Circadian rhythms, which cycle every 24 hours, drive virtually every system in the human body, from circulation and cognition to metabolism, memory and mood. They also play a big role in determining when we are most vulnerable to health problems.
Chronobiology is the study of these internal clock mechanisms. This research has exploded in recent years due to the discovery of specific genes which scientists have named Cryptochrome, Clock, and Period. These specific genes help keep our biological systems in sync with light and darkness creating a surge of biochemical changes at dawn and at dusk.
The body’s master timekeeper is a group of neurons in the hypothalamus, located behind the eyes, called the suprachiasmatic nucleus, or SCN. In darkness, the SCN prompts the pineal gland to release melatonin, the hormone that facilitates sleep. Other chemical changes reduce body temperature, blood pressure and heart rate, all of which are at their lowest overnight.
While at rest, other bodily systems are highly active at night. Stomach acids, the liver and hormone leptin are at their peak and the immune system may also be over- active at night, inflaming airways in asthma sufferers and swelling of arthritic joints. Hormones are being made and balanced at night. Muscle fibers are repaired and built at night and fat metabolism is occurring as well.
In the morning when light on the retinas signals the SCN to shut off melatonin, cortisol, the stress hormone, starts to rise preparing the body for the day. Blood pressure and heart rate increases and a substance called PAI-1, which clots the blood, peaks at 6:30 a.m. Researchers are starting to develop treatment strategies to take advantage of circadian rhythms or restore them when they are out of sync- a field called chronotherapy.
Take advantage of the body’s rhythms and cycles and take medications at these times.
• Cortisol, stress hormone release increases. Heart rate and blood pressure start to climb.
• Heart attacks and strokes are most frequent and severe between 6 a.m. and noon due to changes in proteins that make blood platelets more likely to clot.
• Arthritic joints are stiffest and most painful from 8 a.m. to 11 a.m. due to an overnight rise in pro-inflammatory factors.
- Take thyroid medication, as most doctors recommend taking these in the morning. Remember to wait at least 1 hour before ingesting anything else!
- Take diuretics in the morning to avoid nighttime urination that interrupts sleep.
- Take osteoporosis drugs on an empty stomach to maximize their absorption in the morning right after waking.
- Take osteoarthritis drugs four hours before flare-ups are expected as they usually occur early or mid-morning.
• Skin allergies and hives worsen as natural itch-fighting chemicals decline.
• Fevers tend to be more frequent at this time of day because body temperature reaches its highest point.
• Epileptic seizures in the temporal lobe are most common between 3 p.m. to 7 p.m.
• Alzheimer’s patients experience worsening agitation and confusion at this time of day.
- Take vitamins with lunch. Nutrient absorption requires live enzymes and a balanced meal to slow digestion. Most people do not eat enough at breakfast to provide enough bulk and live enzymes for optimal nutrient absorption, so take your vitamins after lunch.
• Asthma attacks are more frequent and severe at this time of day as airways become more inflamed and irritated.
• Blood pressure is at its highest at around 9 p.m.
• Hunger peaks around 8 p.m. as the body prepares to fast overnight.
• Heartburn is more common as the stomach produces more acid at this time.
- Take acid-blockers at dinnertime, since stomach acid peaks at night.
- Take Beta-blockers and ACE inhibitors at night to ward off blood clots that contribute to early-morning heart attacks
- Take daily aspirin for heart risk to minimize early morning clot formation related to strokes.
- Take statins at bedtime to lower bad cholesterol in the early morning.
- Take non-steroidal anti-inflammatory drugs (NSAIDs) after dinner to control overnight inflammation due to arthritis and minimize stomach issues.
- Take corticosteroids for chronic asthma at bedtime to minimize overnight asthma attacks.
• Blood pressure, core body temperature and heart rate are at their lowest.
• Melatonin, the hormone that facilitates sleep, is high.
• Liver releases large amounts of glucose, and raises blood sugar levels from 4 a.m. to 6 a.m.
In general, experts say going to bed, getting up and eating meals at the same time every day, getting lots of light in the morning and avoiding light at night can go along way to improve your health and mood. Its advice you’ve heard from your parents as a child, but now, there is a lot more information and research as to why it is true. Do it because it’s good for you, not just because they told you so.