Omega-3

Study Quality Assessment:

systematic review and meta-analysis

Authors:

Emma Derbyshire

Findings:

Omega-3 supplementation generally correlated with improvements in blood biomarkers and was effective at improving EPA and DHA status. These effects appear to particularly benefit individuals with lower baseline fatty acid levels, those who are breastfeeding, or those with neuropsychiatric conditions. Multiple studies indicate that omega-3 fatty acids can protect against neurodegeneration in older adults, suggesting a role in maintaining and augmenting brain health across the lifespan, though ongoing research with harmonious methodologies is needed.

Participants:

Systematic review of 25 randomized controlled trials (total n=3633). Participants included individuals across various life stages (pregnancy, infancy, school age, teenage, young adults, middle age, older age/dotage), encompassing healthy individuals and those with ADHD, ASD, depression, or Mild Cognitive Impairment (MCI), but without severe, long-term medical conditions.

Dosage:

The systematic review collated evidence from studies using various dosages, ratios, and intervention periods. It highlights the need for ongoing research using harmonious supplement dosages. A cited meta-analysis showed that >1 g/day docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) significantly improved episodic memory in older adults with mild memory complaints.

Study Quality Assessment:

Systematic review of 25 randomized controlled trials (RCTs) published between January 2013 and May 2018. The review followed PRISMA guidelines. Included studies were English-language human trials. Quality of RCTs was assessed using the Jaded scale. Limitations acknowledged include methodological differences between studies (e.g., dosage, duration, assessment tools), the ideal duration for RCTs being at least 16 weeks, and potential unaddressed confounding factors. The author received funding from Equazen for the review.

All Effects:

Authors:

Matthew F Muldoon

Findings:

The review suggests that increasing the typically low consumption of long-chain omega-3 fatty acids (EPA and DHA) among healthy adults may improve some aspects of cognitive performance. However, evidence from randomized clinical trials is described as comparatively sparse and preliminary, leaving unclear whether these effects are clinically significant, if EPA and DHA effects differ, which specific cognitive dimensions are affected, the dose-response relationships, or the time course of response. RCT findings to date do not show robust benefits or a clear lack of efficacy.

Participants:

The review focuses on cognitive functioning during mid-life in generally healthy adults, summarizing evidence for optimizing cognitive performance. It also discusses studies involving infants, children, elderly individuals, and specific populations like military personnel or those with Alzheimer's Disease or depression for broader context.

Dosage:

Typical U.S. dietary intake of EPA and DHA is low (e.g., <200 mg/day or ~110 mg/day). Reviewed RCTs in non-elderly adults used supplementation doses between 500 and 2400 mg per day of combined EPA and DHA (e.g., 1740mg EPA + 250mg DHA; 1160mg DHA + 160mg EPA). RCTs in elderly individuals used doses ranging from 80 to 2300 mg per day. The review notes that studies using doses under 800mg/day generally found no treatment effects, and dose-response relationships remain unclear.

Study Quality Assessment:

The review analyzes existing research, including observational studies and Randomized Clinical Trials (RCTs). Methodological aspects discussed include: use of placebo-controls (e.g., olive oil, oleic acid), neuropsychological test batteries, sample sizes from reviewed RCTs (e.g., N=54 to N=228 for mid-life adult trials listed in Table 1), and limitations such as sparse evidence from RCTs, small trial sizes, potential for unblinding (e.g., "fishy belching"), issues with placebo choice, and incompletely addressed methodological concerns regarding dose and duration. A financial disclosure for the review authors is provided, noting no relationship with the NIH funding and a past grant from Isodi Natura for some authors.

All Effects: