This Everyday Protein May Do More Than Support Muscle

Key takeaways

• In a three-month controlled clinical trial, older adults who consumed 25 grams of isolated whey protein daily improved measures of functional capacity, peripheral muscle strength, and expiratory muscle strength.

• The whey group also showed improvements in several lung-function measures, including airflow and forced exhalation tests.

• Researchers reported changes in inflammatory and immune-related markers, but these biomarker findings should be interpreted more cautiously than the functional outcomes.

• The trial was small, and the abstract does not clarify key details such as blinding, participants’ baseline protein intake, or whether their overall diets were controlled.

• The study supports whey protein as a convenient way to help meet protein needs in later life—not as a replacement for resistance training or an overall protein-rich diet.

Maintaining muscle is one of the most practical goals of healthy aging. Muscle supports mobility, balance, independence, and the ability to stay active—but protein intake often falls short as appetite, food routines, and calorie needs change over time.

Whey protein is a convenient option because it provides a concentrated source of high-quality protein, including essential amino acids that help stimulate muscle protein synthesis. But most research has focused on muscle and exercise outcomes. This trial asked a broader question: could daily whey protein also support breathing-related function and physical capacity in older adults?

Protein is part of the aging equation

Researchers assigned older adults to either a control group or a whey-protein group. The whey group consumed 25 grams of isolated whey protein daily, seven days per week, for three months.

By the end of the trial, participants receiving whey protein improved functional capacity, peripheral muscle strength, and expiratory muscle strength. They also improved across several measures of lung function, including forced expiratory volume, airflow, and peak expiratory flow.

That combination is notable. Strength in the arms and legs is important for everyday movement, while expiratory muscle strength and lung-function measures relate to the ability to move air effectively during breathing. Together, they point toward a potential role for adequate protein intake in maintaining whole-body function—not just muscle size.

Function matters more than a biomarker

The study also reported reductions in several inflammatory and immune-related markers, alongside increases in IL-10 and Klotho. These findings are interesting, but they are not the main reason to pay attention to this trial.

Biomarkers can shift for many reasons, and small nutrition studies that measure numerous outcomes can produce results that are difficult to interpret in isolation. Functional outcomes are easier to understand and more relevant to daily life: Can someone move more easily? Generate more strength? Maintain capacity for walking, climbing stairs, and staying active?

On those measures, the whey-protein group showed a promising signal.

What the study cannot tell us

This was a relatively small study, with 27 people in the whey group and 38 in the control group. It lasted only three months, so it cannot answer whether the improvements persist with longer-term use or translate into better mobility over years.

The abstract also leaves important questions unanswered. It does not clearly describe whether the control group received a matched placebo, whether participants or researchers were blinded, how much protein participants were consuming before the study, or whether their overall food intake changed during the intervention.

That matters because whey protein may work primarily by helping people reach a more adequate total daily protein intake. The results do not prove that whey is uniquely beneficial compared with other high-quality protein foods.

Practical tips 

The useful takeaway is not that everyone needs a protein shake. It is that consistently meeting protein needs becomes increasingly important with age—and whey can be a simple tool when food alone makes that difficult.

• Aim to include a meaningful protein source at each meal rather than concentrating nearly all protein at dinner.

• Pair protein intake with resistance training when possible; exercise gives muscle a reason to use the amino acids it receives.

• Use whey protein for convenience, such as at breakfast, after a workout, or when appetite is low.

• Build the rest of your protein intake around foods such as Greek yogurt, cottage cheese, eggs, fish, poultry, tofu, tempeh, legumes, and lean meats.

• Choose products based on protein content, taste, tolerance, and added ingredients—not on dramatic “anti-aging” claims.

The takeaway

This small clinical trial suggests that 25 grams of daily whey protein may support strength, functional capacity, and breathing-related performance in older adults. It is encouraging, but not definitive.

The broader message is stronger than any single supplement: adequate protein is a foundational part of maintaining function with age. Whey may be a practical way to help close the gap, especially when combined with regular resistance training and an overall nutrient-dense eating pattern.

Reference:
Moura-Maia MS, Paula-Vieira RHR, Ramos-Gomes NV, et al. Whey Protein Supplementation Positively Modulates Lung Function and Pulmonary and Systemic Immune Response in Older Adults: A Randomized Controlled Clinical Trial. Journal of the American Nutrition Association. 2026;45(5):475-488. doi:10.1080/27697061.2026.2615981.