L-Theanine, an amino acid primarily found in tea leaves, specifically green and black tea, has been gaining attention for its potential health benefits. First discovered in tea leaves over half a century ago, it’s also present in certain mushrooms and a few other plants. While many are familiar with its calming effects, its role in metabolic health and potential for aiding weight loss is less widely known. This article provides an overview of L-theanine, including its potential benefits and risks and its dosage.
What is L-Theanine?
L-theanine is a unique non-protein amino acid found in tea that is known for its various health benefits, including calming the nerves, anti-depression, improving cognition, sleep, and immune regulation properties. As an amino acid, it is not produced by the human body and is not essential for humans. Within the tea plant, L-Theanine is mostly formed in the roots and transported to the leaves, influencing tea’s comforting aroma. Different factors, such as the harvest period and the variety of tea leaves, can determine the actual concentration of L-Theanine present. It is thought to be a source of the savory taste known as umami.
Calming and Cognitive Effects
Renowned for its calming effects, L-Theanine promotes relaxation without causing drowsiness. It works by crossing the blood-brain barrier, influencing neurotransmitters like GABA and dopamine, which regulate mood and stress responses. This ability has made it popular for mental health improvements and stress reduction, as shown in various animal studies and human trials. Research on alpha brain wave activity suggests that consuming L-Theanine increases these waves, usually associated with a state of wakeful relaxation. This increase allows for better stress management and heightened creativity, helping maintain focus even in high-stress situations. Studies have shown that L-theanine boosts alpha waves, promotes alert relaxation. L-theanine promotes relaxed alertness.
Unlike caffeine, which can lead to jitters, L-Theanine enhances focus and attention, working synergistically with caffeine in tea to improve cognitive performance. This makes it a favorite among those looking to boost their mental clarity without the downsides of stimulants. Adding L-theanine to a caffeine supplement helps “improve performance and cognitively demanding tasks according to one research study”. The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness.
Sleep Improvement
While it boosts relaxation, L-Theanine also supports better sleep by reducing stress and promoting a calming effect. Its ability to reduce anxiety and promote relaxation can facilitate a restful night, making it a popular choice among those with sleep difficulties. L-theanine promotes good sleep hygiene and can help you slumber your way to a healthier weight. For more on the sleep/weight loss connection. Research suggests that L-theanine could help people relax before bedtime, get to sleep more easily, and sleep more deeply. A 2018 study found that people reported having greater sleep satisfaction after taking 450-900 mg of L-theanine daily for 8 weeks. The study participants had generalized anxiety disorder and were taking antidepressants.
Read also: Guide to Keto Fiber
L-Theanine and Weight Management
Weight loss strategies are often associated with heavy strength workouts or high-intensity cardio sessions, not calm and relaxation. But it’s actually an effective nutrient for speeding up fat loss.
Some studies suggest that L-Theanine can aid in regulating blood sugar levels. By influencing key hormones and signaling pathways, it may help improve insulin sensitivity and glucose metabolism, highlighting its potential role in metabolic health. L-Theanine may indirectly assist with weight management by improving sleep and stress levels, factors known to affect cravings and weight gain. Although not a direct weight loss supplement, its holistic benefits can contribute to a healthier lifestyle. It is backed by a lot of research as one component in the legendary fat loss supplement, green tea.
One of the biochemical effects of L-theanine supplementation is a reduction in appetite. When you’re anxious or stressed, your body yearns for something that’ll provide pleasure.
As part of a calorie-controlled diet, replacing a snack with green tea or another low-calorie hot beverage could aid weight loss. The L-theanine in green tea can create a savory taste, also known as umami flavor. Research suggests that umami flavors may increase feelings of fullness, which often helps with weight loss.
L-Theanine fights the negative effects of caffeine on the brain. The potency of L-theanine in tea is the main reason why a steaming cup of green tea offers such relaxing effects. Have you ever felt the urge to binge on all the bad foods when you’re stressed? The phenomenon of ‘stress eating’ is real, and it can lead to some major side effects for your waistline. Research suggests that stress affects the hypothalamic-pituitary-adrenal (HPA) axis, glucose metabolism, insulin sensitivity, along with appetite-related hormones and hypothalamic neuropeptides.
Read also: Do Carnivores Need Vitamins?
Plant-based ingredients have been proposed as alternative treatments for obesity. L-Theanine (THE), a unique nutraceutical component of tea, is known for its neuroprotective and cognitive benefits. L-theanine also has a positive effect on the body’s nutritional metabolism. Lin et al. demonstrated that THE can regulate glucose, lipid, and protein metabolism by activating insulin and AMPK-related pathways. Peng et al. found that THE activates AMPK and induces browning and thermogenesis of white adipose tissue in the groin, thereby improving insulin sensitivity in mice. Zheng et al. reported that THE reduces the levels of triglycerides (TG) and free fatty acids in mice serum.
Animal Studies and Metabolic Effects
L-Theanine's weight loss benefits are primarily attributed to its ability to suppress fat accumulation and increase energy expenditure. For example, a study by Zheng et al. In a diet-induced obesity study, Peng et al. (2021) discovered that administering 100 mg of L-Theanine to mice improved glucose tolerance and insulin sensitivity, and reduced total cholesterol, and free fatty acids in high-fat diet-fed mice.
L-theanine helped the mice's bodies generate more heat (burn more calories) and turned their white fat into a type of fat that burns energy more like brown adipose tissue (BAT). It also activated another protein, AMPK, which is important for energy balance. L-theanine raised levels of a molecule called α-ketoglutarate in fat cells, which can activate gene expression by changing their DNA structure. Overall, L-theanine helped reduce obesity and improved glucose tolerance and total cholesterol levels in mice fed a high-fat diet.
Animal studies have shown promising results, the lack of human studies makes it difficult to definitively say that L-Theanine is a primary supplement for weight loss.
L-Theanine, Caffeine, and Catechins Synergy
L-Theanine in combination with caffeine may reduce body weight and fat accumulation. The combination of L-Theanine and caffeine can contribute to reduced fat accumulation primarily by enhancing metabolic rate and promoting fat oxidation. Caffeine increases the body's ability to break down fat cells for energy, a process known as lipolysis, especially when combined with physical activity. Meanwhile, L-Theanine mitigates some of the negative side effects of caffeine, such as jitteriness and increased heart rate, allowing for better focus and potentially more effective workouts. Together, they may create a conducive environment for weight loss by boosting metabolism and improving exercise performance. Furthermore, by supporting neurotransmission, your hormonal axis is likely to be regulated, aiding weight loss.
Read also: Weight Loss with Adderall: What You Need to Know
L-Theanine, caffeine, and catechins form a potent trio that can significantly enhance weight loss efforts. Catechins, found in green tea, are known for their antioxidant properties and their ability to boost metabolism, thereby aiding in fat loss. As we've discussed, L-Theanine can help mitigate some of the less desirable effects of caffeine, such as jitteriness and increased heart rate. Moreover, L-Theanine can enhance the cognitive benefits of caffeine, helping you stay focused and alert.
Green tea supplies antioxidants called catechins, which boost metabolism and help burn fat more efficiently. L-theanine promotes relaxation and stress relief, which may help with stress-related eating and cravings. Enhanced Focus and Mental Clarity: L-theanine promotes relaxed alertness. Reduced Jitters from Caffeine: Sports nutrition formulas may contain caffeine for its performance-enhancing benefits. But caffeine can cause jitters, anxiety, and an increase in heart rate. Stress Reduction: Physical exertion and competition can be stressful. L-theanine helps reduce stress by increasing the production of calming neurotransmitters such as GABA, serotonin, and dopamine. Enhanced Sleep Quality: Adequate rest is crucial for muscle recovery and overall athletic performance. Synergistic Effects with Other Ingredients: In combination with other ingredients commonly found in sports supplements, such as amino acids and vitamins, L-theanine can enhance the overall effectiveness of the formula. For these reasons, the best caffeinated pre-workout supplements will always include L-Theanine.
Cardiovascular Benefits
Preliminary research indicates that L-Theanine might support cardiovascular health by reducing blood pressure and helping to mitigate stress-related damage to the cardiovascular system, emphasizing the interconnectedness of relaxation and heart health. Furthermore, the amino acid’s impact on cholesterol and lipid levels suggests a comprehensive cardiovascular benefit, extending beyond the immediate effects of relaxation and stress reduction. L-Theanine’s biological mechanisms contribute to overall heart health by potentially decreasing the risk of hypertension and atherosclerosis. L-theanine may help reduce stress, and a reduction in stress and increased relaxation can lower the heart rate. In turn, this may help lower blood pressure.
Anti-Inflammatory Properties
Emerging research suggests L-Theanine may possess anti-inflammatory properties. These properties could be beneficial in managing inflammation-related conditions, underscoring its potential as a natural aid in metabolic health. This amino acid’s ability to modulate inflammatory pathways adds another layer to its health-promoting resume. By targeting specific pro-inflammatory cytokines, L-Theanine can effectively attenuate the body’s inflammatory response, paving the way for innovative approaches to manage diseases like arthritis or inflammatory bowel disease. Its potential anti-inflammatory effects could also help fight illness.
Safety and Dosage
Generally considered safe, L-Theanine can be consumed through tea or supplements. Most people are unlikely to experience side effects when they take L-theanine, but the supplement may interact with some medications. It is essential to speak to a doctor about any current medications before taking L-theanine supplements.
L-theanine may interact with the following drugs and supplements:
- drugs for the treatment of high blood pressure
- other supplements that lower blood pressure
- stimulants, such as those that doctors use to treat attention deficit hyperactivity disorder (ADHD)
- supplements that contain caffeine
The typical dosage ranges from 100 to 200 mg per day, though it’s important to consult a healthcare provider to determine what’s best for individual needs. Safety assessments of L-Theanine indicate a low risk of adverse effects with recommended intake. Whether heightening cognitive functions or promoting relaxation, its versatility as a supplement allows for tailored use according to personal health goals.
Standard Dose: The most common dosage of L-theanine is between 100 to 200 milligrams per day. Higher Doses: Some studies and clinical trials have used doses up to 400 milligrams per day, particularly for specific therapeutic effects such as improved sleep quality or enhanced cognitive performance. Single Dose vs. Split Doses: L-theanine can be taken as a single dose or split into multiple doses throughout the day, depending on the desired effect.
In general, it’s recommended that you don’t exceed 500 milligrams (mg) a day. Most healthy adults can take between 200 mg and 500 mg a day.
Some of the reported side effects of L-theanine include:
- Headaches.
- Dizziness.
- Nausea.
- Jitteriness.
- Irritability.
- Diarrhea.
It’s important to add that these L-theanine side effects are relatively uncommon and tend to be mild. L-theanine is generally considered safe for most people, but it’s always a good idea to talk to your healthcare provider before taking any new supplement, especially if you have any underlying health conditions or are taking medications.