Tryptophan for anxiety - a misunderstanding?

Chickpeas - naturally high in tryptophan

The idea behind eating foods containing tryptophan, for anxiety reduction in particular, is that since tryptophan is a building block for serotonin (which is known to produce feelings of well-being) that the more tryptophan you eat, the more serotonin the brain will make.

Unfortunately, generally speaking, eating high tryptophan foods will not increase brain serotonin (1).

Studies find no clear justification to increase intake of tryptophan for anxiety

A recent study concluded “it is very difficult to alter blood tryptophan levels through dietary methods alone, outside of a laboratory or research setting”(2).  And they go on to warn against reports in the media that give misleading information regarding diet influencing levels of tryptophan for anxiety or depression.

The problem is that other protein building blocks are absorbed in preference to tryptophan, so even if you eat tryptophan rich foods, the other proteins in those foods prevent tryptophan levels from increasing.

Even the use of tryptophan supplements may not be very helpful in reducing either anxiety or depression. One study found that even with three grams of pure tryptophan (in conjunction with the high carbohydrate, low fat, low protein diet which is required to maximize tryptophan absorption), the test subjects didn’t experience any lowering of either depression or anxiety that could be related to tryptophan intake(3).  It has been established, though,  that tryptophan supplements will increase sleepiness and reduce the time it takes to get to sleep in cases of mild insomnia (4) .

The debate continues

There’s continued debate on the subject though, and even some scientists don’t seem to be able to let go of the idea that dietary tryptophan may correlate with improved mental well-being.

One study found that “developed nations ranking high in dietary tryptophan intake, rank low in suicide rates, independent of national wealth, alcohol intake and happiness”(5).  

So maybe there are other elements at work here – what about exercise, length of exposure to daylight, relaxation or meditation practices, to name a few, all of which have been shown to increase serotonin levels? 

Still, scientists seem to agree on one thing: increasing carb intake increases insulin in your blood and this makes it easier for tryptophan to enter the brain, where it can be converted to serotonin. Then, if nothing else, the serotonin reduces cravings for sweet or starchy foods.

If you restrict carbs, you lower serotonin and this produces those cravings that can be difficult to control. This isn’t very good news for those on low carb diets! It seems likely that lowered serotonin levels may be one of the reasons why excessive dieting can lead to anxiety problems for some people.

In the end, all this seems to be saying is that: 

  • if you don’t eat carbs you’ll start to crave them – pretty basic commonsense! 
  • carbs help to create a sense of calm satisfaction, in other words, comfort foods are called comfort foods for good reason! 
  • Diet is only one factor in the big anxiety/depression picture,

And finally it suggests that…

  • brain chemistry is a lot more complicated than we currently understand.

If you have been wondering whether to take supplements of tryptophan for anxiety problems, it may be better to save your money and focus on other supplements and herbs that have been shown to be effective.

More than anything, take a look at the big picture for getting your body/mind back into balance

1 Simon N. Young, Nov 2007, 'How to increase serotonin in the human brain without drugs', J Psychiatry Neurosci. ; 32(6): pp. 394–399.

2  Nerissa L. Soh and Garry Walter, February 2011,'Tryptophan and depression: can diet alone be the answer?' Acta Neuropsychiatrica, Volume 23, Issue 1, pp. 3–11. 

3 Samuel Seltzer, Dorothy Dewart, Robert L. Pollack, Eric Jackson, 1982–83,'The effects of dietary tryptophan on chronic maxillofacial pain and experimental pain tolerance', Journal of Psychiatric Research, Volume 17, Issue 2: pp.181–186.

4 Ernest Hartmann, 1982–83, 'Effects of L-tryptophan on sleepiness and on sleep,'Journal of Psychiatric Research, Volume 17, Issue 2, , pp. 107–113. 

5 M. Voracek, Mar 2007, 'Dietary tryptophan intake and suicide rate in industrialised nations', J Affect Disord. ;98(3): pp. 259-62. .