Coffee intake linked to faster cognitive decline after four cups a day

Researchers from Australia and the United States presented a study at the International Conference of the Alzheimer’s Association (AAIC) 2024 that examined the relationship between coffee consumption and fluid intelligence in older adults. The analysis covered about 8,500 participants with an average age of 67.8 years. Participants who drank four or more cups of coffee each day showed a markedly accelerated reduction in fluid intelligence compared with those who consumed none or up to three cups daily. In contrast, moderate coffee intake (one to three cups) was not associated with cognitive decline and may even have modest health benefits. The same study found that high tea consumption was linked to better fluid‑intelligence scores, suggesting a protective effect. Limitations include reliance on self‑reported coffee use, a sample that was 60 % female, lack of data on earlier life consumption, and no consideration of brewing method or coffee type. The findings add to existing evidence that moderate coffee consumption is generally safe, while excessive intake could impair age‑related cognitive performance.