The Role of Melatonin in Kidney Health

The latest science is telling us that melatonin’s therapeutic reach may extend way beyond sleep and it’s almost getting easier to ask: what chronic diseases doesn’t melatonin play a role in? Recent years have seen a flurry of studies showing the protective and therapeutic benefits of melatonin against the most significant chronic diseases of our time- heart disease, cancer, dementia, diabetes and yes kidney disease.

For this reason, I thought I’d highlight some of the lesser known benefits of melatonin in today’s article and how they relate to kidney disease.

So let’s get into it.

What is melatonin?

Melatonin is a hormone primarily produced by the pineal gland. It actually comes from the neurotransmitter serotonin that is derived from the amino acid tryptophan. Within the pineal gland, serotonin is converted into melatonin. Because melatonin is released in response to the level of light we are exposed to – low melatonin during the day and high melatonin at night- it is also referred to as the ‘hormone of darkness.’

 

https://www.researchgate.net/publication/40454967_Illuminating_Rationale_and_Uses_for_Light_Therapy

Things that reduce melatonin synthesis

The production of melatonin varies from person to person and is affected by other factors such as age (it decreases with age), disrupted light/dark cycles, night work and being overweight. Studies have also shown that the production of melatonin is impaired in people with CKD.

Low levels of melatonin make it harder to fall asleep. In fact, the use of screen devices around bedtime is significantly associated with insomnia, poor sleep quality and daytime fatigue because it reduces the amount of melatonin we produce. The obvious effect of making less melatonin is trouble sleeping but I’m going to show you that the consequences are far more wide reaching.

Actions of melatonin

• Sleep promotion
• Regulates circadian rhythm
• Antioxidant
• Anti-inflammatory
• Stimulates immune function
• Lowers blood pressure
• Anti-ageing
• Helps control blood glucose levels
• Reduces development of diabetic complications
• Anti-cancer effects
• Cholesterol lowering
• Regulates mood
• Regulates reproduction

Are you surprised to see how many health benefits melatonin actually has? Don’t worry, you’re not the only one.

Let’s take a closer look at some of these actions.

1. Antioxidant

Many of melatonin’s benefits are primarily due to its antioxidant and free radical scavenging properties.

Antioxidants are substances that can prevent or slow damage to cells caused by free radicals. Free radicals are unstable atoms that can damage cells, causing illness and ageing. If we have too many free radicals or not enough antioxidants, it begins a process called oxidative stress.

Oxidative stress and the chronic inflammation it leads to, is well known to contribute to many diseases including cancer, diabetes, heart disease and kidney disease.

The great thing about melatonin is that it has direct antioxidant and free radical scavenging properties AND it also increases the expression or activity of some of the key antioxidant enzymes in the body such as superoxide dismutase and glutathione peroxidase so you’re really getting more bang for your buck!

These antioxidant enzymes are our first and most important line of defence against potentially destructive free radicals and play an indispensable role in our antioxidant protective capacity. Strengthening the body’s primary antioxidants systems offers the most powerful free radical protection available.

One of the other great things about melatonin is that it’s both fat and water soluble which means it can enter all cells of the body to exert its antioxidant actions.

2. Anti-inflammatory

Several studies have shown that melatonin can regulate the activation of the immune system and decrease the production of pro-inflammatory molecules, reducing acute and chronic inflammation.

There is plenty of evidence that shows the close association between chronic diseases and chronic inflammation. Long term inflammation is linked with the development of most chronic diseases including heart disease, cancer, autoimmune diseases, diabetes and kidney disease and we know that reducing inflammation and oxidative stress is key in the treatment of chronic disease.

3. Cardiovascular health

 

https://journals.lww.com/cardiovascularendocrinology/fulltext/2012/03000/The_role_of_melatonin_in_hypertension___a_brief.4.aspx

For people with CKD, the leading cause of mortality is cardiovascular disease (CVD) so managing the risks of CVD is an important consideration.

Melatonin has been shown to improve cholesterol levels and has also been reported to be linked to a large number of cardiovascular related functions such as regulation of blood pressure, modulation of inflammatory factors that contribute to CVD and protection of the heart against lack of blood flow and oxygen.

Recent research continues to demonstrate that melatonin may protect against and treat a range of cardiovascular conditions including heart attack, stroke, high blood pressure and hardening of the arteries (atherosclerosis).

The way that melatonin reduces blood pressure is thought to be due to a few different mechanisms which include an increase in nitric oxide levels which leads to vasodilation or relaxation of blood vessels, it also reduces adrenaline (epinephrine) and noradrenaline (norepinephrine)- neurotransmitters involved in the stress response that cause an increase in blood pressure as well as through its antioxidant activity.

Animal studies have shown that melatonin can protect other organs such as the brain and the kidneys against high blood pressure.

4. Diabetic Nephropathy

https://academic.oup.com/ckj/article/13/4/522/5728763

Diabetes is the leading cause of CKD and one of the key reasons for this is increased oxidative stress and inflammation causing kidney cell damage. Studies have shown that people with diabetes have lower melatonin levels and that diabetics who had disturbed sleep (likely driven by melatonin deficiency) had markers of more severe diabetic nephropathy.

Melatonin has been shown to have an influence over both blood sugar and insulin. The science of melatonin’s role in diabetes risk and treatment is complicated and not yet well enough understood but there’s a robust body of research that indicates melatonin has a protective effect over metabolic health and can lower diabetes risk.

Melatonin deficiency may predispose to diabetic nephropathy by affecting blood vessel function, increasing free radical production and inflammation and increasing fibrosis or scarring of the kidneys.

So what does this mean for kidney disease?

Well, melatonin is protective to the kidneys for a number of reasons.

Probably the number one reason is due to its antioxidant and anti-inflammatory effects.

The kidneys are especially vulnerable to oxidative stress and damage from free radicals and prooxidants produced within the body which can lead to progressive kidney damage, so it makes sense then that boosting antioxidant levels within the body is one way to protect the kidneys.

In chronic injury (like in kidney disease), melatonin plays an important role by suppressing pro-inflammatory mediators and initiating a protective effect against inflammatory damage.

Melatonin also helps to lower the activity of the renin angiotensin system (RAS). Overactivity of the RAS increases blood pressure, causes sodium retention and contributes to inflammation and fibrosis (scarring of the kidneys). Reducing the activity of the RAS therefore lowers blood pressure, inflammation and reduces the development of fibrosis.

High blood pressure is the second leading cause of CKD and contributes to the progression of kidney disease so managing blood pressure will also have a protective effect on further damage to the kidneys. Vasodilation or relaxation of blood vessels also helps to prevent reduced blood and oxygen delivery to the kidneys which is another contributing factor to kidney damage.

https://www.nature.com/articles/s41440-019-0223-9

And finally, evidence suggests that melatonin is capable of reducing the development of diabetic complications like diabetic nephropathy by reducing inflammation and oxidative damage, improving blood vessel function and reducing fibrosis or scarring of the kidneys.

Administration of melatonin in animal studies showed that it reduced oxidative stress and inflammation, lowered creatinine, reduced protein loss in urine and improved kidney function and structure. Clinical trials are currently being done in humans to determine the benefits of melatonin administration in people with CKD.

Ok, so we’ve gone through some of the problems associated with having low melatonin and the therapeutic benefits of melatonin when it comes to kidney disease. The next logical question is- how do you increase your melatonin levels?

Boosting Melatonin Levels

• Increase dietary intake of melatonin containing foods (yes, some foods contain melatonin!) such as: oats, asparagus (high potassium), mint, broccoli, brussels sprouts (high potassium), goji berries, apples, cherries, cherry juice, pineapple and strawberries.
• Meditate.
• Get outside and expose your eyes to bright light when you wake up- this helps to produce more melatonin later at night.
• Reduce exposure to bright light at night- melatonin reacts to light exposure, the more light you are exposed to at night, the less melatonin your body produces. White and blue light wavelengths are the main culprits.
• Folate and vitamin B6 boost the formation of serotonin which is the precursor to melatonin and zinc and magnesium increase the formation of melatonin from serotonin.

Supplementing with melatonin

The other obvious way of increasing melatonin levels is to supplement with melatonin. Melatonin supplementation has typically been recommended for people with insomnia, to prevent jet lag and for people with various sleep disorders. For this reason, most of the research in terms of dosage has been done in these populations.

There is no consensus about the optimal dosage of melatonin. In studies, dosages range from 0.1mg to 12mg with the typical recommended dose for sleep issues between 1mg and 5mg. In studies using melatonin specifically for its antioxidant and anti-inflammatory effects in people with cancer, dosages of 20mg are typically used.

Research into the optimal dose of melatonin for its non-sleep benefits is ongoing so hopefully over time we will have a better understanding about what dosage of melatonin to use for its other specific therapeutic effects.

Melatonin should be taken at night about an hour before going to bed.

Don’t forget

Make sure you consult your health care practitioner before you begin taking any new supplements to ensure it is appropriate for your use. In some countries a prescription is required from a doctor in order to purchase melatonin while in other countries it can be purchased over the counter.

One thing to be aware of when purchasing melatonin over the counter is that not all melatonin supplements are created equal! A recent scientific investigation found that the actual melatonin content found in many supplements on the market may vary significantly from what the product labels claim. Before you begin using melatonin, be sure to do your research and get your melatonin from a trusted source.

Cautions

Melatonin may potentiate the effect of blood pressure lowering medication and diabetic medication so closer monitoring of blood pressure and blood sugar is advised when starting on melatonin.

Theoretically, melatonin may increase the risk of bleeding when taken alongside blood thinning medication so make sure you speak to your doctor before taking melatonin with warfarin or other anticoagulant medication.

So there we have it. A review on some of the key therapeutic benefits of melatonin and how it relates to CKD. I hope you’ve found this information useful, if you have, please let us know by clicking the ‘SHARE’ button below- or better yet, come join our community over on our Facebook page and leave us a comment.