How does our diet influence our sleep?
To sleep well, we need to synthesise a hormone called melatonin.
Melatonin itself is dependent on a sufficient level of serotonin, called the “serenity hormone”.
The synthesis of serotonin in our brains requires the intake of an amino acid — tryptophan — through our diets.
This amino acid is contained in foods such as dairy products, eggs, fish, poultry, chocolate, and almonds.
Be careful, however, with the method of cooking chosen as this amino acid is sensitive to heat.
It is preferable to use low-temperature cooking methods, such as steaming.
In order for tryptophan to be transformed into serotonin and then into melatonin, it also requires the intervention of essential vitamins and minerals: Vitamins B3, B5, B6, B9, B12, vitamin C, iron, copper, and the amino acid methionine.
A diversified diet with animal and vegetable proteins and one that is rich in colourful vegetables and fruits will allow for the contribution of these co-factors.
As far as iron is concerned, animal proteins provide iron that is better assimilated than vegetable proteins.
B12 is also only found in foods of animal origin.
For lacto-vegetarians and vegans, it will thus be necessary to analyse and supplement according to deficiencies.
Consuming complex carbohydrates and wholegrain products or legumes in the second half of the day promotes the synthesis of serotonin.
Thus, a dinner rich in wholegrain cereals, such as wholegrain rice or pasta, or rich in legumes, such as lentils, chickpeas, or coloured beans, will help you sleep better.
But, they should be accompanied by a good portion of vegetables.
For the latter, which will make up half of your plate, think about colour and variety so that they will provide the vitamins and minerals essential for these chemical reactions.
Wholegrain cereals have the advantage of being rich in fibre, which acts on satiety, and in vitamins and minerals (B-group vitamins, magnesium, zinc, iron, selenium, and the antioxidant vitamin E).
Legumes are remarkably interesting for their richness in fibre, vegetable proteins, vitamins, and minerals.
We can recommend green or coral lentils, chickpeas, split peas, beans, and dried beans in various colours.
If you feel a little hungry around 5 pm, the ideal snack to promote good sleep will consist of a small handful of almonds, fresh or dried fruit, and a square of dark chocolate with a minimum of 70% cocoa.
This snack will increase the assimilation of tryptophan, an amino acid precursor of serotonin.
We can also promote digestion in the evening — and, therefore, better our sleep — by choosing detoxifying foods that help our liver to process waste, such as artichokes, turmeric accompanied by pepper and a good vegetable oil rich in omega 3 to optimise its absorption, broccoli, rosemary, and black radish.
As liver cells regenerate at night, these foods will be beneficial for your sleep.
Which micronutrients are best for a good night’s sleep?
There are a certain number of micronutrients that will help you get a good night's sleep.
Omega 3
These good lipids, also called polyunsaturated fatty acids, ensure the fluidity of the membranes of our neurons and increase communication between them.
You can find omega 3s in:
- Small oily fish, such as mackerel, sardines, herring, etc.
- Vegetable oils extracted cold and from 1st pressure from rapeseed, walnut, camelina, and flax (but the latter is difficult to preserve because of its sensitivity to oxidation).
- Oleaginous fruits such as nuts, hazelnuts, and almonds
- Omega 3 eggs (hens fed with flax seeds)
- Meat and poultry from animals fed with flax or alfalfa
- Some leafy greens, such as lamb’s lettuce and lettuce
Vitamin D
This precious fat-soluble vitamin has a variety of uses in our bodies.
It strengthens our bones, participates in our immune defences, impacts our nervous balance, and has a positive influence on the quality of our deep sleep.
Our body can synthesise vitamin D through UV rays if we are lucky enough to benefit from 15 minutes of daily sun exposure on our face and forearms. This means that many people in the northern hemisphere do not have enough.
Where can we find it in our food?
- Cod liver oil to drink or in capsules
- Small oily fish, such as mackerel, sardines, or herring
- Milk
However, vitamin D supplementation is often necessary.
A blood test is necessary to determine the dose to be taken.
Magnesium
Magnesium is our anti-stress ally to promote sleep via the synthesis of neurotransmitters.
It is found in large quantities in:
- Bananas
- Almonds, cashews, walnuts
- Dark chocolate with more than 70% cocoa
- Whole grains
- Legumes
- Green vegetables
- Seafood, sea lettuce
- Wheat germ
Are there foods and drinks to avoid or limit in the evening?
Yes, indeed, there are some foods to avoid in the evening.
Remember also that all meals rich in fat, such as red meat, delicatessen, cheese, and fast food, are difficult to digest and take a long time to be fully digested.
They will inevitably disturb your sleep.
Also note that ultra-processed products rich in hydrogenated fats are not only unfavourable to our health but also to our sleep.
Chocolate rich in cocoa is good due to its high magnesium content and antioxidant properties but it also acts as a stimulant and should be avoided in the evening.
Do not forget that dinner should be the lightest meal of the day, not only to not store fat but also to sleep well.
As for drinks, it is recommended to avoid coffee and tea after 3pm as they can delay our sleep.
Alcohol is a false friend that gives us the impression that it helps us fall asleep but it actually affects the quality of our sleep by reducing the phases of deep sleep and increasing night-time awakenings.
What to drink to sleep better?
Our body is made up of 60% water and needs to be regularly hydrated to function well.
It is essential to drink between 1,5 L and 2 L of water per day, preferably separate to mealtimes.
Hydration fights against fatigue and optimises our concentration, and would thus also influence our sleep.
Some water is enriched with magnesium, our anti-stress and sleep ally, and can be an interesting choice to consider with the effect it has on overall magnesium levels.
Green tea is also an excellent antioxidant source and helps our liver to filter waste products.
Conclusion
In short, our diet plays a crucial role in the quality of our sleep.
By making the right choices at the right times of the day, you will positively influence the quality of your sleep.
Always think about eating a range of colours.
Investing in your diet also means investing in your sleep and, therefore, in your long-term health.
Muriel Bouquier Ouziel is a nutritionist, pharmacist, and micro-nutrition and healthy-eating specialist.
She lives in London and offers tailor-made nutritional and micro-nutritional assessments and support.
Muriel offers face-to-face and Skype consultations.
For more information, visit www.mbonutrition.com or visit Muriel on LinkedIn and Facebook.