Serotonin: Effects on Health and How to Raise Your Levels

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As I was re-recording some audio articles the other day, I realized how often I mention serotonin. Yet, I’ve never written about it, and I can only assume that many readers don’t really know what it is.

I’ll briefly explain what it is, how it affects your health, and give you three things you can do today to naturally improve your serotonin levels. 

What is serotonin?

5-hydroxytryptamine (5-HT), more commonly known as serotonin, is a neurotransmitter that not only affects cognitive function, it also plays key roles in metabolism.

Only about 2% of your total serotonin is found in the nervous system, yet that small amount plays a significant role in your mental health. The rest is found throughout your body, including your gut.

Serotonin is synthesized from tryptophan, an amino acid that gives turkey its sleep-inducing reputation. In reality, it’s probably not the turkey alone that causes people to nap after Thanksgiving dinner. Carbohydrates also increase 5-HT production, and most people eat plenty of them with their holiday meal.

That said, supplements like 5-hydroxytryptophan (5-HTP) do seem to induce sleep and relax the mind as 5-HTP gets easily converted to 5-HT.

Effects of 5-HT

Serotonin affects almost every area of the body, from brain function to bone formation. The following is a brief overview of how 5-HT affects you and your health.

Appetite

Serotonin depletion induces appetite and causes weight gain, whereas increasing levels inhibits appetite. In some people, increasing serotonin through supplementation or drug treatments reduces appetite and body weight.

It doesn’t work for everyone, though. Multiple physiological steps and other chemicals and compounds are involved in the appetite-reducing process. If one of the other steps is broken, 5-HT won’t be as effective at reducing appetite.

Some antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) which inhibit serotonin transporter (SERT), interfere with its secretion and may increase appetite. That’s part of the reason some antidepressants are known to cause weight gain.

Serotonin inhibits appetite, which means compounds and drugs that increase serotonin may decrease appetite. Since sleep debt reduces 5-HT production, it’s little surprise that insufficient sleep leads to an increased appetite and food intake as well.

Bone health

Serotonin plays an essential role in bone formation and bone remodeling. However, at extremely high levels, it can contribute to osteoporosis.

Bowel regularity

Serotonin stimulates gut motility, helping to move food through the digestive tract and enhancing nutrient absorption along the way.

Beyond discomfort and the growth of a BIF (butt in front), reduced motility or constipation can lead to numerous digestive problems.

Serotonin also impacts the bladder, which further serves to remove unwanted compounds.

Cardiovascular health

Serotonin levels impact heart rhythm, vascular tone, and blood platelet aggregation. A dysfunction in any of these areas could lead to serious health complications.

Energy expenditure

Though it isn’t to the same extent as thyroid hormone, serotonin does affect energy expenditure.

Research shows 5-HT activates brown adipose tissue, a highly thermogenic type of fat tissue.

At the same time, serotonin may enhance energy intake by stimulating gut motility and increasing nutrient intake from the gut.

Mental health

Serotonin clearly plays a role in mental health. Not only does serotonin reduce depression and anxiety, but its levels may also affect other conditions such as:

• Schizophrenia
• Obsessive-compulsive disorders
• Addictions
• Parkinson’s disease
• Attention deficit hyperactivity disorder (ADHD)
• Autism

Treating these conditions is usually far more complicated than shifting serotonin levels alone, but some people do experience relief when they naturally raise their levels.

Nausea, vomiting, and diarrhea

An acute and significant rise in serotonin can cause nausea and diarrhea. This helps you eliminate food or other substances that could make you sick.

The steep rise in blood levels might also leave you feeling lethargic afterwards.

Sexual function

Though increased serotonin may lower feelings of anxiety and enhance sleep, chronically high levels can cause very low libido in men and women.

In women, high serotonin is a known cause of hypoactive sexual desire disorder (HSDD). For men with low libido, this might be something to consider in addition to low testosterone.

Not surprisingly, SSRIs are also known to lower libido when used as antidepressant medications.

Sleep

Serotonin can be metabolized to melatonin, your body’s primary sleep hormone. Because you can convert l-tryptophan to 5-HT, you may increase melatonin levels by supplementing with tryptophan or eating tryptophan-rich foods.

Improving serotonin and GABA levels can have a significant impact on sleep quality and quantity.

How to Naturally Balance Serotonin

As you’ll see, strategies to improve serotonin levels are some of the same strategies involved in improving other aspect of health and fitness. However, there are some nuances, so be sure to pay attention.

Each of these is easy enough to act on today.

Sunshine or light therapy

Anyone who’s experienced seasonal affective disorder knows the impact that sunshine or light therapy has on their mental health. By getting outdoors on a sunny day, or using a light therapy lamp for 15-20 minutes, you can significantly alter how you feel, which in part is due to changes in serotonin levels.

Of course, exposure to sunshine, without sunblock, is ideal. It stimulates serotonin production while also improving vitamin D levels.

Regular exercise

Moderate-intensity exercise improves serotonin levels. It also decreases blood levels of branched-chain amino acids (BCAAs) and raises blood concentration of tryptophan, which may increase brain levels of serotonin.

Diet

Dietary choices can play a significant role in serotonin levels. If your diet contributes to obesity, the obesity will shut down serotonin production.

However, long-term adherence to a very-low carbohydrate, or ketogenic diet may also sabotage serotonin levels. If you are diabetic, obese, or have metabolic syndrome, a low-carb diet may be appropriate for a while. 

As insulin sensitivity improves and you get control of your weight, it’ll be important to reintroduce some carbohydrates, at least with your evening meals to support normal serotonin levels.

One other interesting thing about your diet…branched-chain amino acids inhibit tryptophan transport into the brain. While BCAAs are crucial for building muscle, and provide numerous other health benefits, supplementing with BCAAs between meals, or especially at night before bed, may affect serotonin levels and sleep. Though they’re good, you can have too much of a good thing.

Supplements

Though many supplements and botanicals indirectly impact serotonin levels, three have a more direct effect:

1. Tryptophan: As previously mentioned, tryptophan is metabolized to serotonin, and increasing tryptophan intake increases serotonin, as long as it’s not taken with branched-chain amino acids.
2. 5-hydroxytryptophan (5-HTP): As a supplement, 5-HTP is superior to plain tryptophan. Tryptophan can be converted to serotonin, but it can also be converted to other compounds in the body. 5-HTP, on the other hand, can only be converted to 5-HT, so it’s more likely to raise serotonin levels.
3. SAMe (S-adenosyl-L-methionine): SAMe seems to increase 5-HT turnover, though more research is needed to identify how it works. That said, there’s a good amount of research showing it supports normal serotonin levels and may reduce symptoms of depression or anxiety.

Now that you have more of a background, you’ll better understand the significance of diet, exercise, and lifestyle topics that affect serotonin levels.

Sometimes, we need a reminder of how those choices affects us in other ways beyond how we look in the mirror. The choices you make and habits you create often affect you more in ways you cannot see than in the ways you can.

Photo by Radu Florin on Unsplash