<<Disclaimer: Verify this information before applying it to your situation.>> Part 2 - Dietary Fructose Intolerance ---------- [Ref. #3] Scand J Gastroenterol. 2000 Oct;35(10):1048-52 Full text in PDF format (paste this address together): http://www.waldenu.edu/residency/summer03/handouts/Role%20of%20Nutrition- Hunter.pdf Fructose- and sorbitol-reduced diet improves mood and gastrointestinal disturbances in fructose malabsorbers. Ledochowski M, Widner B, Bair H, Probst T, Fuchs D. Dept. of Clinical Nutrition, Institute of Medical Chemistry and Biochemistry, University of Innsbruck, Austria. BACKGROUND: Fructose malabsorption is characterized by the inability to absorb fructose efficiently. As a consequence fructose reaches the colon where it is broken down by bacteria to short fatty acids, CO2 and H2. Bloating, cramps, osmotic diarrhea and other symptoms of irritable bowel syndrome are the consequences and can be seen in about 50% of fructose malabsorbers. We have previously shown that fructose malabsorption is associated with early signs of mental depression and low serum tryptophan concentrations. It was therefore of interest whether a fructose-reduced diet could not only improve gastrointestinal complaints but also depressive signs seen in fructose malabsorbers. METHODS: Fifty-three adults (12 males, 41 females), who were identified as fructose malabsorbers according to their breath-H2 concentrations, filled out a Beck's depression inventory- questionnaire, and a questionnaire with arbitrary scales for measurement of meteorism, stool frequency and quality of life for a 4-week period before dietary intervention and 4 weeks after dietary change as for fructose- and sorbitol-reduced diet. RESULTS: Depression scores were reduced by 65.2% after 4 weeks of diet (P < 0.0001), and there was a significant reduction of meteorism (P < 0.0001) and stool frequency (P < 0.01). Improvement of signs of depression and of meteorism was more pronounced in females than in males. CONCLUSION: Fructose- and sorbitol-reduced diet in subjects with fructose malabsorption does not only reduce gastrointestinal symptoms but also improves mood and early signs of depression. ---------- [Ref. #4] J Clin Invest. 1996 Nov 15;98(10):2398-402 Full text HTML format: http://www.jci.org/cgi/content/full/98/10/2398 Full text PDF format http://www.jci.org/cgi/reprint/98/10/2398.pdf Molecular analysis of the fructose transporter gene (GLUT5) in isolated fructose malabsorption. Wasserman D, Hoekstra JH, Tolia V, Taylor CJ, Kirschner BS, Takeda J, Bell GI, Taub R, Rand EB. Children's Hospital of Philadelphia, Division of Gastroenterology & Nutrition, Pennsylvania 19104, USA. Fructose, a naturally occurring monosaccharide, is increasingly used as an added sweetener in processed foods in the form of high fructose corn syrup. Increased fructose intake combined with the identification of children with clinical evidence of isolated fructose malabsorption (IFM) has stimulated interest in possible disorders of fructose absorption. The intestinal absorption of fructose is carried out by the facilitative hexose transporter, which has been designated as GLUT5. Functional properties and tissue distribution of GLUT5 suggest that IFM might be due to mutations in the GLUT5 gene. To test this hypothesis, we screened the GLUT5 gene for mutations in a group of eight patients with IFM and in one subject with global malabsorption, as compared with 15 healthy parents of subjects and up to 6 unrelated controls. No mutations were found in the protein coding region of this gene in any of the subjects. A single G to A substitution in the 5' untranslated region of exon 1 was identified in the subject with global malabsorption. This subject and her healthy mother were heterozygous for the variant sequence, suggesting that it was unlikely to be clinically significant. In addition, sequence analysis of each of the 12 GLUT5 exons was performed in the index case and confirmed the negative single-strand conformation polymorphism findings. These studies demonstrate that IFM does not result from the expression of mutant GLUT5 protein. ---------- [Ref. #5] Cochrane Database Syst Rev. 2002;(1):CD003198 Tryptophan and 5-hydroxytryptophan for depression. Shaw K, Turner J, Del Mar C. School of Population Health, University of Queensland, Public Health Building, Herston Rd, Herston, Queensland, Australia, 4006. [log in to unmask] BACKGROUND: 5 Hydroxytryptophan (5-HTP) and tryptophan are so-called natural alternatives to traditional antidepressants, used to treat unipolar depression and dysthymia. OBJECTIVES: To determine whether 5-HTP and tryptophan are more effective than placebo, and whether they are safe to use to treat depressive disorders in adults. SEARCH STRATEGY: Trials were searched in computerized general (Medline, Psychlit, and Embase) and specialized databases (Cochrane Controlled Clinical Trials Register, Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trial Register); by checking reference lists of relevant articles; by handsearching relevant specialist journals; and by contacting relevant authors where appropriate. Publications in all languages were sought. SELECTION CRITERIA: Trials were included if they were randomized, included patients with unipolar depression or dysthymia, compared preparations of 5- HTP or tryptophan with placebo, and included clinical outcomes assessed by scales assessing depressive symptoms. DATA COLLECTION AND ANALYSIS: Data was extracted independently by the three reviewers, onto data collection forms. Inclusion criteria were applied to all potential studies independently and a coefficient of agreement (Kappa) was calculated for them. Disagreement was resolved by reaching consensus. Trial quality was scored according to risk of bias. Analysis for 5-HTP and tryptophan were combined due to the small number of included trials. MAIN RESULTS: 108 trials were located using the specified search strategy. Of these, only two trials, involving a total of 64 patients, were of sufficient quality to meet inclusion criteria. The available evidence suggests these substances were better than placebo at alleviating depression (Peto Odds Ratio 4.10; 95% confidence interval 1.28-13.15; RD 0.36; NNT 2.78). However, the evidence was of insufficient quality to be conclusive. REVIEWER'S CONCLUSIONS: A large number of studies appear to address the research questions, but few are of sufficient quality to be reliable. Available evidence does suggest these substances are better than placebo at alleviating depression. Further studies are needed to evaluate the efficacy and safety of 5-HTP and tryptophan before their widespread use can be recommended. The possible association between these substances and the potentially fatal Eosinophilia-Myalgia Syndrome has not been elucidated. Because alternative antidepressants exist which have been proven to be effective and safe the clinical usefulness of 5-HTP and tryptophan is limited at present. ---------- [Ref. #6] Adv Exp Med Biol. 1999;467:461-8 Eosinophilia-myalgia syndrome case-associated contaminants in commercially available 5-hydroxytryptophan. Klarskov K, Johnson KL, Benson LM, Gleich GJ, Naylor S. Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA. Recently, 5-hydroxy-L-tryptophan (5-OHTrp) has been promoted as an alternative to banned L-tryptophan as a dietary supplement. It has been claimed to help alleviate obesity, insomnia, depression, and headaches. However, eosinophilia-myalgia syndrome (EMS)-like symptoms have also been associated with ingestion or exposure to 5-OHTrp. HPLC-UV analysis of EMS- implicated 5-OHTrp revealed the presence of peak X, described as case- implicated. We show that peak X is actually a family of contaminants with the same molecular weight (234 Da) and similar HPLC retention times. We also demonstrate that all eight samples of commercially available 5-OHTrp analyzed by HPLC-MS contained three or more contaminants of the peak X family. The significance of these findings is discussed. * * * * Send administrative questions to [log in to unmask] *