title: Associations between toenail arsenic concentration and dietary factors in a New Hampshire population.
abstract: BACKGROUND
  Dietary factors such as folate, vitamin B12, protein, and methionine are important for the excretion of arsenic via one-carbon metabolism in undernourished populations exposed to high levels of arsenic via drinking water. However, the effects of dietary factors on toenail arsenic concentrations in well-nourished populations exposed to relatively low levels of water arsenic are unknown.
  
  
  METHODS
  As part of a population-based case-control study of skin and bladder cancer from the USA, we evaluated relationships between consumption of dietary factors and arsenic concentrations in toenail clippings. Consumption of each dietary factor was determined from a validated food frequency questionnaire. We used general linear models to examine the associations between toenail arsenic and each dietary factor, taking into account potentially confounding effects.
  
  
  RESULTS
  As expected, we found an inverse association between ln-transformed toenail arsenic and consumption of vitamin B12 (excluding supplements) and animal protein. Unexpectedly, there were also inverse associations with numerous dietary lipids (e.g., total fat, total animal fat, total vegetable fat, total monounsaturated fat, total polyunsaturated fat, and total saturated fat). Finally, increased toenail arsenic concentrations were associated with increased consumption of long chain n-3 fatty acids.
  
  
  CONCLUSIONS
  In a relatively well-nourished population exposed to relatively low levels of arsenic via water, consumption of certain dietary lipids may decrease toenail arsenic concentration, while long chain n-3 fatty acids may increase toenail arsenic concentration, possibly due to their association with arsenolipids in fish tissue.
authors: Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
authors: Joann F
authors: JF
authors: Gruber
authors: Margaret R
authors: MR
authors: Karagas
authors: Diane
authors: D
authors: Gilbert-Diamond
authors: Pamela J
authors: PJ
authors: Bagley
authors: M Scot
authors: MS
authors: Zens
authors: Vicki
authors: V
authors: Sayarath
authors: Tracy
authors: T
authors: Punshon
authors: J Steven
authors: JS
authors: Morris
authors: Kathryn L
authors: KL
authors: Cottingham
mesh_terms: D000368:Aged; D001151:Arsenic / Q000032:analysis*; D016022:Case-Control Studies; D004032:Diet; D004041:Dietary Fats / Q000032:analysis; D004281:Docosahexaenoic Acids / Q000032:analysis; D060766:Drinking Water / Q000737:chemistry; D015118:Eicosapentaenoic Acid / Q000032:analysis; D004781:Environmental Exposure; D005260:Female; D005395:Fish Oils / Q000032:analysis; D005492:Folic Acid / Q000032:analysis; D006801:Humans; D008297:Male; D008715:Methionine / Q000032:analysis; D008875:Middle Aged; D009262:Nails / Q000737:chemistry*; D009513:New Hampshire; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D001749:Urinary Bladder Neoplasms / Q000503:physiopathology; D014805:Vitamin B 12 / Q000032:analysis; D060986:Water Wells / Q000737:chemistry*
chemical_list: D004041:Dietary Fats; D060766:Drinking Water; D005395:Fish Oils; D004281:Docosahexaenoic Acids; D005492:Folic Acid; D015118:Eicosapentaenoic Acid; D008715:Methionine; D001151:Arsenic; D014805:Vitamin B 12