Scientists have performed many extensive studies on L-lysine and anxiety. So far, these studies have uncovered some promising findings about how L-lysine supplements may reduce anxiety levels. According to the Anxiety Disorders Association of America, anxiety is the most common mental illness in the United States. It affects over 40 million adults, or over 18 percent of the population. Furthermore, the cause of many anxiety disorders is unknown and pharmaceutical drugs for anxiety often come with unwanted side effects.
What is L-lysine
L-lysine is an essential amino acid. Essential amino acids are critical for consumption because the human body needs them, but the body can't make them on its own. This means that L-lysine must be obtained through food sources, vitamins or supplements. A 160 pound person needs about 2.7 grams of the amino acid every day.
L-Lysine and Anxiety
The studies on L-lysine and anxiety primarily focus on deficits of the amino acid. In one study on rats, it was found that L-lysine deficiencies disrupted the normal rhythmic release of serotonin, a chemical in the brain that promotes feelings of happiness. When the rats experienced stress-induced anxiety, their psycho-behavioral responses were significantly abnormal compared to the rats that were used as a control.
A similar study finds that L-lysine inhibits anxiety in rats by promoting increased serotonin levels. Yet another study found that supplementation with the amino acid lessened plasma cortisol in response to chronic stress and reduced anxiety.
In a double blind, placebo-controlled and randomized study of 108 healthy Japanese adults, researchers found that a mere weeklong oral supplement program of L-lysine, along with L-arginine, significantly reduced anxiety levels. The adults in the study did not necessarily have deficiencies of the amino acid, but were rather suspected to have low dietary intake of it. Also of importance is that the adults in the study were a mixture of those who experienced chronic stress-induced anxiety and those who experienced chronic trait anxiety.
The supplementation program resulted in both types of participants seeing lowered levels of stress. This finding could indicate that the amino acid is effective at lowering the anxiety levels of persons with anxiety from stressful situations and those who display trait anxiety that may be caused by deeper, more complicated reasons.
What the Findings Mean
The findings from these studies might mean that L-lysine plays a significant role in lowering anxiety levels in those known to have a deficiency of the amino acid, or in those who are just suspected to have a low dietary intake of it. The findings also indicate that the amino acid is effective at eliminating stress-induced anxiety and trait anxiety. Experts say anxiety disorders that the amino acid could play a role in alleviating include:
- Generalized Anxiety Disorder (GAD)
- Obsessive-Compulsive Disorder (OCD)
- Panic Disorder
- Posttraumatic Stress Disorder (PTSD)
- Social Anxiety Disorder (SAD)
- Other specific phobias
How to Get L-lysine
Take L-lysin as a vitamin supplement or obtain it from food sources. Food sources that contain the amino acid include:
- Red meat, pork and poultry
- Cheese (especially parmesan cheese)
- Fish (mainly cod and sardines)
- Fenugreek seed
You can also take the amino acid in vitamin form. The FDA recommends a daily allowance of the following for each group:
- Birth to four months: 103 mg per kilogram of body weight per day
- Children five months to two years: 69 mg per kilogram of body weight per day
- Children three to 12 years: 44 mg per kilogram of body weight per day
- Adults 13 and older: 12 mg per kilogram of body weight per day
The human body needs L-lysine to live and it is therefore considered safe and non-toxic. However, everyone should be careful not to overdose on the amino acid by taking large amounts of it in vitamin form. It is recommended that persons with cardiovascular disease and those with elevated cholesterol or triglyceride levels consult with their doctor before starting a supplementation program as it has been found that overdosing on L-lysine has a tendency to slightly worsen these conditions.
Overall, L-lysine has great potential as a treatment option for those with chronic anxiety. The amino acid has no known side effects, unlike many other anxiety medications, and is readily available in vitamin supplements and food sources.