COPD Study: Fortified Whey Protein Beverage Increases Muscle Strength

Men with moderate-to-severe chronic obstructive pulmonary disease (COPD) who drank a beverage composed of whey protein fortified with magnesium and vitamin C had lower levels of the inflammation-associated protein interleukin-6 in their blood, compared to those who did not receive the beverage, a study has shown.

Improved muscle mass and strength and a better health-related quality of life also were reported by those who consumed the beverage. 

The study, “Fortified whey beverage for improving muscle mass in chronic obstructive pulmonary disease: a single-blind, randomized clinical trial,” was published in the journal Respiratory Research.

Muscle wasting and unintentional weight loss are common features seen in people with COPD, which may lead to problems in the muscles of the lung and reduced exercise capacity. Factors that promote muscle wasting include malnutrition, smoking, and chronic inflammation.

Nutritional support is a potential therapeutic strategy in preventing disease progression and complications. Evidence suggests that dietary whey protein — one of the primary proteins found in dairy products — and magnesium may play a role in muscle preservation and inflammation reduction. 

Furthermore, dietary intake of antioxidants, such as vitamin C, also may improve COPD-related symptoms and severity.

Researchers based at the Shiraz University of Medical Sciences in Iran  created a whey beverage fortified with magnesium and vitamin C to investigate the effect of these combined nutrients on maintaining muscle mass and quality of life in male COPD patients.

The goal was “to evaluate the effect of the combination of these nutrients, independent of exercise training on muscle mass maintenance and quality of life in [patients] with moderate-to-severe COPD,” the researchers wrote.

The study (Iran trial code IR.SUMS.REC.1396.85) included 46 men with moderate-to-severe COPD who were were assigned randomly to the whey beverage or a control group. In total, 44 patients completed the eight weeks of the study.

The average age of patients was 62.76 years. They had a mean body-mass index (BMI, a measure of body fat) of 21.08 (considered a normal weight) and poor lung function as measured by FEV1 (the amount of air forced out from the lungs in one second).

Before the study began all participants were given a book about COPD and nutrition with information on nutritional requirements and coping strategies emphasizing protein, magnesium, and vitamins.

Then, patients in the intervention group received 250 mL (8.5 ounces) of the fortified beverage daily containing 15.9 grams of whey protein, 275 milligrams of magnesium, and 685 milligrams of vitamin C, along with dietary advice and routine care for eight weeks. Participants in the control group received dietary advice and routine care only.

Patients in the intervention group were supplied with the beverage at home. 

The primary outcome of the trial was the levels of proteins associated with inflammation (biomarkers) in the blood. Secondary outcomes included any changes in malnutrition status, body measurements, muscle strength, and health-related quality of life (HRQoL).

Results showed that after eight weeks of intervention, compared to baseline, the inflammatory-associated proteins TNF-alpha and interleukin-6 (IL-6) were present in significantly lower levels in those who received the whey beverage. The antioxidant biomarker called GSH also was lower in the intervention group compared to baseline. 

However, compared to controls, only IL-6 was reduced significantly in patients who received the whey beverage. 

Fat-free mass index (FFMI), a measure of skeletal muscles plus organs normalized to height, and overall body protein were increased significantly in the intervention group compared to the control group. A test for handgrip strength also showed significant improvements in the intervention group.

HRQoL was measured using the St. George’s respiratory questionnaire (SGRQ). Compared to the control group, patients in the intervention group showed significant improvements in the overall SGRQ scores and SGRQ impact scores, which measure psychological and social functioning disturbances.

“Future studies are suggested to better elucidate the best nutritional strategies for managing or improving the respiratory function and nutritional status in patients with COPD,” they added.