Can caffeine protect older women from dementia? Maybe, maybe not

Back in October, I received an email from Providence Medical Group whose headline announced that consuming more caffeine may protect older women from dementia. The article stated that a new study published in the Journals of Gerontology, Series A: Biological Sciences and Medical Sciences “showed that the risk of developing dementia or cognitive impairment is reduced for women 65 and older by consuming more than 261 milligrams of caffeine per day.”
Woohoo! That’s about two or three 8-ounce cups of coffee or roughly six cups of tea. I’m not a coffee drinker, but I can pound down pounds of tea each day. And, naturally, I have no desire to develop dementia.
“The mounting evidence of caffeine consumption as a potentially protective factor against cognitive impairment is exciting given that caffeine is also an easily modifiable dietary factor with very few contraindications,” said Ira Driscoll, Ph.D., the study’s lead author and a professor of psychology at the University of Wisconsin-Milwaukee.
The research was funded by the National Heart, Lung and Blood Institute and the 6,467 postmenopausal women were part of the Women’s Health Initiative Memory Study. These women were questioned about the type, amount and frequency of caffeine they consumed each day.
“The women who participated in the study were given annual exams to assess their cognitive function. In 10 years or less, 209 women received a diagnosis of probable dementia, and 388 were classified as having probable dementia or some form of cognitive impairment,” the article said.
“Women who consumed above the median levels (the mean being 261 milligrams) of caffeine were less likely to develop dementia than those who consumed below the median (an average intake of 64 milligrams per day).
“Researchers considered other risk factors in the study: hormone therapy, age, race, education, body mass index, sleep quality, depression, hypertension, prior cardiovascular disease, diabetes, smoking and alcohol use.”
Now, despite the recent information about false news stories, I have no reason but to believe an article published by an esteemed health organization such as Providence. But, just for giggles, I went to the National Institute of Health’s website.
“Caffeine has well-known short-term stimulating effects on central nervous system, but the long-term impacts on cognition have been less clear,” the website says. They go on to say that the findings are somewhat inconsistent, “but, most studies (3 out of 5) support coffee’s favorable effects against cognitive decline, dementia or Alzheimer’s disease (AD).”
“In conclusion, coffee drinking may be associated with a decreased risk of dementia/AD. This may be mediated by caffeine and/or other mechanisms like antioxidant capacity and increased insulin sensitivity. This finding might open possibilities for prevention or postponing the onset of dementia/AD.”
Words like “may” and “might” opened the door to suspicion. An article published by the National Health Service in the United Kingdom questions the study by the University of Wisconsin-Milwaukee, et al.
They say that the study relied too heavily on self-reporting and that it didn’t take into consideration that the coffee, tea and soft drinks consumed may have been decaffeinated or of the sort that doesn’t contain caffeine.
As the actual levels of caffeine were not measured in the study, it may have been another component in coffee, tea or cola that was having a positive effect on the cognitive ability of the women,” NHS said. That’s consistent with the statement the NIH published.
The other point that NHS made is that the women in the study were predominately white and well-educated which isn’t representative of the general population in either of our countries.
“Although some confounding factors were adjusted for, some were not, for example other aspects of women’s diets and family history of dementia,” NHS said. They also pointed out that the measures of cognitive function were not consistent throughout the study and that using different measures might have resulted in over- or under-estimates of cognition.
The conclusion of all of the studies is that there needs to be more studies. My conclusion is that if you drink caffeinated beverages now don’t increase or decrease them because of an inconsistent study. It’s just interesting, isn’t it?
Kathy Hubbard is a member of Bonner General Health Foundation Advisory Council. She can be reached at 264-4029 or [email protected].