Mental, emotional, and physical stress are a normal part of life. Stress tolerance is of prime importance to aging well. Chronic, unresolved stress is a strong factor for diminished brain health and aging faster. It takes a toll on your brain as well as overall metabolism, digestive tract, joints, and immune system. Theanine, a unique type of amino acid found in green tea, is a highly popular nutrient used for its stress-relief and calming effects. Recent studies demonstrate surprising ways that theanine helps stress management of many types.

Theanine Calms Brain Stress

Within the brain, theanine helps buffer stress chemicals. It blocks the attachment of glutamic acid to glutamate receptors. Glutamate is a stimulatory neurotransmitter necessary for wakefulness and alertness. Some amounts of it are necessary with normal brain function.

During stress, high levels of glutamate are released. Too much glutamate release or lack of clearance out of your brain is noxious to tissues. It can lead to a myriad of concerns like disrupted sleep or feeling anxious, wound-up, or over stimulated. It can also cause poor focus, memory, and concentration. A healthy brain should be able to keep a natural balance between glutamate and stimulation versus rest and repair. Theanine helps buffer glutamate and stress effects and is considered a choice neuroprotectant nutrient.

Several randomized control trials (RCT) have demonstrated the benefits of theanine in its effect on helping the brain to manage stress and stimulation. A randomized, double-blind, placebo-controlled, crossover trial using imaging studies in healthy adults 18-40 years old showed improved stress tolerance and lower levels of cortisol during multi-tasking activities with the use of theanine.

Another RCT study evaluated l-theanine’s effects on mental health and cognitive functions. Participants received either 200 mg/day of l-theanine or a placebo for 4 weeks. Measurements were taken for cognitive function, sleep efficiency, and other measures. Those individuals who received theanine experienced better sleep quality and cognitive abilities.

Other studies found that l-theanine caused reductions in stress-elevated heart rate and irritable nerves. A double-blind study in healthy adults demonstrated improved attention to auditory information. Participants given 400 mg of l-theanine experienced better reaction times in processing verbal information versus those who received a placebo.

Theanine Supports Gut Health and Metabolism

It is easy to focus on the great benefits that theanine has on brain-stress support, but it also has a connection to other types of stress management in the gut and elsewhere. When theanine was combined with a diet rich in fiber, studies showed it played an important role in regulation and production of short chain fatty acid (SCFA) levels in the colon. This is significant, as SCFA compounds are essential to the integrity and protection of the mucosal barrier in the large intestine. This is necessary to protect what your gut lining comes in contact with, absorbs to nourish the rest of your body, or defends against and detoxifies.

Short chain fatty acids aid in multiple metabolic activities like managing insulin sensitivity and body weight. SCFA metabolism affects blood sugar management within your liver and skeletal muscles.

SCFAs can also travel across the blood brain barrier where they “talk” with the hypothalamus in the brain which suppresses your appetite. SCFAs aid mitochondrial energy production, AMPK activation and fat burning. SCFAs are vital to healthy physiology. L-theanine with dietary fiber supports production of SCFA levels that have far reaching health benefits.

Theanine Supports Immunoglobulins, and Villi

Other remarkable effects of theanine were discovered in the digestive tract. Theanine increased levels of immunoglobulins IgA, IgE, and IgG. These immune proteins are integral for immune tolerance to foods, germs, and chemicals. Learn more about immunoglobulins in the article Viruses, Vaccinations, and Depression.

In addition, theanine increased the height of the villi within the small intestine. Villi are finger-like projections essential for absorption of digested food particles. They vastly increase the surface area within the small intestine. Healthy villi look like a thick, plush carpet. Worn-down villi look like a thin Berber carpet. When villi are worn down, it is much more difficult to absorb nutrients from your diet and supplements which creates vast ripple effects throughout your body.

Athletes and Recovery

Strenuous exercise is often a challenge to the immune system. Exercise induces a pro-inflammatory state with oxidative stress. Over time, this can make athletes at higher risk for immune imbalances, inflammatory excess, and infections. In a recent study, members of an elite Polish rowing team were given theanine or a placebo for 6 weeks. Individuals who received 150 mg of theanine showed a healthier balance with interleukin-10 (IL-10) and Th1/Th2 balance. Theanine aided in immune and inflammation recovery after exercise.

Joint Health

On a different topic of theanine’s benefits, scientists explored its benefits for joint health. In this study published in Nutrients July 2020, theanine showed highly promising effects for cartilage protection. Cell and animal studies demonstrated that theanine inhibited expression of NF-kappa B, IL-1B, MMP-3, MMP-13, COX-2 and prostaglandin E2 which produce oxidative stress. Theanine helped protect cartilage cells against the cellular stress induced by these compounds.

A simple way to think about theanine is that it helps stress - lots of different types of stress. In your brain, it helps mood and stress tolerance, cognitive activities, and supports sleep quality. In your gut, it helps support SCFA production which has a snowball effect on metabolism throughout your body. It helps protect the villi and immunoglobulins within the small intestine which impacts immune system and nutritional status. It helps modulate stress responses on the immune system during athletic activities. Finally, we saw that it helped protect cartilage cells from oxidative stress.

Stress happens. Aging well with a lifetime of challenges just doesn’t happen by itself. Many different tools are needed to manage all forms of stress. Theanine is one of those tools.

Theanine may be used at night with other nutrients like calcium, magnesium, and taurine to promote enhanced relaxation and quality sleep. Theanine is in our Sleep Helper supplement. It may also be used during the day with nutrients like fisetin, omega-3 DHA, and pantethine to help daytime stress management. It may be combined with other nutrients for the immune system, gut, and/or joints for a synergistic approach. Consider the addition of theanine to your nutritional stress management arsenal.