L-theanine is a potent amino acid that's naturally found in green tea. Black tea and oolong tea also contain L-theanine in smaller doses. Besides drinking tea, you can boost your intake of L-theanine by taking supplements.
L-theanine, or theanine, functions like gamma-aminobutyric acid (GABA) and other neurotransmitters that help relax the brain without triggering a sedative response.
Here are five scientifically-proven reasons to consume green tea, a natural source of L-theanine.
Studies suggest that L-theanine can help with anxiety and promote relaxation.
According to a 2007 study published in the journal Biological Psychology, L-theanine can help reduce your body’s stress response (e.g., increased heart rate) by decreasing the activity of the sympathetic nervous system, more commonly known as the "fight or flight" response.
Keep in mind, however, that L-theanine isn't effective if you're already in an anxious state.
L-theanine affects your brain's alpha frequency band and boosts your mental alertness. This interaction makes you feel alert and relaxed, minus the jitters associated with coffee.
Surprisingly, when L-theanine in black or green tea is combined with caffeine, its effects can be easily felt within 30 minutes. So if you need a brain boost but hate the coffee jitters, sip a calming mug of green tea instead.
While L-theanine can't make you feel sleepy, it can help you fall asleep faster by calming the part of your brain associated with restlessness, anxiety and stress. (Related: Have you heard of l-theanine? This compound is crucial for improving brain health and mental well-being.)
L-theanine helps calm your mind and allows your body to naturally revert into a state of rest. L-theanine can also benefit those with hyperactivity issues such as attention-deficit hyperactivity disorder (ADHD).
Stress can increase your blood pressure, especially if you're suffering from chronic stress.
L-theanine promotes healthy blood vessel function by increasing natural nitric oxide production in your body and lowering blood pressure when you're feeling very stressed.
Cholesterol isn’t a risk factor for cardiovascular disease but oxidized LDL (low-density lipoprotein) cholesterol is harmful. Increasing your L-theanine intake helps prevent oxidation of LDL and atherosclerosis (hardening of the arteries).
Chronic stress can weaken your immune system and make you more susceptible to illness and infection. This is because stress downregulates certain immune cells and activates other cells.
L-theanine fights this process by strengthening the immune cells that protect you from infections, such as those that cause the common cold or flu.
Drink green tea moderately to naturally boost your intake of L-theanine. Alternatively, you can drink black tea or take supplements from a trusted brand.
Ideally, L-theanine doses range from 100 to 200 milligrams (taken once or twice daily). Check dosage instructions on the supplements you bought or consult a physician to determine the best dosage for you.
L-theanine usually takes effect within 30 to 60 minutes. It is generally safe to take L-theanine after meals or on an empty stomach in the morning or at night.
Pregnant or breastfeeding women should avoid taking L-theanine. It also isn't recommended for children.
Ask your physician if you can safely supplement with L-theanine to avoid side effects like irritability, nausea, an upset stomach or interactions with medications for other health conditions.
It is best not to take L-theanine supplements long-term, but they are most effective when taken for a couple of weeks up to four months.
Drink green tea in moderation or take L-theanine supplements to fight anxiety and naturally relieve stress.
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