Oxidative Stress
The rust of biology. Oxidative stress occurs when reactive oxygen species (free radicals) exceed your antioxidant defenses. It damages DNA, proteins, and lipids, driving aging and disease. Yet some oxidative stress is necessary - it signals adaptation and fights pathogens.
What Are Free Radicals?
Reactive Oxygen Species
Superoxide (O2•−), hydrogen peroxide (H2O2), hydroxyl radical (•OH). Unstable molecules seeking electrons.
Where They Come From
Mitochondria (electron leak), immune cells, environmental toxins, radiation, metabolism.
What They Damage
Lipid membranes (lipid peroxidation), proteins (oxidation), DNA (mutations). All cell components vulnerable.
Chain Reactions
One radical can trigger thousands of reactions, damaging many molecules before being neutralized.
Necessary Evil
ROS are also signaling molecules. They trigger adaptation (hormesis), kill pathogens, regulate cell functions.
Oxidative Stress
When ROS production exceeds antioxidant capacity. The imbalance causes damage.
Your Antioxidant Defense System
Endogenous (Made by Body)
- Glutathione: Master antioxidant, inside cells
- SOD: Converts superoxide to H2O2
- Catalase: Converts H2O2 to water
- Glutathione peroxidase: Requires selenium
- Uric acid: Major blood antioxidant
Exogenous (From Diet)
- Vitamin C: Water-soluble, recycles vitamin E
- Vitamin E: Protects membranes
- Carotenoids: Beta-carotene, lycopene, etc.
- Polyphenols: Flavonoids, resveratrol, etc.
- Selenium, zinc: Required for antioxidant enzymes
What Increases Oxidative Stress
Chronic Inflammation
Immune cells produce ROS as weapons. Chronic inflammation = chronic oxidative stress.
High Blood Sugar
Glucose auto-oxidation. Advanced glycation end products (AGEs). Mitochondrial overload.
Environmental Toxins
Air pollution, heavy metals, pesticides, radiation, cigarette smoke all generate ROS.
Seed Oils
Polyunsaturated fats oxidize easily. When heated or in body, form lipid peroxides.
Poor Sleep
Sleep deprivation increases oxidative markers and reduces antioxidant capacity.
Overtraining
Excessive exercise without recovery increases ROS beyond adaptive capacity.
Nrf2: The Master Switch
Nrf2 is a transcription factor that activates over 200 protective genes when triggered by oxidative stress:
What Nrf2 Activates
Glutathione synthesis, SOD, catalase, heme oxygenase-1, quinone reductase, phase 2 detox enzymes.
Natural Nrf2 Activators
Sulforaphane (broccoli), curcumin, resveratrol, EGCG (green tea), exercise, fasting.
Hormesis: Mild stress activates Nrf2, upregulating defenses. This is why some "stressors" are beneficial.
Reducing Oxidative Stress
Reduce Sources
Control blood sugar, reduce inflammation, avoid toxins, don't overtrain, limit seed oils.
Support Glutathione
NAC, glycine, whey protein, sulfur foods, adequate selenium. Master intracellular antioxidant.
Eat Antioxidant-Rich Foods
Colorful vegetables, berries, herbs, spices, green tea, dark chocolate. Whole foods over supplements.
Activate Nrf2
Cruciferous vegetables, exercise, fasting, cold exposure. Upregulate your own antioxidant system.