What you carry at this position in your DNA and what research says about it.
Omega Fat Conversion: 8/10 evidence, 24 publications.
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Sample genotype (not yours): C/C
Efficient Omega Fat Conversion with Mixed Cholesterol Effects
Highly active enzyme levels allow efficient conversion of plant-based fats into active omega-3 and omega-6 fatty acids. The accompanying cholesterol profile is mixed: higher HDL and lower triglycerides, but also higher LDL and total cholesterol, so the net cardiovascular effect is roughly neutral.
What this genotype means: Highly efficient conversion of plant-based omega fats; Higher HDL cholesterol and lower triglycerides; But higher LDL and total cholesterol (net-neutral lipid effect).
Sample genotype (not yours): C/G
Typical Omega Fat Conversion and Lipid Balance
Moderate enzyme activity results in typical conversion rates of plant-based fats into active omega fatty acids. Cholesterol and triglyceride levels generally remain within the standard average range.
What this genotype means: Standard conversion of plant-based omega fats; Typical baseline cholesterol and triglyceride levels.
Sample genotype (not yours): G/G
Reduced Omega Fat Conversion with Mixed Cholesterol Effects
Lower enzyme activity limits the conversion of plant-based fats into active omega-3 and omega-6 fatty acids. The accompanying cholesterol profile is mixed: lower LDL and total cholesterol, but also lower HDL and higher triglycerides, so the net cardiovascular effect is roughly neutral. Direct marine omega-3s help compensate for the reduced synthesis.
What this genotype means: Impaired conversion of plant-based omega fats; Lower LDL and total cholesterol; But lower HDL and higher triglycerides (net-neutral lipid effect).
Gene function and biological role
Gene Function: The FADS1 gene encodes fatty acid desaturase 1, a critical enzyme that regulates how the body metabolizes polyunsaturated fatty acids [1]. This enzyme catalyzes the rate-limiting step in converting short-chain plant-derived fatty acids into active, long-chain forms like arachidonic acid and eicosapentaenoic acid [1] [2]. These long-chain fats are essential components of cell membranes and serve as precursors for key signaling molecules [2]. Because of this role, FADS1 activity directly influences circulating lipid levels and cardiovascular health [3]. Variations in this gene can significantly alter how an individual responds to plant-based versus animal-based dietary fats [2].
Variant Impact: The rs174548 variant is an intronic change in the FADS1 gene that strongly influences its expression levels across multiple human tissues [1]. This genetic variation is one of the strongest known regulators of lipid and fatty acid concentrations in the bloodstream [3]. By altering the abundance of the desaturase enzyme, the variant dictates the efficiency of converting dietary plant oils into highly active omega-3 and omega-6 fatty acids [1] [4]. Consequently, it is heavily associated with variations in blood levels of triglycerides, LDL cholesterol, and HDL cholesterol [3] [5].
Key Insight: This variant acts as a metabolic dial determining how well you convert plant-based oils into active omega fats, making it a key genetic factor in vegetarian dietary efficiency.
Location: FADS1. Chromosome 11 · 11q12.2 · 61.8 Mb
Estimated prevalence by population
Global 49.1%; European 48.4%; African 62.4%; East Asian 20.9%; South Asian 69.7%; Americas 25.9%; Ashkenazi 57.7%; Finnish 36.2%; Middle Eastern 39.2%; Amish 58.7%.
Estimated CC genotype frequency.
Global 40.6%; European 42.3%; African 33.2%; East Asian 49.6%; South Asian 27.6%; Americas 50.0%; Ashkenazi 36.5%; Finnish 47.9%; Middle Eastern 46.8%; Amish 35.8%.
Estimated CG genotype frequency.
Global 10.3%; European 9.3%; African 4.4%; East Asian 29.5%; South Asian 2.7%; Americas 24.1%; Ashkenazi 5.8%; Finnish 15.9%; Middle Eastern 14.0%; Amish 5.5%.
Estimated GG genotype frequency.
Showing effects for C/C genotype
Nutrition & Metabolism
Macronutrient Metabolism
Omega-3 Conversion. Evidence: 8/10. Source: PMID 24816252. Highly Efficient.
Cardiovascular & Metabolic
Lipids & Cholesterol
LDL Cholesterol. Evidence: 8/10. Source: PMID 31217584. Higher Levels.
HDL Cholesterol. Evidence: 6/10. Source: PMID 20864672. Higher Levels.
Triglycerides. Evidence: 9/10. Source: PMID 20864672. Lower Levels.
Blood Cell & Iron Traits
Eosinophil Count. Evidence: 8/10. Source: PMID 27863252. Higher Count.
Hemoglobin Levels. Evidence: 9/10. Source: PMID 34594039. Lower Levels.
Showing effects for C/G genotype
Omega-3 Conversion. Evidence: 8/10. Source: PMID 24816252. Typical.
LDL Cholesterol. Evidence: 8/10. Source: PMID 31217584. Typical Levels.
HDL Cholesterol. Evidence: 6/10. Source: PMID 20864672. Typical Levels.
Triglycerides. Evidence: 9/10. Source: PMID 20864672. Typical Levels.
Eosinophil Count. Evidence: 8/10. Source: PMID 27863252. Typical Count.
Hemoglobin Levels. Evidence: 9/10. Source: PMID 34594039. Typical Levels.
Showing effects for G/G genotype
Omega-3 Conversion. Evidence: 8/10. Source: PMID 24816252. Reduced.
LDL Cholesterol. Evidence: 8/10. Source: PMID 31217584. Lower Levels.
HDL Cholesterol. Evidence: 6/10. Source: PMID 20864672. Lower Levels.
Triglycerides. Evidence: 9/10. Source: PMID 20864672. Higher Levels.
Eosinophil Count. Evidence: 8/10. Source: PMID 27863252. Lower Count.
Hemoglobin Levels. Evidence: 9/10. Source: PMID 34594039. Higher Levels.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Highly active desaturase enzymes in this genotype facilitate the rapid conversion of plant-derived short-chain fatty acids into vital long-chain lipids like arachidonic acid [1]. This efficient synthesis means the body can effectively generate essential fats from vegetarian sources like flaxseeds and walnuts [1] [2]. Its effect on blood lipids is mixed rather than uniformly favorable: this efficient-conversion allele is associated with higher HDL cholesterol and lower triglycerides, but also with higher LDL and total cholesterol [3] [4]. Because these opposing effects largely offset one another, the overall cardiovascular impact is roughly neutral. This profile remains well suited for plant-rich diets, as the body naturally maintains a strong supply of active polyunsaturated fats [1].
Highly efficient conversion of plant-based omega fats; Higher HDL cholesterol and lower triglycerides; But higher LDL and total cholesterol (net-neutral lipid effect).
Sample genotype: CG (Heterozygous)
Balanced enzyme expression in this heterozygous genotype leads to intermediate conversion rates of dietary plant oils into active long-chain fatty acids [1]. The body retains a moderate ability to synthesize essential lipids like arachidonic acid from plant-based precursors [1] [2]. Circulating levels of LDL cholesterol, HDL cholesterol, and triglycerides typically fall within the average baseline range [3] [4]. Because metabolic efficiency is moderate, a balanced intake of both plant-derived and direct marine-derived omega-3 fatty acids supports optimal lipid levels. This genotype represents the most common genetic baseline globally, offering a stable metabolic middle ground.
Standard conversion of plant-based omega fats; Typical baseline cholesterol and triglyceride levels.
Sample genotype: GG (Homozygous)
Reduced expression of the desaturase enzyme in this genotype significantly impairs the conversion of plant-derived short-chain fatty acids into active long-chain forms [1]. Consequently, blood levels of essential lipids like arachidonic acid and phosphatidylcholine are notably lower [1] [2]. This metabolic limitation makes it difficult for the body to obtain sufficient active omega-3 and omega-6 fats solely from plant sources like seeds and nuts [2]. Its effect on blood cholesterol is mixed rather than uniformly unfavorable: this genotype is associated with lower LDL and total cholesterol, but also with lower HDL cholesterol and higher triglycerides [3] [4], so the opposing effects largely offset and the overall cardiovascular impact is roughly neutral. To compensate for reduced synthesis, incorporating direct sources of active omega-3s such as fatty fish or algae-based supplements is highly beneficial [2].
Impaired conversion of plant-based omega fats; Lower LDL and total cholesterol; But lower HDL and higher triglycerides (net-neutral lipid effect).
Variants with shared genetic architecture
rs174546 · FADS1 Gene · Chr 11 · Fatty Acid Metabolism
rs174554 · FADS1 Gene · Chr 11 · Omega Fat Conversion
rs174545 · FADS1 Gene · Chr 11 · Fatty Acid Metabolism
Genetic variants influencing circulating lipid levels and risk of coronary artery disease.
An atlas of genetic influences on human blood metabolites.
Genetic analyses of diverse populations improves discovery for complex traits.
Content updated August 2026.
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