Diagnostics key to increasing global omega-3 consumption: Review
Commissioned by the Global Organization for EPA and DHA Omega-3s (GOED), the review breaks down the range of testing options available—from dietary assessments to blood and breast milk sample analysis—and provides an overview of potential benefits of omega-3 long chain polyunsaturated fatty acids (ω-3 LCPUFA) status testing for cardiovascular disease, neurological dysfunction, pregnancy complications and dry eye.
“Seeing the overview of scientific evidence on omega-3 levels and health outcomes really gives you a sense of where the strongest evidence exists and where there might be gaps,” said Harry Rice, PhD, vice president of regulatory & scientific affairs at GOED. “A review like this will undoubtedly be invaluable during a discussion on dietary reference intakes for EPA/DHA.”
The review was conducted by researchers from Midwest Biomedical Research, the Nlumn consulting firm and Indiana University School of Public Health.
Why diagnostic testing is needed
Historically, dietary intake surveys have been used in lieu of the more invasive sampling of adipose tissue (the main storage compartment of fatty acids), however the paper noted that accuracy is limited by confounders like inaccurate recall and the natural variation in nutrient digestion, absorption and metabolism among individuals.
“A systematic literature review published by de Groot et al. identified 3 main types of factors, beyond diet, that are potentially associated with ω-3 LCPUFA levels in the body: 1) unmodifiable (sex, genetics, age), 2) modifiable (body size, physical activity, alcohol, smoking) and 3) bioavailability (e.g., form of supplement consumed and conversion of ALA to ω-3 LCPUFA),” the reviewers wrote.
Among these, age, female sex, wine consumption, and triglyceride form all appeared to be associated with higher levels, whereas genetic factors, higher body mass index and smoking were linked to lower levels.
The GOED-commissioned review also highlighted a 2020 statement by the International Society for the Study of Fatty Acids and Lipids (ISSFAL) emphasizing the importance of measuring blood omega-3 levels in research both at baseline and post intervention to properly evaluate efficacy. It noted that this has not been common practice and that dosages administered in studies do not always translate to detectable levels in the blood or organs.
“This underscores the need for a clear understanding of ω-3 LCPUFA status to further establish benefits, support interpretation of results and help establish dietary requirements,” the reviewers wrote.
State of omega-3 diagnostics testing
Because of the impractical nature of adipose tissue sampling—where a biopsy is usually collected under the skin of the buttock, abdomen or upper arm—the paper puts forth blood or breast milk samples as a more accessible but still accurate approach to fatty acid measurement.
The review provides a table of commercial laboratories offering these biospecimen analyses including OmegaQuant, Lipid Technologies, Quest Diagnostics, Cleveland Heart Lab, NutraSource, LabCorp, Lipid Analytical Laboratories, Boston Heart Diagnostics, Mayo Clinic Laboratories, Creative Proteomics Lipidomics and Nightingale Health.
“Although measurement of tissue or blood levels of EPA and DHA will reduce some of the variability introduced by relying on dietary intake records or simply comparing outcomes based on treatment assignment, biosample measurements come with their own set of problems affecting interpretation,” the reviewers wrote.
Beyond inherent differences in samples taken from plasma compared to red blood cells, for example, and the fact that a number of analytical procedures have not been extensively validated, they noted that some methodologies are proprietary, limiting comparison of results across trials that employ different testing methods.
“As described herein, evaluating ω-3 LCPUFA status is a critical and necessary step in the process of striving to reap the potential health benefits of increasing ω-3 LCPUFA intake,” the review concluded. “This fact has been underappreciated by laypersons and the research community. Increased ω-3 LCPUFA status testing is expected to favorably impact personal and public health.”
Source: The Journal of Nutrition
“ω-3 Polyunsaturated Fatty Acid Status Testing in Humans: A Narrative Review of Commercially Available Options”
doi: https://doi.org/10.1016/j.tjnut.2024.03.015
Authors: Mary R. Dicklin et al.
