Ask The Expert

Citrus Prevention
Q: I've heard that something called limonene can be an effective cancer preventive. Is that true, and where can it be found?

A: Limonene is what's called a monoterpene and is found most abundantly in the essential oils of citrus fruits and other plants. For example, D-limonene comprises more than 90 percent of the essential oil from orange peel (Citrus sinensis). Animal studies have shown monoterpenes in general have antitumor activity. The mechanism of action is not entirely clear, but certainly one beneficial aspect is that they act as detoxifying enzymes. Several clinical trials are currently under way to see how limonene works in breast and prostate cancer treatment.

Melatonin Instead Of Tranquilizers
Q: I've been taking Xanax for months to help me cope with stress and would like to wean myself off of this drug. Are there natural products that could make this easier?

A: Benzodiazepines, which include Ativan, Librium, Valium and Xanax, are tranquilizers prescribed for short-term relief from stress and anxiety. The drugs can be problematic because of potential abuse and dependence. Furthermore, patients often have difficulty discontinuing these therapies because of the resulting insomnia.

The hormone melatonin may help. Known to affect sleep and sleep cycles, studies show melatonin secretion is frequently disturbed in those with chronic sleep problems. Recently, an Israeli research group postulated that if melatonin indeed promotes sleep, it might be helpful to individuals who are trying to discontinue benzodiazepine therapy. In a randomized, crossover trial, the team enrolled 34 subjects on benzodiazepines and gave 18 of them 2 mg melatonin in a controlled-release formulation and gave 16 placebo nightly for six weeks. Participants were encouraged to reduce their benzodiazepine dosage 50 percent during week two, 75 percent during weeks three and four, and to discontinue completely during weeks five and six.

Results showed that 14 out of 18 subjects (78 percent) who received melatonin therapy—but only 4 out of 16 (25 percent) in the placebo group—were able to discontinue benzodiazepine therapy altogether. Sleep-quality scores were significantly higher in the melatonin group as well.

The researchers then had all subjects try melatonin (blinded) for six additional weeks. Six more subjects in the original placebo group discontinued benzodiazepine therapy. The six-month, unblinded follow-up assessments revealed that of the 24 patients who discontinued benzodiazepines and received melatonin, 19 (79 percent) maintained good sleep quality. It appears melatonin may be a useful adjunct in weaning patients off these potentially addictive drugs.

"Ask The Expert" is written by Dan Lukaczer, ND, director of clinical services at the Functional Medicine Research Center, a division of HealthComm International Inc., in Gig Harbor, Washington.