William S Harris

William S Harris
University of South Dakota | USD · Department of Internal Medicine

Doctor of Philosophy

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631
Publications
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Introduction
Fatty acids and health
Skills and Expertise

Publications

Publications (631)
Article
Full-text available
Epidemiological and clinical trial evidence indicates that n -6 polyunsaturated fatty acid (PUFA) intake is cardioprotective. Nevertheless, claims that n -6 PUFA intake promotes inflammation and oxidative stress prevail. This narrative review aims to provide health professionals with an up-to-date evidence overview to provide the requisite backgrou...
Article
Full-text available
This study in dogs had two objectives: first, to determine whether a daily supplement of marine omega-3 (EPA and DHA) would (1) increase red blood cell EPA + DHA levels (i.e., the Omega-3 Index derived from dried blood spot analysis) and (2) impact health-related measures. Dogs were recruited from five private veterinary clinics in the United State...
Article
Full-text available
Omega‐3 polyunsaturated fatty acids (n3 PUFA), specifically eicosapentaenoic acid (EPA, 20:5n3), and docosahexaenoic acid (DHA, 22:6n3), are essential for maintaining health. To better understand their biology, it is important to define their bioavailability. The aim of this cross‐over study was to investigate and compare the acute effects on plasm...
Article
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Linoleic acid (LA), as a part of the wider debate about saturated, omega-6 and omega-3 fatty acids (FAs) and health, continues to be at the center of controversy in the world of fatty acid research. A robust evidence base, however, demonstrates that higher intakes and blood levels of LA are associated with improved cardiometabolic health outcomes....
Article
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Background Empirical evidence has demonstrated associations between pre-pregnancy obesity and perinatal maternal depressive symptoms. Omega-3 is an essential fatty acid derived from dietary sources that is critical for fetal brain development. Pre-pregnancy obesity is associated with higher omega-3 intake, but a weaker association between dietary i...
Preprint
Full-text available
Background Empirical evidence has demonstrated associations between pre-pregnancy obesity and perinatal maternal depressive symptoms. Omega-3 is an essential fatty acid derived from dietary sources that is critical for fetal brain development. Pre-pregnancy obesity is associated with higher omega-3 intake, but a weaker association between dietary i...
Article
Background Circulating levels of n-3 polyunsaturated fatty acids (PUFAs) have been associated with frailty among Koreans (a population with a high intake of fish), but whether this association exists in Western populations with low fish intake is unknown. The present study examined the hypothesis that the prevalence of frailty was inversely associa...
Article
Introduction: Intake of omega-3 fatty acids (ω–3) may protect against CVD, but this evidence was generated from studies with limited ethnic diversity, and thus, findings may not be generalizable to wider populations, especially those with low habitual intake of ω–3. This study aimed to investigate the association between ω–3 in erythrocyte membrane...
Article
Full-text available
HDL-apolipoprotein A-I exchange (HAE) measures a functional property associated with HDL’s ability to mediate reverse cholesterol transport. HAE has been used to examine HDL function in case-control studies but not in studies of therapeutics that alter HDL particle composition. This study investigates whether niacin and omega-3 fatty acids induce m...
Article
BACKGROUND The effect of marine omega-3 PUFAs on risk of stroke remains unclear. METHODS We investigated the associations between circulating and tissue omega-3 PUFA levels and incident stroke (total, ischemic, and hemorrhagic) in 29 international prospective cohorts. Each site conducted a de novo individual-level analysis using a prespecified ana...
Article
BACKGROUND: It is unknown whether dietary intake of polyunsaturated fatty acids (PUFA) modifies the cardiovascular disease (CVD) risk associated with a family history of CVD. We assessed interactions between biomarkers of low PUFA intake and a family history in relation to long-term CVD risk in a large consortium. METHODS: Blood and tissue PUFA dat...
Article
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Dietary omega-3 fatty acids are promising nutrients in dementia. Several prospective cohort studies have examined the relationships between circulating omega-3 (an objective biomarker of dietary intake) and incident dementia, the largest to date being a report from the UK Biobank (n = 102,722). Given the recent release of new metabolomics data from...
Article
BACKGROUND The relationship between omega-3 fatty acids and atrial fibrillation (AF) remains controversial. OBJECTIVES This study aimed to determine the prospective associations of blood or adipose tissue levels of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with incident AF. METHODS We used participant-...
Poster
Full-text available
Elevated NLR and RDW have been associated with increased risk of all-cause mortality. In this poster presentation, we confirm previously reported monotonic inverse associations of long-chain omega-3 fatty acid (Omega3%) concentrations with NLR and RDW.
Article
Despite their widespread associations with a wide variety of disease phenotypes, the genetics of red blood cell fatty acids remains understudied. We present one of the first genome-wide association studies of red blood cell fatty acid levels, using the Women's Health Initiative Memory study - a prospective cohort of N = 7,479 women aged 65-79. Appr...
Article
Background: Tissue levels of n-3 polyunsaturated fatty acids (PUFAs) have been inversely related with risk of myocardial infarction (MI). Whether ratios of n-3 to n-6 PUFAs, reflecting both dietary intake of n-3 PUFAs and competing n-6 PUFAs, are better predictors of future MI than n-3 PUFA fractions is unclear. We aimed at investigating whether s...
Article
High red blood distribution width (RDW) is associated with decreased red blood cell deformability, and high neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and innate-adaptive immune system imbalance. Both RDW and NLR are predictors of chronic disease risk and mortality. Omega-3 index (O3I) values have previously been show...
Article
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Introduction: Previous studies have reported inverse associations of circulating and tissue levels of pentadecanoic acid (15:0), heptadecanoic acid (17:0) and trans -palmitoleic acid ( trans 16:1n-7), which have been proposed as potential biomarkers of dairy fat intake, with risk of type-2 diabetes and certain cardiovascular outcomes. Hypothesis: W...
Article
Background: The role of nutritional status and the risk of contracting and/or experiencing adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are unclear. Preliminary studies suggest that higher n-3 PUFA intakes are protective. Objectives: This study aimed to compare the risk of 3 coronavirus disease 201...
Article
Full-text available
Objective To assess the prospective associations of circulating levels of omega 3 polyunsaturated fatty acid (n-3 PUFA) biomarkers (including plant derived α linolenic acid and seafood derived eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) with incident chronic kidney disease (CKD). Design Pooled analysis. Data sources A...
Article
Full-text available
The Omega-3 Index (O3I) is the red blood cell (RBC) eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) content expressed as a percentage of total RBC fatty acids. Although a validated biomarker of omega-3 status in humans, little is known about the O3I status of dogs and cats; species in which omega-3 fatty acids have known health benefits...
Preprint
Full-text available
High red blood distribution width (RDW) is associated with decreased red blood cell deformability, and high neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and innate-adaptive immune system imbalance. Both RDW and NLR are predictors of chronic disease risk and mortality. Omega-3 index (O3I) values have previously been show...
Article
Full-text available
There is inconsistency regarding the association between long-chain n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA; 20:5n3) and docosahexaenoic acid (DHA; 22:6n3) and the risk of type 2 diabetes. The present study aimed to investigate the association between the Omega-3 Index (erythrocyte EPA + DHA) and glycemic status as a func...
Article
Full-text available
Information on the Omega-3 Index (O3I) in the United Kingdom (UK) are scarce. The UK-Biobank (UKBB) contains data on total plasma omega-3 polyunsaturated fatty acids (n3-PUFA%) and DHA% measured by NMR. The aim of our study was to create an equation to estimate the O3I (eO3I) from these data. We first performed an interlaboratory experiment with 25...
Article
Background and Objectives Diet may be a key contributor to brain health in midlife. In particular, Omega-3 fatty acids have been related to better neurological outcomes in older adults. However, studies focusing on midlife are lacking. We investigated the cross-sectional association of red blood cell (RBC) Omega-3 fatty acid concentrations with MRI...
Article
Full-text available
This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plasma, whole blood (WB), and blubber from wild Alaskan (Bristol Bay) belugas (Delphinapterus leucas) (BBB, n = 9) with oceanaria-based belugas (OBB, n = 14) fed a controlled diet consisting of primarily herring (Clupea harengus) and capelin (Mallotus villo...
Preprint
Full-text available
Background The role of nutritional status and risk for contracting and/or suffering adverse outcomes from COVID-19 infection are unclear. Preliminary studies suggest that higher n-3 PUFA intakes may be protective. Objectives: The purpose of this study was to compare risk for three COVID-19 outcomes (testing positive, hospitalization, and death) as...
Preprint
Information on the Omega-3 Index (O3I) in the United Kingdom (UK) are scarce. The UK-Biobank (UKBB) contains data on total plasma omega-3 polyunsaturated fatty acids (n3-PUFA%) and DHA% measured by NMR. The aim of our study was to create an equation to estimate the O3I (eO3I) from these data. We first performed an interlaboratory experiment with 25...
Article
Full-text available
Docosahexaenoic acid (DHA) might help prevent Alzheimer’s disease (AD). Red blood cell (RBC) status of DHA is an objective measure of long-term dietary DHA intake. In this prospective observational study conducted within the Framingham Offspring Cohort (1490 dementia-free participants aged ≥65 years old), we examined the association of RBC DHA with...
Article
Higher omega-3 fatty acid blood levels, as assessed by the Omega-3 Index (O3I, erythrocyte EPA+DHA percentage), have been linked with lower risk for cardiovascular disease and total mortality. Since seafood is an excellent source of EPA and DHA, we reasoned that people living on the coast with direct access to fresh seafood might have higher O3I le...
Article
Full-text available
Purpose To evaluate the relationship between red blood cell (RBC) polyunsaturated fatty acid (PUFA) levels, and dietary PUFA and fish intake, with prevalent and incident age-related macular degeneration (AMD) in a US cohort of postmenopausal women. Methods This analysis included 1456 postmenopausal women from the Women’s Health Initiative (WHI) Cl...
Article
Full-text available
Primary ventricular fibrillation (PVF) is a major driver of cardiac arrest in the acute phase of ST-segment elevation myocardial infarction (STEMI). Enrichment of cardiomyocyte plasma membranes with dietary polyunsaturated fatty acids (PUFA) reduces vulnerability to PVF experimentally, but clinical data are scarce. PUFA status in serum phospholipid...
Article
Full-text available
Background: n-3 and n-6 PUFAs have physiologic roles in sleep processes, but little is known regarding circulating n-3 and n-6 PUFA and sleep parameters. Objectives: We sought to assess associations between biomarkers of n-3 and n-6 PUFA intake with self-reported sleep duration and difficulty falling sleeping in the Fatty Acids and Outcome Resea...
Article
Recent trials in pregnant women on the effects of supplemental DHA on early preterm birth (ePTB) risk have shown that there is a maternal blood docosahexaenoic acid (DHA) level below which risk for ePTB was increased and supplemental DHA was effective at reducing risk. However, DHA levels were expressed in different terms across these trials making...
Article
Red blood cell (RBC) fatty acid (FA) patterns are becoming recognized as long-term biomarkers of tissue FA composition, but different analytical methods have complicated inter-study and international comparisons. Here we report RBC FA data, with a focus on the Omega-3 Index (EPA + DHA in % of total FAs in RBC), from samples of seven countries (USA,...
Article
Full-text available
Background: Evidence for the role of omega-3 fatty acids in the prevention of atrial fibrillation (AF) remain inconsistent, with some recent RCTs even suggesting possible harm. Whether long-term dietary intake of these fatty acids, as assessed using objective biomarkers, is related to AF is not known. Aims: To prospectively evaluate circulating and...
Article
Full-text available
OBJECTIVE Trans fatty acids (TFAs) have harmful biologic effects that could increase the risk of type 2 diabetes (T2D), but evidence remains uncertain. We aimed to investigate the prospective associations of TFA biomarkers and T2D by conducting an individual participant-level pooled analysis. RESEARCH DESIGN AND METHODS We included data from an in...
Article
The neutrophil-lymphocyte ratio (NLR) is a biomarker of systemic inflammation and measures innate-adaptive immune system balance. The omega-3-index (O3I) measures the amount of EPA+DHA in blood. Both a low O3I and an elevated NLR are associated with increased risk for chronic disease and mortality, including cardiovascular diseases and cancer. Hypo...
Article
Background Blood levels of marine n‐3 PUFA (20:5; 22:6) are inversely associated with cerebral white matter lesion volume (WML), suggesting that n‐3 may offer one approach to reduce this major vascular contributor to cognitive impairment and dementia. This trial determined whether n‐3 slows WML progression and sustains white matter integrity over 3...
Presentation
Full-text available
RBC long-chain omega-3 (n–3) fatty acid (FA) percentages (of total fatty acids) are associated with lower risk for total mortality, but it is unknown if a suite of FAs could improve risk prediction. Our objective was to compare a combination of RBC FA levels with standard risk factors for cardiovascular disease (CVD) in predicting risk of all-cause...
Article
Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects witho...
Preprint
Full-text available
Low red blood cell (RBC) membrane content of EPA and DHA, i.e., the omega-3 index (O3I), and elevated RBC distribution width (RDW) are risk factors for all-cause mortality. O3I and RDW are related with membrane fluidity and deformability. Our objective was to determine if there is a relationship between O3I and RDW in healthy adults. Subjects witho...
Preprint
Full-text available
The EPA+DHA content of red blood cell membranes, i.e., the omega-3 index (O3I), reflects omega-3 fatty acid status. EPA and DHA modulate inflammation via effects on cell signaling and the synthesis of pro-resolving lipid mediators. The neutrophil-lymphocyte ratio (NLR) is a measure of innate-adaptive immune system balance and is a biomarker of syst...
Article
A recent paper reported that 14 weeks of treatment with 2100 mg of EPA+DHA from krill oil had no effect on cognitive function in US Army Ranger trainees. Although the authors stated that poor compliance “may have contributed to a failure to detect a response,” no indication of exactly how poor the compliance was is given. We have therefore calculat...
Article
Full-text available
Background RBC long-chain omega-3 (n–3) fatty acid (FA) percentages (of total fatty acids) are associated with lower risk for total mortality, but it is unknown if a suite of FAs could improve risk prediction. Objectives The objective of this study was to compare a combination of RBC FA levels with standard risk factors for cardiovascular disease...
Article
Full-text available
Objectives Higher omega-3 fatty acid blood levels, as assessed by the Omega-3 Index (O3I, erythrocyte EPA + DHA expressed as a % of total fatty acids), have been linked with lower risk for cardiovascular disease and total mortality. Seafood is an excellent source of EPA and DHA. The purpose of this study was to determine if individuals living in a...
Article
Background The roles of omega-3 (n3) fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] and low-dose aspirin in the primary prevention of ischemic cardiovascular disease (CVD) are controversial. Since omega-3 (n3) fatty acids and aspirin affect cyclooxygenase activity in platelets, there could be a clinically-relevant effect o...
Article
Full-text available
The US Dietary Guidelines for Americans (DGA) provide dietary recommendations to meet nu-trient needs, promote health, and prevent disease. Despite 40 years of DGA, the prevalence of under-consumed nutrients continues in the US and globally, although dietary supplement use can help to fill shortfalls. Nutrient recommendations are based on Dietary R...
Article
Full-text available
The health effects of omega-3 fatty acids have been controversial. Here we report the results of a de novo pooled analysis conducted with data from 17 prospective cohort studies examining the associations between blood omega-3 fatty acid levels and risk for all-cause mortality. Over a median of 16 years of follow-up, 15,720 deaths occurred among 42...
Article
Full-text available
Background The factors other than dietary intake that determine tissue concentrations of EPA and DHA remain obscure. Prior studies suggested that, in women, endogenous estrogen may accelerate synthesis of DHA from ɑ-linolenic acid (ALA), but the effects of exogenous estrogen on RBC n–3 (ɷ-3) PUFA concentrations are unknown. Objective We tested the...
Article
Full-text available
OBJECTIVE Prospective associations between n-3 fatty acid biomarkers and type 2 diabetes (T2D) risk are not consistent in individual studies. We aimed to summarize the prospective associations of biomarkers of a-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with T2D risk through an in...
Article
Full-text available
Objective: Prospective associations between n-3 fatty acid biomarkers and type 2 diabetes (T2D) risk are not consistent in individual studies. We aimed to summarize the prospective associations of biomarkers of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with T2D risk through an...
Article
Full-text available
Background: The association between long-chain omega-3 polyunsaturated fatty acids (n-3 PUFA) and prostate cancer (PC) remains unclear. Methods: We compared incident PC rates as a function of the Omega-3 Index [O3I, erythrocyte eicosapentaenoic and docosahexaenoic acids (EPA + DHA)] in 5607 men (40-80 years of age) seen at the Cooper Clinic who...
Article
Very-long chain omega-3 fatty acids (EPA and DHA) have anti-inflammatory properties that may help reduce morbidity and mortality from COVID-19 infection. We conducted a pilot study in 100 patients to test the hypothesis that RBC EPA+DHA levels (the Omega-3 Index, O3I) would be inversely associated with risk for death by analyzing the O3I in banked...
Article
Background The importance of providing the newborn with docosahexaenoic acid (DHA) from breast milk is well established. However, women in the United States, on average, have breast milk DHA levels of 0.20%, which is below the worldwide average (and proposed target) of >0.32%. Additionally, the relationship between maternal red blood cell (RBC) and...
Preprint
Full-text available
Very-long chain omega-3 fatty acids (EPA and DHA) have anti-inflammatory properties that may help reduce morbidity and mortality from COVID-19 infection. We conducted a pilot study in 100 patients to test the hypothesis that RBC EPA+DHA levels (the Omega-3 Index, O3I) would be inversely associated with risk for death by analyzing the O3I in banked...
Article
Background and Purpose The red blood cell fatty acid composition objectively reflects the long-term dietary intake of several fatty acids. In patients undergoing carotid endarterectomy, we explored whether red blood cell status of selected fatty acids related to symptomatic carotid artery disease. Methods We included patients with symptomatic (n=2...
Article
Background Previous studies have suggested that omega-3 polyunsaturated fatty acids (n-3 PUFA) can favorably influence cardiac autonomic tone. However, data regarding n-3 PUFA status and heart rate recovery (HRR) in healthy adults are sparse. Purpose To examine the association between n-3 PUFA status and HRR. Methods Participants included 13,912...
Article
Background The effects of fish oil products containing docosahexaenoic acid (DHA) on LDL-C levels are controversial. Objective To determine if changes in erythrocyte DHA are associated with changes in LDL-C levels. Methods In this prospective observational study, erythrocyte DHA levels and LDL-C levels were measured in 9253 individuals who presen...
Article
Full-text available
Omega-3 (n-3) treatment may lower cardiovascular risk, yet its effects on the circulating lipidome and relation to cardiovascular risk biomarkers are unclear. We hypothesized that n-3 treatment is associated with favorable changes in downstream fatty acids (FAs), oxylipins, bioactive lipids, clinical lipid and inflammatory biomarkers. We examined t...