Are you having trouble sleeping at night? Sleep difficulties could be caused by your diet. Here are 12 foods that are scientifically proven to promote rest and help you get a bit of much-needed shut eye:
Chicken contains Vitamin B6 which produces tryptophan - an amino acid that encourages secretion of serotonin. Serotonin, the 'happy hormone' is a natural sedative, increasing tiredness, making it easier to get to sleep, and reducing night disturbances(1).
2. Warm milk
Dairy is another great source of tryptophan(2), but a glass of warm milk could be advantageous in other ways too. Not just an old wives' tale, warm milk may have psychological benefits, reminding you of your childhood and providing a calming effect.
Salmon contains Vitamin B12, which scientists have found 'exerts a direct influence on melatonin' (3) - the hormone that regulates your sleep/wake cycles and helps keep the body clock in check. Melatonin supplementation is often used as a treatment for insomnia.
Mushrooms are full of Vitamin D which affects the diencephalon (4) - the region of the brain that controls the sleep/wake cycles. According to researchers, Vitamin D deficiencies are a major cause of sleep disorders.
Dark leafy greens like spinach are good sources of magnesium. Magnesium has been found to increase total length of sleep (5) because it promotes the production of melatonin in the body, balancing the sleep/wake cycle.
Tuna contains nicotinamide (niacin) - a Vitamin B3 that has been shown to increase rapid eye movement (REM) sleep (6) and encourages a good night's rest. Other oily and fatty fishes like salmon, mackerel, and sardines are also good choices.
7. Pumpkin seeds
If you suffer from restless leg syndrome - a common cause of night disturbances - you may have an iron deficiency. Increased iron intake, from pumpkin seeds for example, can increase sleep efficiency in restless leg sufferers from 75.7 to 84.0 per cent. (7)
8. Tonic water
Similarly, quinine has been claimed to reduce legs cramps during the night (8) which can affect sleep. Quinine is found in tonic water, but stick to just a small glass before bed as giant quantities could have some unpleasant side effects such as diarrhoea.
9. Herbals teas
Some ingredients of herbal teas, like valerian and kava, are believed to target GABAa receptors in the body. (9) These receptors transmit data directly to the brain and, as they act as mild sedatives, they instruct the brain to take a little rest.
Potassium, found in large quantities in bananas, has been seen to quickly relax muscles (10) in animals, and although research on humans is limited, it is expected to have similar results. Relaxing the muscles and unwinding is a good way to encourage sleep.
11. Egg white omelette
Egg whites are chock full of serine - an amino acid that regulates blood sugar and provides mild sedative effects. In studies, ability to get to sleep, and duration of sleep, are better with serine (11) supplementation than with a placebo.
Carbohydrates like bread are a great source of energy - they cause a rapid rise in blood sugar (12), followed by a 'crash'. In some instances, such as before bed, this crash can actually be beneficial. Aim to eat about an hour before bed for best results.
(1) Hartmann, Ernest. Effects of L-tryptophan on sleepiness and on sleep. Journal of Psychiatric Research, Vol. 17, Iss. 2, 1982-1983, Pages 107-113
(2) Shattock, Paul & Whiteley, Paul. The role of tryptophan in autism and related disorders. The Nutrition Practitioner, Summer 2006
(3) Mayer, G, Kroger, M, Meier-Ewert, K. Effects of vitamin B12 on performance and circadian rhythm in normal subjects. Neuropsychopharmacology, Nov 1996
(4) Gominak, S.C, Stumpf, W.E. The world epidemic of sleep disorders is linked to Vitamin D deficiency. Medical Hypotheses, Volume 79, Issue 2, August 2012, Pages 132-135
(5) Abbasi, Behnood et al. The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. Journal of Research in Medical Sciences, Dec 2012
(6) Peuhkuri, Katri, Sihvola, Nora, Korpela, Riitta. Diet promotes sleep duration and quality. Nutrition Research, Volume 32, Issue 5, May 2012, Pages 309-319
(7) Kryger, Meir H, Otake, Kazuo, Foerster, John. Low body stores of iron and restless legs syndrome: a correctable cause of insomnia in adolescents and teenagers. Sleep Medicine, Volume 3, Issue 2, March 2002, Pages 127-132
(8) Simon Connolly, Priscilla et al. reatment of Nocturnal Leg CrampsA Crossover Trial of Quinine vs Vitamin E. Archives of Internal Medicine, 1992
(9) Gyllenhaal, Charlotte et al. Efficacy and safety of herbal stimulants and sedatives in sleep disorders. Sleep Medicine Reviews, Volume 4, Issue 3, June 2000, Pages 229-251
(10) Bonaccorsi, A et al. Mechanism of Potassium Relaxation of Arterial Muscle. Journal of Vascular Research, Vol. 14, No. 5, 1977
(11) Ito, Yukihiko et al. Effects of L-serine ingestion on human sleep. SpringerPlus, Aug 2014
(12) Jéquier, E. Carbohydrates as a source of energy. American Journal of Clinical Nutrition, Mar 1994