Licorice (Glycyrrhiza glabra and G. uralensis)
A mainstay in Traditional Chinese Medicine (TCM), licorice extracts may be of benefit for those who have reached the exhaustion stage and are no longer producing sufficient cortisol. Licorice has the ability to decrease the breakdown or metabolism of hydrocortisone by the liver, thus increasing the amount of cortisol in circulation and reducing the strain on the adrenal glands to produce it. The combination of low doses of licorice with supplemental DHEA may help balance the HPA axis.
Sedative herbs such as hops, passionflower, poppy, and valerian can provide calming effects to reduce stress. The herbal lemon balm has been shown in a number of studies to reduce stress. This is yet another herbal that has shown benefit in reducing negative effects of stress on the body.
In a recent small clinical trial including 20 stressed volunteers, a standardized lemon balm extract (Cyracos®) was shown to significantly combat anxiety symptoms and insomnia. The extract “reduced anxiety manifestations by 18%, ameliorated anxiety-associated symptoms by 15% and lowered insomnia by 42%.”
A class of herbs known as adaptogens are helpful in regulation of the HPA axis. Dr. Nikolai Lazarev, a noted Russian pharmacologist during the cold war era, coined the term “adaptogenic herb” to describe about 25 of the hundreds of medicinal herbs having particular properties. These properties are unique to this class of herbs making them important for human health, and a very valuable supplement.
To be classified as an adaptogen, herbs must have the following three properties:
- There can be no toxicity associated with them;
- They must have a normalizing ability, (i.e. the same dose can raise or lower physiologic properties), and
- The mechanisms by which the herbs carry out their effects must be due to more than one physiologic or pharmacologic mechanism. Unlike any other compound, adaptogens condition your body to respond favourably to stress.
- Adaptogenic herbs can become an important supplement to support a healthy HPA axis stress response. The list of adaptogenic herbs include about twenty-five known herbs, and of these several have been studied for their affects on the HPA system. Ginseng (Panax ginseng), Rhodiola (Rhodiola rosea), Cordyceps (Cordyceps sinensis) Eleuthero (Eleutherococcus senticosus), and Ashwaghanda (Withania somnifera) to name a few and more information on them follow:
The adaptogenic herb Rhodiola (Rhodiola rosea) has demonstrated in a number of studies to improve both physical endurance and cognitive performance when the correct supplemented dosage it taken. Its ability to reduce fatigue associated with stress is documented in well-designed research papers. The apparent mechanism of action of Rhodiola is related to its ability in assisting neurotransmitter transport in the brain and the blunting of catecholamine release.
A large, phase III placebo-controlled clinical trial was conducted in Sweden in 2009, studying participants aged 20-55 years with a diagnosis of stress-related fatigue. Subjects taking the Rhodiola extract had significantly lower cortisol responses to chronic stress than did the placebo recipients—and as a result they had lower scores on scales of burnout and improved performance on cognitive testing.
Ashwagandha, also known as Withania somnifera, is an important Ayurvedic medicinal herb. It has many uses in traditional Indian medicine such as treatments for stress, fatigue, pain, diabetes, gastrointestinal and rheumatologic disorders. Ashwagandha has shown promising effects in neuro-protection as scientists have discovered that this adaptogenic herb prevents damage to neurons and improves neurological function in the face of stress. Additionally, data suggests that Ashwagandha may reduce the harmful effects of stress on male reproductive capacity.
This herb is probably the most recognized of the adaptogen herbs in the West ( also known as Panax ginseng). There are eleven species of this medicinal herb, Pamax ginseng being among the most widely studied American Ginseng. Panax quinquefolius is another species within the Panax genus that shares medicinal properties. While Siberian ginseng (Eleutherococcus senticosus), is technically not a true ginseng botanical, it still has similar beneficial properties and is closely related to the Panax family of plants.
A wealth of studies exist that show stress reducing properties of true ginseng and the other ginseng related herbals. For example, the isolated polysaccharides from P. ginseng have demonstrated anti-fatigue properties in one recent study. American ginseng extract shows a reduction in oxidative endothelial damage due to diabetes. Anti-depressive effects and the positive modulation that benefits the HPA axis is outlined in a research paper on protective ginsenosides in Panax and other ginseng plants showing usefulness in the management of chronic stress.
Holy basil (Occiumum tenuiflorum)
If a person has adrenal gland disorder it is common for them to show signs of increased cortisol and blood glucose levels. Increased blood glucose is also seen in people receiving chronic glucocorticoid treatment. Ocimum sanctum, or holy basil, is a herb widely grown in India that is known for its ability to control blood sugar. Clinical trials in humans have also shown the benefits of holy basil extract for improving immune function, as well as decreasing stress and depression associated with anxiety. Studies in healthy human subjects showed that treatment with 300 mg of holy basil extract for 4 weeks increased antibody levels and cells in the immune system.
The herb Bacopa monnieri is used in the classical Indian medicinal system of Ayurveda as a tonic for the nervous system and is known to promote mental health. It has also been shown to possess anti-anxiety properties.
At the time of this writing, a clinical trial is currently underway in Australia to test the effects of Bacopa and another herb, pycnogenol, in reducing cognitive decline with aging. The trial will evaluate the effects of Bacopa supplementation for up to a year on mood, cognition, blood pressure, inflammation, and oxidative stress, among other tests.
Oxidative stress damages cells and is associated with various health disorders. Cordyceps sinensis is a type of mushroom used in Chinese medicine that has been found to boost the immune system and possesses anti-tumor and antioxidant properties.