American Association for the Advancement of Science  [Printer-friendly version]
December 21, 2005

EXPERTS PONDER THE GLOBAL RISE OF CHRONIC DISEASE

[Rachel's introduction: Chronic disease from unhealthy diets,
physical inactivity and the use of tobacco is causing the premature
deaths of up to 35 million people worldwide -- in all social classes -
-according to scientists at a recent conference sponsored by the
AAAS (American Association for the Advancement of Science). In
America, 75 percent of us will soon achieve a body weight that
negatively affects our health.]

By Paul Recer

A growing global epidemic of chronic disease, such as heart disease,
stroke, cancer and diabetes, will cause at least 35 million deaths
this year, costing the world economy billions of dollars, even though
medical science has identified the principal causes and knows ways to
prevent it, experts said at a AAAS seminar in Washington, D.C.

Speakers at the first Philip Hauge Abelson Advancing Science Seminar
said that twice as many premature deaths are caused worldwide by
chronic diseases as by all infectious diseases, maternal and perinatal
conditions and nutritional deficiencies combined. And while the toll
from infectious diseases is declining globally, deaths from chronic
disease are expected to increase by 17 percent in the next 10 years.

The 8 December seminar included speakers from the World Health
Organization (WHO), from pharmaceutical and medical device
manufacturers and from university research labs. It was the inaugural
event in a series named for Abelson, a researcher in physics, biology
and other sciences, and the editor for 22 years of Science, which is
published by AAAS. Abelson died last year at the age of 91.

Alan I. Leshner, AAAS chief executive officer and executive publisher
of Science, said the seminar series would address major societal
challenges and focus on the frontiers of science and technology.

Robert Beaglehole, WHO's director of Chronic Diseases and Health
Promotion, said in the keynote address that the toll of premature
death from chronic disease is increasing worldwide principally because
of unhealthy diets, physical inactivity and the use of tobacco and the
aging of populations in almost all countries.

Diet and the lack of physical activity is contributing to a growing
pattern of obesity, a key risk factor for diabetes and early heart
disease. And it's not just happening in the rich countries, such as
the United States and South Africa, where recent reports show that 75
percent of women aged 30 and over are overweight. A "very frightening
statistic," said Beaglehole, is that in countries both rich and poor,
about 22 million children worldwide under the age of five are already
obese.

"We've done a lot to observe the emergence of this problem," he said.
"We have done practically nothing to solve it."

Beaglehole said that common misunderstandings about chronic disease
have affected policy decisions and slowed the worldwide response to
the emerging epidemic.

For instance, he said it's widely believed that premature heart
disease, stroke, diabetes and other chronic diseases are mostly a
plague among the elderly and among the rich in high-income countries.

Actually, said Beaglehole, 80 percent of deaths from chronic diseases
are in low- and middle-income countries. A WHO report found that poor
people, in all but the least developed countries, are more likely than
the rich to develop chronic diseases and are more likely to die early.
And it is not just the elderly who are victims. The WHO report found
that almost half of the deaths from chronic diseases occur in people
under 70 years old.

"A very dangerous misunderstanding is that chronic disease is the
result of unhealthy lifestyles under the control of individuals,"
Beaglehole said. "The reality is that poor people and children have
very limited choices, and it is unfair to blame them for the
environmental conditions in which they suffer."

There's also the belief by many that chronic diseases and premature
deaths cannot be prevented.

"The reality is that approximately 80 percent of premature heart
disease, stroke and type 2 diabetes is preventable, as are 40 percent
of all cancers -- many of which result from tobacco consumption," said
Beaglehole. "A few known risk factors explain the vast majority of
premature chronic disease deaths."

A global effort to attack the causes of chronic disease could reduce
death rates by 2 percent a year and save 36 million lives within a
decade, he said. Ninety percent of the lives saved, said Beaglehole,
would be in low- and middle-income countries. Slowing the epidemic of
premature death from chronic diseases will have to involve policy
issues beyond the health field, he said. For instance, farm subsidies
often affect the type of food available in some countries. An example:
The consumption of full fat milk is encouraged in schools in some
European countries because of subsidies, said Beaglehole. Excessive
fat, sugar and salt in the diet lead to obesity, type 2 diabetes,
heart disease and stroke.

Other specialists at the Abelson seminar reported recent findings that
offer new hope for treatment and management of heart disease, high
blood pressure, obesity, diabetes and cancer.

Eric J. Topol, provost of the Cleveland Clinic Lerner College of
Medicine, said studies of families with heart attack have demonstrated
specific genes that are causative or induce susceptibility. This will
allow strategies of lifestyle and individualized therapy early in life
to prevent heart attacks decades later.

The battle against the growing epidemic of obesity will require
fundamental changes in attitudes toward food and exercise, said Holly
Wyatt, the program director at the Centers for Obesity Research and
Education at the University of Colorado Health Sciences Center. In
American society, she said, "we've had a lot of pressures to not
expend more energy than we have to and we had a lot of pressure to eat
more than we need."

To change the behaviors that lead to obesity will require
encouragement from virtually every element in society -- employers,
schools, churches, community centers and retail stores, she said. Such
programs have worked in the past to discourage tobacco use and
encourage using seat belts in cars. Without such an effort, Wyatt said
that by 2008 about 75 percent of Americans will be at a body weight
that negatively affects health.

Basic research on how the kidneys regulate salt in the body has given
medical science a new understanding of the causes of high blood
pressure, a major risk factor for heart attack, stroke and kidney
failure, said Rick Lifton, Sterling Professor and chairman of Genetics
atYale University School of Medicine. He said there are biological
pathways and gene mutations that cause the kidneys to sequester
sodium, leading to increases in blood pressure. Drugs to counter these
effects could lead to dramatically improved treatments for
hypertension, a disorder that affects a billion people world wide and
is linked to about 5 million deaths annually.

Dr. Gerald I. Shulman, an investigator of the Howard Hughes Medical
Institute and professor of internal medicine and cellular & molecular
physiology at Yale University, said that new, non-invasive studies
using magnetic resonance spectroscopy have demonstrated that the
development of insulin resistance in type 2 diabetes is directly
related to the build-up of fat inside muscle and liver cells where it
disrupts normal insulin signaling and action in these organs. Studies
in transgenic and knockout mice as well as in humans have shown that
removing this excess intracellular fat can restore insulin sensitivity
and cure type 2 diabetes. The results from these studies provide new
targets for novel therapies that might be developed to reduce
intracellular fat levels and reverse insulin resistance in patients
with type 2 diabetes, said Shulman.

Copyright 2005. American Association for the Advancement of Science