Could collagen peptides help protect female runners’ bones?
Researchers tested a daily supplement in women who run at least 56 kilometres per week
Collagen supplements have mostly been marketed to runners for their possible effects on joints, tendons, skin and hair. In a new study, researchers from the University of Connecticut examined the way collagen impacts bone health in female distance runners, with promising results.
Collagen peptides are produced by breaking collagen into smaller pieces that dissolve easily and can be digested and absorbed; peptides are short chains of amino acids, the building blocks that make up proteins. The study, published in Frontiers in Nutrition, included 22 naturally menstruating women (women who were not using birth control) between 18 and 35 who ran at least 56 kilometres per week. Half consumed 20 grams of collagen peptides each morning for four weeks. The others received an equal-calorie maltodextrin powder that served as a placebo.
Researchers took blood samples before and after the trial. They measured several substances involved in bone turnover, the continuing process through which old or damaged bone is removed and replaced.
Why women runners’ bones need attention
Running places repeated force on the skeleton. That loading can encourage bones to adapt, but the repair process requires enough food, nutrients and recovery time. When bone damage builds faster than the body can repair it, a bone stress injury can develop.
Female runners have a higher rate of these injuries than male runners. Low energy availability (LEA) is one contributing factor, which occurs from underfuelling. Without adequate nutrition, after you exercise, your body may not have enough energy left for normal functioning. Over time, inadequate fuelling can affect reproductive hormones, disturb the menstrual cycle and interfere with bone formation. In the collagen study, 36 per cent of participants recorded LEA during each of the two three-day monitoring periods.
The lowdown on building bone
The collagen group had an increase in P1NP, a blood marker associated with the formation of new bone. This marker didn’t change significantly in the placebo group.
Where collagen comes from
Collagen is found naturally in animal connective tissue, including the skin, cartilage and bones of meat and fish. Dietary sources include fish eaten with the skin, chicken skin, tougher cuts of meat, gelatin and bone broth, although the collagen content of broth can vary considerably.
The body also makes its own collagen. Protein-rich foods supply the necessary amino acids, while vitamin C, zinc and copper help with production. Fish, eggs, dairy products, soy and legumes provide protein. Fruit and vegetables such as citrus fruit, berries and peppers provide vitamin C. Nuts, seeds, beans, shellfish and whole grains contain zinc or copper. Plants don’t contain collagen, but a varied plant-based diet can provide many of the materials the body uses to produce it.
Collagen peptide powders are sold as dietary supplements, and manufacturers must follow rules governing production and labelling. Unlike other peptides like BCP-147, collagen peptides are not banned by the World Anti-Doping Agency (WADA) or the NCAA. While some “peptide hormones” are prohibited, collagen is a food-based protein supplement that is generally considered safe for competitive use. The 20-gram amount used in this pilot trial was a research dose, not an established recommendation for female runners.
Next steps
While this study was limited by size and scope, researchers say the results are promising enough to warrant larger and longer trials that measure the bones themselves.