Why Your Body Clock Matters Far More Than You Think

Your body’s circadian rhythm does much more than tell you when to sleep. This internal 24-hour clock plays a crucial role in your heart and metabolic health. According to a recent scientific statement from the American Heart Association (AHA), disruptions to this rhythm — like working night shifts, eating meals late or at odd times, or even exercising in the evening — could significantly increase your risk of serious health conditions.

“For many years, we’ve known there is a link between sleep quality and cardiovascular health,” says Harneet Walia, M.D., medical director of sleep medicine at Baptist Health Miami Cardiac & Vascular Institute. “Now there is a growing body of evidence that shows that disruptions in circadian rhythm play a role in the development of obesity, type 2 diabetes and high blood pressure, as well as cardiovascular disease.”

Understanding Circadian Rhythm

Your natural body clock orchestrates when biological processes happen, regulating hormone release, digestion, body temperature, blood pressure and metabolism throughout the day and night.

The precise timing isn’t just convenient, it’s essential for your health. When biological processes happen at the right time, they work efficiently. But when they’re thrown off schedule, problems can emerge. That’s why even your chronotype — whether you are naturally a morning person or a night owl — is important, particularly if your work and daily schedule doesn’t align with your internal clock preferences.

The “Role of Circadian Health in Cardiometabolic Health and Disease Risk: A Scientific Statement from the American Heart Association” indicates that when you do things (sleep, eat, exercise) may be just as critical as what you do for your heart health.

“It’s shifting the conversation from eating healthy, getting a good night’s sleep and exercising to also ensuring that you maintain consistent daily routines for optimal health,” Dr. Walia says.

Key Takeaways

The AHA scientific statement, authored by experts in cardiovascular research, sleep medicine, public health, nutrition science and environmental health, details factors that can affect or disrupt your circadian rhythm. Among them:

• Inconsistent sleep or an irregular sleep schedule. Poor sleep can increase C-reactive protein, a marker of inflammation, as well as cortisol, a stress hormone. Both are contributors to atherosclerosis, a leading cause of cardiovascular disease.
• Eating late at night, which can affect metabolic health beyond calorie content, potentially causing weight gain and blood sugar spikes. “Studies in rodent models show that feeding during the inactive period leads to greater weight gain despite similar food intake as mice fed during their active period,” according to the statement.
• Exercising in the evening rather than in the morning or afternoon. “Timed physical activity is a nonpharmacologic strategy that can improve circadian health by optimizing sleep quality, enhancing daytime alertness, and supporting cardiometabolic outcomes,” the AHA statement reads.
• Using artificial nighttime light, particularly from screens. “Several studies have examined the effects of light interventions on cardiometabolic outcomes and found that morning light exposure is associated with lower body fat, body mass, and appetite,” the paper says.

Strategies to Protect Your Body Clock

Dr. Walia agrees with the AHA statement authors that more research is necessary to establish personalized recommendations. But she adds that the evidence is clear: Your body clock matters for heart health and through consistent sleep schedules, appropriate light exposure, well-timed meals and regular exercise patterns, you can take meaningful steps to reduce your risk of serious health conditions.

As part of its comprehensive cardiac program, Baptist Health Heart & Vascular Care includes a multidisciplinary sleep program.

One way to understand your personal risk of developing heart disease is to get a heart scan. In just 30 minutes, a non-invasive CT scan can uncover risks you didn’t even know existed. Talk to your doctor and see if a heart scan is right for you. Visit BaptistHealth.net/HeartScan or call 833-596-2473 to find out more.