• Projected Long-Chain n-3 Fatty Acid Intake Post-Replacement of Vegetables Oils with Stearidonic Acid-Modified Varieties: Results from a National Health and Nutrition Examination Survey 2003-2008 Analysis

      Bowen, Kate J; Richter, Chesney K; Skulas-Ray, Ann C; Mozaffarian, Dariush; Kris-Etherton, Penny M; Univ Arizona, Dept Nutr Sci; Univ Arizona, Arizona Ctr Aging (WILEY, 2018-10-01)
      Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake is well below the amount recommended by the 2015-2020 Dietary Guidelines for Americans (0.25 g/day), supporting the need for alternative dietary sources. Stearidonic acid (SDA)-enriched soybeans were bioengineered to endogenously synthesize SDA, which can be readily metabolized to EPA in humans; thus, incorporating the derived SDA-enriched soybean oil into the food supply is a potential strategy to increase EPA. We performed a dietary modeling exercise using National Health and Nutrition Examination Survey 2003-2008 repeat 24-h dietary recall data (n = 24,621) to estimate the potential contribution of SDA-enriched oils to total long-chain n-3 fatty acid intake (defined as EPA + DHA + EPA-equivalents) following two hypothetical scenarios: (1) replacement of regular soybean oil with SDA soybean oil and (2) replacement of four common vegetable oils (corn, canola, cottonseed, and soybean) with respective SDA-modified varieties. Estimated median daily intakes increased from 0.11 to 0.16 g/day post-replacement of regular soybean oil with SDA-modified soybean oil, and to 0.21 g/day post-replacement of four oils with SDA-modified oil; the corresponding mean intakes were 0.17, 0.27, and 0.44 g/day, respectively. The percent of the population who met the 0.25 g/day recommendation increased from at least 10% to at least 30% and 40% in scenarios 1 and 2, respectively. Additional strategies are needed to ensure the majority of the US population achieve EPA and DHA recommendations, and should be assessed using methods designed to estimate the distribution of usual intake of these episodically consumed nutrients.
    • Prospective clinical trial examining the impact of genetic variation in FADS1 on the metabolism of linoleic acid- and ɣ-linolenic acid-containing botanical oils

      Sergeant, Susan; Hallmark, Brian; Mathias, Rasika A; Mustin, Tammy L; Ivester, Priscilla; Bohannon, Maggie L; Ruczinski, Ingo; Johnstone, Laurel; Seeds, Michael C; Chilton, Floyd H; et al. (OXFORD UNIV PRESS, 2020-05)
      Background: Unexplained heterogeneity in clinical trials has resulted in questions regarding the effectiveness of gamma-linolenic acid (GLA)-containing botanical oil supplements. This heterogeneity may be explained by genetic variation within the fatty acid desaturase (FADS) gene cluster that is associated with circulating and tissue concentrations of arachidonic acid (ARA) and dihomo-gamma-linolenic acid (DGLA), both of which may be synthesized from GLA and result in proinflammatory and anti-inflammatory metabolites, respectively. Objectives: The objective of this study was to prospectively compare the capacity of a non-Hispanic white cohort, stratified by FADS genotype at the key single-nucleoside polymorphism (SNP) rs174537, to metabolize 18-carbon omega-6 (n-6) PUFAs in borage oil (BO) and soybean oil (SO) to GLA, DGLA. and ARA. Methods: Healthy adults (n = 64) participated in a randomized, double-blind, crossover intervention. Individuals received encapsulated BO (Borago officinalis L.; 37% LA and 23% GLA) or SO [Glycine max (L.) Men.; 50% LA and 0% GLA] for 4 wk, followed by an 8-wk washout period, before consuming the opposite oil for 4 wk. Serum lipids and markers of inflammation (C-reactive protein) were assessed for both oil types at baseline and during weeks 2 and 4 of the intervention. Results: SO supplementation failed to alter circulating concentrations of any n-6 long-chain PUFAs. In contrast, a modest daily dose of BO elevated serum concentrations of GLA and DGLA in an rs174537 genotype-dependent manner. In particular, DGLA increased by 57% (95% CI: 0.38, 0.79) in GG genotype individuals, but by 141% (95% CI: 1.03. 2.85) in TiT individuals. For ARA, baseline concentrations varied substantially by genotype and increased modestly with BO supplementation, suggesting a key role for FADS variation in the balance of DGLA and ARA. Conclusions: The results of this study clearly suggest that personalized and population-based approaches considering FADS genetic variation may be necessary to optimize the design of future clinical studies with GLA-containing oils.