Sleep and the immune system are intrinsically linked. Sleep problems may arise because of medical or behavioral reasons, but modern life frequently dictates a work schedule late into the evening, disrupting our natural sleep/wake cycles. Dr. Seheult describes the importance of sleep early in the night when the majority of restorative slow-wave sleep occurs. A primary means of achieving high-quality sleep begins early in the evening, by reducing light exposure (especially blue light from screens) and decreasing stimuli that might keep us awake (like television). In this clip, Dr. Roger Seheult explains the different parts of sleep and the value of each phase.
Dr. Patrick: what have you found some of the most robust practices for improving sleep? Like even the lowest hanging fruit too. So things that are the lowest hanging fruit and things that are more robust.
Dr. Seheult: so the most important time of sleep is the sleep that you get at the beginning of the night. There's really two types of sleep that are the best at making you feel healthy. And they are slow-wave sleep, which is right at the beginning of the night. In fact, this is the type of sleep that is associated with growth hormone secretion, especially in children. If there was ever the fountain of youth, this would be it. Growth hormone makes you feel younger, makes you look younger. In fact, we were giving growth hormone injections many years ago until we realized that it can cause problems because of where they were getting it from. But that's another story. But growth hormone and slow-wave sleep at the beginning of the night is very, very important. Yeah, REM sleep is toward the end of the night. That's when you dream, and that's also a good part of sleep as well, but nothing beats slow-wave sleep with these large delta waves if you were to look at this on a polysomnography. So the most important time to sleep is really that time before midnight. And there's a lot of research in the last four or five years that has been going into this holy grail of slow-wave sleep and what happens at the beginning of the night.
So with that being said, think about what's going on in the United States right now. Okay? And over the last 50 years. We've essentially turned night into day, right? If you've ever seen those satellite pictures of what the United States looks like at night, it's lit up on both coasts. And if you look at our area here in Southern California, it's very bright. It's probably one of the brightest in the nation, probably only second to New York, and the DC, New York, you know, area. But here's what's happening, people are coming home later, they're, you know, eating later, staying up later, they've got a lot of work to do. And they're putting their faces in front of screens, which is emitting light.
Now, what does that light do at that hour, what that light does at that hour in just about everybody is it shifts the circadian rhythm and delays it. So whereas you would feel sleepy normally at let's say, 9 or 10 at night, you're now going to start to feel sleepy at 11 or 12 at night. And so you don't go to bed until later. So you would normally be waking up 7, 8, 9 hours later because that's how much sleep you're really supposed to get. But unfortunately, that goes into 8,9 in the morning, and you're supposed to be already at work at your desk, or you know, now with COVID, you're at home working somewhere. Or because of the fact that there's so much density, you've got to get up at 4 in the morning, 5 in the morning to get in your car to do your two-hour commutes to beat the traffic to get at your desk.
And so what we've done, essentially, over the last 50 years, is we have sandwiched the amount of available hours that we have for sleep. And what's been cut off is that first part of the night before 12 where the best, most restful part of the night is going to happen. You know, it's been said many times, and from people hundreds of years ago, I don't know how they knew this, but over 100 years ago, they said that that two hours of sleep before midnight is worth more than four hours of sleep after midnight. And the science is actually showing that to be true. It's amazing.
An essential mineral present in many foods. Iron participates in many physiological functions and is a critical component of hemoglobin. Iron deficiency can cause anemia, fatigue, shortness of breath, and heart arrhythmias.
A chemical that causes Parkinson's disease-like symptoms. MPTP undergoes enzymatic modification in the brain to form MPP+, a neurotoxic compound that interrupts the electron transport system of dopaminergic neurons. MPTP is chemically related to rotenone and paraquat, pesticides that can produce parkinsonian features in animals.
The highest level of intake of a given nutrient likely to pose no adverse health effects for nearly all healthy people. As intake increases above the upper intake level, the risk of adverse effects increases.
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