21 Jan Save Your Eyes From Cataracts: N-Acetylcarnosine (NAC)
Cataracts are the leading cause of blindness, accounting for about 42 percent of all cases of blindness worldwide (affecting about 17 million people). Twenty-eight thousand new cases are reported everyday. About 20 percent of all people over 60 have at least the beginning of a cataract in one or both eyes, and that figure rises to 80 percent for people over 75.
The most common type of cataract – a nuclear cataract – is characterized by a butty haze inside the lens. This haze is the physical manifestation of a random clumping together of the once beautifully ordered arrangement of lens proteins called crystallins. As the cataract develops in size and density, it reduces the amount of light that passes through the lens and scatters the light that does get through. Thus, instead of all the light rays being focused precisely to a point on the retina, forming a sharp, clear image of what we are seeing, many of the rays are spread out across the retina, forming a fuzzy image. Colors may be dulled or distorted, and there may be an annoying halo of light around bright objects, causing a glare effect.
Causes of Cataracts
Causes of cataracts include cumulative ultraviolet radiation damage from sun exposure, heredity, poor nutrition, smoking, high blood pressure, kidney disease, diabetes, and the long-term use of corticosteroids (the last two are major risk factors for cataracts). Oxidative free radicals produced by the above-listed causes are thought to damage vital biomolecules, including lipids and proteins, resulting in the clumping together of these proteins. The antidote to free radicals, of course, is antioxidants, such as glutathione, lipoic acid, and vitamins C and E. Consequently, many scientists believe that abundant consumption of antioxidants may delay the onset of cataracts.
Nutrients for Vision
Good nutrition is a key element of effective prevention for most age-related diseases, and cataracts are no exception. A number of nutrients can benefit our eyes, and may help prevent diseases such as cataracts, glaucoma, and macular degeneration. These nutrients include the tripeptide glutathione (the most abundant and important antioxidant in the human body, critical for protecting the lens from free radical damage); vitamins A and C; vitamin E and some of the B vitamins; various bioflavonoids (especially quercetin and hesperidin) and carotenoids (especially lutein and zeaxanthin); the amino acids taurine, N-acetylcysteine (a precursor of glutathione), and acetyl L-carnitine; the hormone melatonin; the alkaloid vinpocetine; the herbs bilberry, ginkgo, and garlic; the minerals zinc and selenium; and, last but certainly not least, the saturated fatty acid, lipoic acid (“the antioxidant’s antioxidant”), which plays a central role in maintaining the body’s antioxidant network.
Cataract-Dissolving Analog: N-Acetylcarnosine (NAC)
N-acetylcarnosine (NAC), like its parent compound, carnosine, occurs naturally throughout the human body. Both compounds are found primarily in the heart and skeletal muscles (the word carnosine is derived from the Latin word for flesh) and in the brain. Carnosine was discovered in 1900 in Russia, and it is in Russia that most of the recent research on the N-acetylcarnosine derivative has been carried out. Research with N-acetylcarnosine, as with carnosine, demonstrates that it is effective not only in preventing cataracts but also in treating them. NAC has been shown to improve vision by partially reversing the development of the cataract, thus increasing the transmissivity of the lens to light.
The structural difference between NAC and carnosine is that one hydrogen atom in carnosine replaces an acetyl group (CH3CO-), and this substitution occurs at a nitrogen atom. An important chemical difference between carnosine and N-acetylcarnosine is that carnosine is relatively insoluble in lipids (fats and fatty compounds), whereas N-acetylcarnosine is relatively soluble in lipids (as well as in water).
This means that N-acetylcarnosine may pass through the lipid membranes of the corneal and lens cells more easily than carnosine, and may thereby gain access more readily to the cells’ interior, which is primarily aqueous. There, the N-acetylcarnosine is gradually broken down to carnosine (and, perhaps, to histidine), which then exerts its beneficial effects.
N-Acetylcarnosine also Reduces Cataracts
In one study, Russian scientists conducted two randomized, double-blind, placebo-controlled trials of 6-months and 24-months duration, with eye drops consisting of a one percent aqueous solution of NAC administered as two drops twice daily. They treated a total of 49 elderly patients (average age 65) with cataracts ranging in severity from minimal to advanced (but not to the point of requiring surgery); the total number of eyes affected was 76. Using a variety of sophisticated optical techniques, they monitored the condition of the cataracts, visual acuity, and glare sensitivity.
The eyes treated with NAC were substantially improved in 6 months: the measured transmissivity of the lenses increased in 42 percent of the eyes, by 12-50 percent; in 90 percent of the eyes, visual acuity improved by 7-100 percent; and in 89 percent of the eyes, glare sensitivity improved by 27-100 percent. These improvements were sustained for the duration of the 24-month trial. In no eyes was any worsening of the condition seen. By contrast, the condition of the untreated eyes in the control group worsened. Visual acuity dropped in 89 percent of the controls by 17-80 percent after 24 months.
Another interesting study by the same team also evaluated patients between the ages of 48 and 60, who had various degrees of eyesight impairment, but who did not have the symptoms of cataract. After a course of treatment ranging from 2 to 6 months, the conclusion was that the eye drops alleviated eye-tiredness and continued to improve eyesight (i.e. there was more clear vision). The subjects reported that the treatment “brightened” and “relaxed” their eyes. This is an important indicator that the eye drops have a value both for preventive purposes, as well as medical applications.
Our Ultimate Eye Treatment For Cataracts Has N-Acetylcarnosine.