Gut health: What to eat for better sleep, according to science

What's causing your restless sleep? Is it a lumpy mattress, or limp pillows? Perhaps you need a scent of lavender from your best diffuser for essential oils to drift off. However, if you can't pinpoint the reason, it could be your diet that's causing the problem. A diet rich in salt and carbohydrates and low in healthy foods and certain amino acids could be interfering with your sleep. 

In a survey of 2,000 UK adults commissioned by Bioful, 80% suffered from gut-health related issues, indicating gut health issues may be more common than we might think. Disturbed sleep isn't often thought of as a side-effect of bad gut health, but it's true: a diet rich in salt and carbohydrates and low in healthy foods and certain amino acids could be interfering with your sleep. 

Researchers from the University of Tsubaku, Japan, sought to examine the relationship between gut health and sleep in more detail. Good gut health stimulates the pathways in the body responsible for creating serotonin and melatonin, the homones responsible for your deep sleep and light sleep cycles. 

Professor Yanagisawa, lead author of the study, said: "We found that microbe depletion eliminated serotonin in the gut, and we know that serotonin levels in the brain can affect sleep/wake cycles."

"Thus, changing which microbes are in the gut by altering diet has the potential to help those who have trouble sleeping."

Foods with plenty of an amino acid called tryptophan, like turkey, tuna, oats, nuts and seeds, are best for encouraging the production of serotonin. Milk also contains tryptophan, which is why it's often said a glass of milk before bed can help you drift off to sleep. Serotonin also plays a key role in regulating anxiety and mood, so if you can regulate the hormone, you'll be happier long-term.

In general, it's also good for your gut to eat foods with plenty of fibre, which prevents constipation and promotes healthy digestion. Fibrous vegetables like broccoli, along with peas and legumes like beans and chickpeas are all great sources of fibre. A green smoothie with broccoli, kale and a fibrous fruit like apple will certainly do the trick nicely (but you'll need the best blender to extract the fruit and veg's fibre content, not just the juice).