Polynesian herbalists and folk medicine practitioners have long prized the greenish-white fruit of the noni tree -- known scientifically as Morinda citrifolia -- for its medicinal properties. Although the tree is believed to have originated in Southeast Asia, it grows today in most of the world’s tropical regions. What noni fruit lacks in visual appeal, it may well make up in health benefits, based on the findings of preliminary scientific studies.

May Protect Against Stroke Damage

Drinking the juice from noni fruit may help to protect you against the damage that a stroke can cause. Researchers at Japan’s Kobe Gakuin University conducted an animal study to determine if the antioxidant and anti-inflammatory properties of noni juice would protect laboratory mice from the brain damage caused by a temporary interruption of cerebral blood flow. Researchers divided test animals into three groups. Over the course of seven days, one group received drinking water supplemented by 3 percent noni juice, another got 10 percent noni juice in its water and a control group received untreated water. On the seventh day, researchers obstructed the flow in the test animals’ middle cerebral arteries for a period of two hours. Once normal blood flow was restored, animals that received noni juice showed less neurological deficit than those in the control group. Researchers published their findings in a 2009 issue of “Biological and Pharmaceutical Bulletin.”

Analgesic Properties

Based on the traditional use of noni fruit to relieve the pain of inflammatory conditions such as arthritis, a team of German researchers studied the effects of noni fruit in reducing sensitivity to pain among test animals. Researchers added a 10-percent solution of freeze-concentrated noni fruit puree to the drinking water of laboratory mice, which were then subjected to pain using a hot plate test. In an article in the January 2010 issue of “Phytotherapy Research,” they reported that the noni juice produced a reduction in pain sensitivity comparable to that of tramadol, a prescription analgesic used to treat moderate to severe pain.

Helps Lower Cholesterol

Dyslipidemia -- elevated blood levels of cholesterol -- is a major risk factor for the development of cardiovascular disease. A Pakistani-Saudi research team used water- and ethanol-based extracts of noni fruit, leaves and roots to treat laboratory rats in which dyslipidemia had been induced. They found that all three extracts significantly reduced cholesterol and triglyceride levels in animals that had had dyslipidemia induced through the administration of a high-fat diet. Results were published in a 2010 issue of “Lipids in Health and Disease.”

Antibacterial Properties

Taking their cue from the traditional use of noni fruit to treat bacterial infections, a team of Indian researchers conducted in-vitro testing to determine how effective noni fruit extracts would be against three common bacteria responsible for a variety of illnesses. Using a number of agents, including chloroform, methanol, ethanol and acetone, they prepared extracts from dried noni fruit powder. They found that all extracts exhibited moderate antibacterial activity against E. coli, Staphylococcus aureus and Proteus vulgaris. In a 2009 issue of “Journal of Applied Chemical Research,” researchers expressed the hope that their findings will establish a platform for further studies into noni fruit’s antibacterial properties.