Kudzu, St. John's Wort, and Alcohol Intake

St. John's wort in a mortar

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Preliminary studies investigated the effect of two herbs, kudzu (Pueraria lobata) and St. John's Wort (Hypericum perforatum) on alcohol intake.


Kudzu root, a starchy white root native to Japan and China, has been used for in traditional Chinese medicine to reduce alcohol intake and hangovers.

Wing Ming Keung, a pathology professor at Harvard University, has studied kudzu since 1993, looking for active compounds that could one day be used as a drug for reducing alcohol cravings for alcohol rehab and treatment.

His research team gave hamsters alcohol or water, then injected them with kudzu extract and again gave them alcohol or water. Alcohol consumption dropped by more than 50% after administration of kudzu.

In May 2005, a study led by Dr. Scott Lukas at the McLean hospital near Boston was published, comparing the effect on kudzu and placebo on alcohol intake in humans. Lukas and his colleagues used a real-life setting — an apartment with a television, reclining chair, and fridge stocked with beer.

They found that male and female subjects who took the kudzu capsules drank an average of 1.8 beers in 90 minutes, compared to the average of 3.5 beers consumed by the subjects who took the placebo. Lukas speculated that it may increase blood alcohol. As a result, people are intoxicated after drinking less.

Kudzu was first mentioned in the Divine Husbandman's Classic of the Materia Medica, which dates back to the late Han period. Kudzu was introduced to the United States in 1876 at the Centennial Exposition in Philadelphia.

Countries were invited to build exhibits to celebrate the 100th birthday of the United States. The Japanese exhibit was a beautiful garden decorated with kudzu vines which captured the interest of many people. Kudzu was used not only as an ornamental plant but was widely planted in the southern United States to prevent soil erosion.

The problem was that the warm climate of the south is ideal for kudzu growth. In fact, in the summer the vines can grow up to one foot a day. There are many stories about kudzu growing inside people's homes through open windows, and growing onto roads and bridges. It's even been called "the plant that ate the south".

Kudzu is available in health food stores in capsules, tablets, and alcohol-free liquid tinctures. The dried root is also available in Asian herbal stores. Kudzu root has a bland, chalky taste. When the powdered root is mixed with water, it acts as a thickener similar to arrowroot. In Asia, kudzu is also used as a food. It is mixed into stir-fries or made into tea.

More research is needed before it can be safely used for alcohol treatment and rehab. For instance, other studies have found that kudzu contains isoflavones that have weak estrogenic activity (one of kudzu's traditional uses is for menopausal hot flashes). Kudzu has also been found to interact with the drug methotrexate.

St. John's Wort

St. John's Wort is one of the most popular herbs in North America and Europe. Although it's known in alternative medicine as an herbal antidepressant for mild to moderate depression, it has a long history of folk use as an antiviral, an anti-inflammatory, for nerve injury and pain, and as a topical treatment to promote wound healing.

Recent preliminary studies have found that St. John's Wort may also decrease alcohol intake. Researchers at the Bradford School of Pharmacy in the UK found that a particular constituent in the plant, called hyperforin, appears to be responsible.

Hyperforin is in the red pigment that's released when the bright yellow flowers are crushed. While little is known about the safety of long-term or regular use of St. John's wort, the herb can interact with many medications.

Using Kudzu and St. John's Wort

Due to the limited research, it's too soon to recommend either herb for reducing alcohol intake or as a treatment for alcoholism. 

It's important to keep in mind that supplements haven't been tested for safety and dietary supplements are largely unregulated. In some cases, the product may deliver doses that differ from the specified amount for each herb.

In other cases, the product may be contaminated with other substances such as metals. Also, the safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

It's also important to note that self-treating a condition and avoiding or delaying standard care may have serious consequences. If you're considering using either kudzu or St. John's wort for any health purpose, make sure to consult your physician first to discuss the potential risks, benefits, and alternatives.

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