You have probably heard of melatonin, the hormone from your pineal gland that puts you to sleep. Its production is triggered by darkness and this sleep/wake cycle is called your circadian rhythm. Melatonin is well known as an oral supplement for insomnia.
Recent scientific research has shown that putting you to sleep is only the tip of an iceberg. The actions of melatonin in your body are very vast. Importantly, it helps prevent and treat two big killers of Americans, cancer and heart disease. The defense it provides against these diseases is as an antioxidant, which protects the body from stress and aging.
Melatonin and Cancer
Melatonin benefits your immune system and has direct anticancer effects. It helps prevent the most common kinds of cancer in the US, including prostate, breast, and colorectal. For example, studies are suggesting that light exposure at night, such as shift work, may decrease melatonin production and therefore increase the risk of breast cancer.
A meta-analysis is a type of scientific evaluation that is considered a high level of evidence in our current western medicine paradigm. Meta-analysis of studies using 20 mg of melatonin, taken orally by cancer patients, concluded that its use during cancer treatment resulted in: significantly increased rates of cancer remission, better 1-year survival rate, and greatly reduced side effects of cancer treatment.
Some of the side effects of chemotherapy that melatonin has been shown to reduce are nerve damage, decreased platelet levels, and fatigue. This is particularly remarkable because these side effects are hard to treat when they occur.
Noteworthy study examples of melatonin’s anticancer benefits:
- In a Phase II study, 14 breast cancer patients took 20 mg melatonin before starting treatment with Tamoxifen. Most patients had less anxiety, four of these patients achieved a partial response with decreasing tumor activity! This is amazing, even though the number of patients in this study was small, and four is also a small number. We need more research along these lines with larger numbers of patients to validate that anti-tumor effect.
- In a study with non-small cell lung cancer patients, the patients taking 20 mg melatonin had increased 5- year survival rates and better tolerance to chemotherapy than patients not taking melatonin.
- In a colon cancer study, people taking 20 mg melatonin alongside a chemotherapy drug called irinotecan, had higher rates of disease control than the people taking irinotecan alone.
Additional studies outline other potential benefits for cancer patients including: less risk of anxiety and depression in general, less post-surgical depression, better sleep quality and quantity, and better quality of life.
Melatonin and Heart Disease
As we age, our nocturnal melatonin production declines, sometimes to the point of not working at all. Supporting melatonin levels may protect us from some of the diseases of aging, such as cardiovascular disease. Melatonin is found to do this through a beneficial effect on the heart and blood vessels.
Some exciting points of current research in cardiovascular disease:
- Melatonin supplementation can prevent heart failure following a heart attack.
- Melatonin supplementation can help normalize blood pressure in people on hypertension medication and in the elderly.
- Melatonin can improve left ventricular ejection fraction, which is a measurement of heart efficiency and helps detect heart failure.
- Low melatonin levels are linked to higher heart attack rates in the obese.
Melatonin has a high safety profile. Even though it is a hormone, you can stop and start melatonin without side effects.
Surprisingly, some foods contain melatonin! Eating melatonin containing foods will increase the amount of melatonin in your blood stream. Animal foods with the highest levels are eggs and fish. Plant foods with the highest levels are nuts, mushrooms, legumes and seeds.
The dose of supplemental melatonin ranges from 1-20 mg depending on the person, age, and medical condition being treated. It is best to seek guidance from your naturopathic physician on the appropriate dose for you. Your ND will also review your overall health and medications to make sure it is appropriate for you to use melatonin.
Lastly, don’t forget to avoid those light emitting devices before bedtime (cellphones and laptops); they decrease melatonin levels!
1. Oncotarget. 2017 Jun 13; 8(24): 39896–39921. Published online 2017 Mar 18. doi: 10.18632/oncotarget.16379 Melatonin for the prevention and treatment of cancer, Ya Li,1 Sha Li,#2 Yue Zhou,1 Xiao Meng,1 Jiao-Jiao Zhang,1 Dong-Ping Xu,1 and Hua-Bin Li#1,3.
2. Melatonin: Exceeding Expectations, Russel J. Reiter, Dun Xian Tan, and Annia Galano, 01 SEP 2014, https://doi.org/10.1152/physiol.00011.2014.
3. Molecules. 2018 Jul; 23(7): 1819. Published online 2018 Jul 22. doi: 10.3390/molecules23071819, Melatonin in Heart Failure: A Promising Therapeutic Strategy? Frederic Nduhirabandi and Gerald J. Maarman.
4. Nutrients. 2017 Apr; 9(4): 367. Published online 2017 Apr 7. doi: 10.3390/nu9040367. Dietary Sources and Bioactivities of Melatonin, Xiao Meng,1 Ya Li,1 Sha Li,2,* Yue Zhou,1 Ren-You Gan,3 Dong-Ping Xu,1 and Hua-Bin Li1,4.