Ginger: a root of ancient medicine

Research on ginger

Despite the long history of empirical evidence, there is still not much scientific evidence corroborating the medicinal value of ginger with regard to most of the medical problems listed above. However, several smaller scientific studies have seemed to demonstrate ginger's medicinal value in curing/controlling motion sickness and nausea.

In one controlled study reported in 1982 in the prestigious medical journal Lancet, motion sickness—susceptible college students were subjected to a computerized rotating chair. Ginger powder (at a dosage of 940 milligrams) proved better than Dramamine (a well-known anti-nausea drug) at controlling the nausea caused by motion sickness.

In another study conducted on a cruise ship traveling in rough seas, ginger again proved as effective as Dramamine. And in yet another study of ginger's effectiveness in controlling motion/seasickness, ginger proved much better than placebos in controlling the nausea caused by seasickness in a group of naval cadets sailing in heavy seas.

Based on some of these results, health authorities in Germany (where the practice of herbal medicine is much more mainstream) now routinely recommend ginger for the prevention of motion sickness.

In a 1991 study, a group of pregnant women suffering from nausea related to morning sickness received either 250 milligrams of ginger or a placebo four times a day for four days. Seventy percent of women in the study felt that their symptoms were better relieved with ginger than with the placebo.

And in two other separate investigations, women who were given ginger prior to undergoing gynecological surgery suffered much less post-operative nausea than did those who received a placebo—a rate of effectiveness equal to that of Reglan, a prescription drug used for the same purpose.

But not everyone agrees that ginger is an effective, or appropriate treatment for nausea. Some studies, including a NASA-sponsored Louisiana State University study, have concluded that ginger was ineffective in motion sickness prevention. It should be noted, however, that some have questioned whether the dosages used in these studies may have been too low, and/or the quality of ginger used may have been inferior, thus contributing to the negative results.

Some studies have found that ginger inhibits the blood clotting process. Other studies have refuted that finding, and some of the disagreement may be related to the amounts given and the form. It may be that fresh ginger has a more inhibitory effect than dried ginger. So, despite the (mostly) positive results in controlling post-operative and pregnancy-related nausea, many authorities strongly recommend against using ginger in those two circumstances, in part due to its possible effects on blood clotting.

People who practice Ayurvedic medicine believe that ginger is useful in relieving the pain of rheumatic disorders. Several very small studies have attempted to look at this effect, and based on patient self-reports, have reported relief of symptoms. The largest study, done in Denmark, showed no real difference in symptoms treated with ginger than those treated with ibuprofen or a placebo.

How it works

No one really knows for sure how ginger works. It is generally believed that ginger works directly on the gastrointestinal tract, which is why it doesn't prevent the dizziness related to motion sickness—just the nausea. As a result, many people now prefer ginger to anti-motion sickness drugs, since, unlike most of these drugs, which work directly on the central nervous system, ginger doesn't cause side effects such as drowsiness.

Dosage

When used to prevent motion/seasickness, it is recommended that 1000 milligrams in capsule form be taken thirty minutes before travel. Following the initial dose, one to two more 500 milligram capsules can be taken as needed every four hours, with a recommended maximum adult dosage of 4 grams (4000 milligrams) per day.

Ginger tea is a less potent option. You can make it by chopping up a two-inch section of fresh ginger and steeping it in water for about 15 minutes; it's good with honey and lemon. You can also use ginger ale, but try and make sure it's made with real ginger.

Side effects and precautions

There have been no reports in the recent medical literature of notable adverse reactions to medicinal amounts of ginger, and the Food and Drug Administration (FDA) includes ginger on its list of foods that are "generally recognized as safe." However, there is a caveat, as the American Pharmaceutical Association Practical Guide to Natural Medicine points out that "laboratory studies indicate that consuming very large quantities [of ginger] could depress the central nervous system and cause abnormal heart rhythms."

As for ginger's safety when used to prevent motion/seasickness and nausea, there's no clear-cut answer. When taken in the amounts needed to prevent motion/seasickness, ginger appears to have no adverse effects. However, because of the possible relationship between ginger and blood clotting, there has been a great deal of concern expressed at the use of ginger to control post-operative nausea and/or the nausea and vomiting caused by morning sickness.

And ginger may interact with certain drugs, especially warfarin (Coumadin), a blood thinner. As a result, medical authorities recommend that, until research has definitively shown it to be safe, pregnant women should avoid taking ginger without the advice of a physician. And even if you're not pregnant, don't take medicinal dosages of ginger without your doctor's approval if you are taking any blood-thinning, diabetes, or heart medications. In fact, it's a good idea to mention all your medications—including any herbs or supplements you take—every time you visit the doctor or pharmacy.