The simultaneous release of seven large-scale studies examining a range of scientific paths in Alzheimer’s disease is an exciting reflection of the momentum in Alzheimer research, according to the Alzheimer’s Association. The studies, funded by National Institute on Aging (NIA) and published in the most recent edition of Archives of Neurology, come as Congress is considering the president’s proposed budget that gives low priority to medical research funding and threatens to sidetrack important and substantive scientific advances in Alzheimer research.
Today, four million Americans have Alzheimer’s disease. However, as baby boomers age, that number is expected to swell to 14 million, swamping the resources of the healthcare system and devastating millions of families financially and emotionally. The Alzheimer’s Association says research is critical to averting this catastrophe.
“There is an enthusiasm as well as an urgency within the Alzheimer scientific community that we are moving ever closer to finding the answers to this debilitating disease,” said Alzheimer’s Association President and CEO Sheldon Goldberg. “News of these and other important studies in the pipeline tell us we are making significant progress. Congress and the administration must recognize that federal funding of Alzheimer’s research at this critical juncture is key to avoiding a looming national epidemic.”
The Alzheimer’s Association, which is the largest private funder of Alzheimer research, says solid information on what aging Americans can do to reduce their risk of developing Alzheimer’s disease is beginning to crystallize and is reflected in many of the studies released today.
The Cardiovascular Connection
According to Bill Thies, head of medical and scientific affairs at the Alzheimer’s Association, two of the studies released today, one on dietary fat and the other on blood pressure, “reinforce previous research showing that what is good for the heart is good for the head.”
In a study from Rush-Presbyterian/St. Luke’s Medical Center in Chicago, researchers found that those with diets high in saturated fats and trans-unsaturated fats were more likely to develop Alzheimer’s; diets high in polyunsaturated fat and monounsaturated fat actually decreased risk of Alzheimer’s. Those who consumed the most saturated fat had 2.3 times the risk of developing Alzheimer’s compared with those who consumed the lowest amount of saturated fats.
Researchers in Sweden found that blood pressure played an important role in the risk of developing Alzheimer’s in subjects ranging in age from 75 to 101. According to Thies, “The pattern of blood pressure is typical of atherosclerosis, reinforcing the link between cardiovascular health and risk for Alzheimer’s, as well as the need for careful monitoring and control of this condition.”
Treatment or Prevention
It has been suggested that the antioxidants: carotenes, vitamin C, vitamin E and other nutrients, might reduce cellular damage to neurons and protect against dementia. After four years, researchers at Columbia University found that consumption of carotenes or vitamins A and E either through the diet or by supplements did not decrease risk of developing Alzheimer’s. Participants in the study had an average age of 75.
“This large-scale study is at variance with earlier indications that these supplements are effective as treatment for Alzheimer’s,” said Thies. “This tells us that more work needs to be done before we completely understand the value of these agents. Antioxidants taken earlier in life may still prove to have some preventative benefit, consistent with earlier observational studies.”
A University of California at San Diego treatment trial of an estrogen supplement in postmenopausal women with Alzheimer’s disease found no association between elevated blood estrogen levels and cognitive functioning after 2 months or 12 months of treatment.
In a second estrogen study, researchers in the Netherlands found that the levels of estrogen in older women and men without Alzheimer’s had no correlation with better memory performance or larger hippocampal volume, the portion of the brain most affected by AD.
“The role of estrogen in cognitive function is still not clearly understood. The UCSD study is important confirmation of earlier studies showing that estrogen is not effective as a treatment of Alzheimer’s,” said Thies. “However, whether estrogen may still prove important in the prevention of the disease is a question that may be answered by the ongoing portion of the Women’s Health Initiative, the long-term NIH-sponsored study on women’s health.”
The Role of Genetics
Researchers from Chicago’s Rush-Presbyterian/St. Luke’s Medical Center measuring the effect of a variant of the Apolipoprotein E gene (APOE 4) on the incidence of Alzheimer’s disease found the APOE 4 gene variant to be associated with an almost three-fold increase in the risk of developing Alzheimer’s in the Caucasian population, and no increased risk among African-Americans associated with APOE 4.
“This and a few other studies looking specifically at the prevalence of Alzheimer’s disease among minority communities raise many questions,” Thies said. “The Alzheimer’s Association is committed to funding an increased number of studies among ethnic populations in order to better understand and interpret the particular medical, cultural and biological issues of diverse communities.”
Quality of Life
In a study examining both life expectancy and the quality of life for individuals with Alzheimer’s disease, researchers found a severe level of impairment in the last years of Alzheimer’s as well as a shortened life expectancy. “Ultimately, Alzheimer’s is fatal,” Thies said. “Until research provides the answers, Alzheimer’s will continue to exact a terrible toll on those with the disease as well as on their families, friends and caregivers.”