Natural daylight may improve youngsters' eyesight

Photo by Sally Kneidel, Phd

This post now a Google News Link and on wwwbasilandspice.com

In the last 30 years, the number of nearsighted Americans has increased dramatically, by 66%.  Nearsightedness, or myopia, is the inability  to focus on distant objects. In the early 1970s, 25% of Americans were nearsighted. Now, says epidemiologist Dr. Susan Vitale of the National Eye Institute, 42% of Americans are nearsighted.

Why?

Does too much reading cause nearsightedness?
Scientists have believed for decades that nearsightedness is caused by genetics (family history) and the amount of "near-work" that a person does, such as reading. For Americans, that could include watching TV and playing video games. Dr. Don Mutti, an optometrist at Ohio State, says, "Kepler wrote...400 years ago, that he thought his nearsightedness was due to his intense study of astronomical tables and so forth."

Dr. Mutti has been researching the causes of myopia.  For the past 20 years, Dr. Mutti has followed a group from childhood to adulthood, tracking their habits to see who develops myopia.  Heredity does, to a large degree, influence who will become myopic later on.  But Dr. Mutti has discovered something else, something surprising and unexpected.

In his study, the amount of "near-work" such as reading and watching TV did not predict who would be nearsighted later. Said Dr. Mutti about his most current research, "near-work had no influence at all".

Dr. Mutti found an unexpected cause...
What did predict nearsightedness was the amount of time spent indoors vs. outdoors during childhood.

Said Dr. Mutti: "If you have two nearsighted parents and you engage in a low level of outdoor activity, your chances of becoming myopic by the 8th grade are about 60%. If children engaged in over 14 hours per week of outdoor activity, their chances of becoming nearsighted were now only 20%.  So it was quite a dramatic reduction in the risk of becoming myopic."

This could seem to support the "near-work" theory - if you're not outside, then you must be inside reading or watching TV. But Mutti looked at that possibility, and ruled it out. Mutti looked at exercise too, and ruled that out as well.  Children exercising indoors did not get the same benefit of better vision as children spending time outdoors.

Outdoor light may benefit the eye
Mutti is now conducting a study to test his suspicion that outdoor light levels may be responsible, that outdoor light may have a beneficial effect on the eye. He suspects that outdoor light may change some aspects of retinal physiology.

Let's use natural lighting in all our schools
Sounds good to me. Daylight can save energy, as well as possibly preserving our vision.  In fact, one of the most cost-effective changes a school can make toward saving energy is using natural daylight to illuminate classrooms.  See Jeff Barrie's award-winning documentary "Kilowatt Ours" or the article on Treehugger to learn more about schools that have made the move to natural daylight, and have saved money and reduced their carbon footprint by doing so. Could these progressive schools be protecting eyes and protecting the planet at the same time?

Sources:
Susan Vitale, PhD, et al. December 2009. "Increased Prevalence of Myopia in the United States Between 1971-1972 and 1999-2004." Archives of Ophthalmology 127(12):1632-1639.

Deborah Amos. January 11, 2010. "Medical detectives focus on myopia". Morning Edition, National Public Radio.

Nathan Seppa. January 16, 2010. "Nearsightedness increasing." Science News. www.sciencenews.org

Jeff Barrie. "Kilowatt Ours".

Jasmin Malik Chua. "Natural light gives you smartypants". August 28, 2007. www.treehugger.com

I took the photo of the child above in the village of Welverdiend, South Africa. A few of my previous posts about Welverdiend are "An African village seeking solutions" and "African village of Welverdiend believes in the power of good" and "My visit to a traditional healer".  Enter the word Welverdiend in this blog's search window to find more about visiting the village.

Ground beef: a risky choice for families and the planet

Story by Sally Kneidel, PhD, of sallykneidel.com

The New York Times reported on October 11 that eating ground beef is still risky. Well, yes, but what's new about that? Of course it's still risky. Every now and then the media decide to write up something about the hazards of beef as though it were new, but the situation remains as it has been for some time.

The New York Times article focused on E. coli, a short name for the bacterium Escherichia coli. We all have E. coli in our intestines; most strains of E. coli are harmless. But one strain can be deadly to humans, causing bloody diarrhea and kidney failure. That strain is E. coli 0157. It lives in the bowels of half of the beef cattle in the United States. A very small number of these bacteria can kill you - some say as few as ten bacterial cells.

 A beef-cattle feedlot in photo above. Photo courtesy of http://oceanworld.tamu.org

Virtually all cattle in feedlots spend their days and nights standing around in manure, and so their coats are usually contaminated with E. coli 0157. Keeping the bacteria out of their meat is a challenge. After cattle are killed in a slaughterhouse, the carcasses pass through a hot-steam area, then are sprayed with a disinfectant to get rid of E. coli 0157. In some slaughterhouses and processing plants, the carcasses are irradiated. The radiation kills bacteria, although there is some debate about effects that irradiated food may have on human consumers.

Young Dancer Paralyzed by E. coli

In the U.S., there are occasional outbreaks of E.coli 0157 poisoning, where several people in one town will become extremely ill and a few may die. Since children eat half the hamburgers sold in the U.S., the victims are often children. The poisoning is usually traced to a single hamburger restaurant that has a batch of meat contaminated with E. coli 0157. The New York Times article featured a children's dance instructor, Stephanie Smith, who was left paralyzed at the age of 22 after ingesting a hamburger contaminated with E.coli 0157 in 2007.

Before the advent of feedlots, dangerous E. coli from cattle could not survive in human digestive tracts because our stomachs were too acidic for them. But the unnatural corn diet fed to beef cattle in feedlots, to marble their flesh and increase their weight gain, increases the acidity of cattle's stomachs so that it's more similar to ours. So the cattle's E. coli 0157 have adapted to a more acidic stomach and now can survive in our stomachs too.

A Possible Solution

It doesn't have to be this way. According to a study by Dr. James Russell at Cornell University, feeding cows their natural diet of hay instead of corn for only five days before slaughter will reduce the acidity in their stomachs and get rid of the acid-loving and dangerous E. coli 0157. Any remaining E. coli would not be able to survive in our acidic stomachs and so would not be dangerous to humans..

Of course, if cows were not fed corn in the first place, but were fed hay or allowed to graze, then we wouldn't have any problem at all with the dangerous E. coli 0157. So, remind me, why is it that cattle are fed corn? Oh yes, it's that familiar corporate incentive: shaving pennies from production costs to maximize profits. Because corn-fed cattle gain more weight and gain it faster, they make more money for beef producers. And we Americans have gotten used to that fat-laced meat and now prefer it.

Is beef worth the risks, and the ecological down-side? You might be surprised at how fast you can get used to a life without beef. Aside from the E. coli issue, consider that a recent Worldwatch document declared beef and dairy products to be the two ecological "hot spots" in our diet - that is, the two diet items whose production does the most long-lasting damage to the planet.

Anyone for a Tofurkey sausage? All plant-based and indescribably delicious.

Sources:
Sally Kneidel, PhD, and Sadie Kneidel. 2005. Veggie Revolution: Smart Choices for a Healthy Body and a Healthy Planet. Fulcrum Books.

BBC Online Network. "Change of Diet Could Defeat Killer Bug." http://news.bbc.co.uk/1/hi/health/169255.stm

Sarah DeWeerdt. "Is Local Food Better?" Worldwatch Institute

Michael Moss."E. coli path shows flaws in beef inspection." October 11, 2009. New York Times.

Photo courtesy of http://oceanworld.tamu.org 

Key words:: beef feedlots E. coli health meat cattle diet hot spots

Environmental education: A new necessity for healthy kids?

As a new generation of American children face more adult stresses than ever before – pressure to achieve adequate test scores, rising rates of childhood obesity and its accompanying diabetes, asthma, hypertension, and emotional complications - scientists have found an unexpectedly simple cure. The American Journal of Preventative Medicine reports this month that the silver bullet for children’s physical and emotional health is no medicine at all: rather, it’s access to natural green space.

In a recent study of 3800 children ages 3 to 18, mostly poor and African-American, scientists documented a dramatic health disparity in children living in urban neighborhoods with varying amounts of green space. Children with access to more wild areas – from vacant lots to city parks - gained weight more slowly than their less green counterparts, and were less likely to be obese as adults. They also displayed higher cognitive functioning and fewer symptoms of ADHD. Adult residents of greener neighborhoods, meanwhile, tend to display lower stress, lower weight, and better health.

These results come as no surprise to some policy makers.

In an attempt to patch over educational gaps left by No Child Left Behind, the groundbreaking No Child Left Inside Act passed the House in September. No Child Left Behind demands that children meet grade level standards in reading, math, and science. In a push to prepare students adequately on these subjects, this legislation has sidelined topics deemed more superfluous, including environmental education. It’s not surprising, then, that in a recent study, two thirds of American adults failed a basic environmental quiz and 88% failed a basic energy quiz. “Forty-five million Americans think the ocean is a source of fresh water and 130 million believe that hydropower is America's top energy source,” the study findings report.

No Child Left Inside would provide $500 million over the next five years to fund environmental education in K-12 classrooms. As the environmental education movement gathers steam, more and more educators acknowledge the necessity of training the newest generations to be wise stewards of our dwindling natural resources. As today’s children reach adulthood, they will have to make unprecedented decisions about our energy resources and the health of an overtaxed planet.

Biologists use the term mutualism to describe a relationship between two species that benefits both parties. For example, a hummingbird drinking nectar from a flower both feeds itself and pollinates the plant. Perhaps humans and the earth are mutualistic as well. By preserving the health of our green spaces , we are also protecting the health of our children.

by Sadie Kneidel