DHA-Rich Fish Oil Increases the Omega-3 Index in Healthy Adults and Slows Resting Heart Rate without Altering Cardiac Autonomic Reflex Modulation

Omega-3 Status Evaluation in Australian Female Rugby League Athletes: Ad Libitum Fish Oil Provision Results in a Varied Omega-3 Index

Optimal omega-3 status, influenced by increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is vital for physiological health. This study investigated the impact of ad libitum fish oil supplementation on the omega-3 status of female athletes in a professional rugby league team during a competitive season. Twenty-four (n = 24) athletes participated, and their omega-3 status was assessed using the Omega-3 Index (O3I) and arachidonic acid (AA) to EPA ratio through finger-prick blood samples taken at the start and end of the season. They were given access to a fish oil supplement (PILLAR Performance, Australia) with a recommended daily dose of four capsules per day (2,160 mg EPA and 1,440 mg docosahexaenoic acid). At the beginning of the season, the group mean O3I was 4.77% (95% confidence interval [CI: 4.50, 5.04]) and the AA to EPA ratio was 14.89 (95% CI [13.22, 16.55]). None of the athletes had an O3I exceeding 8%. By the season's end, the O3I was a significantly increased to 7.28% (95% CI [6.64, 7.93], p < .0001) and AA to EPA ratio significantly decreased to a mean of 6.67 (95% CI [5.02, 8.31], p < .0001), driven primarily by the significant increase in EPA of +1.14% (95% CI [0.77, 1.51], p < .0001). However, these changes were varied between the athletes and most likely due to compliance. This study has demonstrated that using the objective O3I feedback scale is possible with elite female rugby athletes, but individual strategies will be required to achieve daily intake targets of EPA + DHA.

Omega-3 fatty acids and autonomic function in adolescents with anorexia: A randomized trial

OBJECTIVES

Patients with anorexia nervosa (AN) have autonomic nervous system (ANS) dysfunction as measured by heart rate variability (HRV). Omega-3 fatty acids may improve heart rate regulation. Our aim was to describe ANS response to a mid-day meal in adolescent females with AN in a 12-week treatment program, randomized to receive either omega-3 supplements or placebo.

METHODS

This pilot study was a longitudinal, double-blind, randomized controlled trial. Each group was subdivided into an acutely ill cohort and a chronically ill cohort. Linear and non-linear measures of slope, mean, and pre/post-meal changes in HRV were measured at baseline, 6 weeks, and 12 weeks.

RESULTS

Twenty-four women (n = 12 placebo; n = 12 omega-3) were enrolled. By program end, the acute omega-3 group alone showed no change in any pre-meal slope. Acute and chronic omega-3 groups, but not placebo groups, demonstrated physiologically expected post-meal heart rate increases at 12 weeks. For all measures at 6 and 12 weeks, the chronic placebo and omega-3 groups had smaller physiologic responses to the meal compared with the acute groups.

CONCLUSIONS

Participation in a 12-week partial hospitalization program may improve autonomic function in response to mealtime, with possible additional benefit from omega-3 PUFA, particularly in those with acute illness.

IMPACT

Autonomic function with meals improves with a 12-week partial hospitalization program in adolescent females with anorexia nervosa. Omega-3 polyunsaturated fatty acids may improve autonomic function, especially in adolescent females with acute forms of anorexia nervosa. Longer duration of illness in adolescent females with anorexia nervosa is associated with blunted autonomic response to meals.

Relationship Between Fish Oil Use and Incidence of Primary Liver Cancer: Findings From a Population-Based Prospective Cohort Study

Background: N-3 long-chain polyunsaturated fatty acids (LCPUFAs) prevented non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) in studies of mouse models. We examined prospective relationships between fish oil use and risk of primary liver cancer and the major histological subtypes, such as HCC and intrahepatic cholangiocarcinoma (ICC).

Methods: We included 434,584 middle-aged and older men and women who were free of cancer at recruitment of the UK Biobank (2006–2010). Information on fish oil use and other dietary habits was collected via questionnaires. Cox proportional hazards models were used to compute the hazard ratio (HR) and 95% CI of liver cancer associated with fish oil use, with adjustment for socio-demographic, lifestyle, dietary, and other clinical risk factors.

Results: At baseline, 31.4% of participants reported regular use of fish oil supplements. During a median of 7.8 years of follow-up, 262 incident liver cancer cases were identified, among which 127 were HCC and 110 were ICC cases. As compared with non-users, fish oil users had a significantly 44% (95% CI: 25–59%) lower risk of total liver cancer, and 52% (95% CI: 24–70%) and 40% (95% CI: 7–61%) lower risk of HCC and ICC, respectively. Higher intake of oily fish also was associated with a lower risk of HCC (≥2 vs. <1 serving/week: HR = 0.46; 95% CI: 0.23–0.96; P-trend = 0.027) but not ICC (P-trend = 0.96).

Conclusion: Habitual use of fish oil supplements was associated lower risk of primary liver cancer regardless of cancer histological subtypes, potentially supporting a beneficial role of dietary n-3 LCPUFAs in liver cancer prevention.