Could Coffee or Tea Lower Your Odds for Dementia and Stroke?

A few cups of your favorite brew -- coffee or tea -- each day might help keep stroke and dementia at bay, a large new study suggests.

For close to 14 years, scientists stacked up coffee and tea consumption against the risk of stroke and dementia among nearly 366,000 healthy Brits between 50 and 74 years of age.

The researchers -- led by Yuan Zhang of Tianjin Medical University in Tianjin, China -- observed that those who drank 2 to 3 cups of coffee along with the same amount of tea every day had a 32% lower risk for stroke, and a 28% lower risk for dementia, compared to those who drank neither.

And drinking coffee -- even in very small amounts -- was linked to a lower risk for both. The same was true of tea.

The lowest risk for stroke and dementia was seen among participants who downed either 2 to 3 cups of coffee daily, 3 to 5 cups of tea, or a combined 4 to 6 cups of both.

While lower risk was seen for ischemic strokes resulting from a blood clot or narrowed arteries, there was no reduction in risk for a less common form of stroke (hemorrhagic) that results from blood vessel breakage.

Proceed with caution

But don't toast the news with a big jolt of caffeine just yet.

The findings don't prove that coffee and tea protect against either stroke or dementia -- only that there is an association.

"People need to remember that an association does not guarantee that the same outcome will happen" for everyone, Connie Diekman, a former president of the Academy of Nutrition and Dietetics who reviewed the findings says.

So what's likely protective about coffee or tea?

A previous study pointed both to "caffeine and the antioxidant actions provided by the

plants that coffee and tea come from," Diekman, a St. Louis food and nutrition consultant and sports dietitian shares.

"It appears from this [new] study that the mechanism is once again the caffeine and the antioxidant action," she adds. "This finding certainly supports what we know about so many plant foods: They offer many health-related benefits beyond just the vitamins and minerals they contain."

Another U.S. expert agreed, noting that coffee and tea contain several chemical compounds, not just caffeine, which have health benefits.

"There are many possibilities of how these chemicals could work in the body, from antioxidants, anti-inflammation, increase blood flow, protect blood vessels from damage, and so on," Lona Sandon, an associate professor and program director in clinical nutrition at University of Texas Southwestern Medical Center in Dallas says. "These effects could influence the risk of dementia or stroke."

How much coffee or tea should you consume?

Neither Sandon nor Diekman was particularly concerned about the quantity of coffee or tea in question.

Sandon notes that 4 to 6 cups is fairly common in many countries, while Diekman notes that current guidelines indicate that 3 to 5 (8-ounce) cups of coffee a day appear to be safe for most adults.

The point now is whether non-drinkers should start based on these findings, Diekman shares.

"That question," she said, "still needs more research."

Although there are many health benefits to consuming coffee or tea including a lower likelihood of type 2 diabetes, heart disease, Parkinson's Disease, liver disease and endometrial cancers; you should still be cautious about how much you consume. Too much caffeine can make you anxious or irritable and cause you to have trouble sleeping. If you are concerned about how coffee or tea may affect your health or are experiencing any complications, consult your doctor.