Dear Doctor: I know you recently talked about sleep problems, but I'm having trouble and hope another question is OK. I read that some foods make it harder to for you to sleep well. What are they? If you cut them out of your diet, will you start sleeping better?
Dear Reader: Getting a good night's sleep has always been a popular topic of discussion in this column. And with the stresses and uncertainty of the last 18 months, the volume of questions about sleep has increased.
People for whom nighttime is a battle are likely familiar with the standard advice about good sleep hygiene. This includes a cool and quiet bedroom, a regular bedtime that you actually stick to for more than just a couple of days, daily physical exertion, and avoiding screens and other bright lights for at least two hours before retiring.
Now, thanks to some recent research, the food-sleep connection is emerging into the mainstream, as well. The idea that food can affect sleep has deep roots. The practice of sipping a cup of warm milk to encourage drowsiness dates back centuries. And most of us know that a rousing jolt of caffeine, while welcome in the morning, negatively affects sleep when indulged in too late in the day.
Over the last decade or so, a number of studies have focused on the food-sleep connection, with interesting results. Although their methodologies differed, the researchers came to similar conclusions. They found that when the study participants ate a diet that favored fresh and fiber-rich fruit, vegetables and leafy greens, as well as unsaturated fats, they reported an improvement in their overall sleep. This included falling asleep, staying asleep and quality of sleep. A diet high in sugar, salt, ultra-processed foods and saturated fats, on the other hand, was associated with both lower sleep quality and an increase in sleep disruption.
Dietary choices also turned out to have an effect on daytime alertness, with the less healthful diet taking a negative toll. The Mediterranean diet, with its focus on fresh fruits and vegetables, healthful oils, beans and legumes, seafood and lean proteins, was seen to be especially beneficial to the sleep patterns of middle-aged and older adults. A study that focused on fatty fish, which is a good source of vitamin D and omega-3 fatty acids, found that it appeared to help with sleep efficiency. Interestingly, carbohydrate consumption that was too low also appeared to negatively affect sleep. And while some of this is related to blood sugar control, researchers now believe the more healthful way of eating, which has a positive effect on metabolism, also plays a role in resetting our body's circadian clock.
Unlike the one-and-done nature of sleep medications, we approach good sleep hygiene on multiple fronts. It takes discipline to stick to a regular bedtime, to put away our phones and screens, and to say no to a sugary late-night snack. But it's over time and with consistent effort that we get our best shot at something many of us crave, which is a restful and refreshing night's sleep.