title: Fatty acid composition in the mature milk of Bolivian forager-horticulturalists: controlled comparisons with a US sample.
abstract: Breast milk fatty acid (FA) composition varies greatly among individual women, including in percentages of the long-chain polyunsaturated FAs (LCPUFA) 20:4n-6 (arachidonic acid, AA) and 22:6n-3 (docosahexaenoic acid, DHA), which are important for infant neurological development. It has been suggested that owing to wide variation in milk LCPUFA and low DHA in Western diets, standards of milk FA composition should be derived from populations consuming traditional diets. We collected breast milk samples from Tsimane women at varying lactational stages (6-82 weeks). The Tsimane are an indigenous, natural fertility, subsistence-level population living in Amazonia Bolivia. Tsimane samples were matched by lactational stage to samples from a US milk bank, and analysed concurrently for FA composition by gas-liquid chromatography. We compared milk FA composition between Tsimane (n = 35) and US (n = 35) mothers, focusing on differences in LCPUFA percentages that may be due to population-typical dietary patterns. Per total FAs, the percentages of AA, DHA, total n-3 and total n-6 LCPUFA were significantly higher among Tsimane mothers. Mean percentages of 18:2n-6 (linoleic acid) and trans FAs were significantly higher among US mothers. Tsimane mothers' higher milk n-3 and n-6 LCPUFA percentages may be due to their regular consumption of wild game and freshwater fish, as well as comparatively lower intakes of processed foods and oils that may interfere with LCPUFA synthesis.
authors.affiliation: Integrative Anthropological Sciences, University of California Santa Barbara, Santa Barbara, California 93106-3210, USA. melaniemartin@umail.ucsb.edu
authors.forename: Melanie A
authors.initials: MA
authors.lastname: Martin
authors.forename: William D
authors.initials: WD
authors.lastname: Lassek
authors.forename: Steven J C
authors.initials: SJ
authors.lastname: Gaulin
authors.forename: Rhobert W
authors.initials: RW
authors.lastname: Evans
authors.forename: Jessica G
authors.initials: JG
authors.lastname: Woo
authors.forename: Sheela R
authors.initials: SR
authors.lastname: Geraghty
authors.forename: Barbara S
authors.initials: BS
authors.lastname: Davidson
authors.forename: Ardythe L
authors.initials: AL
authors.lastname: Morrow
authors.forename: Hillard S
authors.initials: HS
authors.lastname: Kaplan
authors.forename: Michael D
authors.initials: MD
authors.lastname: Gurven
mesh_terms: D000293:Adolescent; D000328:Adult; D001838:Bolivia; D005227:Fatty Acids / Q000032:analysis*; D005228:Fatty Acids, Essential / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005260:Female; D006801:Humans; D007774:Lactation / Q000378:metabolism* / Q000502:physiology; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D008875:Middle Aged; D008895:Milk, Human / Q000737:chemistry*; D009752:Nutritional Status; D014481:United States; D055815:Young Adult
chemical_list: D005227:Fatty Acids; D005228:Fatty Acids, Essential; D005231:Fatty Acids, Unsaturated