Does higher coffee intake lower or raise dementia risk?

Higher coffee intake shows conflicting results across recent cohort studies. A 2021 Edith Cowan University paper tracking participants for 126 months linked more cups to slower cognitive decline and less cerebral amyloid accumulation, while other work from Tianjin Medical University and the University of South Australia suggests heavy consumption may shrink brain volume and raise dementia risk.

Coffee ranks second only to crude oil in global commodity trade volume, with roughly 3 billion cups consumed daily, so the health question matters widely. Much of the disagreement comes down to dose: moderate intake appears protective in several datasets, while very high daily caffeine loads are where the negative findings cluster, leaving the safe upper limit unresolved.

Coffee is a commodity second only to crude oil in global trade volume, and its consumption growth in the East has been particularly rapid, which is why scientific research on its relationship with human health continues to deepen. Interestingly, the conclusions of related studies are not consistent: some find that drinking coffee can delay cognitive decline, while others suggest that excessive consumption may shrink brain volume and increase dementia risk. This article reviews several representative cohort studies from around 2021, involving the work of Edith Cowan University in Australia, Tianjin Medical University, and the University of South Australia, attempting to clarify the complex relationship between coffee intake and Alzheimer's disease and stroke, and to explore the relationship between the number of cups consumed daily and the safe upper limit of caffeine.

Coffee ranks second only to crude oil in global commodity trade volume, which reflects people's strong demand for it. The East was originally the birthplace of tea, but in recent years coffee consumption has soared, and it has become an important choice for many office workers to stay alert daily, with related health research also increasing.

Intriguingly, the research conclusions are not consistent. Some findings show that drinking coffee helps reduce the risk of dementia; other findings suggest that drinking coffee may actually increase the likelihood of developing dementia. Faced with these contradictory scientific evidences, people cannot help but wonder: is coffee beneficial or harmful to health?

It is estimated that coffee is one of the most popular beverages in the world, with about 3 billion cups consumed globally every day.

What is commonly called dementia mainly refers to Alzheimer's disease, which is the most common neurodegenerative disease, and its typical pathological manifestation is the deposition of β-amyloid and Tau amyloid proteins in the brain.

In November 2021, a research team from Edith Cowan University in Australia published a paper in the journal Frontiers in Aging Neuroscience, titled: Higher Coffee Consumption Is Associated With Slower Cognitive Decline and Less Cerebral Aβ-Amyloid Accumulation Over 126 Months: Data From the Australian Imaging, Biomarkers, and Lifestyle Study.

This study, which tracked participants for more than ten years, suggests that increasing coffee consumption may reduce the risk of developing Alzheimer's disease. Specifically, higher coffee intake may be associated with a slower rate of β-amyloid accumulation in the brain.

Dr. Samantha Gardener, the first author of the paper, stated that the survey data reflect an association between coffee intake and several important biomarkers related to Alzheimer's disease. People who drink more coffee have less β-amyloid accumulation in their brains.

Also in November 2021, the team led by Wang Yaogang from Tianjin Medical University published a research paper in PLOS Medicine, concluding that drinking coffee or tea can reduce the risk of stroke and dementia.

The study found that drinking 2 to 3 cups of coffee, or 3 to 5 cups of tea, or a combination of 4 to 6 cups of coffee and tea per day is associated with the lowest risk of stroke or dementia.

The researchers proposed that there is an interactive effect between coffee and tea on stroke and dementia, involving several mechanisms. One of them is that coffee, as a major source of caffeine, also contains polyphenols and other bioactive components that may be beneficial to health. These components are believed to have neuroprotective effects, including inhibiting the accumulation of β-amyloid.

While coffee has positive effects on the brain, it may also have negative consequences. In August 2021, a study with conclusions contrary to previous positive research—that drinking coffee is actually associated with reduced brain volume—attracted widespread attention. "Excessive coffee drinking can reduce brain volume" once became a hot topic on Weibo, and Coffee Workshop also reported on it.

Researchers from the University of South Australia published a paper titled High coffee consumption, brain volume and risk of dementia and stroke in the journal Nutritional Neuroscience.

The study found that compared with people who drank only two cups of coffee a day, those who drank more than six cups a day had relatively smaller brain volume and a 53% higher risk of developing dementia.

Many studies have shown that coffee intake has a positive impact on the likelihood of developing dementia. If you pay close attention to the amount consumed in these studies, you will find that the number of cups falls within a certain range. Previous research has pointed out that drinking 3 to 5 cups of coffee a day is associated with a roughly 65% lower risk of dementia in later life.

Rather than obsessing over the number of cups, it is better to focus on total caffeine intake. In many studies on the health benefits of coffee, participants' caffeine intake typically did not exceed the FDA-recommended upper limit of 400 milligrams.

So, you who are reading this article, how many cups of coffee do you drink a day?

Image source: Internet

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The above content is compiled by CoffeeHunters, a coffee news website.