Moving as We Age
“We are asking: are all aspects of neuromuscular decline inevitable with aging?"
Kent recently received a 5-year, multimillion-dollar grant from the National Institutes on Aging (NIA) for research that builds upon her 20-plus-year studies of muscle fatigue and aging. Kent asks: how much of muscular decline is rooted in the molecules of our muscular and nervous systems—due to the process of aging itself? How much of it is due to lifestyle changes that go along with our bodies growing older? Kent intends that her work, done in collaboration with assistant professor Mark Miller, associate professor Katherine Boyer, and research professors Stuart Chipkin and Carol Bigelow, will add to our collective understanding of how muscle function and fatigue impact the body’s mobility over time.
As the body ages, if a person moves around less or stops exercising, they can get caught in a vicious cycle: the perception that one’s body is less able to move about safely causes a person to engage in less activity, then their muscles break down, which renders their body less able to move with ease. “It’s a downward spiral,” says Kent. “None of our systems respond well to a sedentary lifestyle.”
Muscular decline is not a given. Kent points to research, such as that cited by Dan Buettner in the book Blue Zones, on societies where a high number of people live to be 100, and suggests looking at what practices in those societies support active aging. Any amount of physical activity is helpful, Kent emphasizes, and even for people who have never been active, when they become so, “it can be profoundly changing to the way they think about themselves. There are opportunities through life where we are open to making changes—so, how do we invoke behavioral change?”
Kent’s highly interdisciplinary research is based at the Muscle Physiology Lab in Totman, and at several Core Facilities in the Institute for Applied Life Sciences (IALS): the Center for Personalized Health Monitoring, Human Magnetic Resonance Center, and the Center for Human Health and Performance. “Kinesiology is very interdisciplinary to begin with,” Kent points out, and it has to be, in order for researchers to be able to look at how a whole organism functions. Since IALS was established in 2014, she says, she and her collaborators have been able to use its state-of-the-art equipment to approach their studies from multiple angles: “It’s been a game changer.”
Kent is also leading a two-year grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, which funds what she terms the “adipose project,” focusing on how fat could interfere with muscle strength and function. Sedentary older adults have more fat within their muscles, she explains: “It just gets deposited over time.” As we age, fat accumulates in muscle cells and between the fibers of muscle and muscle groups. “So if you have this beautifully designed tissue made up of many different cell types, and then you insert droplets of fat into it,” Kent asks, “how does that affect the force the muscle needs to produce in order to move your limbs?” The research team is employing novel in vivo imaging techniques available through the IALS facilities to tie what’s happening in individual cells, to what is happening in groups of cells, to what is going on in the entire neuromuscular system.
Kent suggests that her work has highlighted the importance of looking at the entire organism: “Since everything relates, to move away from being so reductionist—to really look at how the multi-system of how an organism moves can impact everything.” What has made her career successful, she reflects, is her persistence and enthusiasm “to integrate how different systems work together, while still being able to drill down and look at individual mechanisms.”
Kent’s pathway into her field began as an athlete seeking to be successful in competition. On her quest, she became fascinated by the biochemical aspects of exercise physiology. “At some point I had to make a choice between science and competing at an international level,” Kent relates. “So instead of pursuing gold medals I became interested in pursuing quality of life and understanding chronic disease.” She discovered the work of Britton Chance, the first researcher to apply magnetic resonance spectroscopy (MRS)—which is akin to magnetic resonance imaging (MRI) but studies the chemical composition of tissue—to humans. “That had a huge impact on the direction of my career. Magnetic resonance spectroscopy is real-time biochemistry.”
Between 2015 and 2016, Kent was instrumental in bringing a huge magnetic resonance instrument to IALS. When the call went out from the Massachusetts Life Sciences Consortium, Kent says, “Everybody worked on getting it. That was pretty cool. Our faculty was able to have a facility built to their needs. We’ve become a regional destination for integrative and in vivo research in many disciplines.”
Kent plans in the next few years to continue to work on her collaborative studies and potentially expand them to encompass middle age. “What we do in our middle age may set us up for a healthy older age,” she says. She intends her research into body systems to help “provide a better idea of what is inevitable and what is modifiable.”
Laura Marjorie Miller