Dr. Grossman’s Blog

Accumulated weight around the waist (abdominal fat) may be linked to an increased risk of age-related macular degeneration (AMD). AMD is the most common cause of loss of vision and blindness in adults.

A recent study published in the Archives of Ophthalmology examined the association between changes in the waist-to-hip ratio (a measure of abdominal obesity) and risk of AMD. A total of 12,515 people aged 45 to 64 were followed over six years.

Researchers found that a higher waist-to-hip ratio (WHR) was associated with elevated risk of AMD.

The good news is that study participants who reduced their WHR generally saw a reduction in risk of AMD. Overall, a 3 per cent or more decrease in WHR was associated with a 29 per cent reduced risk of AMD. The effect was greatest among those participants classified as obese: a decrease in WHR was associated with 59% lower odds of AMD.

Researchers concluded that middle-aged people who had a 3% or greater reduction in WHR over time were less likely to have AMD, particularly among those who were initially obese.

Learn more about Age-Related Macular Degeneration (AMD)

SOURCE: Peeters, et al. Changes in Abdominal Obesity and Age-Related Macular Degeneration: The Atherosclerosis Risk in Communities Study, Arch Ophthalmol. 2008;126(11):1554-1560

U.S. researchers found that antioxidants disrupt a link between two processes in the retina that, in combination, contribute to macular degeneration. Antioxidants also extend the lifetime of irreplaceable photoreceptors and other retinal cells.

The “destructive synergy” that causes macular degeneration occurs when a buildup of a compound called A2E disrupts energy production in mitochondria, the “power plants” in cells, the researchers said. The lack of energy interferes with daily cleaning and maintenance of photoreceptors and another type of retinal cell. This leads to more buildup of A2E and a continuing cycle that results in the destruction of the vital visual cells that can’t be replaced.

The study was published online in the Journal of Biological Chemistry.

For more information and specific research studies by eye condition on nutrition and vision, go to <a href=”http://www.naturaleyecare.com”>Natural Eye Care for Macular Degeneration</a>

The findings provide hope for treating blindness caused by optic-nerve damage, but
also look promising for spurring similar regeneration in the spinal cord and brain.
Researchers said Monday a newly discovered growth factor could hold the key to regenerating damaged optic nerves — and more. The research team at Children’s Hospital in Boston say they have found a naturally occurring, previously unrecognized growth factor that stimulates regeneration in injured optic nerves.
The findings provide hope for treating blindness caused by optic-nerve damage, but
also look promising for spurring similar regeneration in the spinal cord and brain,
they said.

The growth factor is called oncomodulin and when it was added to retinal nerve cells
in the lab, with known growth-promoting factors already present, the growth of axons
– or cells in the optic nerves — nearly doubled.

No other growth factor was as potent, the researchers said.

More Nerve Regeneration

In live rats with optic-nerve injury, oncomodulin released from tiny sustained-release
capsules increased nerve regeneration five- to seven-fold when given along with
a drug that helps cells respond to oncomodulin, the team said.

Oncomodulin also appears to switch on a variety of genes associated with axon growth,
the researchers said.

“Out of the blue, we found a molecule that causes more nerve regeneration than
anything else ever studied,” said one of the study investigators. We expect
this to spur further research into what else oncomodulin is doing in the nervous
system and elsewhere.

The data are published in the May 14 online edition of Nature Neuroscience.

For more related research, go to www.naturaleyecare.com (see “Research” section).

FRIDAY, Aug. 29 (HealthDay News) — Eating plenty of antioxidant-rich food such as blueberries, artichokes and pecans may help protect against macular degeneration, the leading cause of age-related blindness in the United States and other developed countries.

U.S. researchers found that antioxidants disrupt a link between two processes in the retina that, in combination, contribute to macular degeneration. Antioxidants also extend the lifetime of irreplaceable photoreceptors and other retinal cells.

The “destructive synergy” that causes macular degeneration occurs when a buildup of a compound called A2E disrupts energy production in mitochondria, the “power plants” in cells, the researchers said. The lack of energy interferes with daily cleaning and maintenance of photoreceptors and another type of retinal cell. This leads to more buildup of A2E and a continuing cycle that results in the destruction of the vital visual cells that can’t be replaced.

Experiments using visual cells from humans, rats and cows showed that antioxidants could completely counter the damage caused by this process, said the researchers from Brigham Young University and Weill Medical College of Cornell University.

“The implication is that people at risk of macular degeneration could help prevent the disease by consuming antioxidants,” study author Heidi Vollmer-Snarr, a Brigham Young chemist, said in a university news release.

The study was published online in the Journal of Biological Chemistry.

“This work by Dr. Vollmer-Snarr and colleagues ties these two damaging processes together and demonstrates the harm they cause in combination is much more than would be expected,” Dr. Paul Bernstein, of the University of Utah’s Moran Eye Center, said in the news release. “This new knowledge,” added Bernstein, who wasn’t involved in the study, “suggests the possibility of interventions which could prove to be powerful ways to prevent or delay age-related macular degeneration.”

For more related studies, go to the “Research” section as www.naturaleyecare.com

A combination of exposure to blue light from sunlight and inadequate levels of antioxidants in the blood contribute to the development of some forms of the eye disease age-related macular degeneration (AMD), say researchers.

Astrid E. Fletcher, PhD, of the London School of Hygiene & Tropical Medicine, and colleagues measured levels of vitamin C and E, the carotenoids lutein and zeaxanthin, and zinc, in the blood of 4,753 seniors with an average age of 73.2 years. The participants were also questioned about sun exposure, and had photographs taken of their retinas.

Results showed that of the 4,400 participants with complete data, 2% had neovascular AMD, an advanced form of the disease, and 50% had early-stage AMD. Overall, there was no link between blue light exposure and neovascular AMD or early-stage AMD. However, participants with a history of blue light exposure and low blood levels of zeaxanthin, vitamin E, and vitamin C were found to be 3.7-times more likely to develop neovascular AMD.

The researchers conclude: Our results suggest that people in the general population should use ocular protection and follow dietary recommendations for the key antioxidant nutrients.

Posted in Nutrition, Sensory on Thu October 16, 2008

Fletcher AE, Bentham GC, Agnew M.Sunlight Exposure, Antioxidants, and Age-Related Macular Degeneration. Arch Ophthalmol. 2008;126:1396-1403.

For more related studies, see the “Research” section at www.naturaleyecare.com

Last month Archives of Ophthalmology published a meta analysis on omega-3 fatty acid and fish intake and its effect on the prevention of age-related macular degeneration (AMD).

This study identified 274 abstracts, 3 prospective cohort, 3 case-control, and 3 cross-sectional studies.

Using quantitative methods, a high dietary intake of omega-3 fatty acids was associated with a 38% reduction in the risk of late AMD. Fish intake (2x per week) was associated with reduced risk of early and late AMD.

More omega-3 and AMD specific studies need to be conducted to further investigate omega-3¹s effect on AMD.

Ref: Arch Ophthalmol. 2008;126(6):826-833.

For more information on related studies and nutrition, go to www.naturaleyecare.com