Public Release: 

Alzheimer's, nutrition, smallpox, and other 'Human Health Frontiers' addressed by AAAS speakers

American Association for the Advancement of Science

Proof of a connection between Alzheimer's Disease and high cholesterol levels could change the way doctors counsel their older patients, researcher Rudolf Tanzi reported October 15 at the American Association for the Advancement of Science (AAAS).

If additional evidence confirms the Alzheimer's-cholesterol connection, genetic testing of patients with high cholesterol levels may help doctors diagnose Alzheimer's at earlier stages, said Tanzi, a professor of neurology at Harvard Medical School.

"In the past, I would have said no to the test, but if it can be shown that high cholesterol predisposes a person to Alzheimer's, I'd be willing to suggest testing for Alzheimer's risk," Tanzi said during the AAAS Advancing Science seminar. "That's empowering you to change your lifestyle. If you can't empower someone, especially with a test for Alzheimer's, then you might make someone falsely confident or falsely anxious."

Tanzi's update on the brain disease affecting 4 million Americans was presented during the AAAS seminar focusing on "Human Health Frontiers."

For more information on Tanzi's presentation, contact the AAAS Office of Public Programs at (202) 326-6431, or his office (c/o Donna Burtanger) at (617) 432-3991.

Nutrition news that turns the food pyramid on its head, research efforts to combat bioterrorism, and new approaches for addressing chronic human conditions such as depression, substance abuse, cancer and spinal cord injury, were also discussed.

A summary of presentations by topic follows, below. (Journalists, please cite the AAAS Advancing Science seminar as the source of this information):

NUTRITION: With advice that turns the U.S. Department of Agriculture's food pyramid upside down, a Harvard University scientist urged consumption of certain oils as a foundation of all healthy diets, and placed pasta and white rice, alongside candy, cake and ice cream.

"When you replace the fat in your diet with carbohydrates, your good cholesterol goes down, and you get higher levels of heart disease," said Walter Willett, Fredrick John Stare Professor of Epidemiology and Nutrition at Harvard School of Public Health.

Instead, Willett said, a balanced diet should include oils, especially canola, soy and others that contain Omega 3, an essential fatty acid, as well as nuts, legumes and fruits and vegetables. Except for whole grains, he said, all carbohydrates should be eaten sparingly.

Contact information on nutrition: Walter Willett at (617) 432-4680.

SMALLPOX: Faced with the threat of bioterrorism, the federal government has stockpiled more than 400 million doses of the smallpox vaccine. Its challenge now is to prepare the public for the deaths that could result from widespread vaccination, an estimated 1.1 per million, according to Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases.

"We need to understand the toxicity of vaccinating so that people can understand that," said Fauci, who showed slides of people whose bodies were covered with painful and disfiguring smallpox lesions. "This is what you will see on the nightly news."

To request interviews with Fauci, please call AAAS, or his office (c/o Margaret Moore) at (301) 435-8581.

STEM CELLS: Although scientists are finding that adult stem cells are capable of developing into other cell types, they report that the federal government's restrictions on the use of embryonic stem cells in federally-funded research is slowing down U.S. stem cell research.

"Clearly, with stem cells in hand, we can approach this dream of constructing pieces of organs and tissues," said John Gearhart, C. Michael Armstrong Professor of Medicine at Johns Hopkins University School of Medicine. But, Gearhart added that he and other researchers had identified "only a half-dozen lines that are actually useful," from among the 72 embryonic stem cell lines the federal government has approved.

"I am very troubled because of the impact of politics on science," Gearhart said. "Our hope is that the rigor of science will show us all the right way to go."

As foreign countries play an increasing role in stem cell research, it is difficult to evaluate results of studies that do not adhere to U.S. standards.

"Some studies don't have appropriate controls," said Wise Young, director of the W.M. Keck Center for Collaborative Neuroscience and a professor at Rutgers University. "You can't transplant a placebo, but you could have randomized transplantation. We don't now know if any of the recovery results in spinal injuries come from a spontaneous regeneration or from a placebo effect."

Under current federal law, the United States will have a struggle to maintain its leadership role in the field of stem cell research.

"It will put us at a significant disadvantage," said Mark Frankel, director of the AAAS Program on Scientific Freedom, Responsibility and Law. "Researchers in other countries may not find it acceptable to work with us, and our young investigators may increasingly pursue work abroad."

Frankel suggested that scientists should respond respectfully to ethical concerns about the use of embryonic stem cells, while educating the public about the benefits and enlisting the help of patient advocacy groups in communicating with both public and policymakers. "Scientists ought to be concerned about the public's perceptions," Frankel said.

Contact information on stem cells: John Gearhart, (410) 614-3976; Wise Young, (732) 445-2061, or Mark Frankel, (202) 326-6793, Additional information on stem cell research is available from Pamela Hines, Science editor, (202) 326-6509,

ADDICTION AND MENTAL ILLNESS: Greater understanding of how the brain works has transformed treatment of mental illness and substance abuse, and begun to transform public perceptions of those diseases.

"We have begun to understand mental phenomena in many different ways," said Alan I. Leshner, CEO of AAAS and former director of the National Institute for Drug Abuse.

Using visual images and graphs, Leshner demonstrated the tremendous impact of drug use on learning and on memory, and the role of triggers in setting off the phenomenon of craving. "We can see how drug use changes the brain," Leshner said, adding that the use of drugs "usurps the brain's motivational priorities."

"Not only does using drugs substitute one motivation for another, it rearranges those priorities," said Leshner.

To request interviews with Leshner, please contact Ginger Pinholster in the AAAS Office of Public Programs, (202) 326-6421,

Additional information is also available from session moderator Floyd Bloom, President of AAAS. Contact AAAS, or Bloom at (858) 784-9730,

MICROBES: Scientists have only begun to scratch the surface of the microbial world, but new molecular technologies offer hope that unknown impact of microbes on human health will become increasingly understood.

"We know very little about the diversity of life on our planet," said David Relman, an associate professor at Stanford University and acting Chief of Infectious Disease at the Veterans Affairs Palo Alto Health Care System. "The division shows up within the human body. We're only learning now how to identify these organisms. People can be infected and perhaps made sick by microorganisms we can't grow in the laboratory. There are organisms that may play an important role, but are completely unknown to us."

To overcome the limitations of traditional techniques of cultivation, scientists are using modern genomic techniques to determine the human host's response to infection at the molecular level, Relman said. "We're getting tantalizing bits of evidence that microbes may play a role in diseases such as Crohn's and multiple sclerosis."

Microbes have not evolved as "neatly" as scientists had thought, leading to new insights regarding ways of combating disease.

"Multiple processes shape microbial diversity," said Claire Fraser, president and director of The Institute for Genomic Research (TIGR), in Rockville, MD. "Horizontal gene transfer is probably playing a larger role than we had appreciated...The propensity of microbial species to take up DNA has implications for understanding the emergence of virulence."

Fraser suggested said that scientists have begun to discuss the creation of a "pathogen database" that could allow them to track the evolution of species. "This would put us in a better position in terms of combating disease," she said. "It's not inconceivable that we could eventually predict outcomes and use this data for vaccine development."

Contact information on microbes: Claire Fraser, (c/o Bob Koenig) (301) 838-5880; David Relman, 650-852-3308; Rudolf Tanzi, (c/o Donna Burtanger) at (617) 432-3991.


Founded in 1848, the American Association for the Advancement of Science (AAAS) has worked to advance science for human well-being through its projects, programs, and publications, in the areas of science policy, science education and international scientific cooperation. With over 134,000 members from 130 countries and 272 affiliated societies comprising more than 10 million individual members, AAAS is the world's largest federation of scientists. The association also publishes Science, an editorially independent, multidisciplinary, weekly peer-reviewed journal that ranks as the world's most prestigious scientific journals. AAAS administers EurekAlert!, the online news service, featuring the latest discoveries in science and technology.

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