Are herbal and dietary supplements effective against anxiety and depression?

There has been a massive boom in the use of supplements in recent years, as millions of us try to fight the effects of illness, ageing, and poor lifestyle choices to improve and prolong our health and well-being. Products that were once the preserve of specialist health food stores can now be found alongside our groceries on supermarket shelves, and every month seems to bring news of a newly discovered and exotic sounding remedy that could potentially solve all our problems. But as the market in supplements continues to grow, so do the number of remedies, formulations and doses, making it increasingly difficult for consumers to know what, if anything, is worth taking - and what isn’t.

Although herbal and dietary supplements aren't a replacement for a medical diagnosis and treatment, for some people certain supplements can work well against anxiety and depression, either as a complementary therapy (used in conjunction with conventional medicine) or as an alternative therapy (used instead of conventional medicine). Unfortunately, supplements aren’t monitored by the government in the same way that prescribed medications are, so be sure to get the approval of your health care provider before making a purchase, because some herbal and dietary supplements can interfere with prescription medications or cause dangerous interactions.

Here is a list of popular herbs and supplements that are promoted as being effective treatments for anxiety and/or depression, together with the best available evidence of their efficacy.

Ashwagandha (Indian Ginseng)

Used in Ayurveda, a traditional Indian medicine that can be traced back thousands of years, Ashwagandha has shown effectiveness in reducing cortisol levels when compared to those taking a placebo. Cortisol is the stress hormone that goes up when we’re anxious, and also creates fatigue and mental fogginess when it’s too high. Ashwagandha is classed as an ‘adaptogen’ that corrects the imbalance between the immune and neuroendocrine systems to normalize the bodily functions under stressed conditions. A double-blinded, randomized controlled trial of 64 subjects found that “Ashwagandha root extract safely and effectively improves an individual’s resistance towards stress and thereby improves self-assessed quality of life.” However, it should not be taken by anyone with a stomach ulcer, and those with diabetes or low blood pressure should monitor their condition closely. More information can be found here.

Cannabidiol (CBD)

The two main compounds found in cannabis are cannabidiol (CBD) and tetrahydrocannabinol (THC). THC is the ingredient that produces mind-altering (psychoactive) effects in users, and is the reason cannabis is illegal in many jurisdictions. Whereas CBD has antipsychotic effects, and evidence is emerging of its effectiveness in treating epilepsy, pain, and anxiety. The exact cause for these effects is not yet clear. However, cannabidiol seems to prevent the breakdown of a chemical in the brain that affects pain, mood, and mental function, and side effects are minimal. Anyone wishing to try CBD are advised to research the laws in their area regarding the use of cannabis products. More information can be found here.

Chamomile

A recent study by the University of Pennsylvania compared Chamomile extract with a placebo for the treatment of mild to moderate generalised anxiety disorder, and found that those people given the herbal treatment during an 8 week period, had a statistically significant reduction in their symptoms. It’s generally considered to be safe, although there’s evidence of an increased risk of bleeding when used with blood-thinning drugs, and it can cause allergic reactions in some people who are sensitive to the family of daisy-like plants called Asteraceae, of which chamomile is a member. However, Chamomile, whether in tea, tincture or essential oil form, appears to be one the best medicinal herbs for fighting stress and promoting relaxation, according to research. More information can be found here

Ginkgo Biloba

Also known as maidenhair, Ginkgo Biloba has been used as a medicine in China for thousands of years. Ginkgo extract is now widely used in Europe for treating memory loss, concentration problems, depression and anxiety, where it’s available by prescription or as an approved over-the-counter medication. In one year alone, West German doctors wrote 5.24 million prescriptions for ginkgo leaf extract, which is believed to work by increasing blood supply, reducing blood viscosity, and increasing uptake of both serotonin and dopamine; neurotransmitters that are often low in those who suffer with depression. It can also reduce symptoms of anxiety and stress by lowering levels of the stress hormone cortisol. In trials it was safe and well tolerated, and may be of particular value in elderly patients with anxiety related to cognitive decline. Be aware that Ginkgo leaves contain long-chain alkylphenols which are highly allergenic and are similar to the irritating compounds found in poison ivy, poison oak, and poison sumac, so anyone with a known allergy to any of these plants, should avoid it. More information can be found here.

L-Tryptophan

An essential amino acid that our bodies can't make themselves, we get our L-tryptophan from our food. It is then converted to 5-HTP (5-hyrdoxytryptophan), and then to serotonin, which can affect mood, appetite, and sleep patterns. L-tryptophan is used for treating several diseases where serotonin is believed to play an important role, such as depression, insomnia, and obesity, but although several studies have been carried out, not all of them were of sufficient quality to be reliable, and further studies are needed. Serious side-effects have also been reported. Some people have developed a condition called eosinophilia-myalgia syndrome (EMS), involving muscle tenderness and blood abnormalities. As some prescribed medications for depression also increase serotonin, taking 5-HTP along with these medications may increase serotonin to unsafe levels and cause side effects including heart problems, shivering, and anxiety. Because alternative anti-depressants exist which have been proven to be effective and safe, the clinical usefulness of 5-HTP and tryptophan is limited at present.

Lavender

The smell of lavender is available in a variety of forms; in sachets, sprays, oils, and lotions, and has been used for centuries to calm anxiety without causing drowsiness. More recently it has been placed in a capsule that allows it to be taken orally. It’s not addictive or dangerous, and can be used as and when needed. Although a number of studies have investigated lavender’s effectiveness for anxiety, stress, and overall well-being, the majority were small and of poor quality, and have shown mixed results.

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Omega-3 fatty acids 

High amounts of these fats are found in cold-water fish, flaxseed, flax oil, and walnuts. This natural substance plays a part in the functioning of every cell in the body, and increased consumption of these foods has already been shown to reduce the risk of heart disease, stroke, and Alzheimer's disease. Although more research is necessary, several studies have found Omega-3 supplements to be a well-tolerated complementary therapy (to assist the primary treatment) for adults with depression. However, evidence suggests it is no more effective than a placebo when used by itself. More information can be found here.

Rhodiola

Sometimes called Arctic Root or Golden Root, Rhodiola is also considered an ‘adaptogenic’ herb. It grows at high altitudes in the arctic areas of Europe and Asia, and its root has been used in traditional medicine in Russia and Scandinavian countries for centuries. Studies published in 2007 and 2008 showed improvements in patients with mild to moderate depression and generalised anxiety disorder who took Rhodiola, when compared to those who took a placebo. Further reviews in 2010 and 2011 reached similar conclusions, and found side-effects were generally mild or moderate in severity. More information can be found here.

SAM-e

SAM-e is short for S-Adenosyl-L-Methionine, which is a compound found naturally in the body that helps produce and regulate hormones and maintain cell membranes. As we age, our bodies produce less SAM-e, and a synthetic version has been used as a supplement to treat liver disease and osteoarthritis as well as depression. Although current trials are not conclusive, some studies have recorded statistically significant improvements in depressive symptoms when using SAM-e, compared to conventional tricyclic anti-depressants. Although generally believed to be safe, information on the long-term safety of SAM-e is limited, and there is concern that it may trigger mania in people with bipolar disorder, and increase the likelihood or severity of pneumocystis infection in people who are HIV positive. More information can be found here.

St. John’s Wort

First used as a medicinal herb for its anti-depressant and anti-inflammatory properties by the ancient Greeks, St John’s Wort is probably the best known herb used to treat both anxiety and depression. It has been the subject of a number of studies, some of which have shown it to be more effective than a placebo for treating depression, particularly in German-speaking countries where these products have a long tradition and are often prescribed by physicians. On the other hand, there are several studies in which the results, when compared to a placebo, contradict these findings. There are also reports of significant herb-drug interactions with St. John’s Wort that may outweigh any benefits. This is especially true for blood thinners, birth control pills, hormone-replacement therapy and chemotherapy medications, and it should not be taken in combination with prescribed anti-depressants. More information can be found here.

Valerian Root

If you have difficulty sleeping, studies show that Valerian reduces the time it takes to fall asleep and improves sleep quality, so it may be just what you’re looking for. It’s also a good option for severe anxiety spells, particularly for evening use when you won’t be driving or working. Studies indicate that Valerian increases the amount of a chemical called gamma aminobutyric acid (GABA) in the brain, which helps regulate nerve cells and calms anxiety in a similar way to drugs such as alprazolam (Xanax) and diazepam (Valium). However, in trials, some people have reported little or no benefit. It is generally considered safe in recommended doses, but since long-term safety trials are lacking, don't take it for more than a few weeks at a time, and don’t combine Valerian with other anti-anxiety medications because they can interact. More information can be found here.

If your anxiety and/or depression is interfering with your daily activities, and you’re considering taking a supplement, please talk with your doctor first, especially if you’re taking other medications. The interaction of some supplements and certain medications can cause serious side effects, and although some people find them helpful, in many cases their popularity tends to be based on traditional use, rather than scientific research.

Thank you for reading this blog post. I hope you’ve found it useful. If you have any thoughts to share, or ideas for future posts, please do let me know. I would love to hear from you.

Thomas HallComment