DNA Repair
The body's proofreading system. DNA sustains thousands of lesions daily from oxidation, radiation, and replication errors. Repair mechanisms detect and fix these errors constantly. When repair fails, mutations accumulate—leading to cancer and aging. Supporting DNA repair is central to longevity and cancer prevention.
DNA Repair Pathways
Base Excision Repair
Fixes small base damage. Oxidation, alkylation. Most common repair type.
Nucleotide Excision Repair
Removes bulky lesions. UV damage, chemical adducts. Cuts and replaces section.
Mismatch Repair
Fixes replication errors. Wrong base pairs. Lynch syndrome when defective.
Homologous Recombination
Fixes double-strand breaks. Uses sister chromatid as template. BRCA genes involved.
Non-Homologous End Joining
Also fixes double-strand breaks. Error-prone. Quick but imprecise.
Direct Reversal
Some damage directly reversed. No cutting needed. MGMT enzyme example.
Supporting DNA Repair
NAD+
PARP and sirtuins need NAD+. NMN, NR, niacin support levels.
Zinc
Many repair enzymes are zinc-dependent. p53 is zinc-finger protein.
Folate & B12
DNA synthesis and methylation. Prevent uracil misincorporation.
Magnesium
DNA polymerase cofactor. Essential for synthesis and repair.
Antioxidants
Prevent damage in first place. Less repair needed. Vitamin C, E, glutathione.
Fasting
Activates repair pathways. p53 upregulation. Autophagy clears damaged cells.
What Damages DNA
Oxidative Stress
Free radicals attack DNA. Most common source of damage. Mitochondria major source.
UV Radiation
Creates thymine dimers. Skin cancer risk. Sunburn is DNA damage.
Chemicals
Carcinogens, pollutants. Aflatoxin, benzene. Environmental exposure matters.
Replication Errors
Copying mistakes. Billions of bases copied. Errors inevitable.