Oxidative Stress and Its Impact on Health and Vision

Oxidative Stress and Its Impact on Health and VisioOxidative stress significantly affects health and vision. It is a process in which free radicals are produced, leading to potential harm as these unstable molecules steal electrons from healthy cells. This oxidative damage can manifest visibly as aging skin and ocular changes, such as cataract formation. However, oxidation is not the only factor contributing to accelerated aging and eye conditions; poor circulation and insufficient essential nutrients also play important roles.

Ultraviolet (UV) rays are a major external factor that promotes oxidation. Continuous exposure to sunlight without protective eyewear can increase oxidative damage in the eyes over time. This exposure can harm retinal cells and may lead to various eye conditions, including macular degeneration. Therefore, protecting the eyes from UV rays is crucial for maintaining eye health.

Oxidative Stress and Glaucoma

In essence, oxidative stress, fueled by free radicals and intensified by UV exposure, is a key player in aging and eye health. While oxidation is a natural process, its impact can be reduced by taking preventive actions, such as ensuring adequate nutrition and shielding the eyes from UV radiation. Understanding these factors is essential for preserving both overall health and vision.

Elevated oxidative stress is considered a risk factor for glaucoma. While managing intraocular pressure (IOP) has traditionally been the main treatment approach for glaucoma, there is a growing interest among researchers in using antioxidants to address oxidative stress.1 In glaucoma, oxidative damage is associated with DNA damage in the tissue layers responsible for regulating the outflow of aqueous humor, which can lead to increased IOP, as well as harm to neurons and the optic nerve.2

How do Antioxidants Help?

antioxidant-free radicals-electronsAntioxidants counteract free radicals by providing an electron to stabilize these reactive atoms. This action prevents the oxidation of molecules. Once stabilized, free radicals lose their ability to harm healthy cells, making them less damaging to the body.

  • The body naturally produces certain antioxidants, such as glutathione, superoxide dismutase, and coenzyme Q10. Both glutathione and superoxide dismutase are recognized for their ability to neutralize a wide range of free radicals.
  • The production of glutathione in the liver requires selenium, riboflavin, vitamin C, cysteine, glycine, and glutamine.
  • Vitamins C and E, along with beta-carotene, are examples of nutrients that function as antioxidants. 
  • A diverse array of antioxidants can be found in fruits, vegetables, certain herbs and spices, as well as mushrooms.

As we grow older, a reduction in antioxidant levels within the eyes is thought to significantly contribute to vision decline. For instance, retinal cell damage may gradually occur over several years, resulting from UV sunlight exposure or the slow weakening of the antioxidant defense system.

Antioxidants and Vision Disorders

Oxidative stress and inflammation are key factors in the onset and progression of numerous eye diseases, such as macular degeneration, glaucoma, cataracts, macular edema, and diabetic retinopathy. If left untreated, these conditions can result in a gradual loss of vision and potentially lead to blindness.3 4 Scientific evidence suggests that using specific antioxidants and anti-inflammatory nutrients as supplements may help with the prevention and management of these age-related eye conditions.5

Despite numerous peer-reviewed studies highlighting the crucial role of antioxidants for eye and overall health, many doctors and eye care professionals tend to overlook their benefits. However, you can actively enhance the levels of antioxidants in your body.

Antioxidant Building Blocks

With the proper building blocks, your body is capable of producing certain antioxidants, such as glutathione, superoxide dismutase, alpha-lipoic acid, CoQ10, and vitamin D. However, other antioxidants need to be consumed through diet and supplements. They include resveratrol, carotenoids, astaxanthin, lutein, zeaxanthin, meso-zeaxanthin, vitamin C, bilberry, and vitamin E.

Inflammation and Oxidative Stress

Inflammation is the body’s immune response to injury, aimed at maintaining stability and healing damaged tissues. When exposed to toxins, foreign substances, pollutants, UV radiation, or other intruders, various cellular components undergo oxidation. This oxidation leads to stress, known as “oxidative stress.” The body’s natural reaction to this imbalance is to trigger the immune system, resulting in inflammation. The roles of inflammation and oxidative stress are closely linked and contribute to eye conditions and other diseases, from dry eye syndrome to cancer. Oxidative stress and inflammation can trigger each other; sometimes oxidative stress leads to inflammation, while at other times, inflammation results in oxidative stress.6

The body defends itself against excessive oxidative stress from free radicals, also known as pro-oxidants, through the use of antioxidants. Free radicals are unstable atoms lacking an electron. Antioxidants provide the missing electron, thereby restoring stability.

Over the past 30 years, research has clarified the reasons and mechanisms behind how imbalances between pro-oxidants and antioxidants lead to oxidative stress. Elevated levels of free radicals can harm DNA, lipids, and proteins, which are essential building blocks of cells responsible for a wide range of functions.7 These components form the foundation of carbohydrates, such as simple sugars like glucose, which provide energy, facilitate protein transport, and enable cellular recognition.8 Oxidative damage triggers an immune response, which subsequently leads to inflammation.9 When oxidative stress levels remain consistently high, inflammation becomes chronic, leading to the development of health problems and vision disorders.

Nutrients That Mitigate the Impact of Oxidative Stress

Astaxanthin helps protect the lens crystallins from oxidation and can possibly protect against increasing inflexibility due to its antioxidant effect.10 Sources: pink seafood, krill oil, supplements containing Haematococcus Pluvialis algae.

Bilberry is a nutrient known for reducing oxidative stress and inflammation.11 In one study, researchers explored whether bilberry extracts could lower levels of a biochemical marker associated with oxidative stress. They focused on enzyme levels that rise as a defense against oxidative stress, specifically heme-oxygenase (HO)-1 and glutathione S-transferase-pi (GST-pi). These enzymes were measured in human retinal-pigment cells cultured in the lab.

Prior to exposure to chemicals that elevate oxidative stress, the cells were treated with 25% enriched bilberry extracts and then exposed to hydrogen peroxide (H2O2). In stressed conditions like H2O2 exposure, normally glutathione levels decrease, and free radicals increase. The study found that early exposure to bilberry extract reduced free radical formation in the cell tissue, despite the unchanged toxicity of H2O2. After 4 hours of H2O2 exposure, the levels of defense enzymes rose, indicating that the extract had activated defense mechanisms against free radicals. Source: Supplements made from the fruit and leaves of the bilberry bush.

Carnosine. L-Carnosine can interact with free radicals that target proteins, resulting in the formation of “protein-carbonyl-carnosine adducts.”12 Beyond its antioxidant capabilities, L-Carnosine is particularly effective in safeguarding nerve cells from premature death.13 Carnosine also functions as an anti-glycating agent and a metal chelator. Through these mechanisms, carnosine plays a valuable role in minimizing DNA damage caused by environmental factors.14 The oxidation of lipids results in the production of malondialdehyde (MDA), a biomarker for oxidative stress, with its levels significantly rising in numerous neurological diseases. 

Curcumin has been shown to offer protective effects against cell damage in human retinal pigment cells caused by blue light. It achieves this by safeguarding retinal pigment epithelial cells from oxidation induced by free radicals.15 Curcuminoids may hold promise in the treatment of age-related macular degeneration (AMD),16 supporting findings from previous studies. Source: Cook with the spice turmeric, available in powder and root form. Combine with black pepper to increase absorption. Also available as a supplement.

DHA derivatives protect retinal pigment epithelial cells from oxidative stress. Unlike DHA’s effects in other parts of the body, such as the liver, it does not seem to undergo lipid oxidation in the retina. Patients with primary open-angle glaucoma often exhibit low blood levels of DHA and EPA, along with reduced blood flow to the optic nerve. These omega-3 fatty acids assist in regulating blood circulation within the eye.17 Sources: ground flaxseed and flaxseed oil, salmon, sardines, anchovies, walnuts, herring, oysters, chia seeds. Supplements are often made from fish oil or flaxseed oil. 

GSH is often referred to as the anti-aging antioxidant. It can neutralize a wide range of free radicals and helps protect the retina and optic nerve from oxidative damage.18 Individuals with primary open-angle glaucoma tend to have low levels of circulating glutathione.19 Good food sources: avocado, spinach asparagus, okra, broccoli, fish, chicken, eggs, walnuts, sunflower seeds, turmeric. Supplements: Reduced Glutathione (GSH) is not well absorbed when taken in capsule or pill form. The sublingual form offers 5–10 times better absorption, allowing for a smaller dosage. Be sure to follow the label instructions.

Lutein may aid in combating atherosclerosis by enhancing circulation. Blood levels of lutein are linked to the thickness of artery walls20 and may help reduce plaque buildup by preventing the oxidation of fats in the bloodstream.21 Sources. The richest source of lutein is kale, followed by spinach. Other excellent sources include turnip greens, summer squash, Brussels sprouts, orange foods like corn, pumpkin, paprika, yellow-fleshed fruits, pecans, and avocados. Lutein is a primary nutrient in eye health formulas.

Lycopene. Oxidation of low-density lipoprotein (LDL) is associated with increased risk of atherosclerosis and heart disease. Lycopene, found in high amounts in tomatoes, reduces LDL oxidation,22 though it does not reduce cholesterol levels. This benefit is enhanced when lycopene is consumed through whole tomatoes or paired with alpha-tocopherol, a form of vitamin E.23 Additionally, tomato extract reduces platelet clotting, reducing the risk of cardiovascular events.24 Additionally, tomato extract decreases platelet clotting, thereby lowering the risk of cardiovascular events and stroke by 55–59% compared to controls.25

Sources: Guavas are the richest source of lycopene, followed by red watermelon and tomatoes, particularly when cooked or sun-dried. Other vegetables high in lycopene include sweet red peppers, asparagus, red cabbage, and carrots. Fruits such as papaya, pink grapefruit, and mango also contain lycopene.

Caution: Lycopene may increase the risk of bleeding when taken with anticoagulant medications. It can also interact with blood pressure medications, affect the immune system, increase sensitivity to sunlight, and interact with certain gastrointestinal drugs. Additionally, some individuals may be allergic to lycopene.

 

Magnesium deficiency has been noted in primary open-angle glaucoma (POAG) and is associated with inflammatory and fibrotic responses, as well as heightened oxidative stress (OS). Supplementing with magnesium has been shown to decrease cellular reactive oxygen species (ROS), improve mitochondrial function, and exhibit antifibrotic and anti-inflammatory effects in ocular tissues and other soft tissues susceptible to fibrosis. Sources: spinach and other leafy green vegetables, legumes, nuts, seeds, whole grains, dark chocolate

MSM (Methyl sulfonyl methane), when used with a permeability enhancer, effectively reduced oxidative stress, thereby minimizing oxidative damage and inflammation in animal retinal ganglion cells and preventing demyelination of the optic nerve.26 Sources: Eggs, meat, poultry, fish, wheat germ, Brussels sprouts, asparagus, legumes, kale, garlic, onions, and milk.

 

Pyrroloquinoline quinone (PQQ) acts as an enzyme cofactor in bacteria and functions as a potent antioxidant,27 protecting against mitochondrial decay. It can withstand oxidative exposure 5,000 times more effectively than vitamin C. PQQ influences cell signaling pathways related to the formation of new mitochondria.28 Since the body does not produce PQQ naturally, it must be obtained through food or supplementation. Sources: spinach, parsley, kiwi, carrots, tomatoes, oranges, green tea, papaya, bananas, and dark chocolate. The Asian fermented food Natto contains PQQ.

Resveratrol activates an enzyme known as sirtuin type 1 (SIRT1), which safeguards human lens epithelial cells from oxidative stress.29  This enzyme helps prevent oxidation in the eye’s lens and offers protection against cataract formation. Sources: Sources of resveratrol include grapes, wine, grape juice, peanuts, cocoa, and berries from the Vaccinium species, such as blueberries, bilberries, and cranberries.

 

Vitamin E consists of four tocopherols and four tocotrienols, with alpha tocopherol being the primary form in the body. As a fat-soluble antioxidant, it neutralizes free radicals generated from lipid (fat) oxidation.30 Research has often focused on the effects of isolated components of vitamin E, but these isolated ingredients, while beneficial, are not as effective as the complete vitamin. Some researchers suggest this is because vitamin E interacts and collaborates with other nutrients in a complex metabolic process. Sources: sunflower seeds, almonds, salmon, peanuts, olive oil, broccoli, spinach, shrimp, avocado, butternut squash, trout.

Lifestyle Considerations

Consume foods rich in antioxidants. Antioxidants come from enzymes, phytonutrients like bioflavonoids and carotenoids, as well as certain vitamins and vitamin-like compounds. Research on nutrition to prevent and reverse vision-related diseases often points to increasing your antioxidant levels. Antioxidants play a crucial role in combating free radicals, which are a significant cause of inflammation. A well-balanced diet, supplemented with antioxidant vitamins and minerals, can help protect against oxidative damage.

Include foods rich in Vitamin A or beta-carotene, vitamin C, and vitamin E in your diet. These substances are powerful antioxidants, and many of the nutritional elements involved in preventing and reversing cataracts are associated with enhancing antioxidant levels. Antioxidants are vital in fighting free radicals, which are a leading cause of cataract formation and other eye diseases. A nutritious diet, complemented by antioxidant vitamins and minerals, can help protect against damage from oxidation and free radicals.31 32 33

Sources: Foods that are high in antioxidants include leafy-green vegetables, garlic, onions, beans, celery, sea vegetables, apples, carrots, tomatoes, turnips, and oranges. 

Wear Sunglasses

When outside in the sun, wear 100% ultraviolet-blocking, polarized, wrap-around sunglasses. And, wear a wide-brimmed hat. Ultraviolet light from the sun can harm the eye’s lens. Amber-colored lenses are most effective at neutralizing blue light, with brown lenses being the next best option. Continuous exposure to sunlight raises the risk of macular degeneration, cataracts, and other eye issues.

Note: Cheaper sunglasses may have a UV-blocking coating that can wear off over time. Many people mistakenly believe that the tint protects the eyes, but it’s actually the UV filter on or within the lens that provides protection. Dark lenses without UV protection can cause pupil dilation, allowing more light to enter the eyes.

Avoid Microwaves

Radiation leakage from microwave ovens can directly contribute to conditions like cataracts, so it’s best to avoid frequently peeking through the door window while cooking. The severity of exposure depends on the duration and power of the microwave. Steaming and slow cooking are the best methods for preserving the maximum amount of nutrients in food. Both high-temperature cooking and microwaving can lead to greater nutritional loss. If you choose to use a microwave, warming up foods is preferable to cooking them in it.

Avoid Chemical Toxins

Many synthetic chemicals and pharmaceuticals can cause vision problems. Steroids, for example, taken internally or applied to the skin, are a typical cause of cataracts, because they block the normal metabolism of the connective tissue, one of the components of the lens. In addition, the steroid estrogen, which is prescribed for menopause and breast cancer, impacts eye function.34 Steroids such as glucocorticoids are photosensitizing, and they make you more susceptible to cataracts35 and glaucoma.36 

Stop Smoking

Approximately 20% of all cataracts are caused by cigarette smoking. Men who smoke more than 15 cigarettes daily increase their cataract risk by 42%.37 Female smokers also face a high risk of developing cataracts. Quitting smoking without supplementing the diet with additional vitamins and minerals may not eliminate the increased risk for nearly ten years.38 This is likely because smoking depletes antioxidant levels in the body and eyes. 

Get Exercise and Take Breaks

Engage in regular exercise several times a week. Research indicates that exercise benefits nearly all health conditions, including those affecting vision.

Take breaks. It’s essential to step away from electronic devices, as prolonged computer use is directly linked to various eye conditions, including glaucoma39 and dry eye syndrome.40 Your eyes and body need regular breaks from screens such as computers, phones, and televisions. Rest periods of at least a few minutes every hour can significantly benefit your eyes and overall health.

Ensure that your “rest” activities contrast with your current tasks; the goal is to engage your eyes and body differently. For instance, if you’ve been sitting and doing close-up work, stand up, stretch, and gaze out a window at nature. Even better, take a walk around the block. Conversely, if you’ve been involved in tasks requiring broader visual focus, a rest might involve checking emails on your phone. Incorporating eye exercises during your break is also beneficial. 

Dedicate time each day to meditation. Walking in nature without electronic devices can be highly meditative and offers relaxation for both the mind and body. By successfully focusing your awareness on the act of walking, you can alleviate stress and anxiety. Studies indicate that mindfulness meditation helps reduce anxiety, depression, and pain while also enhancing mental health.41

Check out more glaucoma articles:

January is Glaucoma Awareness Month! Stay informed with our series of articles covering essential topics on glaucoma. Check out all four posts below:

Prevent and Support Glaucoma: The Silent Thief

Regulate Intraocular Pressure Naturally: Fight Glaucoma

Neuroinflammation and Glaucoma: Bridging Brain Health and Vision

Suggested Supplements

Dr. Grossman’s Circulation and Optic Nerve Support Formula

Advanced Eye & Vision Support Formula (whole food) 60 vcaps – our foundation eye formula which is a whole food, organic, GMO free formulation.

Retinal Support (wild-crafted herbal formula) 2 oz

Dr. Grossman’s Meso Plus Retinal Support and Computer Eye Strain Formula with Astaxanthin 90 vcaps – with lutein, zeaxanthin, meso-zeaxanthin, taurine and astaxanthin.

Dr. Grossman’s Advanced Eye and Dr. G’s Whole Food Superfood Multi1 20 Vcap Combo – 2 months supply

ReVision Formula (wild-crafted herbal formula) 2 oz – based on classic Chinese medicine Liver tonic formula to help support healthy circulation and blood flow throughout the eyes and body.

Dr. Grossman’s Vitamin C Plant-Based Formula – 60 caps


OmegaGenics™ EPA-DHA 720 Lemon 120 gels – also available if 240 gelcaps or liquid.


NMN Wonderfeel Capsul 60 vegcaps


H2 Elite Molecular Hydrogen 60 tabs

Recommended Books

Natural Eye Care: Your Guide to Healthy Vision and Healing

Natural Brain Support: Your Guide to Preventing and Treating Alzheimer’s, Dementia, and Other Related Diseases Naturally

Natural Parkinson’s Support: Your Guide to Preventing and Managing Parkinson’s

 

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