Larry Minikes 7/9/20 Larry Minikes 7/9/20

Exercise can slow or prevent vision loss

July 1, 2020

Science Daily/University of Virginia Health System

Exercise can slow or prevent the development of macular degeneration and may benefit other common causes of vision loss, such as glaucoma and diabetic retinopathy, new research suggests.

The new study from the University of Virginia School of Medicine found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45%. This tangle of blood vessels is a key contributor to macular degeneration and several other eye diseases.

The study represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration, a leading cause of vision loss, the scientists report. Ten million Americans are estimated to have the condition.

"There has long been a question about whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. The way that question has historically been answered has been by taking surveys of people, asking them what they are eating and how much exercise they are performing," said researcher Bradley Gelfand, PhD, of UVA's Center for Advanced Vision Science. "That is basically the most sophisticated study that has been done. The problem with that is that people are notoriously bad self-reporters ... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for very first time."

The Benefits of Exercise

Enticingly, the research found that the bar for receiving the benefits from exercise was relatively low -- more exercise didn't mean more benefit. "Mice are kind of like people in that they will do a spectrum of exercise. As long as they had a wheel and ran on it, there was a benefit," Gelfand said. "The benefit that they obtained is saturated at low levels of exercise."

An initial test comparing mice that voluntarily exercised versus those that did not found that exercise reduced the blood vessel overgrowth by 45%. A second test, to confirm the findings, found a reduction of 32%.

The scientists aren't certain exactly how exercise is preventing the blood vessel overgrowth. There could be a variety of factors at play, they say, including increased blood flow to the eyes.

Gelfand, of UVA's Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with a decrease in exercise. "It is fairly well known that as people's eyes and vision deteriorate, their tendency to engage in physical activity also goes down," he said. "It can be a challenging thing to study in older people. ... How much of that is one causing the other?"

The researchers already have submitted grant proposals in hopes of obtaining funding to pursue their findings further.

"The next step is to look at how and why this happens, and to see if we can develop a pill or method that will give you the benefits of exercise without having to exercise," Gelfand said. "We're talking about a fairly elderly population [of people with macular degeneration], many of whom may not be capable of conducting the type of exercise regimen that may be required to see some kind of benefit." (He urged people to consult their doctors before beginning any aggressive exercise program.)

Gelfand, a self-described couch potato, disclosed a secret motivation for the research: "One reason I wanted to do this study was sort of selfish. I was hoping to find some reason not to exercise," he joked. "It turned out exercise really is good for you."

https://www.sciencedaily.com/releases/2020/07/200701100025.htm

Larry Minikes 1/30/19 Larry Minikes 1/30/19

Eating leafy greens could help prevent macular degeneration

October 19, 2018

Science Daily/Westmead Institute for Medical Research

A new study has shown that eating vegetable nitrates, found mainly in green leafy vegetables and beetroot, could help reduce your risk of developing early-stage age-related macular degeneration (AMD).

Researchers at the Westmead Institute for Medical Research interviewed more than 2,000 Australian adults aged over 49 and followed them over a 15-year period.

The research showed that people who ate between 100 to 142 mgs of vegetable nitrates each day had a 35% lower risk of developing early AMD than people who ate less than 69mgs of vegetable nitrates each day.

Lead Researcher Associate Professor Bamini Gopinath from the Westmead Institute and the University of Sydney said the link between vegetable nitrates and macular degeneration could have important implications.

"This is the first time the effects of dietary nitrates on macular degeneration risk has been measured.

"Essentially we found that people who ate 100 to 142 mgs of vegetable nitrates every day had a reduced risk of developing early signs of macular degeneration compared with people who ate fewer nitrates.

"If our findings are confirmed, incorporating a range of foods rich in dietary nitrates -- like green leafy vegetables and beetroot -- could be a simple strategy to reduce the risk of early macular degeneration," Associate Professor Gopinath said.

Spinach has approximately 20mg of nitrate per 100g, while beetroot has nearly 15mg of nitrate per 100g.

The research did not show any additional benefits for people who exceeded 142mgs of dietary nitrate each day. It also did not show any significant connections between vegetable nitrates and late stage AMD, or between non-vegetable nitrates and AMD risk.

One in seven Australians over 50 have some signs of macular degeneration.

Age is the strongest known risk factor and the disease is more likely to occur after the age of 50.

There is currently no cure for the disease.

The research compiled data from the Blue Mountains Eye Study, a benchmark population-based study that started in 1992.

It is one of the world's largest epidemiology studies, measuring diet and lifestyle factors against health outcomes and a range of chronic diseases.

"Our research aims to understand why eye diseases occur, as well as the genetic and environmental conditions that may threaten vision," Associate Professor Gopinath concluded.

https://www.sciencedaily.com/releases/2018/10/181019100558.htm

Larry Minikes 9/24/18 Larry Minikes 9/24/18

An orange a day keeps macular degeneration away: 15-year study

July 12, 2018

Science Daily/Westmead Institute for Medical Research

A new study has shown that people who regularly eat oranges are less likely to develop macular degeneration than people who do not eat oranges. Researchers interviewed more than 2,000 Australian adults aged over 50 and followed them over a 15-year period.

Researchers at the Westmead Institute for Medical Research interviewed more than 2,000 Australian adults aged over 50 and followed them over a 15-year period.

The research showed that people who ate at least one serving of oranges every day had more than a 60% reduced risk of developing late macular degeneration 15 years later.

Lead Researcher Associate Professor Bamini Gopinath from the University of Sydney said the data showed that flavonoids in oranges appear to help prevent against the eye disease.

"Essentially we found that people who eat at least one serve of orange every day have a reduced risk of developing macular degeneration compared with people who never eat oranges," she said.

"Even eating an orange once a week seems to offer significant benefits.

"The data shows that flavonoids found in oranges appear to help protect against the disease."

Associate Professor Gopinath said that until now most research has focused on the effects of common nutrients such as vitamins C, E and A on the eyes.

"Our research is different because we focused on the relationship between flavonoids and macular degeneration.

"Flavonoids are powerful antioxidants found in almost all fruits and vegetables, and they have important anti-inflammatory benefits for the immune system.

"We examined common foods that contain flavonoids such as tea, apples, red wine and oranges.

"Significantly, the data did not show a relationship between other food sources protecting the eyes against the disease," she said.

One in seven Australians over 50 have some signs of macular degeneration. Age is the strongest known risk factor and the disease is more likely to occur after the age of 50.