FADS1 rs174537: Understanding Your Genetic Fatty Acid Processing
The rs174537 variant is a single nucleotide polymorphism located in the FADS1 gene, which plays a critical role in the body's ability to synthesize long-chain polyunsaturated fatty acids. Research indicates that this variant is significantly associated with the efficiency of converting dietary fats into essential compounds like arachidonic acid and EPA.
What each genotype means
Higher FADS1 enzyme activity
Individuals with this genotype typically exhibit higher expression of the FADS1 and FADS2 genes in liver tissue. Research indicates this profile is associated with higher circulating levels of arachidonic acid and potentially higher LDL cholesterol levels compared to those carrying the T allele.
This genotype is the major allele combination in many populations, including approximately 65% of individuals of European ancestry.
Intermediate FADS1 enzyme activity
This heterozygous genotype is associated with intermediate levels of FADS1 and FADS2 gene expression and fatty acid processing efficiency. You may have a fatty acid profile that falls between the extremes observed in GG and TT homozygotes, reflecting a moderate capacity to convert plant-based precursors into long-chain omega-3 fatty acids.
This genotype is common globally, appearing in a significant portion of the population across diverse ancestries.
Lower FADS1 enzyme activity
Individuals with this genotype often show reduced expression of FADS1 and FADS2 genes, which can influence the efficiency of processing plant-based omega-3 fatty acids into EPA and DHA. Studies suggest this profile is associated with lower circulating levels of arachidonic acid and EPA compared to those with the G allele; please discuss your dietary fatty acid intake and any supplementation with your clinician or a registered dietitian.
This genotype is more common in East Asian populations, where the T allele frequency can reach 57%, compared to approximately 35% in European populations.
What is rs174537 and Where is it Located?
The rs174537 variant is a specific genetic change, or single nucleotide polymorphism (SNP), situated on chromosome 11 within the FADS gene cluster. This region is home to three closely related genes: FADS1, FADS2, and FADS3. These genes are responsible for encoding enzymes known as fatty acid desaturases. Because these genes are located near each other on the chromosome, they are often inherited together as a block, which can influence how the body manages various types of dietary fats. Scientists study this specific location because it serves as a primary control point for the biochemical pathways that transform shorter-chain fatty acids into more complex, long-chain polyunsaturated fatty acids (PUFAs) that are vital for cellular health.
The Role of the FADS1 Gene
The FADS1 gene provides instructions for creating the delta-5 desaturase enzyme. This enzyme is a key player in the metabolic pathway that converts dietary precursors into long-chain polyunsaturated fatty acids, such as arachidonic acid (ARA) and eicosapentaenoic acid (EPA). These fatty acids are essential components of cell membranes and serve as precursors for signaling molecules that regulate inflammation and other physiological processes. When the FADS1 gene functions efficiently, the body can readily convert plant-derived fatty acids into these more active forms. Variations in this gene, such as rs174537, can alter the activity level of the delta-5 desaturase enzyme, potentially leading to differences in the circulating levels of these important lipids in the blood.
Research Associations and Evidence Strength
The association between rs174537 and fatty acid levels is considered robust, with some studies describing it as one of the strongest genetic signals for PUFA metabolism identified to date. Research, including large-scale genome-wide association studies (GWAS), has consistently linked the G allele to higher levels of arachidonic acid and increased enzymatic efficiency. Conversely, the T allele is often associated with lower levels of these specific fatty acids. While the evidence for its impact on lipid profiles is strong, associations with complex health outcomes—such as cardiovascular disease or type 2 diabetes—are more nuanced and sometimes mixed across different populations. It is important to note that while genetics influence these pathways, diet and environmental factors also play a significant role in determining overall health outcomes.
Population Frequency and Ancestry
The frequency of the rs174537 alleles varies significantly across different global populations, reflecting historical patterns of natural selection. The G allele, which is associated with enhanced PUFA metabolism, is found at very high frequencies in African populations, where it has been observed to be nearly fixed. In contrast, the T allele is more common in European and other non-African populations. These differences in allele frequency suggest that the FADS1 gene cluster has been subject to strong evolutionary pressures, likely related to the types of diets available to ancestral human populations in different geographic regions. Understanding these frequency differences is essential for interpreting genetic data in a global context.
What You Can and Cannot Do With This Information
Knowing your genotype for rs174537 provides insight into your biological predisposition for processing fatty acids, but it is not a diagnostic tool. You cannot use this information to diagnose a deficiency or a disease, nor should it be used to make unilateral changes to your medical treatment or dietary regimen. If you are concerned about your lipid levels, cardiovascular health, or the potential need for Omega-3 supplementation, you should discuss these findings with a qualified healthcare provider or a registered dietitian. They can help you interpret your results in the context of your overall health, medical history, and current lifestyle. Always consult with a clinician before starting or changing any supplement or medication protocol based on genetic information.
How common is this variant?
The rs174537 variant is common globally, with the G allele reaching near-fixation in African populations while remaining at intermediate frequencies in European and other populations.
Frequently asked questions
Does rs174537 mean I have a disease?
No, rs174537 is a common genetic variation and not a disease-causing mutation. It simply influences how your body processes certain dietary fats, which is a normal part of human genetic diversity.
Should I take Omega-3 supplements if I have the TT genotype?
Genetic results alone do not determine your nutritional needs. You should discuss your diet and any potential need for supplementation with a healthcare professional who can evaluate your overall health and blood lipid levels.
Can this SNP predict my risk of heart disease?
While some studies have explored links between FADS1 variants and cardiovascular markers, the relationship is complex and influenced by many factors. This SNP is not a standalone predictor of heart disease risk.
Is the G allele better than the T allele?
Neither allele is inherently 'better' or 'worse.' The G allele is associated with higher conversion efficiency of certain fats, which may have been advantageous in specific ancestral environments, but health outcomes depend on the interaction between your genes, your diet, and your lifestyle.
Sources & further reading
Educational information only, last refreshed 10/2/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Key regulatory polymorphism governing the efficiency of dietary polyunsaturated fatty acid (PUFA) conversion to arachidonic and eicosapentaenoic acids.
Regulatory variant in FADS1 associated with the efficiency of long-chain polyunsaturated fatty acid biosynthesis.
Variant in the FADS gene cluster associated with plasma levels of long-chain polyunsaturated fatty acids.
Regulates fatty acid desaturase expression, altering conversion efficiency of dietary alpha-linolenic acid to EPA and DHA.
The ancestral C allele of this FADS1 variant influences blood fatty acid profiles, specifically reducing arachidonic acid.
This variant in the FADS1 gene influences how efficiently the body converts plant-based fats into essential Omega-3 and Omega-6 fatty acids.