Dietary Choices and Their Effects on Sleep
Wouldn't it be wonderful if we could find that one thing that, if we added it to our diets, our sleep problems would suddenly vanish?
Unfortunately, that one magic addition hasn't been discovered; however, we are learning more and more about the quality of our diets and the relationships of those diets to our sleep quality.
We all know that life can get in the way of making good food choices, and these choices can indeed have an impact on our sleep. Some of these choices are obvious, but some might be a little less well known.
Hidden sources of caffeine
Many people know that if you're not sleeping well, you should consider cutting out caffeine in the afternoon because of its stimulant properties.
The concentration of caffeine peaks in your bloodstream about 2 hours after you ingest it - and only a half-hour later will half of it be metabolised and out of your system.1
I often suggest that people avoid all caffeine after lunchtime (both coffee and other forms) to be sure it isn't affecting sleep quality or quantity. Typically we think of coffee, but teas, soft drinks, and some prescription medications, supplements, and headache medicines also contain caffeine.2
Not all carbs are created equal
Some of the lesser-known dietary choices we make appear to have a significant impact on our sleep. A broad, moderate intake and varied diet appears to be ideal for sleep. In older women, studies show reduced symptoms of insomnia in those who eat a Mediterranean style diet.3
Higher carb diets are linked with poorer sleep quality, and there is strong evidence that this is down to the carbohydrate quality.4 Large amounts of low-quality carbohydrate (sweets, cakes, noodles) are linked to lower quality sleep. Higher levels of good carbohydrate foods (vegetables, grains, and fruit) are associated with improved sleep quality.
In general, lower carbohydrate or carbohydrate-restricted diet types as associated with waking in the night.4 This is likely because of insufficient energy stores running out before waking for breakfast. The overall message here is moderation, and macronutrient variety is essential for optimising sleep.
Will a bedtime snack keep me up?
Fascinatingly, there's some research that supports the use of certain snacks by some people before going to bed. In those who are not pre-bedtime snackers, starting to snack on anything of any quality is associated with less adequate sleep.
However, in those who are used to snacking before bed, snack quality is strongly associated with how well they sleep. It is tempting to think that you could compensate for a lower quality diet by having a higher quality bedtime snack, but unfortunately, the evidence says that it will not.4
Can tart cherries help my insomnia?
There has been some interesting study on tart cherries. Tart cherry juice was associated with a consistent and significant reduction in insomnia severity scores when compared to placebo (juice that people think is tart cherry but is not). It was explicitly associated with decreases in night wakening and increases in overall sleep, but not in people's sleep latency (speed of falling asleep).5
And though this sounds like good news, the 'effect size' of this study (how strong the effect was) was significantly less than that of cognitive behavioural therapy for insomnia and pharmaceuticals, and there is not enough evidence to know if it is safe long term or what it's medication interactions might be when taken consistently. Always be sure to check with your healthcare provider before taking anything as a remedy or supplement.5
The relationship between diet and sleep
The diet and sleep relationship isn't clear, and there is a lack of certainty about whether sleep has a more substantial influence on diet choices or if the reverse is the case. However, what seems consistent across health literature is that moderation, variety, and quality of food choices seem the soundest choice to make. Always consult your doctor or dietician before making changes to your diet.
Do you think there is anything in your diet that might affect your sleep one way or the other?
Will you take our Sleep Disorders Survey to raise awareness for insomnia?