Broadcast: June 1, 2004
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Sarah Long.
And I'm Doug Johnson. Coming up, new evidence in support of a weight-loss method.
A new plan to try to get more people around the world to lose weight.
And, a new drug in the fight against another big problem: malaria.
Many people who try to lose weight know that no diet is perfect. But two new studies show that a diet low in carbohydrates can cause faster weight loss than a diet low in fats. This was true at least in the short term. Researchers published the findings in the Annals of Internal Medicine.
The studies appear to support popular low-carbohydrate plans like the Atkins diet. Doctor Robert Atkins urged people to eat high-protein foods like meat and eggs. He told dieters to avoid foods high in starch and sugar. Doctor Atkins died last year. He fell on an icy street in New York and suffered a head injury. He was seventy-two years old.
Our body uses carbohydrates for energy. It can also make energy from protein and fat. But proteins generally make people feel more satisfied with less food than carbohydrates do. This is one of the main arguments for a low-carb diet to lose weight.
One of the new studies took place at Duke University Medical Center in Durham, North Carolina. The Robert C. Atkins Foundation paid for the study but was not involved in the research. This organization works to get more people to follow the doctor's ideas.
One-hundred-twenty overweight adults took part in the study. They were between the ages of eighteen and sixty-five. They followed either the Atkins plan or a low-fat diet for one year.
After six months, the people on the Atkins diet lost an average of eleven kilograms. Those on the low-fat diet lost an average of six kilograms.
The Veterans Affairs Medical Center in Philadelphia, Pennsylvania, did the second study. This study did not involve the Atkins Foundation.
One-hundred-thirty-two adults took part. Most had diabetes. The researchers put half the people on a low-carb diet. The other half followed a low-fat diet.
After one year, the low-carb dieters had lost on average as much as eight kilograms. Yet the low-fat dieters lost about the same amount.
What happened? The low-carb dieters lost weight faster in the beginning. But the low-fat dieters lost weight throughout the year. However, the study found that the people with diabetes controlled their blood sugar better with low carbohydrates.
The new research also found that triglyceride levels fell more on the low-carb diet than on the low-fat plan. Triglycerides are fats in the blood that can increase the risk of heart disease.
Levels of so-called good cholesterol also appeared to improve with the low-carb diet. Higher levels of good cholesterol may reduce the risk of heart disease. But levels of bad cholesterol did go up in some people.
Doctor Walter Willett is a nutrition expert at the Harvard School of Public Health. Doctor Willett wrote a commentary on the two studies. In his words, "we can no longer dismiss very-low carbohydrate diets." He says Doctor Atkins should get "credit for his observations that many people can control their weight by greatly reducing carbohydrates."
But other health experts are not satisfied. They want more research done to learn the effects of following the Atkins diet for long periods of time. They warn that people who eat a lot of fat may give themselves a heart attack. And they question how good it is for people not to eat things like fruit.
The Atkins diet and other low-carbohydrate plans have had a big effect on the food industry. Stores sell lots of new low-carb foods as well as lower-carb versions of breads and pastas. But supporters of the Atkins diet say people should not use it as an excuse to fill themselves with fatty foods.
Marketers of the eating plan have been doing more lately to try to explain it to people. They say proteins such as poultry, fish, beef, pork and soy products should be the largest part of what people eat. But they say the next largest part should be green vegetables. After that, the plan calls for smaller amounts of fruits, oils, nuts, cheese and beans. The Atkins advice is that the smallest part of what people eat should be whole grain foods such as barley, oats and brown rice.
But, to lose weight, it says eating should center on protein, leafy vegetables and healthy oils.
Last week the New York Times reported what it said was apparently the first legal action against the Atkins diet. A Florida man said he suffered a blocked artery from high cholesterol after two years on the diet. He asked for twenty-eight-thousand dollars. The Atkins Nutritionals company said the case was part of an effort to scare people into not eating any animal protein.
You're listening to SCIENCE IN THE NEWS, in VOA Special English.
Low-carbohydrate diets or not, more people than ever weigh too much. The World Health Organization says this is a serious problem. It says the opposite problem, hunger, affects about eight-hundred-fifty-million people. But more than one-thousand-million are overweight. And that just counts adults. At least three-hundred-million adults are obese, severely overweight.
Health ministers around the world now have a plan called the Global Strategy on Diet, Physical Activity and Health. They approved it in late May at the meeting of the World Health Assembly in Geneva.
The plan urges people to eat less saturated fats and trans fatty acids. Food products often list trans fats under the name "partially hydrogenated" oil. The plan also urges people to eat less salt and sugar, and more fruits and vegetables. It calls for more physical activity. And it suggests that governments restrict food advertising, especially messages aimed at children.
The plan took two years to develop. The sugar industry and several sugar-producing nations had objected to earlier proposals. They wanted to remove any discussion about limits on sugar. Some sugar producing nations feared that their farmers would be hurt by the new strategy.
The director general of the W.H.O., Lee Jong-wook, praised the strategy as a major success in public health policy. He said it will provide countries with a powerful tool to fight diseases caused by obesity.
Health officials say poor diet and lack of exercise are among the leading causes of heart disease, diabetes and some cancers. They say these kinds of diseases now cause about sixty percent of deaths worldwide.
In the United States, the government estimates that one in three adults is obese. But health officials warn that the problem is spreading in developing nations as they gain more wealth.
And the problem is not just among adults. A group called the International Obesity Task Force estimates that one in ten children worldwide is overweight or obese.
Another big problem in the world is malaria. The World Health Organization estimates that about three-million people a year become infected with this disease. About one-million of them die. Most of the deaths are in Africa. Young children and pregnant women suffer the most.
Now, the United Nations has given its support to another drug to fight malaria. It is a traditional Chinese herbal medicine called artemisinin (are-TEM-is-in-in). This drug comes from a plant called the sweet wormwood. Chinese researchers discovered artemisinin more than thirty years ago. Tests took place in the early nineteen-nineties in Vietnam.
Malaria spreads through mosquito bites. New drugs are needed because the parasites that cause the infection develop resistance. Health experts hope to prevent resistance to artemisinin by giving the drug in combination with other medicines.
But experts also warn against the overuse of malaria drugs by people who do not have the disease. They say that sick people often mistake influenza or other diseases for malaria and take anti-malaria medicine. This can add to the problem of drug resistance. There are home tests for malaria. Health experts say greater use of these tests could help make sure people take malaria drugs only when they really need them.
SCIENCE IN THE NEWS was written by Jill Moss. Cynthia Kirk was our producer. This is Sarah Long.
And this is Doug Johnson. Listen again next week for more news about science, in Special English, on the Voice of America.