A new global review uncovers major gaps and inconsistencies in omega-3 guidance, showing why many populations still fail to meet recommended EPA and DHA targets for lifelong health.
Study: An overview of national and international long chain omega-3 polyunsaturated fatty acid intake recommendations for healthy populations. Image Credit: shine.graphics / Shutterstock
A recent study published in the journal Nutrition Research Reviews summarized national and international recommendations for the consumption of long-chain omega-3 polyunsaturated fatty acids (LC n-3PUFAs).
Global Variability in Omega-3 Guidance
The LC n-3PUFAs, docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and docosapentaenoic acid (DPA), are known to have a wide range of beneficial effects. Higher intake and tissue and circulating status of these fatty acids support cognitive and visual development in early life, promote immune function and cardiovascular health, and may decrease preterm birth (PTB) incidence and the risk of depression, cognitive decline, or Alzheimer’s disease. However, most evidence remains observational, and causality has not been firmly established.
Various global and national health authorities, expert groups, and ministries recommend including LC n-3PUFA-rich foods in the diet. However, recommendations vary by country and region and remain absent or limited in several life stages and world regions, with substantial inconsistency in how intakes are expressed (for example, mg per day, percent of total fatty acids, or mg per kilogram of body weight). To date, there is no up-to-date global overview of LC n-3PUFA intake recommendations from technical and scientific documents (TSDs) that underpin food-based dietary guidelines (FBDGs) or other expert group reports.
Review of Global Technical Documents
In the present study, researchers examined FBDG TSDs and expert group reports to provide an overview of intake recommendations for LC n-3PUFAs for healthy populations across life stages. They used the Food and Agriculture Organization’s global online repository for FBDGs to identify countries with guidelines for healthy populations. Structured Google searches were performed to identify additional TSDs.
The study included 42 TSDs for review; most TSDs (71%) were quantitative intake recommendations for LC n-3PUFAs. Twenty-six TSDs contained health messages, 12 offered guidance on safety or high intakes of LC n-3PUFAs, and 14 discussed supplementation. Five TSDs were categorized as international dietary reference value (DRV) TSDs, three as national DRV TSDs, 15 as national FBDG TSDs, and 19 as expert body TSDs.
Most TSDs (54%) covered general healthy populations, with all age groups and sexes. Others were sex- or life stage-specific, covering adults only (14%), infants and children only (10%), older adults only (5%), and pregnant or lactating individuals only (12%). Eleven TSDs provided LC n-3PUFA intake recommendations for infants and young children. One TSD recommended that DHA intake should be 0.32% of total fatty acid intake for the first six months of life.
Child and Adolescent Intake Variability
One TSD provided an adequate intake (AI) of 200 mg/day of DHA for Korean infants up to 5 months of age. For young children aged 1–3 years, intake recommendations varied from an AI of 40 mg/day of EPA + DHA + DPA to 250 mg/day of DHA + EPA. Twelve TSDs provided recommendations for older children aged 4–12 years, ranging from an AI of 55 mg/day of EPA + DHA + DPA at four years to 500 mg/day of DHA + EPA at ten years.
Further, 11 TSDs provided recommendations for adolescents aged 13–18, with considerable heterogeneity in the amounts of LC n-3PUFAs recommended. The AI ranged from 70 mg/day of DPA + DHA + EPA at 13 years in Australia and New Zealand to 500 mg of DHA + EPA for those aged ≤18 years in South Africa and France. Eighteen TSDs provided recommendations for adults aged ≥18 years. Seven of these, including three international TSDs, recommended 250 mg/day of DHA + EPA.
Pregnancy, Lactation, and Older Adults
Seventeen TSDs provided recommendations during pregnancy, with AI ranging from 110 mg/day of EPA + DHA + DPA in Australia and New Zealand to 250 mg/day of DHA or 500 mg/day of DHA + EPA in France. Six TSDs recommended a minimum DHA + EPA intake of 250 mg/day for adult health. One international TSD defined 300 mg/day of EPA + DHA as optimal for fetal and infant development and adult health.
Higher intakes up to 1 g/day were recommended specifically for pregnant individuals with low LC n-3PUFA status to decrease PTB risk. For older adults, five TSDs provided recommendations, with AIs ranging from 90 mg/day of DHA + EPA + DPA in older females over 51 years to 250 mg/day for adults over 65 years. Twenty-six TSDs contained health messages focused on chronic disease prevention, pregnancy, and early infancy.
Safety Guidance and Upper Limits
Several TSDs recognized the relationship between LC n-3PUFA intake and outcomes related to fetal and infant cognition, brain health, and retinal function. One international TSD acknowledged a critical role for DHA in brain and retinal development in those aged 0–24 months. Three TSDs provided guidance on high LC n-3PUFA intakes specific to infancy, childhood, or adolescence.
One international TSD reported no upper limit for DHA intake in infants aged 0–6 months. Recommendations from Australia and New Zealand similarly stated it was not possible to define an upper limit for DHA + DPA + EPA intake in infants, although an upper limit of 3 g/day was set for other childhood age groups. For adults over 18 years old, the upper limit of EPA + DHA intake was 2-5 g per day.
Global Patterns and Policy Implications
Taken together, the study provided an overview of global and national dietary recommendations for LC n-3PUFA intake across life stages for healthy individuals. TSDs included quantitative intake targets, health messages, and high-intake guidance. The most frequently recommended intake was 250 mg/day of DHA + EPA, with an additional 100–200 mg/day of DHA during pregnancy. Food intake alone may not meet this requirement, warranting supplementation and, in some contexts, the development of sustainable alternative EPA and DHA sources, especially given that population intakes in many countries fall well below recommended thresholds.
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