Did your nanna ever tell you to have a glass of milk before bed? Well, there is truth to the story – milk can in fact be the best nightcap.
Dairy foods are filled with a variety of essential vitamins and minerals. Milk is arguably the most widely tolerated and accessible components within the dairy products food group. It contains calcium to help keep bones strong, protein to maintain muscle tissue and a variety of vitamins needed to regulate blood pressure, muscle contractions and energy release.
Milk is also a good, natural source of tryptophan – and this makes it excellent for helping you fall asleep.
What is tryptophan?
Tryptophan is an essential amino acid found naturally in a range of foods. Amino acids act as building blocks to make proteins. An essential amino acid means that it is something that our bodies cannot produce themselves and so must be sourced from the diet.
Along with milk, some good food sources of tryptophan include:
- Nuts and seeds – especially pumpkin seeds, chia seeds, sesame seeds, sunflower seeds, flaxseeds, cashews and almonds
- Soy foods such as soybeans, tofu and tempeh
- Beans and legumes such as lentils, kidney beans and white beans
- Cheese such as mozzarella, cheddar and parmesan
- Meats like lamb, beef and pork
- Chicken and turkey
- Fish – especially salmon, tuna, halibut, snapper and trout
"Serotonin is also known as the ‘mood’ hormone, and increased levels are associated with happiness and relaxation. Melatonin is known for its role in controlling your sleep-wake cycle."
The role of tryptophan in sleep and mental health
Tryptophan is used to make the brain transmitters serotonin and melatonin. Serotonin and melatonin are hormones that play a role in regulating various functions such as sleep and appetite.
Serotonin is also known as the ‘mood’ hormone, and increased levels are associated with feelings of happiness and relaxation. Melatonin is known for its role in controlling your sleep-wake cycle. Its production is stimulated in decreasing light, with highest concentrations seen during the night.
Studies have shown that inadequate tryptophan can be attributed to poorer mental health by inducing depression-like symptoms. For people who already suffer from clinical depression, poor tryptophan levels can increase their vulnerability to relapse. Conversely, increasing tryptophan levels can increase serotonin levels, which can result in a better mood, reduce irritability and increase agreeableness in everyday life.
Melatonin, and serotonin to a lesser degree, can affect the duration and quality of sleep. Not only can it help you get to sleep faster and have a deeper sleep, it can also help deter you from waking up until it’s light outside again. Research shows that increased melatonin can help prevent sleep disorders such as insomnia, as well as being an aid to get over jet lag.
Looking for more nutrition advice? To find an Accredited Practising Dietitian in your area visit daa.asn.au