While there are many physiological and psychological triggers of poor sleep, we should understand that our diet can effect our sleep. What are some of the foods that improve or sabotage our slumber? Let’s take a look at a few truths and myths.
A turkey dinner makes you sleepy? MYTH
Tryptophan is an amino acid found in both animal products and some plant sources (e.g. tomatoes, sunflower seeds, soybeans). It is essential for creating chemicals in the brain known as neurotransmitters. One of these is melatonin which helps you sleep. Since turkey meat is one of the highest animal sources of tryptophan, some people believe this is why you get so sleepy after a big turkey dinner. This actually isn’t true. A typical tryptophan supplement has 1.5g to get you sleepy, whereas 500g of turkey meat only has around 410mg. That means you’d need to eat around 1.5kg of turkey to get the same effect. What’s more likely to make you sleepy is the total size of the meal, especially if there’s a large portion of carbohydrates.
Does a big carbohydrate dinner make you sleepy? TRUE – for a while…
Eating a large portion of potatoes, a supersized pasta meal, or an extra sugary dessert triggers the release of insulin as blood sugars rise. As the blood sugars are removed from circulation, which can be within 1-2 hours, you feel fatigued and tired. You might know this as the sugar or carb crash. The problem is, sometimes, the insulin works a little too well and you wake up hungry. The other effect of a big meal, is your body has to dedicate more resources to digesting the extra food. Usually, our digestion slows down during sleep, but a large meal makes our digestive system work harder for much longer. This interrupts our normal sleep processes. The large meal can also trigger gastric reflux, meaning we don’t get the quality sleep we need.
Eating more fish can improve sleep. TRUE
This is especially true for fatty fish such as salmon, sardines, mackerel and even mussels. If you’ve been reading my posts for a while, you know I LOVE including lots of seafood in my diet. One study found that those who ate salmon three times a week had improved sleep as well as better mental acuity during waking hours. It’s suggested that this is due to the omega 3 fatty acids and vitamin D in the seafood.
Popcorn and nuts are a good snack before bed. TRUE
If you’re feeling peckish in the hours after dinner and you’re still binge watching New Amsterdam on Netflix, avoid grabbing that Magnum ice cream from the freezer. You don’t want that insulin spike at that hour (see carbohydrates above). Instead, reach for some popcorn (sans butter and salt) and some nuts. Popcorn is high in fibre and has a reasonably low glycemic index (how quickly it’s turned into glucose). If you include some almonds, peanuts, brazil nuts or walnuts (unsalted of course!) you’re getting protein as well as magnesium and zinc which promote melatonin, another chemical that's helpful for sleep. If you have a magnesium deficiency caused by a poor diet, chronic stress, diabetes or digestive issues, you may benefit from a magnesium supplement.
Alcohol gives you a better sleep. MYTH
The recommended amount of alcohol is no more than 10 standard drinks per week with the daily amount being 2 standard drinks for men and 1 per day for women. If you’re like me and you enjoy a nice shiraz with dinner or during social activities, what happens if we indulge in one or two extra drinks? Initially, alcohol serves as a sedative by slowing down our nervous system, making us sleepy. However, after going to bed, our body is still working hard to metabolise the alcohol. Here's the kicker…. the energy component of alcohol (kilojoules) is utilised before any food in our digestive system. So, after our body has had the initial rest and the sedative effect begins to wear off, we wake up with energy to burn. OK, you may not feel like jogging around the block, but your sleep cycle is now disrupted. Alcohol also dehydrates by increasing urination and sweating. Then we get thirsty and need (and should) drink more water. All of this leads to a disturbed sleep.
Kiwi fruit helps you sleep. TRUE
I couldn't pass up including this left field study. You might already know that kiwifruit is packed with vitamins C and E, but did you know it's also a great source of folate? Folate deficiency has been linked to restless leg syndrome and insomnia, so upping your intake may help. Additionally kiwifruit is one of the few fruit that is high in serotonin which helps regulate our sleep/wake cycles. The study found that eating 2 kiwifruit an hour before bed improved sleep.
If you have disturbed sleep that is impacting your ability to engage in your daily activities, it’s important you seek support. Over time, poor sleep can lead to in obesity, type 2 diabetes, cardiovascular disease and lowered immune function. Check in with your nutrition is a low effort first step to catching more Z’s.