Warning About Body Weight and Cancer / Diet and Disease Prevention / Polio Update / Discovery About a Disorder that Makes Children 'Old Too Early'
I'm Sarah Long with Bob Doughty, and this is the VOA Special English program SCIENCE IN THE NEWS.
Today -- a new warning about body weight and the risk of cancer. Also, experts come out with a report on diet and the prevention of disease. Later, a polio update, and a discovery about a rare condition that makes children old too early.
Scientists have provided fat people with yet another reason to lose weight -- cancer. A major new study from the American Cancer Society says obesity greatly increases the risk of some cancers. The researchers say the condition is linked to about ninety-thousand cancer deaths in the United States each year. And, the scientists say that the risk of cancer death rises as the weight increases.
The sixteen year study involved nine-hundred-thousand Americans. None had cancer at the start of the study. All were overweight based on a measurement method that compares height and weight. For example, a woman who is one-hundred-sixty-two centimeters tall and seventy-eight kilograms would be considered fat. A one-hundred-eighty-two centimeter tall man would be too heavy at more than one-hundred kilograms.
The researchers found that the fattest men increased their risk of death from cancer by fifty-two percent over men of normal weight. For the heaviest women, the increase was sixty-two percent.
The study found that some cancers are more likely to affect fat people than other cancers. For example, the researchers say an extremely heavy woman is six times more likely to die from cancer of the uterus than a woman of normal weight. Severely obese men increase their risk of death from liver cancer by four times compared to men who are not fat.
Obesity in women also increases their risk of death from breast, cervix and ovary cancer. Men who are too heavy also die of prostate and stomach cancer at a higher rate than men of normal weight. And the heightened risk of several other cancers is the same for heavy people of both sexes.
The study does not provide a reason for the link between cancer and overweight. But, researchers suspect hormones are involved. For example, lead researcher Eugenia Calle [kal] says too much fat can interfere with insulin activity. She says this could increase the risk of colon cancer, among others.
Mizz Calle says that it is important to make the public understand how dangerous obesity is. She says it is similar to the risks caused by smoking tobacco. Her work was published in the New England Journal of Medicine.
International health and agriculture experts have released a new study on diet, nutrition and exercise. The report is expected to serve as a starting point for developing a world plan to fight deadly diseases. Thirty independent experts worked with the United Nations Food and Agriculture Organization and the World Health Organization for more than two years. The study is called "Diet, Nutrition and the Prevention of Chronic Diseases."
The report estimates that in two-thousand-one, chronic diseases caused almost sixty percent of the fifty-six-million total deaths for the year. Such sicknesses include heart problems, cancer, diabetes, obesity, weak bones and disease of the teeth and mouth. To fight the rising number of deaths from chronic diseases, the report proposes a diet low in fats, sugars and salt yet high in vegetables and fruits. In addition, it suggests people get regular physical activity.
Experts believe few people in the world are eating the suggested amounts of fruits and vegetables. They say about seventy-five percent of a person's daily diet should include carbohydrates, or foods like rice, grain, potatoes and bread. Foods high in protein, such as beans and meat, should make up about fifteen percent of one's diet. The remaining ten percent should include foods high in natural sugars.
The head of the World Health Organization, Gro Harlem Brundtland, says the majority of chronic disease cases are in the developing world. She says that history has shown even the simplest changes in diet and physical activity can be effective in a short amount of time. However, she says these changes need to be put in place throughout national populations. Doctor Brundtland notes that most developing countries do not have the resources in their health systems. They also cannot pay for the growing number of health cases caused by chronic diseases.
The report is the first world policy answer to the problems caused by poor diets and a lack of exercise. Doctor Brundtland says that long-term progress toward a change in population health will take time.
You are listening to the VOA Special English program SCIENCE IN THE NEWS. This is Bob Doughty with Sarah Long in Washington.
More than eighty percent of all new cases of polio are now found in a single country – India. Most new cases of the disease are in the northern state of Uttar Pradesh. So far this year, Uttar Pradesh has had more than nine-hundred new cases. There were two-hundred-sixteen new cases reported in the state in all of last year.
Only seven countries in the world are still infected by the virus that causes poliomyelitis, the full name of the disease. They are India, Nigeria, Egypt, Pakistan, Afghanistan, Niger and Somalia.
The polio virus can spread quickly. It is spread through human waste. This is yet another reason why it is important to wash hands as a way to reduce the spread of infection.
Polio starts with a high body temperature, tiredness and pain in the head, neck, arms or legs. People with polio often become paralyzed. They become unable to move their arms or legs. Sometimes they die.
Polio can be prevented with a vaccine. The immunization is usually given to babies. The best vaccine is a liquid that is swallowed.
The World Health Organization started a very successful program in the Democratic Republic of Congo. Children who are nine to twelve years old learn all about childhood vaccinations and diseases in school.
Each child is then responsible for five or six babies in the community to make sure a health worker vaccinates them. The children visit the babies and their mothers regularly. They write down any problems and keep a record of the immunizations.
One class of children checked on one-hundred-sixty-four babies in their community. Ninety-nine percent of these babies received their immunizations. This compared to national rates of thirty to fifty percent. The project in the Democratic Republic of Congo is now being expanded to more schools.
American and French scientists have linked a damaged gene to a rare disease that speeds up aging in children. Hutchinson-Gilford Progeria [pro-JEER-ia] Syndrome causes young people to age up to ten times faster than normal. Victims lose their hair and usually die of heart disease or brain problems around age thirteen. Progeria is a Greek word meaning "old too early." No cure is known.
Doctor Francis Collins of the National Human Genome Research Institute near Washington D-C led the American-based study. Researchers examined the genes of twenty progeria victims and their parents. They found that eighteen children had the imperfect gene. Around the same time, scientists in Marseilles, France, identified the same imperfect gene in two other progeria victims. The results of their independent studies were published in the magazines Science and Nature in April.
Genes are carried on chromosomes. Almost every human cell has forty-six chromosomes. There are hundreds of genes in each chromosome. The imperfect gene that causes the disease produces an abnormal protein called lamin [LAY-min] A. The protein takes over the formation of the nucleus of cells. In time, these cells die, which weakens the ability of tissues to redevelop. This causes aging to take place.
Researchers believe their discovery will lead to a deeper understanding of heart conditions that kill millions of older adults. They say that historically, major discoveries linked to other rare conditions have led to progress in medical treatments and drugs.
Science in the News was written by Caty Weaver, Jill Moss and Karen Leggett. It was produced by Cynthia Kirk. This is Bob Doughty. And this is Sarah Long. Join us again next week for more news about science in Special English Program on the Voice of America.