Latest study suggests coffee intake could reduce cognitive decline

By Elizabeth Moulson, Masters, Experimental Psychology

Coffee is a firm staple for many students at this time of year, but did you know that it does more for your brain than just an energy boost? Elizabeth Moulson explores the newly discovered cognitive benefits of your favourite caffeinated drink.

From strong filter coffee to a creamy cappuccino, coffee is a staple in many student morning routines for a quick burst of energy. In the UK, an estimated 95 million daily cups of coffee were consumed in 2017 with an increase of 25 million over the last decade alone.

As well as providing a much needed caffeine rush in the morning, recent research led by Dr Samantha Gardener has suggested that a morning coffee may also provide protective effects against cognitive ageing and even reduce the risk of developing Alzheimer’s Disease (AD).

The study recorded cognitive health and regular coffee consumption of 227 Australian adults (aged 60 or over) across a 10-year span. Participants completed a series of cognitive tasks measuring their memory, language skills, attention levels and processing speed at 18-month intervals.

A 2016 meta-analysis found that drinking two cups a day lead to lower incidence rates of cognitive disorders

This data, combined with the Commonwealth Scientific and Industrial Organisation Food Frequency Questionnaire (CSIRO FFQ), linked high coffee consumption to slower cognitive decline and revealed that the consumption of two cups a day could produce an 8 per cent decrease in cognitive decline over a 10-year period.

Notably, the cognitive tasks provided researchers with a measure of Preclinical AD Cognitive Composite (PACC) levels, which have been recognised to reliably measure the cognitive decline in healthy adults. Higher PACC levels in an individual across the study would suggest the early onset of Alzheimer’s Disease. The results revealed an association between high coffee consumption and lower PACC levels, suggesting coffee not only slows cognitive decline but may also have preventative effects against AD.

Given the prevalence of AD in the population, with one in every six people aged 80 estimated to be affected, these optimistic findings may hold importance for preventative measures. Researchers also noted that high coffee ingestion appeared to slow down the aggregation of amyloid protein within the brain, a prime suspect in AD development.

Quite how coffee exerts apparent protective effects in the brain isn’t fully understood, although its activity at the binding site of regulatory protein adenosine may have a role. Adenosine is responsible for controlling several important physiological functions, including memory, cognitive performance, and sleep.

Gardener and colleagues theorised that caffeine may mimic adenosine and thereby counteract the typical decline caused by natural aging. However, this remains a theory and the precise mechanism producing the observed results is yet to be completely explained.

Although the researchers reported several limitations to the research, including potential bias in self-reporting questionnaires and lack of differentiation between different coffee preferences (such as caffeinated or decaffeinated, brewing method, addition of milk or sugar etc.), the research is supported by previous findings.

A 2016 meta-analysis including nine published cohort studies found that drinking two cups a day lead to lower incidence rates of cognitive disorders than one cup. Moreover, a cross-sectional study in 2019 with 411 participants associated two cups of coffee a day with lower rates of amyloid protein. Taken together, these findings warrant future in-depth research into this association with the potential of reducing the rate of AD development in future generations.

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However, as exciting as these results may be, it is important to ensure daily coffee consumption does not exceed the recommended limit of 400 milligrams of caffeine a day (around four cups). Additionally, avoiding excessive use of flavour enhancers, such as sugar, creamer, and syrup is advised to maximise the protection offered by coffee.

So, whether you’re a regular pret-a-manger goer or caffeinating your way through your studies, rest assured that 2 cups of coffee may be beneficial in the later years.

Featured Image: Epigram/Sarah Dalton

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