Reducing Oxidative Damage and Understanding Anti-oxidants
Every cause of skin damage, from sunlight, smoking, stress to lack of sleep, involves generating highly reactive and toxic by-products of oxygen in your skin. These are known as ‘free radicals’, and are produced when one of the factors mentioned consumes an oxygen electron (normally paired), leaving an unpaired (free) electron.
In response to this imbalance, free radicals regain their missing electron by stealing it from other chemicals. They can react with almost anything, including DNA, lipids in cell membranes, proteins, and other vital structures, leaving them damaged. Injury due to free radicals (known as oxidative damage) is a key trigger for inflammation and matrix breakdown in the skin, both processes in skin ageing.
The skin has its own antioxidant defence systems to combat free radicals. These include enzymes that promote destruction of free radicals, as well as antioxidant ‘decoys’ that prevent damage by ‘taking the bullet’ themselves, thus protecting your skin. Key vitamin antioxidants are vitamin E and vitamin C.
When toxic free radical production outstrips the body’s defences a state of oxidative stress occurs. Oxidative stress is an important element of skin ageing. The body’s production of antioxidants declines with age, while the cumulative exposure to free radicals increases, overwhelming its defences. Targeting free radicals is an effective means to slow ageing and a central component of anti-ageing systems. Indisputably, diets rich in antioxidants are associated with fewer wrinkles and better complexions. Antioxidants are available as dietary supplements, but the efficacy of these plant-derived compounds and vitamins are not well understood.
Vitamins and supplements, and their role in healthy ageing
Vitamin E is the most important antioxidant naturally present in human skin. It acts as a decoy target for free radicals, diverting them from causing injury. It is then regenerated by vitamin C, allowing it to repeatedly neutralise free radicals and protect skin from damage. Being oil- and fat-soluble it is particularly suited to preventing free radical damage to lipids (fats) in the cell membranes. Vitamin E also has significant effects on inflammation and immune function. As it is not made by the skin it must be obtained through diet or supplementation. A standard daily Western diet contains three or four mg of vitamin E, less than half the recommended daily intake.
Vitamin C is the most abundant natural antioxidant in skin. It too functions as a decoy target for free radicals. As mentioned, vitamin C regenerates vitamin E, and is also required for collagen synthesis. Sunlight and smoking rapidly deplete Vitamin C, leaving skin less protected the next time it is exposed.
Vitamin A and beta-carotene
Vitamin A is a member of the retinoid family of chemicals that have potent effects on ageing skin. Retinoids are the only topical agents for which robust evidence exists regarding their beneficial actions on ageing and sun-damaged skin.
Vitamin B3 belongs to the family of antioxidant compounds essential to the body for energy metabolism and DNA repair.
Selenium is a metal ion that is a natural constituent of some of the skin’s important enzymes, including the antioxidant defence enzymes, glutathione peroxidise and thioredoxin.
Alpha-lipoic acid is a free radical scavenger, with additional actions to regenerate antioxidant defences.
The mitochondria are the energy producing powerhouse of the cell. Free radicals transport oxygen in and out of the mitochondria. This makes the mitochondria the major target for oxidative damage. If the mitochondria are damaged, oxygen use for energy production is less efficient, thus further increasing free radical production. This vicious cycle is common to many ageing processes.
Coenzyme Q10 (CoQ10) is a key antioxidant inside the mitochondria as well as a key component of efficient energy production. Reduced levels of CoQ10 lead to increased formation of free radicals. Levels of CoQ10 decline in the skin from the mid-thirties onwards. This decline is fastest in those with repeated overexposure to the sun and in smokers. Bolstering CoQ10 levels and its defence against free radical attack is a strategic part of dietary supplementation.
CoQ10 synthesis in the human body is assisted by numerous vitamins, including vitamin B, vitamin C, and folic acid. Of these, vitamin B6 probably has the biggest impact.
Melatonin is a hormone produced naturally in the human body. Its job in regulating sleep cycles is well known and it is widely used in the prevention and treatment of jet-lag.
Carnosine is a multifunctional antioxidant found in meat, and as such is one antioxidant often lacking in a vegetarian diet. Its long-term effects in human ageing are unclear, although it is widely touted as an effective anti-ageing therapy.
Polyphenols (also known as flavanoids) are a large family of naturally occurring plant-derived antioxidants. Some of the most popular polyphenols include:
- Epigallocatechin gallate (EGCG) – found in green tea
- Silymarin and silybin – found in milk thistle
- Quercitin – found in onions, apples, green tea and black tea
- Hesperidin and rutin – found in citrus fruits
- Proanthocyanidin – found in grape seed extract
- Genistein, daidzein, aglycone – found in soybean products
- Resveratrol – found in grapes, wine, peanuts, and knotweed
- Ellagic acid – found in many red fruits and berries, including raspberries, strawberries, blackberries, cranberries, grapes, pomegranate, and some nuts including pecans and walnuts
- Sulphoraphane and indole-3-carbinol – found in broccoli as well as other cruciferous vegetables (members of the cabbage family)
- Lycopenes – found in red and pink fruits, such as tomatoes, watermelon, pink grapefruit, pink guava, papaya, and rosehip
- Lutein – found in green leafy vegetables, like spinach, kale, collard greens, romaine lettuce, as well as in leeks, peas, and egg yolks
- Luteolin – found in herbs and vegetables including parsley, basil, peppermint, capsicum, rosemary, and celery
- Hydroxytyrosol – found in olive juice and oil
- Curcumin – found in turmeric
- Ginkgo flavonglycosides – extract of the Ginkgo leaves
- Caffeic acid, caffeic acid phenethyl ester (CAPE) and ferulic acid – found in many plants, but particularly high in coffee berry (the unripe coffee bean), apple and orange seeds, peanuts, artichoke, pineapple, cooked sweet corn, as well as the bran of rice, rye, wheat, oats, barley and flax; CAPE is also high in bee propolis (carried back from pine sap by honey bees)
Many products are made from not just one polyphenol but a complex mixture or extract from sources like green tea, pomegranate, grapes, or rosehip. These compounds and extracts have been shown to reduce free radical damage in the laboratory, but their efficacy in the human body is hotly debated.
Stress Reduction Techniques
For the last fifty years or so meditation and yoga have been studied as potential techniques for stress reduction and treatment of depression and anxiety. Meditation may be one of the best anti-ageing exercises to promote both a healthy mind and body. It can dramatically raise melatonin levels in the body, improving sleep, regulating immune function, reducing cell damage, functioning as an antioxidant, and even impeding proliferation of cancer cells. Meditation has been shown to also lower cortisol (stress hormone) and boost DHEA production, the former contributes to thinning of skin, while the latter is linked with age related cognitive decline and risk of heart disease. Mitigation of pain, toxin removal, heartbeat regulation, emotional balancing, and improvement in the body’s ability to heal are other reported benefits.
The therapeutic benefits of yoga include modulation of the stress response, which induces lowering of the heart rate and blood pressure, and quieting breathing. Yoga enhances mood and overall well-being, in a fashion comparable to other exercise and relaxation techniques. However, yoga is different from traditional exercise, combining movement to develop balance, flexibility, and strength with breathing practices. There are many styles and intensities of yoga, suited to differing preferences and physical ability. Hatha yoga has become the most popular type offered in North America, blending physical poses, breathing practice, and deep relaxation or meditation.