What you carry at this position in your DNA and what research says about it.
Caffeine and Kidney Health: 8/10 evidence, 40 publications.
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Sample genotype (not yours): C/C
Typical Caffeine and Kidney Filtration
This genotype is associated with standard caffeine clearance and typical kidney filtration rates. You likely experience average sensitivity to the stimulating effects of coffee and tea.
What this genotype means: Typical caffeine sensitivity; Standard kidney filtration rates.
Sample genotype (not yours): C/T
Slightly Faster Caffeine Clearance and Kidney Protection
Carrying one copy of the T allele is linked to slightly faster caffeine metabolism and enhanced kidney filtration. You may naturally consume slightly more coffee or tea to feel alert.
What this genotype means: Slightly faster caffeine breakdown; Mildly enhanced kidney filtration.
Sample genotype (not yours): T/T
Fast Caffeine Clearance and Enhanced Kidney Protection
Having two copies of the T allele is associated with rapid caffeine metabolism and superior kidney filtration. You likely have a higher tolerance for caffeine and may naturally drink more coffee.
What this genotype means: Rapid caffeine clearance; Enhanced kidney filtration rates; Lower uric acid levels.
Gene function and biological role
Gene Function: CYP1A1 encodes a member of the cytochrome P450 superfamily of enzymes, which are major catalysts for drug and toxin metabolism in the liver [1]. This specific enzyme is primarily involved in the metabolic activation of environmental toxins and polycyclic aromatic hydrocarbons [1]. It is located head-to-head with the neighboring CYP1A2 gene on chromosome 15 [2]. Together, these closely linked genes play a central role in how the body processes dietary stimulants, medications, and environmental compounds [2].
Variant Impact: The rs2472297 variant is an intergenic single nucleotide polymorphism located in the regulatory region between the CYP1A1 and CYP1A2 genes [2]. This genetic change influences the expression and activity of these metabolic enzymes, particularly in response to dietary stimulants [2]. The T allele is strongly associated with faster clearance of caffeine from the bloodstream [3]. Consequently, individuals carrying this variant tend to consume more coffee to achieve the same stimulating effects [3].
Read on the Caffeine Clearance page
Key Insight: This variant acts as a genetic dial for caffeine clearance, directly influencing how many cups of coffee you naturally choose to drink each day.
Location: CYP1A1. Chromosome 15 · 15q24.1 · 74.7 Mb
Estimated prevalence by population
Global 72.8%; European 57.4%; African 91.8%; East Asian 99.8%; South Asian 93.0%; Americas 81.8%; Ashkenazi 84.8%; Finnish 56.4%; Middle Eastern 92.7%; Amish 80.8%.
Estimated CC genotype frequency.
Global 23.9%; European 36.7%; African 8.0%; East Asian 0.2%; South Asian 6.9%; Americas 17.3%; Ashkenazi 14.6%; Finnish 37.4%; Middle Eastern 7.2%; Amish 18.1%.
Estimated CT genotype frequency.
Global 3.3%; European 5.9%; African 0.2%; East Asian < 0.1%; South Asian 0.1%; Americas 0.9%; Ashkenazi 0.6%; Finnish 6.2%; Middle Eastern 0.1%; Amish 1.0%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Organ Systems
Kidney Function & Disease
Kidney Function. Evidence: 8/10. Source: PMID 31152163. Typical.
Cardiovascular & Metabolic
Gout & Uric Acid
Uric Acid Levels. Evidence: 8/10. Source: PMID 31578528. Typical.
Nutrition & Metabolism
Caffeine & Stimulant Metabolism
Caffeine Metabolism. Evidence: 10/10. Source: PMID 21357676. Typical Speed.
Pharmacogenomics
Antidepressant & Psychiatric Drug Response
Clozapine Response. Evidence: 7/10. Source: PMID 30922102. Typical Clearance.
Showing effects for C/T genotype
Kidney Function. Evidence: 8/10. Source: PMID 31152163. Slightly Better.
Uric Acid Levels. Evidence: 8/10. Source: PMID 31578528. Slightly Lower.
Caffeine Metabolism. Evidence: 10/10. Source: PMID 21357676. Slightly Faster.
Clozapine Response. Evidence: 7/10. Source: PMID 30922102. Faster Clearance.
Showing effects for T/T genotype
Kidney Function. Evidence: 8/10. Source: PMID 31152163. Better Filtration.
Uric Acid Levels. Evidence: 8/10. Source: PMID 31578528. Lower Levels.
Caffeine Metabolism. Evidence: 10/10. Source: PMID 21357676. Fast Speed.
Clozapine Response. Evidence: 7/10. Source: PMID 30922102. Fast Clearance.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Having two copies of the C allele represents the most common genetic profile globally, particularly in East Asian and African populations where the T allele is rare. This baseline profile is associated with typical activity levels of the CYP1A2 enzyme, which is responsible for breaking down caffeine [1]. Because caffeine remains in your system longer compared to T allele carriers, you may feel its stimulating effects more intensely and require less coffee to stay alert [2]. In terms of metabolic health, this genotype is linked to typical levels of serum urate and standard kidney filtration rates [3]. While you do not carry the protective kidney benefits associated with the T allele, your baseline risk remains typical [4].
Typical caffeine sensitivity; Standard kidney filtration rates.
Sample genotype: CT (Heterozygous)
This heterozygous genotype is associated with a moderate increase in the activity of the CYP1A2 enzyme, which accelerates the breakdown of caffeine in the liver [1]. As a result, you may clear caffeine from your system slightly faster than those with the typical C/C genotype [1]. This faster clearance often translates to a natural tendency to consume slightly more coffee or tea to maintain alertness [2]. Beyond caffeine, this genetic variant is associated with favorable markers of kidney health, including a slightly higher estimated glomerular filtration rate (eGFR) [3]. It is also linked to slightly lower levels of serum urate, which may offer mild protection against uric acid buildup [4].
Slightly faster caffeine breakdown; Mildly enhanced kidney filtration.
Sample genotype: TT (Homozygous)
This genotype is linked to highly active CYP1A2 enzyme function, leading to rapid clearance of caffeine from your bloodstream [1]. Because your body processes caffeine so quickly, you are likely to have a higher tolerance and may naturally consume more coffee or tea to feel stimulated [2]. This rapid metabolism also extends to certain medications, such as the antipsychotic clozapine, which is cleared much faster in individuals with this profile [3]. On the health front, the T/T genotype is strongly associated with enhanced kidney function, characterized by a higher estimated glomerular filtration rate (eGFR) [4]. Additionally, you are likely to have lower levels of serum urate, which helps protect against the accumulation of uric acid in the joints and kidneys [5].
Rapid caffeine clearance; Enhanced kidney filtration rates; Lower uric acid levels.
Variants with shared genetic architecture
rs2470893 · CYP1A1 Gene · Chr 15 · Caffeine and Kidney Health
rs4646421 · CYP1A1 Gene · Chr 15 · Toxin Metabolism and Cancer
rs1048943 · CYP1A1 Gene · Chr 15 · Environmental Cancer Risk
Phase I metabolic genes and risk of lung cancer: multiple polymorphisms and mRNA expression.
Sequence variants at CYP1A1-CYP1A2 and AHR associate with coffee consumption.
Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption.
Genetics of 35 blood and urine biomarkers in the UK Biobank.
A catalog of genetic loci associated with kidney function from analyses of a million individuals.
Content updated August 2026.
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