Morning coffee helps women stay sharp and strong as they age

Findings from a new study of almost 50,000 women followed for 30 years suggest that a morning cup of coffee might do more than boost energy; it could also help women stay sharp, strong and mentally well as they age.

The analysis found that women who drank caffeinated coffee in midlife were more likely to exhibit healthy aging. However, the researchers didn't find any links with tea or decaf coffee, while drinking more cola was tied to a significantly lower chance 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. The findings suggest that caffeinated coffee-not tea or decaf-may uniquely support aging trajectories that preserve both mental and physical function."

Dr. Sara Mahdavi, BSc, HBSc, RD, MSc, PhD, post-doctoral fellow at Harvard T.H. Chan School of Public Health, Harvard University, and an adjunct professor at University of Toronto, Faculty of Medicine, Department of Nutritional Sciences

Dr. Mahdavi will present the findings at NUTRITION 2025, the flagship annual meeting of the American Society for Nutrition held May 31–June 3 in Orlando.

"Our study has several key strengths," said Dr. Mahdavi. "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."

The study included 47,513 women from the Nurses' Health Study with dietary and health data collected since 1984. The researchers assessed caffeine intake using validated food frequency questionnaires that included consumption of top contributors of caffeine such as coffee, tea, cola and decaffeinated coffee. Healthy aging was defined as living to age 70 or older, being free from 11 major chronic diseases, maintaining physical function, having good mental health, exhibiting no cognitive impairment and showing no memory complaints.

After 30 years of follow-up, the investigators estimated how the likelihood of healthy aging changed for every 80 mg of caffeine that study participants consumed per day. They also examined specific drinks like coffee, tea, decaffeinated coffee (per 8-ounce cup) and cola (per 12-ounce glass). These preliminary analyses accounted for other factors that might influence healthy aging such as body weight, smoking, alcohol use, physical activity, education level and protein in the diet.

By 2016, 3,706 of the women in the study met all the requirements for being considered healthy agers. In mid-life, ages 45-60, these women typically consumed an average of 315 mg of caffeine per day - roughly the amount in three small cups of coffee or one and a half large cups by today's standards. More than 80% of that caffeine came from regular coffee consumption.

For women in the healthy agers group, each extra cup of coffee per day was tied to a 2% to 5% higher chance of doing well later in life, up to five small cups per day, or about 2.5 cups according to today's measures.

The researchers did not find any significant association between drinking decaffeinated coffee or tea with an increased likelihood of healthy aging. Importantly, each additional small glass of soda-another major source of caffeine-was associated with a 20% to 26% lower likelihood of healthy aging, reinforcing that not all sources of caffeine confer benefits.

"These results, while preliminary, suggest that small, consistent habits can shape long-term health," said Dr. 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."

The researchers note that, in general, up to two cups of coffee per day should be safe and potentially beneficial for most people. Beyond that, drinking more may offer additional benefits for some but may not be healthy for others. In another study, Dr. Mahdavi and colleagues have shown that genetic variation can influence the relationship between caffeine intake and health outcomes, so more caffeine isn't always better, particularly for people with lower caffeine tolerance or specific genetic susceptibility (Mahdavi et al, 2023).

Additionally, coffee contains a range of compounds that could act synergistically to influence aging pathways. To better understand these effects, researchers plan to investigate how specific bioactive compounds in coffee interact with genetic and metabolic aging markers, especially in women. Understanding these mechanisms could guide personalized medicine approaches to develop diets that support longevity and cognitive health for individuals.

Dr. Mahdavi will present this research at 11:45 a.m.- 12:45 p.m. EDT on Monday, June 2, during the Aging and Chronic Disease session in the Orange County Convention Center.