RN Desk: An analysis of health data from 130,000 people shows that compared to those who do not regularly consume tea or coffee, individuals who drink moderate amounts of caffeinated beverages have a 15–20% lower risk of dementia or memory loss.

Recently published in the Journal of the American Medical Association (JAMA), the study analyzed approximately 40 years of health data from nearly 130,000 individuals.

Drinking a few cups of tea or coffee daily not only keeps the body alert but may also significantly reduce the risk of dementia, one of the major diseases associated with aging. According to a recent study by researchers at Harvard University in the United States, moderate consumption of caffeinated beverages helps preserve brain function over time. The news was reported by The Guardian.

Key Findings of the Study

The research found that individuals who regularly consume caffeinated tea or coffee have a 15–20% lower risk of developing dementia compared to those who do not consume these beverages at all.

Participants who drank two to three cups of caffeinated coffee or one to two cups of caffeinated tea daily experienced the greatest benefits. These individuals performed significantly better on cognitive function tests, and the rate of memory decline among them was noticeably slower.

The study’s lead author, Yu Zhang, a nutritional epidemiologist at Harvard University, stated that the association between tea and coffee consumption and brain health is strong. However, he cautioned that the study does not directly prove that drinking tea or coffee alone prevents dementia. Other healthy lifestyle factors common among regular tea and coffee drinkers may also contribute to the reduced risk.

How Caffeine and Antioxidants Work

Scientists explain that tea and coffee contain high levels of caffeine and polyphenols. These components help maintain the health of brain blood vessels and reduce inflammation. They also protect brain cells from oxidative stress, which increases with age and contributes to brain damage.

Caffeine may also reduce the risk of type 2 diabetes. Since diabetes is a major risk factor for dementia, tea and coffee may indirectly help protect brain health. However, researchers noted that decaffeinated coffee did not show the same protective effect, suggesting that caffeine plays a key role in brain protection.

Long-Term Observations

The Harvard research team analyzed data from two large U.S. public health studies over a period of 43 years. Participants regularly provided information about their diet and mental health.

The analysis showed that individuals who consumed the highest amounts of caffeinated coffee had, on average, an 18% lower risk of dementia. However, the benefits appear to have a limit. Drinking more than two to three cups per day did not significantly increase the positive effects. In other words, moderate consumption is more effective than excessive intake.

Expert Opinions and Lifestyle Considerations

Professor Naveed Sattar of the University of Glasgow in Scotland, an expert in cardiometabolic medicine, noted that caffeine has both positive and negative effects. The antioxidants in tea and coffee are beneficial and may encourage people to be more active. However, caffeine can increase blood pressure in some individuals, which is itself a risk factor for dementia.

Yu Zhang advised against viewing tea or coffee as a “magic solution.” Nearly half of dementia cases worldwide are associated with factors such as obesity, smoking, excessive alcohol consumption, and high blood pressure. Therefore, instead of relying solely on beverages, it is essential to maintain a balanced diet, exercise regularly, and ensure adequate sleep. Tea or coffee can be considered part of a healthy lifestyle that supports long-term brain health.