For the next few years, the Salk Institute and the UC San Diego School of Medicine plan to study the health of firefighters, specifically how food intake impacts their well-being.
The San Diego-based research facilities have been awarded a $1.5 million grant by the Department of Homeland Security for the study, which should take about three years to complete. The research includes an in-depth look at whether restricting food intake to a 10-hour window can improve the health of firefighters during their shift work.
Satchidananda Panda, a professor in Salk's Regulatory Biology Laboratory and co-principal investigator of the new study, said firefighters are at high risk for many chronic diseases “because of how shift work disrupts the body's natural rhythms.”
This includes a higher risk of developing cardiovascular diseases.
“We want to understand if we can counter some of the disruptions with simple changes not only to what firefighters eat but also when they eat,” Panda explained in a press release this week.
Salk’s research, so far, indicates that time-restricted eating can improve a firefighter’s health – including weight, blood glucose levels and cholesterol – amid the life-threatening work they endure daily.
According to the Salk Institute, nearly every cell in the human body has a biological clock that tells it when to be active and when to rest. These 24-hour clocks produce circadian rhythms, and the clocks run on nutrients from food.
“Increasing evidence is showing that disruptions to this natural cycle caused by the modern lifestyle, with its artificial light and round-the-clock access to food, can impact our health, resulting in everything from poor-quality sleep to obesity, heart disease, diabetes and cancer,” Salk Institute noted.
Panda’s lab studies the molecular bases of circadian timekeeping in mammals. Previously, his research found that restricting the access of lab mice to food for eight to 10 hours a day resulted in slimmer, healthier animals compared to mice that ate the same number of calories around the clock.
Preliminary studies in humans suggest similar health benefits of so-called “time-restricted eating.”
It’s not about what or how much one eats, but more about the time period when one eats, according to the Salk Institute.
Panda is collaborating on the study with Pam Taub, MD, associate professor of medicine at the UC San Diego School of Medicine. The duo will test the effectiveness of a circadian-rhythm-based diet intervention compared to standard nutritional behavioral counseling on firefighters' cardiovascular health.
"Shift workers, like firefighters, are a critical part of our community’s well-being and we need to identify strategies to improve their overall cardiovascular health,” Taub said in a press release. “We believe that a simple lifestyle intervention, such as time-restricted eating, can prevent or help reverse cardiovascular diseases, such as high blood pressure, diabetes and coronary artery disease.
The Salk Institute said the study will incorporate an app developed by Panda’s lab that tracks food intake, sleep and exercise habits.
Then, 150 local firefighters will be randomly assigned to one of two groups: the “circadian group,” whose food intake will be limited to a 10-hour period, or the “behavioral counseling group,” which will serve as the control group.
The firefighters will have their blood glucose and lipid levels measured at regular clinic visits and will wear sensors that will continuously monitor their health.
Firefighters with the San Diego Fire-Rescue Department (SDFD) will work with Salk and UC San Diego on the research.
"We are hopeful this study will give our members information they can apply to their lives, which will reduce the incidence of chronic disease that firefighters are prone to," said SDFD Chief Brian Fennessy.
The Salk Institute said the study will be closely watched by the National Fire Protection Association. Any beneficial results may be extended to other fire departments.
Nearly 20 percent of Americans are shift workers with non-traditional hours of activity and rest. Salk believes the study results could also help these workers and their families, who can also be impacted by these hectic schedules.