In a massive study of nearly 50,000 women over a time frame of 30 years, researchers found that drinking more coffee – to a point – during midlife was linked to less chronic disease, physical mobility issues and cognitive decline in later years. However, other caffeinated products, plus decaffeinated coffee, did not garner the same results.

Researchers out of Harvard University investigated the link between caffeine intake during midlife and how it might contribute to healthy aging in women. They assessed the health data of 47,513 women in the Nurses’ Health Study (NHS) over 30 years, starting in 1984.

“Our study has several key strengths,” said Dr Sara Mahdavi, from the Harvard T.H. Chan School of Public Health. “In addition to the large sample size and 30 years of follow-up, we assessed several different aspects of longevity and healthy aging as well as very comprehensive information on nutritional and lifestyle habits that were collected every four years after the initiation of the study.”

While “healthy aging” is somewhat of an umbrella term, here the scientists classed it as: Being 70 years or older without any of 11 major chronic diseases, having no physical function limitations, no mental health or cognitive impairments, and no memory complaints, as of the participants’ 2014 and 2016 responses. The health data that met these requirements was sorted into a healthy agers group.

In 2016, 3,706 study participants fit in the healthy aging group. When these women were aged 45-60, they regularly consumed around 315 mg of caffeine per day – at the time, three small cups, or about 1.5 large cups by 2025 measurements. More than 80% of their total caffeine intake was from coffee alone.

Those in this group who had higher coffee intake also had better health markers overall. What the researchers found was that for every 80 mg of caffeine – roughly an 8-oz (340-ml) cup of coffee – there was a 2-5% jump in health indicators, after other factors like smoking and alcohol consumption were accounted for. This percentage grew with each cup, up to around five small coffees – or 2.5 cups in 2025 sizes.

What’s more, other caffeinated drinks, as well as decaf, were also assessed. Tea and decaf (also 8-oz cups) had no real impact on healthy aging, while caffeinated cola (12-oz glass) intake was associated with a significant swing in the opposite direction. Each cup of cola per day was statistically tied to a 20-26% drop in the likelihood of healthy aging.

“While past studies have linked coffee to individual health outcomes, our study is the first to assess coffee’s impact across multiple domains of aging over three decades,” said Mahdavi. “The findings suggest that caffeinated coffee – not tea or decaf – may uniquely support aging trajectories that preserve both mental and physical function.”

Many studies have highlighted the potential benefits of coffee, including how a moderate intake appears to boost health in both men and women. It’s also been linked to better heart health and even cancer outcomes. Nonetheless, the researchers note that these latest findings only uncover an association, and there are many variables, including genetic tolerance of caffeine, that can negate the potential health-boosting effects.

Researchers now plan to investigate aging pathways and how the many compounds in coffee could be positively influencing these health markers.

“These results, while preliminary, suggest that small, consistent habits can shape long-term health,” said Mahdavi. “Moderate coffee intake may offer some protective benefits when combined with other healthy behaviors such as regular exercise, a healthy diet and avoiding smoking. While this study adds to prior evidence suggesting coffee intake may be linked with healthy aging, the benefits from coffee are relatively modest compared to the impact of overall healthy lifestyle habits and warrant further investigation.”

Mahdavi presented this new research at the recent Nutrition 2025 conference in Orlando.

Source: Nutrition 2025 via EurekAlert!