Literature review & commentary

Townsend Letter for Doctors and Patients, Nov, 2003 by Alan R. Gaby

Barringer TA, et al. Effect of a multivitamin and mineral supplement on infection and quality of life. A randomized, double-blind, placebo-controlled trial. Ann Intern Med 2003;138:365-371.

Strip teas

The potential of various herbal teas to damage the teeth was assessed by measuring their pH, neutralizable acidity, and ability to erode dental enamel. The pH of the herbal teas ranged from 3.1 to 7.1 and their neutralizable acidity ranged from 3.5 to 60 ml of 0.1M NaOH. The amount of enamel removed during one hour of immersion in the herbal teas ranged from 0 to 9.6 micrometers. In comparison, orange juice had a pH of 3.7 and a neutralizable acidity of 21.4 ml, and removed 3.3 micrometers of enamel. Teas that eroded more enamel than did orange juice included 1) 2 of 3 brands of lemon tea, 2) echinacea/raspberry tea, 3) black currant/ ginseng/vanilla tea, 4) raspberry/cranberry/elderflower tea, 5) raspberry/strawberry/loganberry tea, 6) traditional blackcurrant tea, and 7) peach/passion fruit tea. Tesco blend produced virtually no erosion.

Comment:Direct contact of acidic foods or beverages with the teeth can cause erosion of dental enamel. Many epidemiological studies show a high prevalence of tooth wear, even in young people. Rinsing the mouth once or twice with water or another non-acidic liquid could presumably reduce the capacity of acidic foods and beverages to damage the teeth.

Phelan J, et al. The erosive potential of some herbal teas. J Dent 2003;31:241-246.

DHEA for schizophrenia

Thirty schizophrenic inpatients (mean age, 37.4 years) with illness duration greater than two years and prominent "negative" symptoms were randomly assigned to receive, in double-blind fashion, DHEA or placebo for 6 weeks, in addition to their usual antipsychotic medication. The dose of DHEA was 25 mg/day for 2 weeks, then 25 mg twice a day for 2 weeks, then 50 mg twice a day for 2 weeks. Significant improvements were seen in the DHEA group, compared with baseline, for negative symptoms (p < 0.001), depression (p < 0.05), and anxiety (p < 0.001). The improvement in negative symptoms was significantly greater in the DHEA group than in the placebo group (p < 0.01) from week 3 onward. The mean reduction in negative symptoms, as assessed by the negative subscale of the Positive and Negative Syndrome Scale (PANSS), was 26% in the DHEA group and 12% in the placebo group (p < 0.05). The beneficial effect of DHEA was most pronounced in women. The improvement in negative symptoms was independent of improvement in depression. Compared with placebo, DHEA had no significant effect on positive symptoms. No significant side effects were seen.

Comment: Negative symptoms of schizophrenia (including emotional blunting, social withdrawal, and cognitive deficits), in contrast to the positive symptoms (such as delusions and hallucinations) are often refractory to treatment. The beneficial effects of DHEA, as reported in this study, therefore represent a potentially important advance in the treatment of schizophrenia. DHEA was well tolerated, and did not appear to interact with conventional antipsychotic medication. Although the mechanism of action of DHEA is not clear, this hormone has been called the biochemical embodiment of chi (the life force) by holistic pioneer C. Normal Shealy, MD.