RESEARCH & ARTICLES
Scientific Research on the Addictive Nature of Sugar and the Biological Basis for the Treatment of Overeating.
Fat Is Not the Enemy: A New Perspective On The Pros And Cons Of Oily Foods Adapted from The Mood Cure by author Julia Ross, M.A.
Urinary Neurotransmitter Testing - Problems And Alternatives. Townsend Letter, October, 2006 by Julia Ross, M.A.
People with eating disorders who restrict their food intake are at risk for multiple nutrient deficiencies, including protein, calcium, iron, riboflavin, niacin,79 folic acid,80 vitamin A, vitamin C,81 and vitamin B6,82 and essential fatty acids.83 A general multivitamin-mineral formula can reduce the detrimental health effects of these deficiencies.
Serotonin, a hormone that helps regulate food intake and appetite, is synthesized in the brain from the amino acid L-tryptophan. Preliminary data suggest that some people with bulimia have low serotonin levels.84 Researchers have reported that bulimic women with experimentally induced tryptophan deficiency tend to eat more and become more irritable compared to healthy women fed the same diet,85 , 86 though not all studies have demonstrated these effects.87
Weight-loss diets result in lower L-tryptophan and serotonin levels in women,88 which could theoretically trigger bingeing and purging in susceptible people. However, the benefits of L-tryptophan supplementation are unclear. One small, double-blind trial reported significant improvement in eating behavior, feelings about eating, and mood among women with bulimia who were given 1 gram of L-tryptophan and 45 mg of vitamin B6 three times per day.89 Other double-blind studies using only L-tryptophan have failed to confirm these findings.90 , 91 L-tryptophan is available by prescription only; most drug stores do not carry it, but “compounding” pharmacies do. Most cities have at least one compounding pharmacy, which prepares customized prescription medications to meet individual patient’s needs.
A recent paper1 reports on nine obese patients who completed a weight-loss program, which involved taking a commercial very-low-energy liquid diet under medical supervision. [Optifast?] At the conclusion of their stringent diet, the obese subjects had lost almost 30% of their initial body weight. The percentage body-fat values decreased almost to that of the controls. The lean body mass (except for one subject who had an unusual increase during weight loss) did not differ significantly before and after weight loss.
The plasma tryptophan concentrations and ratios of tryptophan to large neutral amino acids in the obese subjects were, however, low at all times, with these effects persisting after weight reduction. Before weight loss, the subjects had below-normal plasma tryptophan concentrations, with concentrations of the other LNAAs moderately elevated, with the result being a low ratio of tryptophan to LNAAs. After weight loss, there was some reduction in plasma LNAA concentration, but the tryptophan ratio remained low because of persistently low tryptophan concentrations. They found no difference between the subjects and controls in the response of branched-chain amino acids to insulin infusion (uptake from the bloodstream into peripheral tissues). The authors note that obese subjects are often insulin-resistant and that diminished insulin action may cause low plasma tryptophan ratios. Plasma tryptophan ratios are also reported to be below normal in obese subjects, and the ratios may decrease with dieting—a possible reason, the authors suggest, for relapse after diet-induced weight loss.
Breum et al. Twenty-four-hour plasma tryptophan concentrations and ratios are below normal in obese subjects and are not normalized by substantial weight reduction. Am J Clin Nutr 77:1112-8 (2003).[from Life Enhancement website]