Broadcast: September 7, 2004
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Bob Doughty.
And I'm Faith Lapidus. On our program this week: writing new dietary guidelines for Americans.
And, preparing for the next influenza pandemic.
Americans are expected in January to get new advice from the government about what to eat and what to avoid. The Department of Health and Human Services and the Department of Agriculture publish a report every five years. It contains nutritional information and guidelines for the public on diet and physical activity.
The report is based on the work of the Dietary Guidelines Advisory Committee. This group has just come out with its advice for the two thousand five version of the guidelines.
The committee says its findings support the development of dietary guidelines that express messages such as: "Control calorie intake to manage body weight." "Be physically active every day." "Increase daily intake of fruits and vegetables, whole grains and non-fat and low-fat milk and milk products." And, "Choose fats wisely for good health."
The list also includes: "Choose carbohydrates wisely for good health." The committee noted that this represents a major change. For the first time, the list does not say anything directly about sugar. Carbohydrates include the different sugars that people and nature use to sweeten foods. For more than twenty years, the dietary guidelines have directly advised Americans to limit their amount of sugar.
The government will accept comments on the report through September twenty-seventh.
The advisory committee provides explanations and scientific arguments for each message in its full report. Sugars are discussed in the part about carbohydrates.
Most people do not read the full report. The dietary guidelines, however, often appear in schools, health centers and other places. They are also used to develop educational guides.
A commentary in the New York Times criticized the change. It noted that some of the experts on the committee have ties to the food industry. The newspaper said it is difficult to imagine that the change was not the result of influence by the sugar industry.
The Sugar Association said in a statement that it was pleased with the work of the committee. The industry group says the new messages recognize the importance of energy balance. This is the idea that people should not get more calories than they need to meet their energy requirements. The Sugar Association says the new guidance provides a "more helpful message" by not singling out individual nutrients.
But the committee does say there are reasons for people to limit their intake of sugars and syrups added to food. It says a reduced intake of added sugars may help control weight gain and make sure other food needs are met.
Health officials say two-thirds of Americans are overweight or obese. The committee says that while more research is needed, a number of studies suggest a link between sugar-sweetened drinks and weight gain.
One of those studies appeared in the Journal of the American Medical Association shortly before the committee released its report.
The study dealt with the effects of sugar-sweetened colas and other soft drinks. Researchers from the Harvard School of Public Health, Boston Children's Hospital and Brigham and Women's Hospital did the study.
They studied information provided by more than ninety thousand women. This information was collected between nineteen ninety-one and nineteen ninety-nine. The women answered questions two times each year about their food intake.
The researchers say those who drank high levels of sugar-sweetened drinks were more likely to gain weight and develop diabetes. Some of the women had increased their level of sugary drinks to one or more per day during the eight-year period. The researchers say these women gained an average of almost eight kilograms. Other women had decreased their level to one or no sugary drinks per day. On average, these women gained less than three kilograms.
The doctors note that weight gain is a major cause of type two diabetes. This form of the disease usually appears in adults.
The study compared women who drank more than one sugar-sweetened soft drink a day with those who drank less than one a month. The women who drank more were reported to have over an eighty percent higher risk of diabetes than the other women.
There were also findings about women who drank sugar-sweetened fruit drinks. The study says women who drank these every day were two times as likely to develop diabetes as those who drank less than one a month.
Doctor Meir [mare] Stampfer at the Harvard School of Public Health says sugary soft drinks cause a sharp increase in blood sugar. He says this causes the body to produce more insulin, and that causes the sugar levels to go down. He describes the process as a recipe for diabetes, a disease where insulin production weakens.
The researchers say diet drinks and unsweetened fruit juice did not appear to cause an increased risk of diabetes.
Doctor Stampfer says it is easier to gain weight from calories in drinks than in foods. He says drinks sweetened with sugar or high-fructose corn syrup are high in calories, but do not satisfy hunger. When people do not feel full, they often take in more calories than their bodies need. The researchers says soft drinks are the leading way that Americans get added sugar.
The American Beverage Association criticized the study. This trade group recently changed its name from the National Soft Drink Association. It says to blame any one food or drink for increasing the risk of diabetes is "scientifically indefensible."
It says most published medical literature does not list sugar intake as a risk factor for type 2 diabetes. A spokesman for the group says a careful reading of the study shows that an unhealthy lifestyle increased the risk for the women. The study found that the women who drank the most soft drinks were generally less physically active and more likely to smoke. They also generally ate less well than those who drank the fewest sugary drinks. For example, they ate less protein and grain.
The association says the study provides no evidence to support the idea that sugar-sweetened drinks are a cause of type two diabetes. On the issue of weight gain, it says there is no proven link between increased sugar intake and obesity.
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Faith Lapidus.
Public health officials in the United States say they want to be ready in the event of another influenza pandemic. Pandemics are times when diseases spread throughout the world. Three influenza pandemics took place in the twentieth century. The most recent was in nineteen sixty eight. Last month the Department of Health and Human Services proposed a plan. It is called the "Pandemic Influenza Response and Preparedness Plan."
Possible measures include actions like closing schools, restricting travel and keeping infected people away from others. The plan also proposes major federal research to create different kinds of flu viruses in order to study them. Experts say such efforts could reduce the time needed to produce new vaccines.
One fear is that bird flu could develop the ability to spread between people and start a pandemic. Researchers with support from the National Institutes of Health aim to develop a vaccine against avian influenza. Tests are to begin this winter.
The most deadly flu pandemic known struck in nineteen eighteen. As many as fifty million people may have died from the so-called Spanish flu.
Officials announced the pandemic readiness plan on August twenty-sixth. That same day, the vaccine maker Chiron announced that some of it flu vaccine did not pass final inspection for purity. Chiron is one of the two major producers of flu vaccine in the United States. The company said it would halt shipments until more tests were done.
The company is based in California. It produces vaccine at a factory in the British city of Liverpool. Chiron was to release as many as forty-eight million doses of vaccine in September. Now, the company says it expects that will not happen until October.
Health officials say they still expect to be able to meet the needs of the public this flu season. Doctor Julie Gerberding is director of the Centers for Disease Control and Prevention. She noted there have been vaccine delays in the past. The other major supplier, Aventis Pasteur, aims to increase its supply to help make sure there is enough flu vaccine this winter.
SCIENCE IN THE NEWS was written by Caty Weaver and Nancy Steinbach. Cynthia Kirk was our producer. To send us e-mail, write to firstname.lastname@example.org. This is Faith Lapidus.
And this is Bob Doughty. Join us again next week for more news about science, in Special English, on the Voice of America.