Carefully designed oral nutritional supplements can benefit all patients

Nutraceuticals are pharmaceutical grade vitamins, minerals, essential fatty acids and antioxidants that may help correct the nutritional insufficiencies commonly found in our modern Western diet and environment. In turn, they may help prevent susceptibility to infection and chronic deficiencies and disease, according to researchers.

Vitamins A, C, E and B, along with essential fatty acids (EFAs), are particularly important to the eye, studies have shown. Inadequate intake, lack of absorption or deficiencies in vitamins, minerals or EFA increase risk factors for eye disease, cardiovascular disease, cancer, osteoporosis and diabetes, to name a few.

The use of nutraceuticals has grown dramatically over the past decade, as people are now taking a more proactive role in managing their own health care and attempting to prevent disease. This growing interest in natural and herbal products has been used for centuries in some cultures.

Along with this interest, there is also a growing responsibility for health care professionals to educate patients about eye health and how dietary habits and supplementation can help improve the natural antioxidant and protective defenses of the eye, reduce oxidative stress and prevent escalation of disease when possible.

Industrialization has played a key role in nutritional deficiencies by reducing the available nutrients essential to proper body function. Smog, pollution and prolonged storage and transport of foods reduce the nutritional value of today’s fruits, vegetables and other commodities. Today’s farming methods are heavily laden with the use of antibiotics, hormones, fertilizers, pesticides and corn-based food products for livestock.

In addition, today’s lifestyle and diets are in need of great change. Our diets are high in commercially raised meat, dairy products and calorie dense foods and consist of too much omega 6, partially hydrogenated oils, saturated fat and trans fat intake, which triggers inflammation. Our consumption of fast foods, processed foods and canned foods must be decreased, and our intake of filtered water and whole foods along with better sleep and exercise must be improved.

Science of vitamin supplementation

Because these suboptimal conditions now exist, it has been necessary for us to develop the science of vitamin supplementation. Research suggests that nutritional supplements can significantly reduce the risk of ocular and systemic disease. Many diseases are related to damage caused by free radicals, highly reactive molecules that destroy the body. Free radicals are found in everything from unclean air to preservatives in processed foods, yet some are essential for normal metabolic processes of the body.

Nutraceuticals and Whole Foods: Medicine for the Eye
	Whole Food Sources of Nutrient	Functions/Benefits of Nutrient
Vitamins
Vitamin A (alpha and beta carotene)	Kale, spinach, sweet potatoes, carrots, apricots, mango	Antioxidant; neutralizes free radicals; the body converts carotene to vitamin A to maintain proper health of epithelial cells of cornea and conjunctiva — in turn this helps manufacture mucin for the innermost layer of the tear film (see note in article regarding current smokers)
Vitamin B (3,6,12)	Cracked wheat, bulgar, tabouli, whole wheat pasta, lentils, bananas, barley, avocado	B6 is a water soluble member of the B family; aids in the absorption of magnesium, which helps produce a hormone called PGE7 that is necessary for tear production
Vitamin C (ascorbic acid)	Citrus fruits, tomatoes, broccoli, peppers, papaya, kiwi, peppers, guava, Camu Camu	The most abundant water soluble antioxidant in the tear film and the lens; helps neutralize free radicals and recharges Vitamin E; enhances IgE concentrates in the tears; assists in the formation of the less inflammatory prostaglandin from GLA metabolism and offers protection against early cataract development
Vitamin D (D3)	Cod liver oil, salmon, mackerel, sardines, tuna, 15-20 minutes of sunshine per day	Helps reduce CRP and TNF; plays a large role in calcium regulation in the body, promoting bone growth
Vitamin E (Alpha and gamma tocopherol)	Spinach, beets, pumpkin, nuts, seeds, whole grains, wheat germ	Antioxidant; neutralizes free radicals; helps stabilize EFA and inhibits COX2 enzymes and has neuroprotective properties
Minerals
Magnesium, copper, zinc	Essential dietary elements found in nuts, soy, beans, wheat, oysters	Magnesium is useful in muscle relaxation and helps create PGE7 for tear production; copper is used to prevent cooper-deficiency anemia; zinc has been shown to lower the risk of mortality; all important co-factors to promote anti-inflammatory role of GLA
Carotenoids
Lutein zeaxanthin	Green leafy vegetables: spinach, kale; yellow fruits and vegetables: oranges, peppers, corn, melons, spirulina, marigold	These stereoisomers are unique because they selectively accumulate in the retina (2Z:1L); macula lutea gets its name from the yellow color of this carotenoid; a strong antioxidant as well as a filter for blue light that is damaging to the retina; thought to help with glare, photophobia, dark adaptation and contrast sensitivity
Astaxanthin	Microalgae, lobster, shrimp, salmon, crabs	Also naturally occurring in the retina; able to cross the blood-brain barrier; helps reduce retinal photobleaching from high intensity light; functions as a photo protectant; helps aid in accommodation and reduce inflammatory markers
Lycopene	Tomatoes, Gac, watermelons, papaya	Acts as a strong antioxidant; possibly has anti-cancer properties; has positive effects on blood vessel walls and PSA levels
Flavonoids
Anthocyanins	Bilberry, blueberry, choke berry, red grapes, black raspberry	Used in rhodopsin regeneration and thereby improves visual function; useful for night vision and microcirculation of retina
Quercetin	Apples, onions, green tea, raspberry, prickly pear juice, capers	Antioxidant and anti-inflammatory properties; possible anti-cancer benefits; reported to have a questionable drug interaction with fluoroquinolones
Phytochemicals
Polyphenols	Organic unrefined extra virgin olive oil produced without heat, green tea, some berries	Antioxidant; inhibits abnormal blood clotting; has been linked to reduction in cardiovascular disease, cancer and age-related bone loss; helps prevent atherosclerosis; helps prevent progression of diabetes mellitus type 2
Catechins	Green tea	Improves blood vessel health; antioxidant, anti-inflammatory, anti-carcinogenic; boosts immune function
Ginkgo flavonoids (bilobalide/ginkgoglide)	Ginkgo biloba	Improves microcirculation; promotes ocular blood flow; has been linked to improved memory; possibly aids with dementia and Alzheimer’s patients
Pycnogenol	French pine bark extract	Potent antioxidant with affinity for collagen; shown to stabilize damaged blood vessels and lower capillary permeability, thus helping to prevent background diabetic retinopathy
Phytoalexin
Resveratrol	Red wine	Possibly inhibits the production of fat cells; has been linked to life extension, cancer prevention and reduction of cholesterol
Essential fatty acids
Alpha linolenic acid (omega 3)	Wild cold water fish: salmon, anchovies, krill, squid, algae, chia seed oil, flax seed oil, spinach, marine phytoplankton	Wild cold water fish: salmon, anchovies, krill, squid, algae, chia seed oil, flax seed oil, spinach, marine phytoplankton
Linoleic acid (omega 6)	Corn oil, sunflower oil, safflower oil, cottonseed oil, soybean oil, canola oil	Plays a key role in the inflammatory cascade; is known to increase blood pressure and promote harmful clots, allergic reactions and growth of cancerous cells; converts to arachidonic acid, which is found in abundance in meats and dairy products
Other Fatty Acids
Docosahexaenoic acid (omega 3)	Algae, cod, herring, mackerel, sardine, salmon	The most abundant omega-3 fatty acid in the brain and retina; plays a key role in metabolic synthesis and proper fetal cognitive development; thought to help regenerate corneal nerves after refractive surgery and improve ocular irritation due to dry eye by supporting healthy tear production
Eicosapentaenoic acid (omega 3)	Cod, herring, mackerel, sardine, salmon	Thought to improve dysfunction of the meibomian gland by producing a better quality secretion; helps block the production of arachidonic acid, which, in turn, allows for additional cyclic AMP
Gamma linolenic acid (omega 6)	Black currant seed, evening primrose, borage oils, blue-green algae, hemp	Works in conjunction with EFA, astaxanthin and other facilitators (magnesium, zinc, vitamin C, B3 and B6) to produce PGE1 and thus stimulate tear production; has cardiovascular benefits
Oleic acid (omega 9)	Organic unrefined extra virgin olive oil produced without heat, acai	Antioxidant; lowers blood pressure; has been linked to reduction in cardiovascular disease, cancer and age-related bone loss; prevents atherosclerosis; decreases LDL and raises HDL
Source: Cover-Miller DN

Furthermore, our bodies are unable to handle the overload of free radicals, and this cascade of oxidative stress is considered to be one of the primary causes of aging. Researchers have shown for years that antioxidants can slow free radical damage to the body.

Much research has been done regarding nutraceuticals and the ocular health arena. These studies have concentrated on dry eye, macular degeneration, glaucoma, intraocular pressure, cataracts and diabetic retinopathy. Antioxidants or EFA have been noted specifically in the Dry Eye Workshop (DEWS), Age-Related Eye Disease Study (AREDS) 1, AREDS 2, EUREYE, Lutein Antioxidant Supplementation Trial (LAST), Taurine, Omega-3 fatty acids, Zinc, Antioxidant, Lutein (TOZAL) and Women’s Health Study, to name a few.

DEWS results

The Definition and Classification Subcommittee of the International DEWS of 2007 determined that dry eye is a multifactorial disease of the tears and ocular surface that results in symptoms of discomfort, visual disturbance and tear film instability, with potential damage to the ocular surface. The DEWS definition also states that dry eye is accompanied by increased osmolarity of the tear film and inflammation of the ocular surface. These features lead to the dry eye cascade of visual degradation, epithelial cell damage and discomfort.

The DEWS study was able to define and classify dry eye, look at the epidemiology and methodologies to diagnose, as well as determine management and therapy of dry eye. In conclusion, it was found that EFA, linoleic acid (LA) and gamma linolenic acid (GLA) administered orally twice daily produced significant improvement in ocular surface lissamine green staining as well as decreased conjunctival HLA-DR staining.

Increase in EFA has been shown to improve meibomian gland dysfunction and allow for a better quality secretion for the tear film. Also, GLA, when properly converted, can increase prostaglandin E1 manufacturing and stimulate tear production. In Sjögren’s and rheumatoid arthritis patients, GLA has been shown to decrease pro-inflammatory markers and free radical production.

EFA and antioxidants in patients recovering from corneal laser treatments are thought to induce faster corneal nerve regeneration, increase tear production and help patients maintain higher levels of lactoferrin, an indicator for ocular surface health.

EFA byproducts, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements are readily available in a purified form at health food stores. The natural triglyceride (TG) form of the oil is more effective than the less expensive ethyl ester version. The TG form is more bioavailable and less likely to be tainted with PCBs and ethanol. In addition to the ocular benefits, increasing DHA and EPA in the diet has been shown to improve metabolic synthesis and cognitive function, decrease bone loss, regulate insulin levels and lower risk of cardiovascular disease.

AREDS results

A 7-year groundbreaking study known as Age-Related Eye Disease Study (AREDS), sponsored by the National Institutes of Health, is the largest clinical trial to have tested the impact of nutritional supplements on macular degeneration. AREDS was a randomized, placebo-controlled clinical trial that evaluated more than 3,600 men and women.

A note of interest, in large clinical trials sponsored by the National Cancer Institute it was demonstrated that beta carotene (vitamin A) increases the risk of lung cancer in current smokers. Thus, it is contraindicated for smokers to take large doses of beta carotene to combat AMD.

Daily dosages of nutrients used in the study included: vitamin C 500 mg, vitamin E 400 IU, beta carotene 15 mg, zinc 80 mg and copper 2 mg. It showed that vitamin supplements containing high doses of antioxidants and zinc reduced the likelihood of progression of intermediate and advanced degrees of macular degeneration by up to 25% and decreased risk of vision loss by 19%.

In an effort to refine AREDS 1, in September 2006 AREDS 2 got underway. It is a 4,000-patient study designed to evaluate whether supplementation with omega-3 fatty acids and/or lutein and zeaxanthin reduces the risk and rate of progression of AMD. In addition, AREDS 2 will analyze the effects of eliminating beta carotene and reducing the amount of zinc from the original AREDS protocol.

LAST results

Lutein and zeaxanthin are naturally occurring carotenoids that selectively accumulate in the retina. They are known for their antioxidant ability to quench singlet oxygen and absorb visible light in the blue spectrum that reaches the fovea. The Lutein Antioxidant Supplementation Trial (LAST) was carried out as a follow-up to AREDS 1. Increased levels of serum lutein showed increased macular pigment optical density and objectively improved visual function, glare recovery and contrast sensitivity in subjects.

In summary, there has been an abundant amount of research done on nutraceuticals and their positive effects on the body. As the population ages and shows greater interest in health preservation, the government and pharmaceutical companies will continue to further refine and manufacture over-the-counter pharmaceutical grade products with higher quality standards.

The potential benefits for patients from carefully designed oral nutritional supplements are enormous. Formulas based on the latest research will use nutrients synergistically to combat our dietary and genetic shortfalls. – by Denise N. Cover-Miller, OD

Online Resources

www.medicinenet.com www.nutraceuticalsworld.com www.mdsupport.org www.medrounds.org www.nei.nih.gov www.childrenshealthstudy.com www.ocularnutritionsociety.org Source: Cover-Miller DN

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• Denise N. Cover-Miller, OD, is area director of optometry for LasikPlus. She can be reached at 216 Mall Blvd., Suite #100, King of Prussia, PA 19406; (610) 265-5228; fax: (610) 265-1560; dcovermiller@lca.com.