Brief Summary of Minutes of Annual Meeting

The proposed research is relevant to public health because fish oil supplementation and fortification of foods continues to rapidly increase in the US and safety concerns relative to excess intake have not been addressed. This research is the first step in a continuum to understanding mechanisms by which fish oil modulates colitis and progression to cancer. The project explores how omega-3's modulates colitis and cancer risk and will impact recommendations that can lessen disease burden.

Accomplishments Major goals of the project: 1) To determine the effects of omega-3 fatty acids on health related outcomes in both human and rodent models. 2) To define the mechanisms mediating the health promoting effects of omega-3 fatty acids.

What was accomplished under these goals? My laboratory has a colitis-prone mouse model where inflammation progresses to colon cancer. We have characterized both the inflammation and immune-cell population changes and have begun using this model to investigate the influence of diet on colonic inflammation and tumor induction/progression. We are working with the long-chain omega-3 fatty acids from fish, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). I am the PI on a NIH grant that just ended to determine how EPA and DHA might differ in their effects on colitis/colon risk. We recently published that a diet containing excessive amounts of fish oil enhanced inflammation and progression to adenocarcinomas in colitis-prone mice. We have a manuscript accepted by the Journal of Nutritional Biochemistry describing the differential effects of high fish oil on gut barrier function and neutrophil activation. We are actively examining the plasma fatty acids and colon polyp risk in my human samples and published a manuscript in PLEFA regarding this work along with another submitted. Finally, we have completed a project in Tanzania to characterize whole blood fatty acids and the association with growth and cognitive function in Tanzanian children 2-6 with Dr. Harris from OmegaQuant. This analysis is completed and with 2 presentations in 2015 at national meetings and 3 publications in preparation for 2016 submission.

What opportunities for training and professional development has the project provided? The umbrella project is involved in partial training for a postdoctoral student who is working on a manuscript. In addition, we have 2 graduate students and 3 undergraduates that have laboratory training and professional development related to this project.

How have the results been disseminated to communities of interest? 5 publications in 2014-2015 and 4 presentations at the Experimental Biology Meeting in April 2015.

University of Nebraska, C, DiRusso

Studies at the Nebraska Station have demonstrated that the regulatory and metabolic impact of dietary long chain polyunsaturated fatty acids, AA, EPA and DHA, differ from that of the 18 carbon polyunsaturated fatty acids, linoleic and linolenic acids. The questions we are addressing: include (1) what is the contribution of dietary fat to the development and progression of cardiovascular disease, metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH); (2) what is the influence of dietary fat on the metabolic and genetic relationships among NAFLD/NASH, hepatic cholesterol and bile acid transport, and lipoprotein levels; (3) how do dietary polyunsaturated fatty acids and long chain polyunsaturated fatty acids differentially regulate these processes; and (4) what biomarkers of liver found in blood correlate with dietary fatty acid composition to report on these metabolic processes. The studies planned for this funding period build on previous studies from our lab, which demonstrated the regulatory and metabolic impact of dietary long chain polyunsaturated fatty acids, AA, EPA and DHA, differ from that of the 18 carbon polyunsaturated fatty acids, LA and LN. From these studies we determined the metabolic profile of blood lipids and transcription profile of liver is more similar when mice are fed diets containing saturated fat or polyunsaturated fats then when mice are fed diets enriched in the long chain polyunsaturated fatty acids. Studies proposed for the next grant period will extend the rodent studies and will verify findings in human plasma samples provided by other investigators who are members of the NC-1199 multistate group.

^{What was accomplished under these goals? [1] To determine the effects of omega-3 fatty acids on health-related outcomes we have primarily employed cell and mice models. We have continued our characterization of two compounds inhibitors of fatty acid uptake to show that each prevents lipotoxic damage to cells at multiple levels. We have also demonstrated each attenuates the absorption of fatty acids across the gut using mice. These data were reported in two publications and two oral presentations as listed in the "products" sections of this report. [2] To define the mechanisms mediating the health promoting effects of omega-3 fatty acids, we have continued our characterization of the impacts of different fatty acids on the gut microbiota in studies in which mice were exclusively fed diets enriched in saturated fats (C14:0 and C16:0), polyunsaturated fatty acids (C18:2n6 and C18:3n3) or very long chain polyunsaturated fatty acids (C22:6n3 and C20:4n6). A manuscript is in preparation.}

[3] With regards to objective 3, we have not addressed the evaluation aspect of the eXtension website. Rather we have promoted its use to dietetics and nutritional practitioners and the general public in seminars, meetings and other public presentations. These groups for example included: members of the USAID nutrition working group (global health); the interagency working group formulating ready to Use Supplemental Foods (UNICEF in NYC); and students and parents visiting the University of Nebraska campus for recruitment purposes. For the professional groups the talk covered the importance of DHA specifically through the lifecycle. For the public groups, the topics covered include what DHA is, what foods contain DHA and the benefits of consuming foods rich in DHA.

^{_{What opportunities for training and professional development have the project provided? This project supported the graduate work of one student, Ms. Nipun Saini. Ms. Saini successfully completed her training with the receipt of a Ph.D. in December 2015. Undergraduate students who also work as laboratory research assistants on this project include: Samuel Tayler (a Beckman Research Scholar), Tyler Kallman and Jordan Beck. All three will continue through May 2017 when they will graduate with a major in biochemistry.}}

^{_{How have the results been disseminated to communities of interest? The basic science research results have been disseminated in peer-reviewed publications and through oral presentations at national meetings as listed in the "products" section of this report. Dr. DiRusso has also spoken at a global level to development agency on the value of adding DHA omega-3 fatty acids to Ready to Use Therapeutic Foods. These include the US Agency for International Development, UNICEF, The World Food Program and Food and Agricultural agency of the UN. The latter were part of her work as a Jefferson Science Fellow (Aug 2014-Aug 2015) based in Washington, DC. This work continues on a consultant basis through 2020.}}

 Utah State; Bob Ward

Accomplishments. The analysis of oxylipins in the livers of mice fed different amounts of polyunsaturated fatty acids and challenged with an inflammatory stimulus. Our data indicate that higher levels of omega-6 fatty acids promote the production of PGE2, when intakes of omega-3 fatty acids are low. In addition, the concentration of 14-OH DHA was higher in mice fed high omega-3 diets with a low omega-6 intake. Currently, work is underway to characterize the effects of the PUFA content of the animal diet on the oxylipin production. Also the completion of a book chapter on the effects of fish and fish oil intake on the development of cardiovascular disease in diabetics.

Opportunities. The analysis of oxylipins from the mouse livers was a professional development activity for Dr. Ward. The opportunity for this analsyis arose during Dr. Ward’s sabbatical visit to the CARMEN lab in Lyon, France.

Dissemination. The results of this work will be presented in an oral presentation at the annual meeting of the American Oil Chemist’s society in Salt Lake City, Utah in May of 2016. In addition, the data will be included in a manuscript submitted for publication in 2016. A second form of dissemination of the results of this project are in the form of a book chapter completed in 2015. The chapter is titled ‘Fish and Fish Oil for Cardiovascular Disease in Diabetes’ and the book title is Fish and Fish Oils in Health and Disease. The book will be published in 2016 by Elsevier.

What do you plan to do during the next reporting period to accomplish the goals? We are currently measuring the lipid content of the mice fed the different PUFA diets. This data will be used along with the oxylipin data above to better understand the mechanisms through which changes in dietary fat affect inflammation. In addition, the lipid content of the liver tissues from mice from another feeding study will be analyzed. In this case, mice were fed diets that differed in the amount of oxidized protein. Previous work in humans has indicated this affects polyunsaturated fatty acid metabolism.

West Virginia University; Janet Tou

Increasing n-3 fatty acid consumption is recommended for various health benefits. However, there are many types of n-3 fatty acids. Plants are rich in the n-3 fatty acids, ALA. Fish are rich in the n-3 fatty acids, EPA and DHA. However, fish differ in their amount and ratio of EPA and DHA. Also, fish and plant sources of n-3 fatty acids are mainly associated with triglycerides; whereas, krill oil is also associated with phospholipids. Phospholipids have been suggested to have better digestibility. These factors should be considered when choosing dietary n-3 fatty acids. This is because consumption of different n-3 fatty acids influences tissue n-3 fatty acid composition and in turn, this can result in different effects on tissue gene expression, function, and health. Whether increasing tissue n-3 fatty acid reduces inflammation is important to determine because chronic and/or high inflammation interferes with normal tissue function and increase susceptibility to injury and diseases. Also, important to consider is the safety of increasing n-3 fatty acid intake. This is because higher n-3 fatty acids result in structural changes in the tissue that not only alter function, but may increase susceptibility to oxidative damage. In contrast, other studies have reported that n-3 fatty acids protects against oxidative damage. Evaluating the safety of n-3 fatty acid intake is important since development of several diseases have also been attributed to tissue oxidative damage. The proposed study examines feeding rats’ various sources of n-3 fatty acid in order to determine which has the best tissue uptake and promotes maximal health benefits with the fewest side effects.

Major goals of the project The goals of the multi-state project are to improve human health, nutrition, and wellness of the US population, to further characterize the functional effects of n-3 fatty acids on health-related outcomes, to determine the mechanisms through which n-3 fatty acids exert their effects, and to provide scientific-based information via the eXtension website to the public domain. The objectives of the multi-state project are: 1) To determine the effects of omega-3 fatty acids on health-related outcomes in both human and rodent models. 2) To define the mechanisms mediating the health promoting effects of omega-3 fatty acids. 3) To evaluate the effect of an eXtension site on meeting the public's informational needs regarding omega-3 fatty acids. The expected outputs of the multi-state project are: 1) to expand knowledge of the effects of n-3 fatty acids on disease outcomes, thereby, coming closer to confirming specific health benefits of n-3 fatty acids and developing specific RDI's for individual n-3 fatty acids, 2) to further understanding of n-3 fatty acids and to provide insights into the development of specific disease, 3) launch and maintenance of an n-3 eXtension website to provide an easily accessible and accurate avenue for translating knowledge regarding the health effects of n-3 fatty acids to the public. Our contributions to this multi-state project are to perform n-3 fatty acids feeding studies using non-diseased and diseased rat models. Different sources of n-3 fatty acids will be fed and the fatty acid composition of various tissues determined. Eicosanoids derived from n-3 and n-6 fatty acid regulate normal tissue physiology, but an imbalance of n-6 to n-3 fatty acids play a role in the pathophysiology of various diseases. Yet, few studies have examined the role n-3 fatty acids in optimizing renal and pulmonary health. The safety of n-3 fatty acid supplementation will also be evaluated

since higher tissue unsaturation may increase tissue susceptibility to lipid peroxidation resulting in tissue damage. Therefore, the study objectives are to determine whether increased tissue n-3 polyunsaturated (PUFA) deposition alters genes involved in the regulation of inflammation, eicosanoid metabolism, and lipid peroxidation in renal and lung tissue. The expected outputs will assist in indentifying the n-3 fatty acid sources that results in the highest tissue deposition, reduces inflammation without increasing lipid oxidation in order to promote kidney and lung health and to prevent disease.

What was accomplished under these goals? Polycystic kidney disease (PKD) is a genetic disease and a leading cause of end stage renal failure with no medical cure. A complication of PKD is the spread of cysts to the liver and extra-hepatic tissues. Diet offers a potentially efficacious, costeffective, and safe therapeutic option. The popular dietary supplement omega-3 polyunsaturated fatty acids (n-3 PUFAs) has been shown to reduce renal cysts in animal studies. Although liver cysts is one of the most common co-morbidities accompanying PKD, to our knowledge no studies have investigated the effect of diet on hepatic cysts. Based on our study results feeding young female PCK rats soy protein and n-3 PUFA failed to attenuate liver cyst progression. Furthermore, feeding n-3 PUFA as a soybean and fish oil blend resulted in complications of hepatic steatosis. Bone health is also of particular concern since mineral metabolism and bone also worsens with progressive loss of kidney function. Optimizing bone health during the growth stage may preserve against bone loss associated with early renal dysfunction in PKD. Dietary soy protein and n-3 PUFA have been reported to ameliorate PKD and to promote bone health. Based on our results early diet management of PKD using soy protein and/or n-3 PUFAs influenced bone longitudinal growth and mineral balance, but neither worsened nor enhanced bone mineralization, microarchitecture or strength.

What opportunities for training and professional development has the project provided? Training and professional development included Kaitlin Maditz conducting research on n-3 PUFA supplementation on liver cysts and bone health as part of the fulfilment of her doctoral thesis. Some aims were included in undergraduate honor's thesis for Chris Oldaker, BA Biology and Nanika Nanda, B.S. Chemistry Honors and resulted in their co-authorship in the subsequent peer-reviewed publications. Additional measurement of additional gene markers for inflammation and fibrosis was the project for Summer Undergraduate Research Education (SURE) student Sundus Lateef and measurement of additional bone markers was the project for SURE student Matthew Miller and resulted in their co-authorship in the subsequent peer-reviewed publications. Joining this project as collaborators were Drs. Brenda Smith from the Dept. of Nutritional Sciences at University of Oklahoma State, Ryan Livengood from Dept. Pathology at United Hospital Center, WV, and Dr. Vagner Benedito, Genetics and Developmental Biology, WVU. Currently, M.S. Student Lauren Gibson is investigating the spread of cysts observed in the spleen in PKD rats fed n-3 PUFA as a soybean and fish oil blend.

How have the results been disseminated to communities of interest? The results have presented at internal research competitions and international conferences and have been subsequently published in medical and nutrition journals as an original research article as well as a review article. Also, participated in the n-3 PUFA multi-state teleconference regarding updates and determination of the NIFA multi-state next meeting site.

What do you plan to do during the next reporting period to accomplish the goals? We are currently investigating potential mechanisms responsible for the unexpected finding of liver steatosis in PKD rats fed a diet with n-3 PUFA as a soybean and fish oil blend. We are also investigating attenuation of the spread of cysts to extrahepatic tissues such as the spleen, brain, and reproductive tissues. The research is currently in progress.

Target Audience Our target audience is researchers, medical professionals, industry, and consumers. n-3 PUFA supplements are widely used by the public for various perceived health benefits. In response industry has been expanding their sources of commercially available n-3 PUFAs. Due to a growing number of alternate sources of n-3 PUFAs, the ratio and the structural forms of EPA and DHA needs to be taken into consideration. The current studies investigate the n-3 PUFA sources that favor maximal health benefits in the lungs, liver, and kidneys. Based on our current study results health effects and safety differ depending on the n-3 PUFA source and tissue. Therefore, a whole body approach and considering the n-3 PUFA source appears important.

Wisconsin; Jerome Donohoe

In the proposed outputs of defining and expansion Omega 3 enriched food products; the Wisconsin Station has successfully provided a terrestrial agricultural feeding program to review the animal dietary intake of Omega 3 inputs. These inputs support the livestock production to human foods containing higher levels of naturally occurring Omega 3 content than conventional production means. Agricultural animal species with demonstrated significant improvements of Omega 3 structure in human consumable food products include, Holstein cow (milk, cheese, meat), Swine (meat), Chicken (egg, meat), Turkey (meat), Cervid (elk, meat). All species in feeding protocols also demonstrated a significant increase of Omega 3 structure incorporation in their respective organ systems (heart,liver,kidneys, bone marrow) supporting a healthier lifespan for the food production cycle. Other food items that were developed were baked goods with increased Omega 3 values than traditional baked goods such as breads, muffins, and cookies.                                                                                                  

Other research investigations by the Wisconsin Station were in conjunction and support of the Wyoming Station and South Dakota Station. These investigations were in review to an industry concern of rodent health and reproduction performances for research models used for human disease testing. In both the rat and mouse model the same feeding of higher Omega 3 incorporation methodologies used for the livestock feedings of improved Omega 3 content for human food consumption was successfully employed.                                                                                                  

The health promoting improvements to the feeding of an improved Omega 3 dietary input was demonstrated in both the rat and mouse models by the improved organ structures incorporation of increased Omega 3 content in the heart, spleen, liver and kidney while lowering saturated fats in the heart and kidneys.                                                                                                                   The incorporation of higher dietary Omega 3 content into organ systems of the rodents in turn improved the reproduction performances of the rat and mouse. These improvements to reproduction and litter performances were quantified at 30% improvement in the rat model and a 40 % improvement in the mouse model.              

The findings of improved Omega 3 content in agricultural animals for human food consumption support the Outcomes and Projected Impacts. These are depicted in the findings of increased feed inputs to terrestrial based agricultural species of increased Omega 3 intake for which supports food products with increased Omega 3 content for improved health opportunities to the US population.

These findings also support Objective 1 and 2 in determining a health relationship to rodents and the mechanisms mediating the health promoting effects of dietary increase of Omega 3 fatty acids through organ structure content and improved breeding proficiencies.  

University of Missouri; Bongkosh Vardhanabhuti

Delivery system is one of the most important factors in incorporating bioactive lipids into commercial food products. Effective delivery systems should ensure physical stability and prevent oxidation over the shelf-life of the products. In addition, the delivery system should be designed such that functional lipids will be absorbed and delivery to the target in their active form. Microemulsions and nanoemulsions have been developed and utilized as delivery systems to encapsulate functional ingredients especially bioactive lipids. Physicochemical characteristics of lipid micro- or nanoparticles (e.g., particle size, charge, and etc.) could influence the properties, stability, and digestion properties of the emulsions which, in turn, will affect the release and delivery of bioactive compounds.

Research conducted at MO station focuses on developing lipid micro- and nanoparticles using mixed protein and polysaccharides. Current investigation emphasizes on improving particle stability especially at pH near the isoelectric point (pI) of the protein. Generally, protein-based lipid nanoparticles have excellent emulsifying properties but poor stability at or near protein pI. By optimizing protein-polysaccharide interaction, lipid micro- and nanoparticles may be fabricated to have improved stability. In addition, the digestion properties of the particles will also be altered depending on the compositions and fabrication methods. Our goal is to determine how various factors that affect protein and polysaccharide interactions influence the digestion of lipid micro- and nanoparticles as well as the release and delivery of functional lipids. Our research addresses objective 3 of the NC-1199 program: “To apply findings through Basic Research and Translational approach regarding dietary intake and health benefits.” Understanding how health-promoting lipids are digested, absorbed, and utilized when present in different delivery vehicles could lead to the development of functional foods that provide optimum health benefits.

University of Colorado, Mary Harris and Adam Chicco

Major goals: Two projects make up these studies. The first is a human clinical trial supplementing pregnant and breastfeeding mothers with omega-3 DHA to evaluate the effect on maternal inflammatory markers, bone density and body fat in the post-pratum period. The second project examined effect of n-3 fatty acid supplements on inflammatory markers and gonadotrophins in hypogonadotrophic obese and non-obese women.

What was accomplished under these goals? In conjunction with the University of Colorado, Division of Reproductive Medicine, we conducted a study with Alex Polotsky and Zain Al-safi, in 27 women (15 obese and 12 normal weight) on n-3 supplementation and gonadotrophins and ovarian reserve. Supplementation with 4 g Lovasa/day significantly reduced Il-1β and TNF-α in obese but not controls. Supplementation with n-3 fatty acids decreased serum FSH in hypogonadic normal weight women but not in obese women. The ratio of omega-6 to omega-3 PUFA was significantly reduced in plasma and red blood cell components for both groups after treatment (both P < .01). Omega-3 PUFA supplementation resulted in reduction of FSH and FSH response to GnRH by 17% on average (P = .06 and P = .03, respectively) in NW but not obese women. Serum levels of IL-1β and TNF-α were reduced after omega-3 PUFA supplementation (−72% for IL-1β; −56% for TNF-α; both, P < .05) in obese but not in NW women. This reduction, however, was not associated with a hormonal change in obese women. The Omega-Smart Baby follow-up study examined the relationship of DHA with in 27 women, who completed DEXA body composition testing and provided blood samples for analysis of inflammatory mediators and omega-3 docosahexaenoic acid (DHA) status. Red blood cell (RBC) DHA correlated well with dietary intake of DHA (r = .526 ( P= .005). Average dietary intake in DHA was 193.4±157.4 mg/day. Average amount of time postpartum was 31.9 ± 5.2 months for all women enrolled. Mean total months breastfeeding was 15.8 ± 9.6 months. Mean months since cessation of breastfeeding was 16.2 ± 10.1 months. Average amount of weight gain during pregnancy was 31.1 ± 8.7 lbs. Inflammatory markers, IL-1, IL-6, IL-8., TNFα were all highly correlated with one another. Weak negative associations of RBC DHA was (r =- .48, p = .011 with inflammatory marker, MCP-1 and weak positive associations with resistin (r = .54 , p = .004) and lipocalins, mixed proteins from a family of lipid transport molecules generally associated with inflammatory processes (r = .45, p = .018). DHA Intake and RBC DHA status were largely unrelated to body fat and bone density. Only total METS of activity, determined by self-reported questionnaire (PAQ) was consistent and positively associated with greater bone density 16 months to 2 years after cessation of breastfeeding.   The exception was an unexpected negative correlation of RBC DHA with bone mineral content at one of the sites (lumbar hip). These mixed findings are likely explained on the basis of the small sample size and relatively large standard deviations.           

Harris MS, Reece MS, McGregor JA, Wilson JW, Burke SM, Wheeler M, Anderson JE, Auld GW, French JI, and Allen KGD. The effect of omega-3 docosahexaenoic acid (DHA) on gestational length: prenatal supplementation compared to nutrition education. Biomedical Science International. Special Issue” Prevention, Mechanism of Preterm Birth. July, 2015.

Two studies make up the Colorado Station NC1199 project. The first is comprised of human clinical trials (Omega Smart Baby Project) that evaluate the effect supplementing pregnant and breastfeeding mothers with omega (n)-3 DHA on infant body fat and on breastmilk n-3 DHA. The second project focuses on the biological interaction of dietary PUFAs and genetic regulation of their metabolism by delta-6 desaturase, encoded by the Fads2 gene, using gain/loss of function mouse models.  Both studies are interested in defining the requirement and biological roles of PUFAs and PUFA metabolism in the diet.

 Accomplishments from Animal studies: Studies in Dr. Chicco’s laboratory are investigating the effects of PUFA metabolism on the development of metabolic syndrome using novel mouse strains with gain or loss of FADS2 encoding delta-6-desaturase (D6D), the rate-limiting enzyme in the production of long-chain PUFAs from dietary essential linoleic (18:2n6) and alpha-linolenic (18:3n3) acids. We recently completed in vivo experiments in our CO AES-funded project using these mice to evaluate the effects of maternal dietary PUFA composition during pregnancy on the metabolic. phenotype of offspring from Fads2-transgenic (-tg) and wild-type (WT) mice. FADS2-tg mice exhibit elevated serum and tissue PUFA product/precursor ratios reflective of systemic D6D hyperactivity similar to those associated with FADS2 haplotypes and cardiometabolic risk in humans indicated by epidemiological studies. When maintained on a standard chow diet (Harlan 2918; 18% Kcals Fat), FADS2-tg mice develop progressive obesity, glucose intolerance, insulin resistance and hyperlipidemia beginning at 1-2 months of age compared to age-matched FVB wild-type (WT) mice on the same chow diet. Importantly, linoleic acid (18:2n6) represents the majority (91%) of PUFA in 2918 chow, generating a dietary n6:n3 PUFA ratio of >10:1, similar to the modern “western” diet. Based on clinical evidence for potentially beneficial effects of perinatal n3-PUFA supplementation on infant metabolic status, we tested the hypothesis that reducing this ratio to ~3:1 in the maternal diet of FADS2-tg mice would attenuate development of MSx in her offspring. FADS2-tg females were fed 2918 chow supplemented with 2% flaxseed oil (providing ~1% w/w n3 α-linolenic acid; ALA) beginning 2 weeks prior to pairing with a WT male until litters were weaned. Offspring were maintained on the standard 2918 chow diet after weaning, and compared to litters from the same mother without ALA supplementation. As hypothesized, maternal ALA supplementation significantly normalized weight gain and glucose tolerance to near WT levels in male, but not female, offspring for up to 2 months post weaning on the chow diet. Food intake was similar across groups, actually trending higher in the offspring from the ALA supplemented pregnancy. Interestingly, feeding DHA to pregnant dams failed to have the same suppressive effect on weight gain and glucose intolerance in male or female offspring from Fads2-tg mice. Taken together, these studies support a causal link between FADS2 expression and the development of metabolic syndrome, and reveal sex-dimorphic benefits of prenatal n3-PUFA supplementation in this context. The cellular mechanisms responsible for MSx induced by FADS2 overexpression, and its suppression by maternal ALA, but not DHA, supplementation are currently being investigated in our lab. Date from these studies will be presented at the 2016 EB meeting in San Diego this April.

A second series of studies funded by our USDA NIFA grant seeks to define the interaction of Fads2 genotypes with dietary PUFA composition on the metabolic status of adult mice fed a high-fat “western” diet. These studies are in progress, but to date have shown that low Fads2 expression (Fads2 +/- mice) attenuates the development of glucose intolerance, but not weight gain, in response to a western diet compared to normal (WT) mice; while high Fads2 expression exacerbates this. Interaction with dietary PUFA intake are complex, often showing opposing effects of diet on metabolic outcomes depending on the level of Fads2 expression. These projects will be the focus our work in 2016-2018, and our future interactions with the NC-1199 project members.

OH Station Report, Martha Ann Belury

In several clinical studies, we ask the question of whether fatty acid status [e.g., higher blood values for the n-6 PUFA, linoleic acid (LA; 18:2n6) and long chain n-3 PUFAs, eicosapentaneoic (EPA, 20:5n3) and docohexaenoic acids (DHA, 22:6n3)] are related to markers of inflammation and conditions known to be mediated by inflammation. Conditions that we study include the metabolic syndrome, emotional stress and negative affect, women’s cancers and pregnancy-associated changes in mother-fetus dyad health. In a correlational analysis from a sub-cohort of the WHI, we asked whether EPA or DHA predicted for decreased inflammatory markers in breast tissue. In endometrial and breast cancers, it does appear that blood and/or tissue levels of long chain n3 fatty acids predict for reduced risk of cancers (1,3). Although we did not find significant relationships, we did observe trends in this rather small observational study (4). In an intervention study, pregnant women who were supplemented with either high n3 or low n3 oil supplements showed EPA and DHA accumulated in blood and placenta. In addition, several markers of inflammation were decreased in our cohort (5). We also asked whether teenage girls fatty acid intake was a mediator of dietary links with weight gain. Surprisingly, n3 PUFA intake were not associated with lower weight gain, but higher dietary intake of linoleic acid (18:2n6) was associated with lower weight gain (2). We are seeking to identify reasons for this relationship.