The three dietary supplements that are most effective for treating anxiety.

Dietary supplements which contain passionflower, kava or combinations of L-lysine and L-arginine can help reduce anxiety, according to a review published in the Nutrition Journal.

The supplements generally had mild to moderate effects without producing any serious side-effects.

The review included results from 24 separate studies with over 2,000 participants.

The researchers also concluded that St John’s Wort and magnesium were not effective in treating anxiety (Lakhan & Vieira, 2010).

Dr Shaheen Lakhan, the study’s first author, said:

“Our review and summary of the literature on herbal remedies and dietary supplements for anxiety should aid mental health practitioners in advising their patients and provide insight for future research in this field.

We found mixed results — while passionflower or kava and L-lysine and L-arginine appeared to be effective, St John’s Wort and magnesium supplements were not.”

Of the supplements included, kava has been the most extensively studied.

The kava plant is originally from the western Pacific and its roots have traditionally been used to make a drink with anaesthetic and sedative effects.

The researchers found that taking kava on its own…

“… significantly reduced anxiety symptoms in a variety of patient types.

This provides good evidence for the use of kava in patients with GAD, non-psychotic anxiety and other anxiety-related disorders.” (Lakhan & Vieira, 2010).

Passionflower was originally discovered in Peru in 1569.

Nowadays it is often found in supplements in combination with kava and other ingredients.

On its own, though, the researchers found:

“All three of these studies showed a positive benefit for treatment with passionflower, providing good evidence of its effectiveness as an anxiolytic agent [anti-anxiety].

However, since each of these studies was conducted in a different patient type, more research is needed to prove its efficacy in each indication.”

Finally, L-lysine and L-arginine are essential amino acids which can reduce the hormonal stress response.

“Combination nutritional supplements containing lysine or magnesium also appear to hold promise as treatments for anxiety symptoms and disorders.

Both RCTs of L-lysine and L-arginine combinations demonstrated positive results, providing good but limited evidence of its usefulness as a treatment for anxiety.”

[Note: Kava is legal in the US and Canada and many other places, but not in the UK. It is has been linked to liver problems. In some people passionflower can cause drowsiness and confusion. As always, articles on PsyBlog do not constitute medical advice.]