Dr. Barbara Shukitt-Hale is the USDA Lead Scientist in the Laboratory of Neuroscience, USDA-ARS, Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, MA. Her current work involves determining the factors responsible for age-related behavioral and neurochemical changes and possible amelioration of these effects with various nutritional treatments.
ElderBranch interviewed Dr. Shukitt-Hale to discuss her paper, “Coffee, but not caffeine, has positive effects on cognition and psychomotor behavior in aging,” which she wrote along Marshall Miller of the Human Nutrition Research Center on Aging at Tufts University and Psychology Department, Tufts University, Yi Fang Chu and Barbara Lyle of Kraft Foods Global Brands, LLC, and James Joseph of the Human Nutrition Research Center on Aging at Tufts University.
What led you to research on the relationship between cognition and coffee? Why is this study important?
Broadly, our lab studies the effect of nutrition on the brain during aging. For the past decade, much of our research has focused on whole foods that contain high levels of polyphenols. Coffee is perhaps best known as a source of the stimulant caffeine. However, coffee also contains high levels of polyphenols and consuming phenol-rich foods can have direct effects on the brain and also reduces oxidative stress and inflammation. Coffee’s widespread consumption makes it the primary source of dietary antioxidants in the American Diet.
We wanted to explore the link between coffee and brain health because oxidative stress and inflammation are involved in dementia and other brain-related diseases of aging.
This research is important because it shows that the beneficial effects of coffee on the aging brain are not limited to the effects of caffeine.
Please describe your study. What were your in-going hypotheses?
Our study involved two experiments.
In the first experiment, we added the equivalent of 0, 3, 5, 10, or 15 cups of coffee to the diet of aged rats. We then tested the rats to see which doses could improve the aged rats’ memory or mobility.
In the second experiment, we fed rats diets that contained either the two most beneficial doses of coffee or diets that contained the same amounts of caffeine.
We hypothesized that some coffee in the diet would be beneficial but that higher doses might not be as effective.
What were your key findings from your research? Would you make any specific recommendations as a result of your findings?
The key finding of this study is that the beneficial effects of coffee consumption come not just from the caffeine but also from the independent and/or synergistic effects of other bioactive compounds found in coffee.
Moderate coffee consumption appears to have a beneficial effect on the brain during aging, beyond that of caffeine alone.
Are there other beverages or foods that can be deemed as beneficial as an extrapolation of this study?
Many plant species produce polyphenols, which play a role in many of plants’ biological processes.
Tea, for example, also contains caffeine and different types of polyphenols – the effects of tea on aging are also being explored. Similarly, research from our lab has shown that many varieties of berries and nuts also have protective effects in the brain during aging.
What are the next steps to further your work in this area?
Caffeine and polyphenols are not the only two bioactive compounds found in coffee. Further investigation could include other bioactives to explore the synergistic effects of these compounds.