How and what we eat affects our sleep patterns, explains Amanda Ursell.
We all feel better and more energised after a good night’s rest. Consistently poor sleep does the opposite and can lead to a range of health issues. As well as raising our risk of type 2 diabetes and Alzheimer’s disease, it can also lead to diminishing mood and mental capabilities, and increased levels of the steroid hormone cortisol, which the body releases in times of stress. Poor quality sleep can also accelerate the physical signs of premature ageing.
The effect of tiredness on appetite
Scientists have found that lack of sleep can reduce the level of the appetite-controlling hormone leptin and increase the hormone ghrelin, which stimulates our desire to eat. The combination can lead to weight gain, which, in turn, increases our risk of sleep apnoea and snoring – two problems that themselves play havoc with a good night’s rest. Even 5–10% weight loss can significantly improve airflow and help reduce the volume and frequency of snoring.
The importance of routine
Some sleep experts report that people who eat regularly and at regular times throughout the day have more regular sleep habits. Since this is a good habit to get in to anyway, it’s certainly a pattern worth adopting.
Foods to help you nod off…
A warm milky drink at bedtime is a time-honoured tradition to help us fall asleep. In fact, this idea is based on science, as milk contains the protein building block tryptophan, an amino acid which has sleep-inducing effects.
In truth, one glass doesn’t give us enough of this amino acid to have a sleep-inducing action. There is some, although limited, research to suggest that calcium, a mineral found in dairy and fortified alternative milks such as almond milk, is associated with ease of dropping off, with researchers suggesting this may be down to the mineral helping to lower blood pressure. The bottom line? If you find a warm mug of milk helps you to relax and drift off, keep having it.
Rice and Pasta
You could try having a high glycaemic index (GI) carbohydrate for your evening meal. Scientists from the University of Sydney discovered that when men ate high-GI jasmine rice with their dinner, they fell asleep more easily than if they ate a low-GI rice. They speculate this may be down to high-GI carbs increasing the release of the calming brain chemical serotonin. Other high-GI carbohydrates include baked potatoes and couscous, which also may be worth a try.
These are among the richest dietary sources of the trace mineral selenium. Research reveals that, like calcium, less selenium in the diet is associated with finding it more difficult to fall asleep and in getting less so called ‘restorative’ sleep. Aim for three to four nuts a day.
By recording night-time brain waves in a group of adults aged between 35 and 45, researchers from Columbia University Medical Center in New York have revealed how a diet low in fibre and high in saturated fat and sugar is associated with a worse night’s sleep. Eating more fibre was associated with a deeper and better sleep while more saturated fat had the opposite effect. Good fibre sources include wholegrains and fruit and vegetables. Trying our Diet Plan is a great way to nudge your diet towards these healthier choices.
You can buy a host of natural, herbal supplements marketed for bedtime, all with varying claims. You may want to try the herbal supplement St John’s Wort. Used by doctors in Germany as a prescribed method of helping to treat some forms of depression, St John’s Wort is also considered by medical herbalists to treat anxiety, fatigue and sleep problems.
Long upheld as a remedy for a good night’s sleep – with good reason. Chamomile contains plant compounds that have similar effects on our brains as anti-anxiety drugs, helping us to relax. Pukka has one of the biggest selections.
And those to avoid…
Caffeine in drinks and food
We all know by now that caffeine stimulates our nervous system and helps to keep us awake. For most of us, avoiding a cup of coffee, tea or a rich hot chocolate at bedtime is sensible advice we generally follow. The important thing to remember, however, is just how long the breakdown of caffeine in the body takes and to understand that the speed varies widely between different people.
This means that, while avoiding caffeine for two to three hours may be sufficient to clear it from one person’s system, for others it can take up to eight hours, which pretty much means that you need to stop drinking caffeine-containing drinks from early afternoon to help promote good sleep.
To get an idea of how much caffeine is in those regular drinks, a small 150ml cup of coffee (a yogurt-pot size) can provide up to 115mg caffeine and a similar size cup of tea averages around 40mg (60mg when brewed for a long time). The amount in green and white teas ranges from 14mg to 61mg per 200ml mug, while decaffeinated teas can still provide up to 12mg per mug, which means that even too many decaf teas can still disrupt sleep.
You can also expect to get around 38mg caffeine in cans of regular and diet colas and up to 150mg in regular energy drinks. Check the ingredients on cold remedies and painkillers as, to perk you up, manufacturers may add caffeine, with some providing up to 60mg per dose or couple of tablets. It is also worth knowing that a 50g bar of dark chocolate can provide 40mg caffeine, along with other potentially stimulating compounds. Stick to a small section of dark chocolate or switch to milk chocolate (10mg caffeine per 50g) if it’s causing problems.
Even coffee ice creams can be a source of caffeine, with some luxury espresso varieties giving up to 58mg caffeine per serving. In all cases, these treats are best avoided close to bedtime.
While alcohol may indeed help you to fall asleep, it goes on to disrupt the really beneficial restorative sleep, so it’s best to avoid it before bed. If you do indulge, stick with one unit (a small glass of wine with a low ABV content), one shot of spirits or half a pint of lower strength beer or lager.
Medical herbalists describe ginseng as a stimulating herb, believing it to boost energy, and link it with insomnia. It’s worth avoiding both ginseng and other stimulating herbs and spices such as ginger in the form of tea infusions before bedtime.
Cheese and fatty foods
Anecdotal evidence suggests that cheese can frequently be the culprit for keeping people awake, but there’s little scientific evidence to support its sleep-depriving reputation directly. However, its high-fat content means that cheese will delay stomach emptying and may well cause indigestion and restlessness in some people. The same is true of any fat-rich meal, so the advice for evening eating is: keep it light.
Too many drinks
Having a small mug of warm milk or chamomile tea may be helpful, but too much fluid before bedtime will inevitably mean that you wake with a full bladder and need to nip to the loo, disturbing your sleep. Keep drinks small and pop to the loo just before you settle down.