By Dr. Mercola
Gamma aminobutyric acid (GABA), an amino acid, is the major inhibitory neurotransmitter in your central nervous system (CNS). That is, your body uses GABA to dampen nerve activity in your brain, which leads to feelings of calm and relaxation.
Many anti-anxiety medications and sleeping pills, including alprazolam (Xanax) and diazepam (Valium), work by increasing the amount of GABA in your brain. Some natural sedative herbs, such as valerian, also work by increasing GABA.1
In the U.S., millions of Americans struggle to fall asleep each night, including about 10 percent who suffer from chronic insomnia. This latter condition involves difficulty falling asleep and staying asleep, as well as waking up too early in the morning.
It’s thought that maintaining optimal GABA levels may be imperative for restful sleep and avoiding insomnia.
GABA Is Essential for Deep Sleep
In a healthy night’s sleep, you should progress through the following sleep stages (though not necessarily in this order):2
- Stage One, when you’re preparing to drift off
- Stage Two, during which your brainwave activity becomes rapid and rhythmic while your body temperature drops and heart rate slows
- Stage Three, when deep slow brain waves emerge (this is a transition from light sleep to deep sleep)
- Stage Four, also known as delta sleep, this is a deep sleep stage
- Stage Five, or rapid eye movement (REM) sleep, is when most dreaming occurs
Stages three and four, including slow-wave sleep (also known as deep sleep), are incredibly important. Slow-wave sleep is a sleep stage associated with reduced levels of cortisol (a stress hormone) and reduced inflammation.
Deep sleep plays a very special role in strengthening immunological memories of previously encountered pathogens in a way similar to psychological long-term memory retention.3
This means when you’re well rested with sufficient deep sleep, your immune system is able to mount a much faster and more effective response when an antigen is encountered a second time. The activation of GABA receptors (specifically GABA-A receptor) is known to favor sleep.
On the other hand, low levels of GABA are known to interfere with deep sleep,4 such that people with low levels may wake easily and often throughout the night, missing out on meaningful amounts of this crucial slow-wave sleep.
Insomniacs May Have Lower Levels of GABA
One reason why people with insomnia struggle to fall asleep may be low GABA levels. Research published in the journal Sleep found average brain GABA levels were nearly 30 percent lower in people with primary insomnia compared to controls.5
People with lower levels of GABA were also more likely to wake after falling asleep. According to the researchers, “Our study provides the first evidence of a neurochemical difference in the brains of those with PI [primary insomnia] compared to normal sleeping controls.”6
Other research has also shown favorable results using GABA supplementation. In one study, an amino acid preparation containing both GABA and 5-HTP, which your body produces from the amino acid tryptophan, reduced time to fall asleep, increased the duration of sleep and improved sleep quality.7
Another study, this one published in 2016, also found sleep-promoting benefits from a combination of GABA and 5-HTP, including improving the time to fall asleep, sleep duration and sleep quality.8
The chemical 5-HTP works in your brain and central nervous system by promoting the production of the neurotransmitter serotonin, and thereby may help boost mood and enhance sleep. It seems to work in harmony with GABA.
Natural GABA Improves Sleep
There are different types of GABA in supplement form, including a synthetic variety produced from the industrial solvent pyrrolidinone and other chemicals and a natural form made via fermentation with Lactobacillus hilgardi, a beneficial bacteria also used to make the traditional Korean vegetable dish kimchi.
Recent research showed the natural GABA had various sleep-improving effects. The researchers measured brain waves using electroencephalography (EEG) after participants took 100 milligrams (mg) of natural GABA or placebo.
Those who took GABA fell asleep faster and had longer quality sleep time. They also reported feeling more energized in the morning.9
A 2015 study also found GABA produced by fermentation shortened the time it took to fall asleep and also increased non-REM sleep time by 5 percent when taken in combination with Apocynum venetum leaf extract (AVLE).10
Can You Increase Your GABA Levels Via Your Diet?
While foods don’t contain GABA, many do contain glutamate/glutamic acid. Your body produces GABA from glutamate, so eating foods rich in this substance may help to optimize your GABA levels.
Foods naturally high in glutamate/glutamic acid include protein-rich, grass-fed meat, pastured eggs and poultry, raw grass-fed cheese and wild-caught fish, along with sea vegetables, ripe tomatoes and mushrooms.
In addition, foods like fermented vegetables and kefir are rich in beneficial bacteria that have a marked impact on your GABA levels.
For instance, the probiotic Lactobacillus rhamnosus was found to have a marked effect on GABA levels in certain brain regions and lowered the stress-induced hormone corticosterone, resulting in reduced anxiety- and depression-related behavior.11
A deficiency in vitamin B6 can lead to diminished GABA synthesis,12 so be sure your diet includes B6-rich foods such as wild-caught Alaskan salmon, organic grass-fed beef and pastured chicken and chickpeas.
Drinking green tea is another option, as it contains L-theanine, an amino acid that crosses your blood-brain barrier and has psychoactive properties.
Theanine increases levels of GABA (along with serotonin, dopamine and alpha brainwave activity) and may reduce mental and physical stress and produce feelings of relaxation.13 Oolong tea is also known for its ability to increase GABA.
Beyond diet, exercise is also important. Regular exercise is one of the best cures for insomnia, and one reason why this may be is because it increases GABA. In one study, when animals exercised their brains contained new neurons designed to release GABA.14
Try This First for Better Sleep Starting Tonight
If you need more sleep, GABA is only one component that should be addressed. Overall, I suggest you read through my full set of 33 healthy sleep guidelines for details on proper sleep hygiene, but to start, consider implementing the following changes.
If you’ve tried these steps and are still having trouble sleeping, you may want to consider natural GABA (as well as melatonin or 5-HTP).
• Avoid watching TV or using your computer in the evening, at least an hour or so before going to bed. These devices emit blue light, which tricks your brain into thinking it's still daytime.
Normally, your brain starts secreting melatonin between 9 p.m. and 10 p.m., and these devices emit light that may stifle that process. Even the American Medical Association (AMA) now states:15
“… [N]ighttime electric light can disrupt circadian rhythms in humans and documents the rapidly advancing understanding from basic science of how disruption of circadian rhythmicity affects aspects of physiology with direct links to human health, such as cell cycle regulation, DNA damage response, and metabolism.”
• Make sure you get BRIGHT sun exposure regularly. Your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night. If you are in darkness all day long, it can't appreciate the difference and will not optimize your melatonin production.
• Sleep in complete darkness, or as close to it as possible. The slightest bit of light in your bedroom can disrupt your body’s clock and your pineal gland's melatonin production. Even the tiniest glow from your clock radio could be interfering with your sleep, so cover your radio up at night or get rid of it altogether.
Move all electrical devices at least 3 feet away from your bed. You may want to cover your windows with drapes or blackout shades. If this isn’t possible, wear an eye mask.
• Install a low-wattage yellow, orange or red light bulb if you need a source of light for navigation at night. Light in these bandwidths does not shut down melatonin production in the way that white and blue bandwidth light does. Salt lamps are handy for this purpose.
You can also download a free application called F.lux that automatically dims your monitor or screens16 or use blue-light-blocking glasses.
• Keep the temperature in your bedroom no higher than 70 degrees Fahrenheit. Many people keep their homes too warm (particularly their upstairs bedrooms). Studies show that the optimal room temperature for sleep is between 60 to 68 degrees F.
• Take a hot bath 90 to 120 minutes before bedtime. This increases your core body temperature, and when you get out of the bath it abruptly drops, signaling your body that you are ready to sleep.
• Avoid using loud alarm clocks. Being jolted awake each morning can be very stressful. If you are regularly getting enough sleep, you might not even need an alarm.
• Get some sun in the morning, if possible. Your circadian system needs bright light to reset itself. Ten to 15 minutes of morning sunlight will send a strong message to your internal clock that day has arrived, making it less likely to be confused by weaker light signals during the night. More sunlight exposure is required as you age.
• Be mindful of electromagnetic fields (EMFs) in your bedroom. EMFs can disrupt your pineal gland and its melatonin production, and may have other negative biological effects as well. A gauss meter is required if you want to measure EMF levels in various areas of your home. Ideally, you should turn off any wireless router while you are sleeping. You don’t need the Internet on when you are asleep.