GPX1 Variants and Lifespan: Pro198Leu (rs1050450) Explained

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — your resource for evidence-based guidance on longevity & telomeres. Browse all Longevity & Telomeres education

Oxidative stress — the slow damage caused by reactive oxygen molecules — is one of the recurring themes in the biology of aging. Among the enzymes that defend against it, glutathione peroxidase 1 stands out, and the gene that encodes it, GPX1, carries a common variant that has drawn attention in research on longevity, cardiovascular health, and cancer risk. Here is what the science actually supports.

What GPX1 does and why it matters for aging

GPX1 encodes glutathione peroxidase 1, an antioxidant enzyme found throughout the body's cells. Its job is to neutralize hydrogen peroxide and lipid peroxides using glutathione, converting reactive, damaging molecules into harmless water. Because cumulative oxidative damage to DNA, proteins, and lipids is a hallmark of aging, the efficiency of frontline defenses like GPX1 is biologically relevant to how tissues weather decades of metabolic stress.

The Pro198Leu (rs1050450) variant

The most studied GPX1 variant is Pro198Leu, identified by the reference number rs1050450. It swaps the amino acid proline for leucine at position 198. The leucine version is associated with somewhat lower enzyme activity and a blunted response to selenium, the trace mineral GPX1 depends on to function. Carriers of the lower-activity variant may have modestly reduced antioxidant capacity, which is the mechanism researchers explore when linking this gene to health outcomes.

What the research shows

Studies associate the GPX1 Pro198Leu variant with differences in oxidative-stress markers and, in some populations, with cardiovascular measures such as carotid artery thickening and with certain cancer risks — though findings vary across studies and populations, as is typical for common variants of small effect. The consistent thread is mechanistic: reduced GPX1 activity means less capacity to clear a specific class of reactive molecules. It is an association and a tendency, not a diagnosis or a prediction of any individual outcome.

GPX1 in the wider antioxidant network

No antioxidant gene works alone. GPX1 operates alongside SOD2 (manganese superoxide dismutase), whose Ala16Val variant affects how the enzyme reaches the mitochondria, and catalase, encoded by CAT. These enzymes form a relay: superoxide dismutases convert one reactive species into hydrogen peroxide, and GPX1 and catalase finish the job. Your overall resilience to oxidative stress reflects the combined tuning of this network, not any single variant in isolation.

What your genes reveal about oxidative-stress pathways

Pathway-level genetic insight puts GPX1 in context. The Precision Peptide Genetic Test analyzes 14 pathways, 49 peptides, 150+ genetic insights, including antioxidant and oxidative-stress pathway variants. It does not predict your lifespan, diagnose disease, or tell you which supplement to take — selenium status and GPX1 interact, but dosing is a clinical decision, not a genetic verdict. What the report offers is understanding of your antioxidant-defense biology, useful context to discuss with a qualified healthcare provider alongside diet, lifestyle, and any lab testing. PlexusDx tells you about your biology; it does not tell you what to put in your body.

Frequently Asked Questions

What does the GPX1 gene do?

GPX1 encodes glutathione peroxidase 1, an antioxidant enzyme that neutralizes hydrogen peroxide and lipid peroxides using glutathione. By clearing these reactive molecules, it helps limit oxidative damage to DNA, proteins, and lipids — a process central to how cells and tissues age over time.

Is the GPX1 Pro198Leu variant bad?

Not in a simple sense. The Pro198Leu variant (rs1050450) is associated with modestly lower enzyme activity and a blunted selenium response. It is a common tendency, not a diagnosis or a verdict. Many carriers stay healthy, and overall antioxidant capacity depends on many genes and lifestyle factors.

Does GPX1 determine how long I will live?

No. GPX1 is one enzyme in a broad antioxidant network alongside SOD2 and CAT, and lifespan reflects thousands of genetic and environmental factors. A GPX1 variant is associated with oxidative-stress differences, but it cannot predict any individual's longevity or health outcome.

Should I take selenium if I carry a GPX1 variant?

That is a clinical decision, not a genetic one. GPX1 depends on selenium, and status matters, but supplementation depends on your diet, blood levels, and health — details a qualified healthcare provider evaluates. A genetic report offers pathway context; it does not prescribe a supplement or dose.

Curious how your own biology maps to these pathways? The Precision Peptide Genetic Test reads 14 pathways, 49 peptides, 150+ genetic insights across a single at-home saliva sample, giving you pathway-level context to bring to a qualified provider. Know your genetics; don't guess.

This article is part of the PlexusDx Education Hub. Browse all Longevity & Telomeres education

The Precision Peptide Genetic Test analyzes how your genes influence peptide-related biological pathways. It does not recommend, prescribe, or determine which peptides you should use. Consult a qualified healthcare provider before beginning any peptide protocol.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.