Drinking FOUR cups of coffee or tea per day could be the key to longevity in middle-age, study hints

Drinking plenty of coffee and tea in middle and old age may ward off frailty, a study suggests.

Researchers interviewed 12,500 people in their 50s in Singapore about their coffee and tea drinking habits and followed up with them up to 20 years later.

They found those who drank four cups of coffee or more each day had about half the odds of being physically frail in their 70s. 

And compared to non-daily tea drinkers, daily drinkers of black or green tea had about 18 percent lower odds of frailty later on. 

When the study broke down tea by type, daily green tea drinkers had greater benefit, showing 19 percent lower odds of frailty, compared to 12 percent lower odds for black tea drinkers.

Drinking plenty of coffee and tea in middle and old age may ward off frailty, a study suggests (stock) 

The study did not, however, look at how putting milk, sugar or artificial sweeteners in coffee or tea changed these health benefits. 

The researchers did not claim to prove cause and effect, but they believe caffeine may combine with other antioxidant compounds in coffee and tea to slow cells degrading and prevent physical health conditions like heart disease and certain cancers, which can lead to frailty.

To partly test this idea, they also looked at total caffeine consumption, including not only coffee and tea but also soft drinks and chocolate. 

Compared to those who consumed 67.6 milligrams (mg) of caffeine per day or less, those who took in the highest amount, 223-910.4 mg a day, had about 23 percent lower odds of frailty. 

Frailty is a common condition in older adults, and its symptoms can include decreased energy, loss of muscle, weakness and slowness. Besides being a possible sign of other health problems, frailty can make daily life more difficult and put older adults at higher risk of falls. 

Researchers interviewed 12,583 study volunteers about their coffee and tea drinking habits between 1993 and 1998 as part of the Singapore Chinese Health Study (SCHS). 

This research study has followed more than 60,000 Chinese men and women since the 1990s, following up with them every 5 to 6 years, in an effort to untangle the ‘dietary, genetic and environmental determinants of cancer and other chronic diseases in Singapore.’ 

For the present study, researchers used health data from the SCHS’s third follow-up period, spanning 2014 to 2017. In the initial period, the average age of participants was 53 years, and in the second period it was 73.

They found that, compared to adults who did not drink coffee daily, participants who drank four cups of coffee or more each day during midlife (the first time period) had about half the odds of being physically frail at the later timepoint. 

Based on the surveys, it is difficult to draw conclusions about the health benefits of caffeine-free options.

‘At the time of recruitment, decaffeinated coffee and tea were rarely consumed in our study population,’ the researchers write. ‘As such, all coffee and tea consumed by the participants were assumed to be caffeinated.’

A 2023 study of American adults supports the idea that the benefits are linked to caffeine. That study found a reduced risk of frailty among people who drank caffeinated coffee, but not those who drank decaf. 

Caffeine can vary somewhat based on preparation methods, but an 8-ounce cup of brewed coffee contains about 96 mg of caffeine, whereas the same volume of black tea contains about 47 mg and a cup of green tea carries about 28 mg. A 12-ounce can of Coca Cola contains 34 mg of caffeine, and a can of Diet Coke has 46 mg.

To ensure that the results were actually capturing the effects of caffeinated beverages, participants were asked about a wide range of other factors at the first timepoint. 

These include their demographic characteristics, lifestyle factors such as smoking and sleep habits, history of health problems, diet, alcohol consumption and exercise. Statistical analysis controlled for these possibly complicating and confounding factors.

Nearly 70 percent of the study population drank coffee every day, so the researchers divided them by how many cups a day they drank (less than one, one, two to three and four or more). 

But because more than 36 percent of participants did not drink tea daily, tea consumption was categorized as never, monthly, weekly and daily.

In the 2014-2017 time period, study volunteers were evaluated for frailty levels. These assessments accounted for weight loss, exhaustion, slowness and weakness. At this point, 14.8 percent of the study participants qualified as frail. 

The study authors write: ‘Relative to their nonfrail counterparts, participants who were physically frail at the third follow-up were more likely to have been older at the point of assessment; they were also more likely to have had a history of comorbidities, to have smoked, and to have had a higher body mass index at midlife, and also less likely to have been physically active.’