Geschatte leestijd: 5 minutenL-Tryptophan has been convincingly shown to help fall asleep faster. This leads to more testosterone, less fat storage, and better oxygen uptake.
L-Tryptophan
For anyone who has ever bothered to read the ingredients of, for example, a container of protein, Tryptophan is not an unfamiliar name. Proteins are composed of amino acids. L-Tryptophan is an essential amino acid, meaning it is not produced by the body and must therefore be obtained from food. It is found in foods such as milk (hence possibly the warm milk before bedtime), bananas, chocolate, and chickpeas.
Tryptophan plays a role in the production of the neurotransmitter serotonin (Tryptophan → 5-hydroxytryptophan (5-HTP) → Serotonin). This substance affects mood, confidence, sleep, emotion, sexual activity, and appetite. L-Tryptophan can act as a sleep aid, anxiolytic, and antidepressant. People with lactose allergies therefore have a higher risk of depression [1].
Why is sleep so important for muscle growth? Among other reasons, due to the production of testosterone. Research has shown that one hour less sleep means 12% to 15% less testosterone production [2].
French sports scientists also found that less sleep leads to impaired oxygen uptake. Because oxygen is one of the main sources of energy, this affects your energy levels.
Finally, researchers from the University of Bristol investigated the relationship between sleep and fat loss. They concluded that one hour less sleep can lead to almost 3% more fat storage. Enough reasons to take your sleep seriously. Now the question is whether you really need L-tryptophan as an aid and to what extent you should obtain this from supplementation.
L-Tryptophan supplement
L-Tryptophan was first isolated by Frederick Hopkins in 1901 by hydrolysis of casein. From 600 grams of casein, 4-8 grams of tryptophan can be obtained. L-Tryptophan works closely with Vitamin B6, also known as pyridoxine. Therefore, most tryptophan supplements contain added vitamin B6. Supplementation with L-Tryptophan is said to contribute to better sleep. Studies have also shown that L-Tryptophan acts as an antidepressant.
All sounds good, right?
The problem is, as with many studies, that they have been conducted by supplement manufacturers and are therefore not objective. Such independent studies have not shown the same clear picture. In fact, various studies have concluded that a change in diet hardly affects the levels of L-Tryptophan in the body.
This may sound strange if you have just read that you only get L-Tryptophan from food. However, look at the overview below of foods in which it occurs, and you’ll see that you would have to eat very one-sidedly to get too little L-Tryptophan. However, you may wonder if supplementation is necessary. How much should you get daily? A quick calculation shows that you get on average 1.33 grams of L-Tryptophan per 100 grams of protein. The average athlete consumes between 2-3 grams of protein per kilogram of body weight. For example, if you weigh 80kg, that’s 160 to 240 grams of protein depending on your training method and diet plan at the time.
So, the food from which these proteins are derived provides 2.1 to 3.2 grams of L-Tryptophan per day.
Researchers from the Naval Health Research Center in the US investigated how long it takes to fall asleep. They gave subjects 8 grams of L-Tryptophan twice a day. This is more than you would normally get (even on a bulking diet).
The results showed that the subjects who received L-Tryptophan fell asleep twice as quickly! This was mainly attributed to serotonin. The dose was also taken an hour in advance because serotonin levels were found to be highest after 75 minutes. However, serotonin is only calming when the environment is. This was unfortunate for the researchers because they were mainly looking for ways for soldiers in war zones to fall asleep faster. What was a positive outcome was that falling asleep faster also occurred during the day, so supplementation could also be used for a nap.
Now, most athletes don’t live in a war zone. In that sense, you might find it useful. However, the research only focused on the speed of falling asleep, even though manufacturers claim that the quality of sleep also improves. If you have now realized (or already knew) how important sleep is, you can also choose to simply go to bed earlier! The prices of L-Tryptophan supplements are around €28. These are 100 capsules containing 500mg of L-Tryptophan, 10mg of vitamin B6, and 5 grams of vitamin B3. Depending on your needs and how your body responds, you take 1 or 2 capsules before bed. With one jar, you can therefore get ahead for about a month and a half to 3 months. This will cost you about €10 to €15 per month.
Okay, not the most expensive supplement. But again, do you really need it if it’s just about falling asleep faster? I don’t think so. Then just go to bed earlier for that extra hour of sleep and not write articles for a website until midnight.
Therefore, in my opinion, L-Tryptophan should only be considered if you regularly have trouble falling asleep. Regular sleep aids (usually benzodiazepines) have the disadvantage of potential physical and psychological dependence. This is why their use for longer than 4 weeks is not recommended. This has not been studied for Tryptophan. However, there is no reason to believe that there will be no psychological dependence. Long-term use is therefore not recommended. Even for people with structural sleep problems, it is advisable to refrain from using Tryptophan for a period at least equal to the duration of its use. If it’s not just about falling asleep, but your sleep itself is also very irregular and restless, causing you to lack rest?
Consult your doctor to investigate what may be going on. Some people only find out after years that they have been sleep deprived due to, for example, sleep apnea (where breathing stops for several seconds multiple times during the night). By the way, the chance of sleep apnea increases as your neck gets thicker. Not an immediate reason to stop training your neck muscles, but something to be aware of if you do turn out to have sleep apnea.
Side Effects of L-Tryptophan
Side effects described include blurred vision, dizziness, fatigue, and “mild mental discomfort.” In several countries, L-Tryptophan has been banned or temporarily banned as it was associated with a number of cases of illness and death. Initially, the US FDA thought that an outbreak of EMS cases (eosinophilia-myalgia syndrome) was caused by Tryptophan produced in Japan. However, it later turned out that it was likely caused by contamination during the production process. The ban was lifted, but with the warning:
“Based on the scientific evidence that is available at the present time, we cannot determine with certainty that the occurrence of EMS in susceptible persons consuming L-tryptophan supplements derives from the content of L-tryptophan, an impurity contained in the L-tryptophan, or a combination of the two in association with other, as yet unknown, external factors.”
Some medications, especially antidepressants and MAO inhibitors, should not be taken simultaneously with L-Tryptophan.
Conclusion
L-Tryptophan has been convincingly shown to help fall asleep faster. If you use it, do so in periods and only when really necessary. If you can sleep longer simply by going to bed earlier, do that! L-Tryptophan can be useful, but it doesn’t top my list of “must-have supplements”.
References
- Ledochowski M, Sperner-Unterweger B, Fuchs D. Lactose malabsorption is associated with early signs of mental depression in females: a preliminary report. Dig Dis Sci. 1998 Nov;43(11):2513-7. PubMed PMID: 9824144.
- Goh VH, Tong TY. Sleep, sex steroid hormones, sexual activities, and aging in Asian men. J Androl. 2010 Mar-Apr;31(2):131-7. doi: 10.2164/jandrol.109.007856.Epub 2009 Aug 14. PubMed PMID: 19684340.
