What you carry at this position in your DNA and what research says about it.
Omega Fatty Acid Metabolism: 8/10 evidence, 19 publications.
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Sample genotype (not yours): G/G
Efficient Fatty Acid Conversion but Higher Cholesterol Risk
This genotype allows for highly efficient conversion of plant-based omega-3s into active forms. However, it is also linked to slightly higher LDL cholesterol (though triglyceride levels tend to run lower).
What this genotype means: Highly efficient conversion of plant-based omega-3 and omega-6 fats; Slightly elevated risk of high LDL cholesterol and hyperlipidemia; Slightly higher baseline white blood cell count.
Sample genotype (not yours): A/A
Lower Cholesterol Risk but Inefficient Plant Omega-3 Conversion
This genotype is associated with naturally lower LDL cholesterol levels, but requires direct dietary sources of long-chain omega-3s due to poor conversion of plant-based oils.
What this genotype means: Poor conversion of plant-based ALA into active EPA and DHA; Naturally lower baseline LDL cholesterol and triglyceride levels; Slightly lower white blood cell count and slightly higher hemoglobin.
Sample genotype (not yours): G/A
Balanced Fatty Acid Conversion and Moderate Cholesterol Risk
This genotype represents a balanced middle ground, offering moderate efficiency in processing plant-based fats with a typical cholesterol risk profile.
What this genotype means: Moderate conversion of plant-based plant oils to active omega-3s; Typical baseline levels of LDL cholesterol and triglycerides; Average blood cell counts and physiological markers.
Gene function and biological role
Gene Function: The FADS1 gene encodes delta-5 desaturase, a key enzyme in the metabolic pathway that processes polyunsaturated fatty acids [1]. This enzyme is responsible for converting plant-derived short-chain fatty acids into active, long-chain forms like arachidonic acid and eicosapentaenoic acid (EPA) [1]. Proper functioning of this pathway is essential for maintaining cellular membrane integrity and regulating inflammatory responses throughout the body [2]. Variations in this gene can significantly alter how the body processes dietary fats, influencing blood lipid levels and cardiovascular health [2].
Variant Impact: Located within an intron of the FADS1 gene, rs174549 is a common genetic variant that acts as a major regulator of desaturase enzyme activity [3]. The G allele represents the ancestral, highly active version of the enzyme, whereas the A allele reduces enzyme expression and slows down fatty acid conversion [3]. This single nucleotide change has wide-ranging effects on circulating lipid metabolites, blood cell traits, and inflammatory markers [4]. Because it alters the rate-limiting step of fatty acid synthesis, this variant plays a central role in gene-diet interactions involving omega-3 and omega-6 intake [4].
Key Insight: This variant creates a direct trade-off: the genotype that is best at processing plant-based omega-3s also carries the highest risk for elevated LDL cholesterol.
Location: FADS1. Chromosome 11 · 11q12.2 · 61.8 Mb
Origin Story: The high-activity G allele is thought to have been strongly selected for during the transition to agriculture in Europe, allowing early farmers to synthesize essential long-chain fatty acids from a plant-dominated diet rather than relying on marine sources.
Estimated prevalence by population
Global 56.4%; European 49.1%; African 86.2%; East Asian 20.9%; South Asian 70.1%; Americas 29.0%; Ashkenazi 60.4%; Finnish 36.3%; Middle Eastern 45.8%; Amish 62.7%.
Estimated GG genotype frequency.
Global 34.8%; European 42.0%; African 13.2%; East Asian 49.6%; South Asian 27.2%; Americas 49.7%; Ashkenazi 34.6%; Finnish 47.9%; Middle Eastern 43.7%; Amish 33.0%.
Estimated GA genotype frequency.
Global 8.8%; European 9.0%; African 0.5%; East Asian 29.4%; South Asian 2.6%; Americas 21.3%; Ashkenazi 5.0%; Finnish 15.8%; Middle Eastern 10.4%; Amish 4.3%.
Estimated AA genotype frequency.
Showing effects for G/G genotype
Nutrition & Metabolism
Macronutrient Metabolism
Omega-3 Conversion. Evidence: 8/10. Source: PMID 25500335. Highly Efficient.
Cardiovascular & Metabolic
Lipids & Cholesterol
LDL Cholesterol. Evidence: 8/10. Source: PMID 30275531. Slightly Higher.
Blood Cell & Iron Traits
White Blood Cell Count. Evidence: 8/10. Source: PMID 27863252. Slightly Higher.
Hemoglobin Levels. Evidence: 8/10. Source: PMID 38116116. Slightly Lower.
Heart Rhythm & Conduction
Heart Rate. Evidence: 6/10. Source: PMID 23583979. Slightly Lower.
Lifestyle, Fitness & Aging
Height & Body Size
Height. Evidence: 8/10. Source: PMID 36224396. Slightly Taller.
Showing effects for A/A genotype
Omega-3 Conversion. Evidence: 8/10. Source: PMID 25500335. Inefficient.
LDL Cholesterol. Evidence: 8/10. Source: PMID 30275531. Slightly Lower.
White Blood Cell Count. Evidence: 8/10. Source: PMID 27863252. Slightly Lower.
Hemoglobin Levels. Evidence: 8/10. Source: PMID 38116116. Slightly Higher.
Heart Rate. Evidence: 6/10. Source: PMID 23583979. Slightly Higher.
Height. Evidence: 8/10. Source: PMID 36224396. Slightly Shorter.
Showing effects for G/A genotype
Omega-3 Conversion. Evidence: 8/10. Source: PMID 25500335. Moderate Efficiency.
LDL Cholesterol. Evidence: 8/10. Source: PMID 30275531. Typical.
White Blood Cell Count. Evidence: 8/10. Source: PMID 27863252. Typical.
Hemoglobin Levels. Evidence: 8/10. Source: PMID 38116116. Typical.
Heart Rate. Evidence: 6/10. Source: PMID 23583979. Typical.
Height. Evidence: 8/10. Source: PMID 36224396. Typical.
What this genotype means for the people who carry it
Sample genotype: GG (Homozygous)
Carrying two copies of the G allele results in highly active delta-5 desaturase enzymes, enabling efficient conversion of plant-based short-chain fatty acids into long-chain polyunsaturated fatty acids [1]. This means plant sources of omega-3, such as flaxseed or chia seeds, are readily converted into beneficial eicosapentaenoic acid (EPA) [1]. However, this rapid conversion also increases the production of arachidonic acid, a precursor to pro-inflammatory molecules, and is associated with higher levels of LDL cholesterol (while triglycerides tend to run lower) [2]. Large-scale genetic studies show a clear link between this genotype and an increased risk of hyperlipidemia and high cholesterol [2]. While blood cell counts, including white blood cells, tend to be slightly higher, these measurements typically remain within normal clinical ranges [3]. To balance these effects, focusing on a diet rich in anti-inflammatory antioxidants while managing overall saturated fat intake can be beneficial.
Highly efficient conversion of plant-based omega-3 and omega-6 fats; Slightly elevated risk of high LDL cholesterol and hyperlipidemia; Slightly higher baseline white blood cell count.
Sample genotype: AA (Homozygous)
Inheriting two copies of the A allele significantly reduces the activity of the delta-5 desaturase enzyme, leading to inefficient conversion of plant-based short-chain fatty acids [1]. Plant-derived omega-3s, such as those from flaxseed, are not easily converted into the active forms EPA and DHA, making direct dietary sources like fish oil or algae oil highly important [1]. On the positive side, this slower metabolic rate results in naturally lower levels of LDL cholesterol and a reduced risk of hyperlipidemia [2]. Studies also indicate a lower risk of chronic inflammatory conditions, likely due to reduced synthesis of pro-inflammatory arachidonic acid [1]. Other associated traits include slightly lower white blood cell counts and slightly higher hemoglobin levels, though these generally remain within healthy limits [3]. For individuals with this genotype, a diet that directly supplies pre-formed omega-3 fatty acids while taking advantage of naturally favorable cholesterol levels is ideal.
Poor conversion of plant-based ALA into active EPA and DHA; Naturally lower baseline LDL cholesterol and triglyceride levels; Slightly lower white blood cell count and slightly higher hemoglobin.
Sample genotype: GA (Heterozygous)
Possessing one G allele and one A allele leads to a moderate level of delta-5 desaturase enzyme activity, representing a balanced middle ground in fatty acid metabolism [1]. The body retains a partial ability to convert plant-derived short-chain omega-3 and omega-6 fatty acids into their active long-chain forms [1]. At the same time, the risk of elevated LDL cholesterol and hyperlipidemia is lower than that of the G/G genotype, though slightly higher than the A/A genotype [2]. This intermediate state means that while plant-based fats are processed with moderate efficiency, incorporating some direct sources of long-chain omega-3s, like fish or algae oil, remains supportive of cardiovascular health. Blood markers such as white blood cell counts and hemoglobin levels typically fall into average, baseline ranges [3]. Overall, this genotype provides a flexible metabolic profile that adapts well to a variety of dietary patterns.
Moderate conversion of plant-based plant oils to active omega-3s; Typical baseline levels of LDL cholesterol and triglycerides; Average blood cell counts and physiological markers.
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
The Polygenic and Monogenic Basis of Blood Traits and Diseases.
Genetics of blood lipids among ~300,000 multi-ethnic participants of the Million Veteran Program.
The Allelic Landscape of Human Blood Cell Trait Variation and Links to Common Complex Disease.
Content updated August 2026.
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