Broadcast: May 25, 2004
This is SCIENCE IN THE NEWS, in VOA Special English. I'm Sarah Long.
And I'm Bob Doughty. Coming up, we have reports about Alzheimer's disease.
And, a scientific committee finds no link between autism and the measles-mumps-rubella vaccine.
There is more evidence that people with diabetes have an increased risk of Alzheimer’s disease. This disease kills brain cells and usually affects people late in life. It starts with mild memory loss, but gets worse. Over time, it leads to death.
Researchers at Rush University Medical Center in Chicago studied more than eight-hundred people. The research was part of a project called the Religious Orders Study. The men and women were all Roman Catholic, over the age of fifty-five. They included priests and nuns. They were tested yearly for an average of more than five years.
One-hundred-fifty-one of the people in the study developed Alzheimer's disease. These included thirty-one people who also had diabetes. The researchers found a sixty-five percent increase in the risk of Alzheimer's in those with diabetes. This was compared to the people who did not have the blood sugar disease.
The researchers tested the ability of the people to remember and understand things. At the start of the study, they found that those with diabetes did not do as well on these tests as those without diabetes. During the study, the researchers found that diabetes was related to decreases in some mental systems but not in others.
Diabetes is already a known risk for stroke, which can cause some kinds of brain disorders. Diabetes has also been linked to other health effects like heart disease, kidney failure and reduced mental abilities. Some scientists believe that a build-up of sugar in the brain could damage cells and increase the risk of Alzheimer's.
The study adds to research on possible links between diabetes and Alzheimer's disease. The scientists say more research will tell if treatments for diabetes may reduce the risk of Alzheimer's.
There is no cure, but there are treatments that can ease some of the effects of Alzheimer's. Most scientists think the disease is caused by a combination of genetic and environmental influences.
Earlier research found that eating foods high in vitamin E may reduce the risk of Alzheimer's in some people. Such foods include green leafy vegetables, vegetable oils and nuts.
Researchers say people who remain intellectually active may also reduce their risk. But depression and being stressed a lot may increase the risk.
The National Institute on Aging paid for the study. The American Medical Association published the findings in its Archives of Neurology.
More and more people are developing diabetes. In the United States, health officials estimate that one in three children born in two-thousand could become diabetic. They say the only way to prevent this is for many more people to start eating less and exercising more.
People can reduce their chances of getting diabetes. Steps include controlling their blood pressure and cholesterol, not using tobacco and not drinking too much alcohol. Weight control is also important.
In the United States, Alzheimer's disease affects an estimated four-point-five million people. This number is expected to grow sharply as the population gets older. But a new report calls Alzheimer's an "unrecognized public health crisis" among the growing Hispanic population in the United States.
The report is from the Alzheimer's Association, a group that supports research and provides services. It says about two-hundred-thousand Hispanics in the United States currently are living with Alzheimer's. It says this number is expected to grow to one-point-three million by two-thousand-fifty.
Old age is the greatest risk for Alzheimer’s disease. And the report says Hispanics in the United States are expected to live longer than any other ethnic group. It says that by two-thousand-fifty, life expectancy for Hispanics will reach eighty-seven years. They would represent sixteen percent of old people in the United States. Hispanics now make up five percent of older Americans.
The Alzheimer's Association says Hispanics also have increased rates of diabetes. This may put them at higher risk for Alzheimer's. But the group says Hispanics are less likely to see doctors and receive medical treatment.
The report also notes that some studies suggest that education may help protect against Alzheimer’s. But it says ten percent of older Hispanics never attended school. And it says more than half have eight years of schooling or less.
The association says there should be more efforts to educate people about Alzheimer's in their own language. And it wants the government to spend more money on Alzheimer's research.
There may be hope for better ways to slow the progress of Alzheimer's disease.
In one small study, scientists from the University of California, San Diego, worked with eight patients and some genetic engineering. All eight had early forms of Alzheimer's. Doctors took skin cells from each of them. The team changed the genetic structure of the cells to make them produce a protein called Nerve Growth Factor.
Later the doctors returned the cells to the patients. But not to the skin. They placed the cells in a part of the brain involved in memory and understanding. This is where Alzheimer’s first begins to attack.
At first the doctors operated with the patients in a light sleep under anesthesia. Two of the people moved. This led to bleeding in their brains. One of those patients died of a heart attack five weeks later. The doctors put the other six people in a deep sleep under general anesthesia. They say those operations went smoothly.
The doctors later studied images of the patients' brains. They reported increased cell growth activity compared to other people with Alzheimer’s.
Also, the researchers tested the mental abilities of the patients. They say that on one measure, the rate of progression of the disease dropped by half after the cell replacement. On another, the doctors say a reduced rate continued for the eighteen-month to two-year period of the study.
Doctor Mark Tuszynski led the study. He says no harmful effects have been found more than a year after the last operation. But he notes that testing is needed on larger numbers of people. Also, a new study will test a method of directly injecting the genetically engineered cells into the brain.
The scientists reported their findings at the yearly meeting of the American Academy of Neurology.
We close with news about a brain disorder in children. Last week, in the United States, the Institute of Medicine said it found no connection between autism and a common vaccine. The Institute of Medicine is a private organization that advises the government. It is related to the National Academy of Sciences. A committee released its eighth and final report on vaccine safety.
The scientists looked at studies of autism and the M.M.R. vaccine. This is a combined vaccine that prevents measles, mumps and rubella. The scientists also looked at studies of a mercury-based substance once used to protect the vaccine from bacteria. The substance is called thimerosal. And they compared the use of the vaccine with rates of autism.
Doctor Marie McCormick of Harvard University led the committee. She noted that scientists do not know what causes autism. In fact, she says there may be many causes. And she says these may or may not include bad reactions to a vaccine or the effects of mercury in some people. But the committee found no evidence to support accusations by some groups about the M.M.R. vaccine or thimerosal. The committee says any such suggestions are theories only.
SCIENCE IN THE NEWS was written by Caty Weaver and Cynthia Kirk, who was also our producer. This is Bob Doughty.
And this is Sarah Long. Listen again next week for more news about science, in Special English, on the Voice of America.