Looking for a reason to justify your Starbucks habit? Here's one for the ladies: Drinking up to three cups of coffee per day can reduce risks of incident dementia.
In a study published in The Journals of Gerontology: Series A, Ira Driscoll, Ph.D. and colleagues showed that consuming more than 261 mg of caffeine per day can lead to a 36-percent drop in incident dementia risk over a follow-up period of 10 years. This much caffeine translates to up to six 8-ounce cups of black tea, eight 12-ounce cans of cola and three 8-ounce cups of coffee per day.
"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 Driscoll, the study's lead author.
According to her, their study is unique because they were able to assess the association between dementia incidence and caffeine intake using a large, prospectively studied, well-defined women's cohort.
Specifically, the researchers worked with data from the National Heart, Lung and Blood Institute's Women's Health Initiative Memory Study involving 6,467 post-menopausal, community-dwelling women, who are at least aged 65 and have consumed caffeine of some level. Subject intake levels were estimated using questions about tea, cola and coffee intake, including serving size and frequency.
The subjects were followed-up for a maximum of 10 years, with cognitive functions assessed every year. During the course of the study, 388 of the women were diagnosed with some level of global cognitive impairment or probable dementia.
Researchers made adjustments to accommodate risk factors, like age, body mass index, hypertension, sleep quality, alcohol consumption and diabetes, and found that subjects who consumed more than the average 261 mg of caffeine taken by the group per day received lower rates of diagnosis compared to those who consumed caffeine under the median.
While more research is needed to explore the connection between dementia risk and caffeine consumption, the study's results sound good to people who can't go a day without a caffeine fix, which turns out to be a craving dictated by ones DNA.
According to researchers from the University of Edinburgh, those with a gene variant known as PDSS2 were likelier to consume less caffeine. This means that those who absolutely have to have caffeine before they can function lack the gene.
Based on the researchers' findings, those with the gene variant break down caffeine more slowly, causing the substance to remain in the body longer. This then prompts them to consume less caffeine on the overall.