James Brown, Biomedical scientist, and researcher from Aston University’s department of biosciences published an article on March 30th outlining the evidence so far in relation to Melatonin’s role in protecting the heart.
Melatonin, a hormone released predominantly at night-time by the pineal gland, has long been referred to as the ‘sleep hormone’, which is, indeed, what most research on melatonin focuses on.
But melatonin is also an antioxidant that protects cells from harmful ‘free radicals’ that can cause damage to DNA. This protection includes the heart and blood vessels.
Around 17.9 million people every year die from heart disease, and this has prompted particular interest from researchers.
The Heart Foundation defines heart disease as a group of conditions that includes coronary heart disease, arrhythmias, heart failure and valve disease, and suggests that heart disease is a major cause of health problems and death in Australia, but it’s often preventable. The Heart Foundation suggests that many types of heart disease can be prevented or treated with healthy lifestyle choices, medications and/or surgery.
Brown states in his article that research shows that people with cardiovascular disease have lower levels of melatonin in their blood in comparison with healthy people.
Melatonin has been proven to provide protection against ischemia-reperfusion myocardial damage. This is particularly true when it is administered during a reperfusion period. There is, therefore a strong inverse relationship between melatonin levels and cardiovascular disease.
Diurnal rhythms, or biological processes that occur over a 24-hour cycle, influence cardiovascular physiology such as heart rate, blood pressure etc. according to an article available to be read in the National Library of Medicine, National Centre for Biotechnology Information.
So, in other words if a person has low melatonin, they are in a higher risk category to suffer from cardiovascular disease.
Brown states, “Melatonin supplements (2.5mg taken one hour before sleep) have been shown to reduce blood pressure. And, of course, high blood pressure (hypertension) is a known risk factor for cardiovascular disease. Also, so-called cardiovascular events, including heart attacks and sudden cardiac death (unexpected death caused by a change in heart rhythm), occur at a higher rate in the early morning when melatonin is at its lowest.”
Evidently, studies strongly suggest that melatonin protects the heart and blood vessels.
Because melatonin is efficient at interacting with various reactive nitrogen and reactive oxygen species, and also uses upregulation with antioxidant enzymes and downregulation with pro-oxidant enzymes, it additionally lowers blood pressure and has lipid profile normalising and anti-inflammatory properties.
Patients who have suffered a heart attack have reduced night time melatonin levels, which has led to the theory that melatonin use may indeed form part of a standard treatment given straight after the occurrence of a heart attack to improve recovery rates.
In Brown’s article, he states, “Laboratory studies of heart attack (using rats’ hearts kept alive outside of their bodies) have shown that melatonin does indeed protect the heart from damage after a heart attack. Similar studies have shown that when rats’ hearts are deprived of oxygen, as occurs in a heart attack, providing the heart with melatonin had a protective effect.
A large trial in humans where melatonin was injected into the patient’s hearts after an attack did not show any beneficial effects. A subsequent study of the same data found that melatonin reduced the size of damage caused to the heart by being starved of oxygen during a heart attack. Another, similar clinical trial suggested that no beneficial effects were present from giving melatonin to people who had suffered a heart attack.
The evidence does not provide a clear image of the role melatonin plays in helping to prevent damage to the heart during a heart attack. It is contradictory at best. More research is needed to determine how and when to administer melatonin after a heart attack.
Suggestions have been made that giving oral melatonin instead of injecting melatonin directly into the heart may be the explanation as to why findings during the clinical trials are so contradictory.
Trials studying the effects of melatonin on heart attack patients are still being conducted in relatively early stages.
Brown’s article suggests that melatonin pills are ‘only available on prescription in the UK, EU, and Australia’ however, contrary to this statement, this writer happens to know for a fact, through personal experience that melatonin is also available over the counter in some health food stores and some pharmacies here in Australia, although perhaps not as strong as the dosage that can be obtained on prescription.
Foods that are rich in melatonin include eggs, milk, grapes, grains and walnuts. It is also found in wine, which might explain the heart protective-effects of wine. Eating these foods may help provide protection to you against cardiovascular disease.
