and beverages.
Recent research is helping define the tipping point for when protein supplementation goes from helpful to harmful. Here’s what you and your patients need to know.
What your patients are buying
Health-conscious consumers purchase protein supplements to enhance muscle-building, athletic performance, and weight loss. Between protein powders and ready-made shakes and bars, the US market for protein supplements reached a value of $5.83 billion in 2022—and it’s predicted to soar to $10.8 billion by 2030.[]
The fastest-growing segment of this market lies in plant-based proteins. A rising interest in fitness and overall wellness among all age groups has spurred the race for cleaner and more environmentally friendly plant-based proteins—especially those that feature functional ingredients and probiotics.
Several companies are vying to win the hearts of specific groups, like women and vegans. From now through 2030, soy, spirulina, pumpkin seeds, wheat, hemp, rice, and pea protein are predicted to dominate this rapidly growing demand for plant-based protein.[]
Novel insights on protein and heart health
Research from the University of Missouri School of Medicine suggests that consuming 22% of total calories from protein (or about 60 to 90 grams daily) may be the sweet spot for optimal benefits without added risk.[] These findings fall within the latest Dietary Guidelines for Americans, which advises a daily protein intake of 5.0 to 6.5-ounce-equivalents, or 10%–35% of total calories for adults.[][]
Investigators observed the effects of the specific amino acid, leucine, on cardiovascular disease. Leucine’s ability to promote macrophage activity helped clear plaque and debris from blood vessels.[]
However, overconsumption of leucine-containing proteins (found in beef, eggs, and dairy) resulted in overactive macrophage activity and the adverse effect of plaque buildup.[]
Choosing whole foods over supplements
Health authorities typically encourage protein intake through whole foods over processed supplements. Sufficient protein intake supports muscle repair, immune function, hair growth, eye health, proper blood clotting, and fluid balance in the body. Fortunately, most Americans are consuming enough protein already but could benefit from a greater emphasis on seafood and legumes.[]
According to the most recent Dietary Guidelines for Americans, “Intakes of protein foods generally meets or exceeds recommended intake levels. Current patterns generally include meats, poultry, eggs, and nuts, seeds, and soy, while average intake of seafood falls well below recommendations. Beans, peas, and lentils—a subgroup of both the vegetable and protein foods groups—also are underconsumed by most adults.”[]
Protein supplements pros and cons
Consuming protein immediately before or after exercise enhances muscle growth, and for many gym-goers, protein supplements are a convenient way to take advantage of this effect.
Rapidly digestible whey protein is a popular choice, and studies suggest that a single dose of 25 to 30 grams per day is beneficial—however, 40 grams may be detrimental to general health.[]
Protein boosts polypeptide YY production and suppresses ghrelin to promote satiety in overweight and normal-weight people. It also triggers insulin production, improving glucose control in those with diabetes and indirectly protecting against diabetes-related complications. Soy-based protein supplements have positive effects on serum lipids and blood pressure.[]
Nonetheless, excess protein can be hard on the kidneys and promote calcium loss. While the impact on healthy kidneys hasn’t been established, high protein intake exacerbates preexisting kidney problems. Consuming 90 grams or more of protein per day accelerates underlying kidney damage (particularly if the protein is animal-based).[]
Other potential negative effects of protein supplementation may include anger, acne, and the production of harmful metabolites following protein’s fermentation in the gut. Irritable bowel syndrome, colon cancer, intestinal permeability, DNA damage, and inflammation may be linked to higher protein supplementation, but more research is needed to determine any causal relationships.
What this means for you
Although the supplement market may promise better solutions, cheaper and more nutritious proteins can be found in simple staples like lentil soup, canned sardines, edamame, hummus, or shrimp. Discuss your patient's overall dietary patterns and encourage a plant-based and food-first approach to protein, particularly for those with high intakes or preexisting kidney damage.