Chapter 73
Melatonin and Longevity
Sleeping pills are not a good choice. So-called hypnotics include zolpidem (Ambien), which is prescribed most often in the United States. People who take just a half dose or more for a year have a more than three times higher risk of dying prematurely than those who do not take sleep medications. Up to 10 percent of adults are prescribed such drugs, so if they actually kill people, that means they are responsible for a six-figure number of deaths each year. No wonder the manufacturer of Ambien challenged this study, but it was not the only one. It was one of two dozen studies that found a significant association between sleeping pills and premature death. In response to criticism of “reports of an alarmingly high risk of death from commonly used medications,” the lead researcher at the Scripps Clinic Sleep Center replied: “We cannot conceal risks, even if it makes patients afraid and they no longer want to take sleeping pills. Patients have a right to information.”
In addition, we have a right to learn that these agents may not even work. The meta-analysis with the strongest evidentiary value concluded that zolpidem/Ambien and similar drugs do not significantly increase total sleep time. How is that possible? My patients always told me how much better they slept with them. As it turned out, people only think they sleep better. Although they reported that the drugs gave them an extra half hour of sleep, objective data showed that they did not actually sleep meaningfully longer. The subjective impression of sleeping better after popping a pill seems to be a result of the drug’s amnestic effect, meaning it erases the memory of how poorly one really slept. The American Academy of Sleep Medicine advises against using these medications as a first-line treatment for chronic insomnia.
Steep Your Toes in the Water
Eating late at night not only promotes weight gain, as I show in How Not to Diet, but also impairs falling asleep. Normally, core body temperature falls when it is bedtime, and that seems to be the cue to go to bed, but if you’re still munching late, it can interfere. If that’s the case, isn’t a hot shower counterproductive too? No. Once you get out of the bath, the rapid drop in skin temperature can promote the natural evening temperature decline and may even improve sleep. Even a warm footbath can make you fall asleep a quarter of an hour earlier.
Footbaths have been described as an “harmless, simple, and nonpharmacological method to improve sleep quality.” A meta-analysis of trials found that ten minutes under a warm shower, in a footbath, or in a bathtub one or two hours before bedtime may help you fall asleep faster and sleep better.
Special blood vessels that connect arteries and veins in the palms of the hands and the soles of the feet dilate with warm water, and this promotes the transfer of heat from the body’s core to the hands and feet, where it can be dissipated more efficiently to achieve the sleep-promoting drop in core temperature. In older adults, this temperature response is weaker—perhaps explaining age-related sleep difficulties—and that is why it is even more important to influence circulation in the hands and feet.
Can you manage that somehow without getting wet? Maybe with a hot-water bottle at your feet. What about warm socks? Young men who put on socks an hour before bedtime for a study did not feel they slept better. Objectively, however, they slept a half hour longer than without socks, because they fell asleep faster and woke up less often during the night.
Melatonin and Longevity
Some experts recommend the hormone melatonin, a secretion of the pineal gland, our “third eye” in the middle of the forehead, as the first choice for treating insomnia in older adults. The World Sleep Society does not agree, however, because the effect is so slight. People believe they sleep better with melatonin, but a meta-analysis of multiple studies had the objective result that melatonin only helped them fall asleep four minutes earlier, and total sleep duration was extended by about 13 minutes. In addition, concerning contamination has been found (see.nf/melatoninsupplements), but at least there are also natural dietary sources of melatonin (see.nf/melatoninfoods). I was interested in the purported anti-aging effects of melatonin, but as I show in the video see.nf/melatoninaging, the data are confusing. In rats, for example, melatonin significantly promoted survival, but a drug that blocks melatonin had the same effect!
Herbal Sleep Aids?
Valerian root is among the most studied plants in connection with sleep. However, most studies, including the newest and methodologically cleanest, found that valerian does not work significantly better than a placebo. Randomized controlled trials showed that lemon verbena could help insomnia patients at least subjectively, but chamomile could not. A meta-analysis of five studies suggests that chamomile improves subjective sleep quality in people without difficulty falling asleep.
Fish and Sleep Don’t Go Together
Among foods, low amounts of fiber, highly saturated fats, and sugar are associated with lighter, less restorative sleep. Meat consumption leads to short naps, and that could be a sign of sleepiness. Perhaps this explains why insomnia occurs as a side effect of a low-carbohydrate ketogenic diet. Even after controlling for obesity, meat consumption still doubled the likelihood that participants snored, and each daily serving of meat was associated in older adults with a 60 percent higher likelihood of reduced sleep quality and duration. This applied to red meat and to poultry, and fish yielded no objectively better sleep outcomes than chicken, pork, and beef.
Researchers cautioned that perhaps amino acids such as methionine in meat compete with tryptophan during transport to the brain, tryptophan being the precursor of melatonin and the “happiness hormone” serotonin. That could explain why people were in a better mood after eating less fish, poultry, and red meat for two weeks. Plant proteins, by contrast, contain a relatively low proportion of methionine, which is why a study of thousands of people in the plant-based Adventist CHIP program found, after four weeks, a more than 50-percent decrease in insomnia and restless sleep—not to mention fewer emotional upsets, anxiety, or depression.
Salad on the Table in the Evening!
Can a vegetable help here? Lactuca sativa is a plant often used to treat insomnia. What is this exotic-sounding vegetable? Head lettuce! Lettuce extracts were reportedly used as far back as ancient Rome for sedation and intentional sleep induction. Head lettuce contains a hypnotic called lactucin that makes lettuce slightly bitter. In mice and rats, romaine lettuce promoted sleep, and it also contains more lactucin than other varieties, but what about in humans? In see.nf/lettuce I go through all the studies. Bottom line: In a double-blind study, a quarter teaspoon of ground lettuce seeds produced better sleep, whereas placebo did not.
Stress Management
According to the head of the largest and most comprehensive study of centenarians worldwide, average life expectancy should reach well into the 80s if you do no harm to your health at all—meaning you don’t smoke, don’t drink alcohol, exercise regularly, eat a vegetarian diet, and keep your stress under control. “The reasons why someone makes it past 60 or 70, but not to nearly 90,” he and a colleague wrote, “can be explained mainly by health-related decisions.” I have already covered diet and exercise here. How important is stress management?
The American Psychological Association conducted surveys across the United States in which most respondents reported being moderately to highly stressed. Although the prevalence of anxiety disorders has not changed significantly over the past few decades, general stress appears to be worsening. What does that mean for life expectancy?