The link worked OK for me just now. Did you
copy and paste each seprate part of the link into your browser?
Anyway, here is the article:
Short-sightedness may be tied to refined diet
19:00 03 April 02
The food children eat might play as big a
role as books and computer screens when it comes to causing short-sightedness.
Diets high in refined starches such as
breads and cereals increase insulin
levels. This affects the development of
the eyeball, making it abnormally long
and causing short-sightedness, suggests
a team led by Loren Cordain, an evolutionary biologist at Colorado State University in Fort Collins, and Jennie Brand Miller, a nutrition scientist at the University of Sydney.
The theory could help explain the dramatic increase in myopia in developed countries over the past 200 years. It now affects 30 per cent of people of European descent, for example.
"The rate of starch digestion is faster with modern processed breads and cereals,"
says Brand Miller. In response to this
rapid digestion, the pancreas pumps out
more insulin. High insulin is known to lead
to a fall in levels of insulin-like binding
protein-3, the team points out.
That could disturb the delicate
choreography that normally coordinates
eyeball lengthening and lens growth. And
if the eyeball grows too long, the lens can
no longer flatten itself enough to focus a
sharp image on the retina, they suggest.
"It's a very surprising idea," says James
Mertz, a biochemist at the New England
College of Optometry in Boston. But it's
plausible, says Bill Stell of the University
of Calgary in Canada. "It wouldn't surprise me at all. Those of us who work with local growth factors within the eye would have no problem with that - in fact we would expect it."
Metz's institution is now planning studies
in animals. But there is already evidence
to support the theory. While fewer than one per cent of the Inuit and Pacific islanders had myopia early in the last century, these rates have since skyrocketed to as high as 50 per cent. These "overnight epidemics" have usually been blamed on the increase in reading
following the sudden advent of literacy
and compulsory schooling in these societies.
But while reading may play a role, it does
not explain why the incidence of myopia
has remained low in societies that have
adopted Western lifestyles but not Western diets, says Cordain.
"In the islands of Vanuatu they have eight
hours of compulsory schooling a day," he
says, "yet the rate of myopia in these
children is only two per cent." The
difference is that Vanuatuans eat fish,
yam and coconut rather than white bread
The theory is also consistent with
observations that people are more likely
to develop myopia if they are overweight
or have adult-onset diabetes, both of
which involve elevated insulin levels. The
progression of myopia has also been
shown to be slower in children whose
protein consumption is increased.
Journal reference: Acta Ophthalmologica
Scandinavica (vol 80, p 125)