I’ve always wondered how much of an impact my diet really has on my sleep. Sure, I know from experience that caffeine late in the day gives me insomnia at night. I avoid alcohol within a few hours of going to bed—otherwise, I wake up at 3 in the morning.
As for foods supposed to help with sleep, I’m not so convinced. Evidence for the sleep benefits of kiwi fruit, gelatin, and turkey—to name a few I’ve read about on the web—is slim, and the studies they’re based on are small. It’s a stretch to believe that eating more of these foods would actually improve my sleep.
But I’m intrigued by findings published recently from researchers at the University of Pennsylvania. Those of us plagued by short sleep, and who have trouble falling or staying asleep, consume less of certain nutrients than do good sleepers, their data (based on two huge studies) show. For us, foods high in these nutrients may be golden.
Dietary Nutrients and Sleep Length
Investigators looked at links between dietary nutrients and sleep length. Among the discoveries they made was that compared with normal sleepers, short sleepers—people who reported sleeping 5-6 hours a night—consumed less of three nutrients: vitamin C, lutein and zeaxanthin, and selenium. We’ll consider them one by one:
- Vitamin C: Antioxidant found abundantly in citrus fruits and vegetables such as broccoli, kale, and sweet peppers. It cuts down on your risk of heart disease, cancer, and other diseases associated with the immune system.
- Lutein and Zeaxanthin: Two antioxidants often found together in brightly colored vegetables—kale, spinach, broccoli, corn, and orange peppers–and fruits such as tangerines, oranges, and papaya. They’re protective of eye health and decrease your risk of macular degeneration.
- Selenium: Antioxidant found in fish and seafood, meat, Brazil nuts, and sunflower seeds. It lowers your risk of heart disease and some cancers and has a key role in regulating inflammation and immunity.
Would eating more of these foods actually improve our sleep? The U-Penn study did not explore cause and effect so it doesn’t go as far as answering this question. But here’s why the information about dietary nutrients is important to us: as short sleepers, we’re more vulnerable than normal sleepers to a host of life-threatening illnesses, including hypertension, heart disease, type II diabetes, and, it now looks likely, cancer. If upping our intake of broccoli, kale, nuts, and citrus fruits might protect us from these diseases, what is there to lose by doing it? (And it’s possible that eating more of these foods could reduce our susceptibility to insomnia.)
Sleep Length, Food Variety and Water
Two other significant findings are these:
- People who slept 7-8 hours a night had a more varied diet than people who slept less.
- Short sleepers (5-6) drank less tap water than others.
Eating a more a varied diet and drinking more water just might improve our sleep and our long-term health. But take care to steer clear of water and other fluids after dinner to avoid having to get up to go to the bathroom at night.
A second study from this same group shows that people who have trouble falling asleep tend to consume less of certain nutrients while people who have trouble staying asleep tend to consume less of others. Look out for the findings later this month.
What foods seem to improve your sleep?