title: Effects of omega-3 fatty acid supplementation on tumor-bearing rats.
abstract: BACKGROUND
  Dietary fish oil (rich in omega-3 fatty acids: eicosapentaenoic acid and docosahexaenoic acid) suppresses synthesis and activity of proinflammatory cytokines that induce anorexia. We hypothesized that dietary fish oil reverses the feeding pattern of tumor anorexia, increasing food intake and retarding tumor growth.
  
  
  METHODS
  Thirty-two Fischer rats were placed in Automated Eater Meter cages and randomly divided into four groups: tumor bearing (TB) rats eating normal chow diet (TB-Chow); TB rats eating chow diet supplemented with omega-3 fatty acids (TB-omega-3FA); Controls, non-tumor bearing (NTB) rats eating normal chow (NTB-Chow); and NTB rats with omega-3 fatty acid supplementation (NTB-omega-3FA). Doses of 10(6) methylcholanthrene (MCA) sarcoma cells were subcutaneously injected in TB rats. Daily food intake, meal size (MZ), meal number (MN), body weight, and tumor volume were measured, and rats were euthanized at onset of anorexia. Data were statistically analyzed using analyses of variance (ANOVA) and t-tests. Data are reported as mean +/- SE.
  
  
  RESULTS
  Tumor appeared significantly earlier in TB-Chow than in TB-omega-3FA rats (7.5 +/- 0.3 days versus 11.6 +/- 0.8 days, p < 0.05). Daily food intake declined significantly in TB-Chow versus TB-omega-3FA rats 18 days after tumor inoculation and, at onset of anorexia, was 9.41 +/- 1.77 g/day versus 13.32 +/- 0.81 g/day, p < 0.05. Food intake decreased initially by decrease in meal number (at day 15) followed by a decrease in meal size (at day 18). At onset of anorexia, meal size and meal number were significantly decreased in TB-Chow versus TB-omega-3FA rats (0.75 +/- 0.067 g/meal versus 1.05 +/- 0.08 g/meal, p < 0.05) and (9.5 +/- 1.32 versus 12.79 +/- 0.93 meals/day, p < 0.05), respectively. Tumor volume was significantly smaller in TB-omega-3FA versus TB-Chow rats (7.6 +/- 0.6 cm(3) versus 16.5 +/- 1.0 cm(3), p < 0.05), as was tumor weight (7.5 +/- 2.2 g versus 18.1 +/- 1.6 g, p < 0.05).
  
  
  CONCLUSIONS
  In TB rats, omega-3FA improved food intake; restored normal eating pattern, delayed onset of anorexia, tumor appearance, and growth; and prevented body weight loss. Supplementation of omega-3 fatty acids has therapeutic potential in cancer anorexia.
authors.affiliation: Surgical Metabolism and Nutrition Laboratory, Neuroscience Program, Department of Surgery, SUNY Upstate Medical University, University Hospital, Syracuse, NY 13210, USA.
authors.forename: Eduardo J B
authors.initials: EJ
authors.lastname: Ramos
authors.forename: Frank A
authors.initials: FA
authors.lastname: Middleton
authors.forename: Alessandro
authors.initials: A
authors.lastname: Laviano
authors.forename: Tomoi
authors.initials: T
authors.lastname: Sato
authors.forename: Irina
authors.initials: I
authors.lastname: Romanova
authors.forename: Undurti N
authors.initials: UN
authors.lastname: Das
authors.forename: Chung
authors.initials: C
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Qi
authors.forename: Michael M
authors.initials: MM
authors.lastname: Meguid
mesh_terms: D000818:Animals; D000855:Anorexia / Q000209:etiology / Q000517:prevention & control*; D004041:Dietary Fats / Q000494:pharmacology / Q000627:therapeutic use*; D019587:Dietary Supplements; D004435:Eating / Q000187:drug effects; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D023421:Models, Animal; D051381:Rats; D011916:Rats, Inbred F344; D012509:Sarcoma / Q000150:complications / Q000628:therapy*; D016037:Single-Blind Method; D012983:Soft Tissue Neoplasms / Q000150:complications / Q000628:therapy*
chemical_list: D004041:Dietary Fats; D015525:Fatty Acids, Omega-3