Having a couple of cups of coffee or tea each day can be much more than just a simple ritual to start the day: according to a large new study, this habit is linked to a lower risk of dementia and slower cognitive decline In the long term. Far from presenting these drinks as a magic solution, the data suggests that, in the context of a healthy lifestyle, their moderate consumption could provide a small extra layer of protection for the brain.
The work, published in the medical journal JAMA The study, conducted in the United States, analyzed data from over 130.000 healthcare professionals over several decades. The results indicate that those who consumed two or three cups of caffeinated coffee daily Those who drank between one and two cups of tea showed fewer cases of dementia and better performance on various cognitive tests than those who barely drank these beverages or did not drink them at all.
Coffee and caffeinated tea: what the big new study says
The study has been carried out by teams from Massachusetts General HospitalThe Harvard T.H. Chan School of Public Health and the Broad Institute of MIT and Harvard, leading institutions in medical research, collaborated on the study. In total, data from 131.821 participants from two large cohorts were included: the Nurses' Health Study (nurses and nursing staff, started in 1976) and the Health Professionals Follow-up Study (male health professionals, since 1986).
Throughout the monitoring, which in some cases reached up to 43 years of continuous observationParticipants completed periodic questionnaires about their diet, including coffee (caffeinated and caffeine-free) and tea consumption, as well as assessments of possible symptoms of cognitive impairment and objective tests of memory, attention, and other mental functions.
During that period, the following were recorded: 11.033 dementia diagnosesWhen comparing consumption patterns, researchers observed that people who drank more caffeinated coffee exhibited a 18% less risk of developing dementia compared to those who drank little or not at all. Similarly, a lower frequency of subjective memory complaints was detected (7,8% versus 9,5%), and in some analyses, somewhat better performance on certain cognitive tests.
In the case of tea, the pattern was similar: higher consumption of 1 to 2 cups daily It was also associated with a lower likelihood of dementia and better preservation of cognitive function. In contrast, decaffeinated coffee did not show a clear relationship with risk reduction, reinforcing the hypothesis that the main role may lie with the caffeine.
The researchers also analyzed whether a genetic predisposition to dementia modified the association between these beverages and the risk of the disease. According to the results, the possible protective effect of coffee and caffeinated tea was observed in people with high as well as low genetic riskThis suggests that this habit could be relevant regardless of family heritage.
How much is beneficial and where is the limit?
One of the questions that most interests the public is how much would be reasonable to take. The study published in JAMA points out that the The best results were observed with 2-3 cups of caffeinated coffee or 1-2 cups of tea daily. Beyond that, no clearly superior benefit was detected, suggesting the existence of a certain "ceiling" effect.
This idea aligns with what specialists in neurology and nutrition have been advocating. Neurologists like David Pérez, from the 12 de Octubre Hospital in Madrid, point out that, above that moderate consumption, the increased caffeine It can cause problems such as nervousness, anxiety, essential tremor, or difficulty sleeping, especially if coffee is ingested late in the afternoon or at night.
The scientific community insists that coffee should not be seen as an immediate intelligence enhancer, but rather as a possible part of a preventive approach to reduce the risk of neurodegenerative diseases. The improvements in cognitive tests that have been observed are modest and do not make coffee a "miracle supplement" for memory.
Meanwhile, other works published in journals such as Nutrients have linked the moderate coffee consumption with lower overall mortality and a lower risk of cardiovascular disease, type 2 diabetes, stroke, or some respiratory illnesses. However, it is warned that adding large amounts of sugar, syrups, or cream can neutralize some of those potential benefits, by increasing the caloric intake and metabolic impact of the beverage.
In the case of specific groups, such as pregnant women, even greater caution is recommended: international guidelines usually set the limit at daily caffeine around 200 mgwhich is roughly equivalent to two small coffees, although the exact number may vary depending on the coffee variety and the brewing method.
Caffeine and other compounds under scrutiny
Beyond the statistics, the big question is why coffee and caffeinated tea might have this effect on dementia risk. The new study, and previous ones, point to the caffeine as the main candidatesince decaffeinated coffee did not show the same protective results.
From a biological point of view, caffeine acts by blocking the adenosine receptors In the brain, this mechanism has been linked to reduced neuroinflammation and increased plasticity of neuronal connections. Several experimental studies have suggested that this effect could influence processes associated with Alzheimer's and other forms of dementia.
In addition to caffeine, coffee and tea are rich in bioactive compounds such as polyphenols, chlorogenic acids and catechinsSubstances with antioxidant and anti-inflammatory properties. These components help combat oxidative stress and improve vascular function, factors that have also been linked to brain health and age-related cognitive decline.
Another hypothesis considered by the authors is that consuming caffeinated coffee could contribute to better insulin sensitivity Coffee already has a lower risk of developing type 2 diabetes, a disease considered a major risk factor for dementia. By reducing the impact of diabetes on blood vessels and the brain, coffee could indirectly help preserve cognitive function.
However, neurologists and endocrinologists agree that the exact mechanism explaining these results is still unknown. Nutrition experts like Carmen Aragón, from the Spanish Society of Endocrinology and Nutrition, emphasize that further research is needed. controlled clinical trials to confirm the hypotheses and rule out the influence of other factors that may be confounding the observed associations.
A modest effect within a healthy lifestyle
The authors of the study in JAMA They insist that it is a observational researchThis means that it shows associations, but it doesn't allow us to definitively conclude that coffee or caffeinated tea are the direct cause of the lower risk of dementia. It's possible that those who regularly consume these beverages also follow other beneficial habits, such as exercising more or eating a healthier diet.
To minimize this possibility, the team adjusted the statistical analyses based on multiple lifestyle variables, sociodemographic factors, and medical history. Even so, the researchers themselves admit that It cannot be completely ruled out the influence of factors that are not measured or difficult to quantify, such as the actual quality of the diet, the intensity of daily mental activity, or the level of social interaction.
Neurology and public health agree that, in the absence of curative treatments for dementia and Alzheimer's, the key lies in... early prevention of dementiaIn Europe, where the population is aging rapidly and dementia poses a growing health challenge, the importance of a comprehensive approach is emphasized: Mediterranean diet and foods for memoryregular physical exerciseAvoid tobacco, control blood pressure and cholesterol, maintain an active social life and, among other measures, moderate alcohol consumption.
Within that broader framework, coffee and caffeinated tea could be considered a potentially beneficial habitProvided they are consumed in moderation, without excessive sugar, and without displacing other essential components of a balanced diet. In fact, some experts summarize the message by saying that coffee could be an ally, but not the main focus, of a strategy to protect brain health.
For the Spanish and European population, where coffee and tea are part of the daily routine of millions of people, these results offer an additional argument for maintain prudent consumption, without unjustified fear, but also without falling into the idea that they alone will prevent the development of dementia.
Overall, the research reinforces the impression that regular, moderate consumption of coffee and caffeinated tea It may be associated with a small decrease in the risk of dementia and slower cognitive decline, always within a context of a healthy lifestyle; one more piece of the prevention puzzle, which adds to many other everyday decisions capable of making a difference in the long term.
