As you age, these rhythms can slowly slip out of sync, leading to a wide range of health problems that can harm your well-being and shorten your life.
Now, researchers are pointing to effective ways to keep these rhythms on track or at least slow down their loss of function.
Most exciting, if you preserve those rhythms successfully you may increase your life expectancy and stay healthier as you age. Let’s see what researchers are reporting from the latest studies.
One of the most important parts of the body responsible for maintaining your circadian rhythm is in your brain. This brain component is the suprachiasmatic nucleus (SCN). The SCN has been called the “circadian pacemaker” and it’s located in the hypothalamus near the center of the brain.
Your Eyes are Critical to Circadian Rhythm
As light enters your eyes, special types of neurons called intrinsically photosensitive retinal ganglion cells send nerve information about the light to the SCN. The nerve impulses that respond to the daily cycle of daylight followed by darkness at night help the SCN keep our circadian rhythms synchronized with the world around us.However, as you get older, the lens in your eye thickens and starts to yellow with age. This cuts down the amount of light that can get into the eyes and stimulate the SCN by about one percent a year after your teenage years.
If you suffer from cataracts, this condition also restricts the amount of light getting into the eye. At the same time, researchers have found, with the passing years cells in the SCN reduce their production of certain proteins that are linked to our circadian rhythms.
The end result is that the daily activity of your organs including the liver, kidney, thyroid and spleen can be disrupted. And, because of these types of disruptions, you become more susceptible to high blood sugar, diabetes1 and even cancer.2 Another result of this type of change in circadian rhythms is that the body secretes less melatonin, a hormone produced by the brain’s pineal gland. This gland – which a famous philosopher once thought was the seat of the soul – fights cancer and helps you fall asleep each evening.
The reduction in melatonin may also increase your blood pressure. In a study of older people who were in their 60s and up, researchers found that giving them melatonin (a dose of 1.5mg) each night at 10:30 p.m. helped lower their blood pressure. Now, I want to add that dosing with melatonin is tricky, and that is a high dose. Most supplements contain way too much.
In addition, researchers reported that melatonin supplements helped keep daily rhythms involving shifts in blood pressure, heart rate and body temperature smoother and less irregular.3
Circadian Rhythm and Cancer
Other studies show that your risk for tumors increases when your circadian rhythm is thrown off. A study at the University of Pennsylvania School of Medicine found that when your daily schedule is not closely attuned to being awake and eating and exercising during daylight hours, and then sleeping at night the way nature intended, your out-of-sync habits can produce epigenetic effects that make cancer more likely.This type of circadian malfunction slows the function of genes that suppress tumor growth and encourages the actions of genes that stimulate tumors. And if you do get treated for cancer, it can make cancer drugs less likely to be effective.4 In fact, knowledgeable cancer doctors take the circadian rhythm into account when administering chemotherapy.
"Our findings strongly indicate that environmental or physiological disturbances of circadian rhythms such as shift work, abnormal sleep timing, or irregular psycho-sociological stresses can affect variability in both cancer growth and response to cancer drugs," says researcher Yool Lee. "Given this, it is reasonable to expect that resetting of the body clock by scheduled light-exposure, meal-times, or exercise, alongside a carefully timed chemotherapy regimen, would improve anti-tumor treatment.”
How to Improve Your Circadian Rhythms
If you want to help strengthen your circadian rhythms and improve your chances of living longer and healthier you should:* Try to eat your meals and snacks during the day at around the same time each day. Avoid late night snacking which has been linked to cancer.5 * Go outside and get some sunlight around lunchtime. That sun exposure can help the SCN synchronize your circadian rhythms.6 * Get some exercise during the day. Research shows that exercise affects the circadian rhythms of hormone release, sleep, blood pressure shifts and heart rate changes in ways that can improve the health of your cardiovascular system.7 * Try taking a small dose of melatonin in the evening – such as 1.5mg – to help you sleep. It can also help your body maintain its circadian rhythms.
* Avoid your smartphone and computer at night. The blue light emitted by these devices can disrupt circadian rhythms and limit your body’s production of melatonin.8 The research on aging I’ve seen all seems to agree: Keeping your body in rhythm is crucial to remaining healthy as you age. So do everything you can to maintain those daily cycles.
- https://www.ncbi.nlm.nih.gov/pubmed/20562852
- https://www.ncbi.nlm.nih.gov/pubmed/27476975
- https://www.ncbi.nlm.nih.gov/pubmed/26632428
- https://www.ncbi.nlm.nih.gov/pubmed/31039152
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6220994/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751071/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6083774/
- https://www.ncbi.nlm.nih.gov/pubmed/30311830
