It is often said that nutrients in our diet are essential for good sleep. The link between sleep and zinc has been the subject of little research. However, research has shown that zinc deficiency increases the risk of disturbed and short-lived sleep. How do they affect each other? This is what we will tell you in this article.
What is the purpose of sleep?
Definition of sleep
You might think that sleep is a trivial concept, but the definition is not so obvious. The sleep period actually refers to the interval between two periods of waking (so far, so good), when our state of consciousness is least active. It is a form of extreme rest, during which our whole body is in a state of wakefulness: the muscles, the brain and thus alertness, and even the senses are partially asleep.
Why sleep? According to INSERM, 13% of people between the ages of 25 and 45 feel that they waste time sleeping. However, the role of sleep is not limited to ending the day and lazing around in bed. Above all, it allows us to recharge our physical and mental batteries so that we can start a new cycle of activity each day. By reducing the rate of metabolism, it conserves the energy to live, quite simply.
How does sleep work?
Good quality sleep undergoes a succession of cycles lasting about two hours:
- Slow wave or non-paradoxical sleep consists of two stages of light sleep, during which we are still sensitive to waking up and during which brain activity gradually decreases, and two stages of deep sleep, during which our metabolism is completely at rest;
- REM sleep corresponds to the dream period, when brain and eye activity accelerates.
During these sleep phases, the body temperature drops and slows down our digestive system, as well as the neurotransmitters responsible for our nervous impulses (serotonin, melatonin, adrenaline and dopamine).
Without restful sleep, we leave the door open to cardiovascular or autoimmune diseases such as diabetes, as we weaken our immune defences. Fortunately for us, we can do something about this with several magical nutrients, such as zinc.
What is zinc used for?
The benefits of zinc
Zinc is a trace element present in our body as a mineral, whose role is essential in more than 200 enzymatic reactions in the body, such as DNA synthesis and bone growth. But above all, it is involved in the metabolism of energy nutrients: carbohydrates, lipids and proteins. Among its many benefits:
- It has healing properties, which strengthen skin, nails and hair;
- It is an antioxidant against oxidative stress;
- It helps with insulin metabolism;
- Zinc increases the number of T cells and strengthens the immune system...
So if you have a symptom relating to any of these factors, you may have a zinc deficiency.
Where is zinc found?
Zinc levels are highest in animal products such as cheese, milk, meat, fish and eggs, but there are also plant sources of zinc: fresh and dried vegetables, oilseeds and wholegrain cereals.
Although it occurs naturally in our diet, zinc supplements are available in tablet form to provide the necessary levels to the body. As it is mainly present as a trace element, the amount in the body being around 3 grams, zinc supplementation is popular and often recommended to vegetarians and sportsmen, who are fond of ZMB (Zinc, Magnesium and Vitamin B6).
Consequences of zinc deficiency
As zinc is involved in many enzymatic reactions, zinc deficiency can weaken the immune system and its ability to fight infections. Symptoms can range from problems with wound healing, acne or eczema, loss of smell and taste and infertility in men to weakened bones, prostate problems and nervous system dysfunction.
The impact of zinc on sleep
Magnesium, iron and vitamins, but also zinc, are metabolic nutrients and are involved in the chemical balance of our brain. As the brain regenerates during sleep, a zinc deficiency can lead to a decrease in sleep quality.
Like magnesium, zinc contributes to the transformation of tryptophan into serotonin and then into melatonin, the sleep hormone. This hormone is mainly synthesised at night, which makes it the centre of regulation of chronobiological rhythms. It is secreted directly into the brain by the pineal gland when there is no more light. This is how melatonin triggers sleep. It is therefore often used to treat sleep disorders.
Although there are very few studies on the link between zinc and sleep, there are some that show a relationship between zinc intake, blood zinc levels and sleep quality. In an entire population, zinc-deficient individuals had short sleep durations. In addition, people aged 65 and women were more affected.
By cross-referencing data from a national health and nutrition survey of Americans over the age of 16, scientists found that individuals who slept less than seven hours per night were zinc deficient. So there is definitely a link between sleep and zinc, but which one affects the other? Possibly both.
There is no doubt that there is a link between zinc and sleep. Not only studies, but also individual experience prove that zinc deficiency often causes sleep disorders. What if sleep disorders also cause zinc deficiency?