Your Body Has an Internal Clock That Dictates When You Eat, Sleep and Might Have a Heart Attack

Have you ever suffered from jet lag or struggled after turning the clock forward or back an hour for daylight saving time? These are examples of you feeling the effects of what researchers call your biological clock, or circadian rhythm – the “master pacemaker” that synchronizes how your body responds to the passing of one day to the next.

This “clock” is made up of about 20,000 neurons in the hypothalamus. This area near the center of the brain coordinates your body’s unconscious functions, such as breathing and blood pressure. Humans aren’t the only lifeforms that have an internal clock system: All vertebrates – or mammals, birds, reptiles, amphibians, and fish – have biological clocks, as do plants, fungi, and bacteria. Biological clocks are why cats are most active at dawn and dusk, and why flowers bloom at certain times of the day.

Circadian rhythms are also crucial to your health and well-being. They govern your body’s physical, mental, and behavioral changes over each 24-hour cycle in response to environmental cues such as light and food. They’re why more heart attacks and strokes occur early in the morning. They’re also why mice that are missing their biological clocks age faster and have shorter lifespans, and people with a mutation in their circadian clock genes have abnormal sleep patterns. Chronic misalignment of your circadian rhythm with external cues, as seen in night-shift workers, can lead to a wide range of physical and mental disorders, including obesity, Type 2 diabetes, cancer, and cardiovascular diseases.

In short, there is ample evidence that your biological clock is crucial to your health. And chronobiologists like me are studying how the day-night cycle affects your body to better understand how you can modify your behaviors to use your internal clock to your advantage.

[embedded content]
Your body has an internal clock that helps keep it in working order.

How biological rhythms affect your health

Your biological clock affects your health by regulating your sleep-wake cycles and fluctuations in blood pressure and body temperature. It does this primarily by syncing your endocrine system to environmental light-dark cycles so that certain hormones are released in certain amounts at certain times of day.

The pineal gland in your brain, for example, produces melatonin, a hormone that helps regulate sleep in response to darkness. Doctors advise reducing exposure to artificial blue light from electronic devices before bedtime because it can disrupt melatonin secretion and sleep quality.

Your circadian rhythm also affects your metabolism. Among other things, sleep helps you regulate leptin, a hormone that controls appetite. Your leptin levels fluctuate throughout the day according to a rhythm set by your circadian clock. Insufficient or irregular sleep can disrupt leptin production, which can make us hungrier and lead to weight gain.

Source: SciTechDaily