Can Foods Improve Sleep Quality?

With sleeping pills getting bad press these days, the race is on to find more nonpharmacologic, alternative treatments for insomnia. One area of interest is diet and nutrition. Are there foods that could help us sleep?

The evidence for a relationship between food and sleep is mixed, say authors that reviewed 21 studies on the topic. But a new randomized controlled study of the effects of diet on sleep suggests that foods high in fiber, saturated fat, and sugar may significantly affect the quality of our sleep.

Sleep quality is affected by dietary fiber, saturated fat, and sugarWith sleeping pills getting bad press these days, the race is on to find more nonpharmacologic, alternative treatments for insomnia. One area of interest is diet and nutrition. Are there foods that could help us sleep?

The evidence for a relationship between food and sleep is mixed, say authors that reviewed 21 studies on the topic. But a new randomized controlled study of the effects of diet on sleep suggests that foods high in fiber, saturated fat, and sugar may significantly affect the quality of our sleep.

Measuring Sleep Depth and Duration

Twenty-six people (none with insomnia) participated in the study. All were normal sleepers, averaging 7 to 9 hours of a night.

The study was conducted in two 6-day periods. During one of these periods, the participants were allowed to sleep up to 9 hours a night every night. During the other 6-day period, their sleep was restricted to 4 hours a night for the first 4 nights, followed by a night of unrestricted sleep.

Participants underwent polysomnography—the test recording brain waves and the depth and nature of sleep—every night. Investigators kept track of variables such as total sleep time, sleep onset latency, number of arousals, and deep sleep.

A Controlled Diet

On the first 4 days of each 6-day period, participants were given enough food to meet their need for calories, but the type of food was controlled. On days of the controlled diet, participants were given food in which

  • 31% of the energy came from fat ( 7.5% from saturated fat),
  • 53% of the energy came from carbohydrates, and
  • 17% of the energy came from protein.

On days 5 and 6, study participants could eat the foods they wanted as long as the nutrient content could be readily determined.

Participants underwent other testing as well, including a glucose tolerance test and a blood test.

Fiber, Saturated Fat, and Sugar Alter Sleep Quality

Study results showed that participants consumed significantly more calories on the day after 4 nights of restricted sleep (a day when they could eat as much as they wanted) than during the period when they were allowed to sleep as much as they normally slept. This confirms the results of other research showing that people who don’t get enough sleep tend to eat more and gain weight.

But after statistical analysis, investigators identified a few dietary variables that were associated with changes in sleep quality:

  • Eating more foods high in fiber was associated with less stage 1 sleep (the lightest stage) and more slow wave sleep (or deep sleep). Foods high in fiber include fruit with skin; whole grains; legumes, nuts, and seeds; and vegetables such as artichokes, peas, and broccoli.
  • Eating more foods high in saturated fat predicted less deep sleep. Foods high in saturated fat include meat, cheese, and other dairy products.
  • Eating more foods high in sugar and non-sugar/non-fiber carbohydrates was associated with more nighttime wake-ups. Foods high in sugar and starch include fruit juice, pop, white rice, pasta, potatoes.

The study has limitations, including its small size and short duration. Also, whether the results would be the same for people with insomnia is unknown.

But the implications of the study reinforce what we hear elsewhere. For health reasons, we’re told to cut down on meat, dairy, and processed foods, and increase our intake of fruit and vegetables. Now there’s another reason to do that: it may improve the quality of our sleep.

Magnesium May Ease Insomnia and Anxiety

Last week a new friend was telling me about her sons. She has quite a bit of anxiety about their situation and, since reaching menopause, she’s had trouble sleeping. She tried sleeping pills and didn’t like the way they made her feel. But magnesium supplements seem to do the trick.

So I looked for research on magnesium, anxiety and insomnia and here’s what I found.

Magnesium supplements may ease anxiety and improve sleepLast week a new friend was telling me about her sons. She has quite a bit of anxiety about their situation and, since reaching menopause, she’s had trouble sleeping. She tried sleeping pills and didn’t like the way they made her feel. But magnesium supplements seem to do the trick.

So I looked for research evaluating magnesium’s effects on anxiety and insomnia. Not much is out there, and most of what exists are investigations of magnesium in combination with other vitamins and supplements. But some readers of this blog want information about alternative treatments for insomnia, so here’s the gist of what I found.

Magnesium’s Effects on Anxiety Symptoms

Magnesium has several important molecular functions in the body. Both animal and human studies suggest that magnesium deficiency may be linked to anxiety and anxiety-related disorders. In the early 2000s, three randomized controlled trials were conducted to assess the effects of magnesium supplements on anxiety symptoms in humans:

  1. In 80 healthy male subjects, a 4-week treatment of a multivitamin containing large amounts of magnesium, zinc, and calcium significantly decreased anxiety symptoms and perceived stress compared with placebo. The effects got stronger the longer treatment progressed.
  2. In 44 women with premenstrual anxiety (but otherwise healthy), over 4 monthly cycles each, participants were alternately given 200 mg of magnesium, 50 mg of vitamin B6, both the magnesium and the B6, or a placebo pill. The combination treatment provided a small but significant reduction in premenstrual symptoms such as nervous tension, mood swings, irritability, anxiety. By itself, however, the magnesium was no more effective than placebo.
  3. The third study was conducted on 264 people with a diagnosis of generalized anxiety disorder (GAD) for 3 months. The anti-anxiety effects of a compound containing magnesium and two plant extracts was compared with placebo. Both the active treatment and the placebo greatly decreased participants’ anxiety symptoms—the supplement a little more than the placebo.

These results are certainly mixed. First, it’s hard to make claims about the anxiety-reducing effects of magnesium when it’s studied in combination with other substances. It’s also important to realize that the effects of magnesium on the subjects in these studies—healthy men, women with premenstrual anxiety, and people with a diagnosis of GAD—may not generalize to everyone with anxiety or anxiety-related trouble sleeping. So we’ll have to look to future research to confirm or disconfirm magnesium’s calming effects.

Effects of Magnesium on Insomnia

Magnesium affects systems that promote both wakefulness and sleep, so it might have a relationship to insomnia. Two randomized controlled trials suggest that it may improve the sleep and daytime functioning of older adults. (The rationale for exploring the question with older study participants is that as we age, we’re prone to experience changes in the way our bodies absorb, retain, and utilize nutrients, and changes in circadian rhythms. A magnesium deficiency would more likely show up in older adults.)

  1. The 46 participants in this 8-week study (ages 60–75) were divided into two groups: one taking 500 mg of magnesium a day and the other taking a placebo. Compared with the placebo takers, the magnesium takers experienced significant increases in total sleep time and sleep efficiency, and significant decreases in the time it took to fall asleep and insomnia severity. Moreover, their levels of melatonin (a sleep-friendly hormone) were up while their levels of cortisol (a stress hormone) were down.
  2. The 43 participants in this 8-week study (ages 74–82) were also divided into two groups, one taking a food supplement containing magnesium, melatonin, and zinc, and the other, a placebo. Again, compared with participants on the placebo, participants taking the supplement experienced significant increases in total sleep time, sleep quality, and ease of getting to sleep. Their early morning alertness and stamina was also improved.

The results of both studies suggest that magnesium may be an effective sleep aid for older adults. Whether young and middle-aged insomnia sufferers would experience the same benefits remains to be seen.

But if you’re comfortable experimenting with alternative treatments for insomnia, as long as you avoid taking too much, magnesium might be worth trying, especially if you’re older. It has none of the drawbacks associated with other sleep aids. Like other supplements, though, it may need to be taken a few weeks before producing effects.

If you prefer to wait for science to confirm supplementary magnesium’s effects on sleep, you may be waiting a long time. There’s little money to be made on vitamins, minerals, and plant-based supplements—so the research lags. That doesn’t mean magnesium or any other supplement won’t help your sleep. It just means it hasn’t been studied yet.