Collagen Peptides Boost Bone Health in Female Runners

Collagen is a protein found in skin, hair, nails, tendons, cartilage, and bones.

Our bodies naturally produce collagen using the foods we eat. But, in recent years, collagen peptides have gained popularity as a supplement to support joint, hair, skin, and gut health.

A new study led by Jennifer Fields, assistant professor of nutritional sciences in the College of Agriculture, Health and Natural Resources (CAHNR), provides evidence in favor of yet another application for collagen peptides - protecting female runners' bones.

The study was published in Frontiers in Nutrition.

Bone health is a significant concern for endurance runners because, by the nature of their sport, they are consistently putting significant strain on their bones.

By putting stress on the bones, running activates osteoclasts to break down damaged bone. If a runner is, intentionally or not, not consuming enough calories, the osteoblasts that create new bone don't have the fuel they need to rebuild the bone properly. This can lead to injury and long-term conditions like osteoporosis.

"Oftentimes, we associate running with being bad for us, bad for our bones, because runners are at a higher risk of stress-related injuries," Fields says. "But oftentimes, it's due to just simply under fueling and not giving your body enough calories to support training and recovery and adaptation."

This is particularly relevant for female runners due to how the bone remodeling cycle interacts with hormones. Insufficient caloric intake lowers estrogen and progesterone levels, which in turn leads to increased bone breakdown and reduced bone formation.

Fields decided to study if collagen peptides could help intervene in this process, given that 90-95% of the organic bone matrix is comprised of collagen.

Collagen peptides are "incomplete amino acids." Unlike complete amino acids, they do not trigger a response in our muscles. Instead, because of their unique structure (a repetitive pattern of three amino acids), they can trigger osteoclast and osteoblast activity.

"Unlike most dietary proteins, some of the dipeptides and tripeptides that make up collagen peptides can be absorbed intact by our intestine," Fields says. "Those di- and tripeptides are what can potentially act on these osteoblast and osteoclast pathways to trigger a better bone turnover response where we're favoring more bone formation."

In this pilot study, Fields and her collaborators found that collagen peptides did indeed improve bone turnover. Looking at biomarkers in participants' blood, the researchers saw that markers associated with bone formation increased and inflammation decreased in the group that took the collagen peptide supplements.

"We're seeing some good preliminary data to show that four weeks is sufficient to move some of those acute biomarkers," Fields says.

Other studies had looked at collagen peptides for bone health in postmenopausal women. Research on premenopausal women, on the other hand, has been extremely limited, and no one had looked at female runners specifically, despite their elevated risk of impaired bone remodeling and heightened risk of bone stress injuries.

Women's bone density is generally not checked until after they enter menopause. But about 90% of bone mass develops by 18 and the remaining 10% by age 30. This means supporting bone health in young women is critical to ensuring their lifelong health and wellness.

"If we can target the premenopausal population and identify individuals who might be at risk of maladaptive bone responses, then hopefully we can reverse it and prevent early-onset osteopenia and osteoporosis," Fields says.

Collagen peptides also have known benefits for hair, skin, joints, and gastrointestinal health, meaning incorporating them into the diet can have a host of benefits beyond bone health.

"What's great about collagen peptides is that they're universal," Fields says. "It's not a supplement where we're only expecting one outcome. It can be incorporated into the diet as a supplement to help with some of these other health benefits."

This work relates to CAHNR's Strategic Vision area focused on Enhancing Health and Well-Being Locally, Nationally, and Globally.