Ginger is grown commercially in Hawaii, especially on the Big Island and Kauai. Certain microclimates in the islands are ideal for growing some of the world’s highest-quality ginger. In addition to its culinary uses, there is a great deal of interest in its potential health benefits.
In the amounts commonly used in food, ginger is not an especially good source of any specific essential nutrient. However, many non-nutrient components in ginger are being studied for potential health benefits.
Question: What are the potential health benefits of ginger?
Answer: Traditional systems of medicine have reported using ginger for a tremendous number of health problems. Among these, perhaps the best-studied uses are for reducing or preventing nausea in conditions like motion sickness and morning sickness during pregnancy. More recently, ginger is being used to help with the nausea caused by chemotherapy during cancer treatment. There also is growing support for the use of ginger for osteoarthritis and for stomach and intestinal disorders.
Q: How effective is ginger for treating the various types of nausea?
A: Generally, the powder of the ginger rhizome is taken orally at doses ranging from half a gram to 2 grams per day. Other extracts of ginger are sometimes used as well. For seasickness and other forms of motion sickness, doses of about a gram of dried ginger powder have helped to reduce symptoms such as nausea, vomiting and vertigo. Although not all studies have reported effectiveness for motion sickness, there generally are no negative side effects. Consequently, there seems to be little or no downside to giving ginger a try for motion sickness prevention.
A recent summary of the research on using ginger for morning sickness during pregnancy found that it does help to reduce nausea. Interestingly, lower doses of less than 1.5 grams (1,500 milligrams) per day were better than higher doses. There were rarely any negative side effects reported. However, there was some concern that ginger might affect fetal sex hormones, and there was one case report of a spontaneous abortion that occurred in a woman taking ginger for morning sickness.
Consequently, low to moderate dosage is likely both the safest and most effective way to use ginger for morning sickness. Some experts caution against using ginger close to labor because of its anti-coagulant effect on the blood that could increase postpartum bleeding.
Q: Are there any downsides to consuming ginger?
A: Since ginger has a blood-thinning effect, people taking anticoagulant drugs like Coumadin should consult their doctor before taking large amounts of ginger. Moderation seems to be important in the use of ginger.
Q: How does fresh ginger compare with powdered?
A: A 1-ounce piece of fresh ginger (1 inch in diameter and about 21/2 inches long) is equivalent to about 5 grams (5,000 milligrams) of powdered ginger — about five times the daily dose used in most studies.
Q: Are there any other issues to consider?
A: Some ginger products from Asia have contained high amounts of lead, pesticides and/or fungal contamination. Currently, California is suing markets like Trader Joe’s and Whole Foods for selling ginger products with excessive lead content. Hawaii ginger is unlikely to have such contaminants. Testing of ginger grown by wholesale grower Phil Green of Kauai Organic Farms has confirmed the purity of its product.
Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.
