In the news: Drink Up! New findings on coffee & Tea Health Benefits

New Findings on Health Benefits of Coffee & Tea

Coffee and tea are two of the most commonly consumed beverages worldwide. Both have been extensively studied for their potential health benefits, which are largely attributed to their high levels of antioxidant and anti-inflammatory compounds.

Regularly drinking coffee and/or tea has been linked to a lower risk of type 2 diabetes, heart disease and stroke, certain cancers, liver disease, and even gallstones. Several recent studies lend support to some of these benefits or help explain how they may work on a cellular level.

Tea May Cut the Risk of Stroke

Chinese researchers explored the relationship between tea consumption and stroke risk in a large- scale study of nearly ½ million men and women (1).

Overall, about 26% of participants reported drinking tea most every day, predominantly green tea. Among those who drank tea daily, drinking higher amounts and consuming it over longer periods of time were associated with greater risk reduction.

In short, this study in Chinese adults found that higher intake of tea, especially green tea, was associated with a lower risk of both types of stroke – ischemic (the type caused by a blocked vessel supplying blood to the brain) and hemorrhagic (caused by a leaking or ruptured artery in the brain).

Coffee May Cut Liver Cancer Risk in Half 

Researchers in the UK set out to see whether coffee consumption – and the type of coffee consumed – impacts the risk of digestive cancers by following 471,779 participants for 7 ½ years.

The research team reports that compared to non-coffee drinkers, those that consume coffee had a 50% lower risk of developing hepatocellular carcinoma, the most common form of liver cancer. The type of coffee the participants drank didn’t seem to make a big difference: the reduction in risk was similar for instant coffee (49%) and ground regular coffee (53%), with decaf reducing risk by 41%.

According to the researchers (2), their findings are consistent with the World Cancer Research Fund's report, which concluded that there is 'probable' evidence that coffee drinking lowers the risk of liver cancer. The researchers also investigated other digestive cancers, e.g. bowel and stomach, but found no consistent links with coffee drinking.

Shedding Light on How Coffee May Work

A 4-week controlled study (3) looking at drinking 2 cups of dark roast coffee daily vs. no coffee or tea found that coffee drinking reduced DNA damage – a finding shown in previous studies as well. Unrepaired DNA damage in some cells can increase the risk of cancer.

Preliminary research from Baylor University suggests that higher coffee intake may also foster a healthier gut microflora, which in turn, could impact health (4). Though it couldn’t be determined if caffeine, polyphenols, or both were responsible, coffee drinkers were found to have a richer array of gut microflora, more anti-inflammatory bacteria and lower levels of potentially harmful bacteria.

Regular vs. Decaf Coffee and Tea

Some of us go for the mental alertness boost provided by the caffeine these beverages contain. But others who are sensitive to the effects of caffeine (suffering anxiety, irritability or insomnia) should still be able to enjoy the many health benefits of these beverages. Decaf coffee contains the same healthful polyphenols, including chlorogenic acid and lignans that caffeinated coffee does. Teas come from the Camellia sinensis plant, which is used to make all tea varieties like green, oolong and black teas. Though some of the polyphenols and antioxidants are lost in decaffeination, studies indicate that these compounds are still present at levels sufficient to offer potential health benefits.

References

1. Tian T, et al. Tea consumption and risk of stroke in Chinese adults: a prospective cohort study of 0.5 million men and women. Am J Clin Nutr. Epub Nov. 11, 2019.
2. Tran KT, et al. Coffee consumption by type and risk of digestive cancer: a large prospective cohort study. Br J Cancer. 120:1059-1066, May 2019.
3. Schipp D, et al. Consumption of a dark roast coffee blend reduces DNA damage in humans: results from a 4-week randomized controlled study. Eur J Nutr. 58:3199-206, 2019.
4. Jiao L, et al. Presented at American College of Gastroenterology Annual Scientific Meeting, San Antonio Tx, Oct 28-30, 2019.