Is There More Than Caffeine Behind Coffee's Benefits?

A review of 100 years of research says most likely.

April 12, 2013

Caffeine’s pick-me-up properties have pushed countless runners out the door and over the finish line (and no doubt have saved innumerable grades and business meetings). As much as we know about caffeine’s powerful ability to increase energy, improve reaction time and boost alertness, science is unclear what role other compounds found in plant-based foods like coffee, tea and cocoa play. Do they boost caffeine’s potency? Do they provide mental and physical health benefits beyond the stimulant effects of caffeine?

A new study in Nutrition Research Reviews begins to answer these questions by decoding and cataloging 176 studies on coffee, tea, and cocoa that reach as far back as 100 years (the first investigation on caffeine’s effect was published in 1912). The study’s aim was to lay out what science knows and doesn’t know about each of the plant-based foods' influence on the brain and the body as a guide for future research. The study notes that, after water, tea and coffee are the most widely consumed beverages in the world, and understanding these foods’ health implications is crucial.

A passage from the study offers a summary of the state of the research:

“Human research on tea to date has contributed little to our knowledge regarding its behavioural effects beyond that attributed to caffeine; studies demonstrating differences between tea and coffee are inconsistent and do not allow for the assessment of which components are involved in any differential effects of these two caffeine sources.”

The compounds in question are phytochemicals, substance in plant-based food like fruits, vegetables, grains and beans that have health benefits. Phytochemicals may act independently of caffeine or work in concert with it, the authors note. And while there’s much to learn, there's a growing body of research showing that some other compounds in plant-based foods with caffeine are good for us.

The most potent of these compounds is polyphenols—substances with antioxidant properties, or flavonoids, that have been shown to lower blood pressure and aid dementia patients. Another example: Chlorogenic acid lactones, an antioxidant created in coffee during roasting, is believed to influence brain function.

The review emphasizes repeatedly that various studies reach different conclusions on the effects of coffee and tea on brain function and other benefits, which suggests that the synergistic properties of each plant’s phytochemicals, not solely caffeine, are responsible for the effect. Tea, for example, may not hurt cognitive ability, but drinking coffee, not tea, appears to be linked with a lower risk of developing Alzheimer’s disease.

The authors point out that a potential problem for researchers is that caffeine’s effect is so powerful it may make it difficult to extrapolate the role of other compounds.

Future scientists will grapple with that. Our takeaway for now is that if the goal is overall health—not just an endurance boost—the often-recommended advice of eating foods rather than taking supplements applies to caffeine. That is, skip the caffeine pill or caffeine-spiked beverage and brew coffee or tea instead.