But what does the science say about noni?
Noni is supposedly useful for a wide range of health problems, including arthritis, diabetes, high blood pressure, muscle aches and pains, menstrual difficulties, headaches, depression and cancer. Nevertheless, the truth is that noni hasn't been well studied in people for any health condition.
There is, however, a respectable amount of laboratory research using the fruit, and the findings of both animal and test-tube studies suggest that noni juice does indeed have a broad range of biological effects.
In the early 1990s, researchers at the University of Hawaii reported anti-cancer activity using an alcohol precipitate of noni fruit juice (noni-ppt). This was found to significantly prolong-by up to 75 per cent-the life of laboratory mice that had been implanted with Lewis lung carcinoma compared with their matched control brethren. The researchers concluded that noni-ppt appeared to suppress tumour growth indirectly by stimula-ting the immune system (Proc West Pharmacol Soc, 1994; 37: 145-6).
A later study-but one also using mice, so the results, again, may not apply to humans-found improved survival times and curative effects when noni-ppt was combined with suboptimal doses of standard chemo-therapy drugs, such as adriamycin and cisplatin. According to the researchers, these results suggest "important clinical applications of noni-ppt as a supplemental agent in cancer treatment" (Phytother Res, 1999; 13: 380-7).
Noni also appears to be cancer-protective. In a study using Tahitian Noni Juice (TNJ), a popular product made by Morinda Inc, the juice, when given to rats in drinking water, lowered the number of DNA adducts (pieces of DNA bonded to a carcino-genic chemical, indicating the begin-nings of a cancerous cell). Levels of DNA adducts were reduced by 30 per cent in the heart, 41 per cent in the lung, 42 per cent in the liver and 80 per cent in the kidneys. It was concluded that noni's antioxidant properties-comparable to those of vitamin C, grape seed powder and pycnogenol-might explain the apparent cancer-preventative effects (Ann NY Acad Sci, 2001; 952: 161-8).
Several compounds in noni are proven antibacterial agents effective against infectious bacteria such as Pseudomonas aeruginosa, Proteus morganii, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella and Shigella species. Such antibacterial activity by noni explains why the fruit has been traditionally used to treat skin infections, colds, fevers and other bacteria-related health problems (Acta Pharmacol Sin, 2002; 23: 1127-41).
Noni fruit also appears to have analgesic and tranquillizing proper-ties. When French researchers tested an extract of the roots in mice, they discovered "a significant, dose-related, central analgesic activity" as well as sedative effects. The analgesic efficacy of noni extract was nearly (75 per cent) as strong as that of morphine, while remaining non-addictive and side-effect-free (Planta Med, 1990; 56: 430-4).
Other laboratory evidence sug-gests that noni has antiviral, anti-fungal, hypotensive (blood-pressure-lowering), anti-inflammatory and immune-enhancing actions, too.
Only a few studies have looked at the effects of noni juice in humans. One placebo-controlled trial evaluated the effect of noni juice on physical endurance in athletes. In this study, 40 highly trained runners drank TNJ or a placebo (blackberry juice)-100 mL twice a day-for 21 days. Using a treadmill test, their endurance (time to fatigue) was assessed before and after the juice-drinking period. The results showed that endurance was increased by 21 per cent in the TNJ group, whereas no improvement was seen with the placebo drink. The researchers believe that the "potent antioxidant effects" of TNJ brought about their positive findings (J Medicinal Plant Res, 2008; 2: 154-8).
Other research has focused on the effects of noni juice in smokers. In one study, scientists analyzed noni's antioxidant activity by measuring levels of oxygen free radicals in the smokers' blood before and after drinking TNJ. Compared with smokers who drank a placebo (a blend of grape and blueberry juice) for 30 days, those who drank the noni juice showed significant reductions in superoxide anion radicals (SAR) and lipid hydroperoxide (LOOH)-biomarkers of degenerative diseases associated with smoking. "The re-sults suggest an antioxidant activity from noni juice in humans exposed to tobacco smoke," the researchers concluded (Chem Cent J, 2009; 3: 13).
The most promising clinical trial, however, measured the impact of noni juice on DNA adducts in the blood of more than 200 smokers. The results showed that drinking 1-4 oz of TNJ for just one month reduced DNA adduct levels by almost 50 per cent. Thus, a daily dose of TNJ may be able to reduce the risk of cancer in cigarette-smokers (Nutr Cancer, 2009; 61: 634-9).
The bottom line
Although the results of noni research are promising, it's still too early to say whether or not the fruit juice is effective for any particular health condition. In fact, according to the European Scientific Committee on Food, which evaluated TNJ in 2002, there's no evidence that the product has any nutritional benefits beyond those obtained with any other fruit juices (http://ec.europa.eu/food/fs/sc/scf/ out151_en.pdf).
However, since that report, two trials-both, however, funded by Morinda Inc-have found that TNJ may be superior to blackberry juice, and to a blueberry and grape juice blend. But independent research is now needed to confirm whether noni juice is a truly useful healthy drink.
WDDTY VOL 21 NO 3