Drinking coffee may reduce your risk of Alzheimer’s disease, according to findings published in the journal Frontiers in Aging Neuroscience. The study followed a sample of older adults for 10 years and found that those who consumed more coffee showed slower cognitive decline, slower Aβ-amyloid accumulation, and a lower likelihood of Alzheimer’s disease.
Alzheimer’s disease (AD) is a form of dementia that involves progressive memory loss and cognitive decline. This neurodegeneration is believed to be caused by a build-up of a protein called Aβ-amyloid that causes inflammation in the brain. Scientific studies have uncovered promising evidence that coffee consumption might lower the risk of Alzheimer’s, but there has been minimal longitudinal research on this topic.
“Worldwide, a high proportion of adults drink coffee daily, making it one of the most popular beverages globally. In the absence of effective disease-modifying treatments for Alzheimer’s disease, our research is looking at modifiable risk factors that could delay the onset of the disease,” said study author Samantha L. Gardener of Edith Cowan University. “Even a 5-year delay would have a massive social and economic benefit, and these dietary modifications are generally accessible to all as well as being less expensive than medications and with less side effects.”
Gardener and her team examined longitudinal data from a larger study called the Australian Imaging, Biomarkers and Lifestyle study of ageing (AIBL). A sample of 227 older adults who were an average of 69 years old at baseline completed questionnaires that included a question on their coffee drinking habits.
The participants also completed a battery of questionnaires that assessed six cognitive domains — episodic recall memory, recognition memory, executive function, language, attention and processing speed — as well as the AIBL Preclinical Alzheimer Cognitive Composite (PACC). These cognitive assessments were completed at baseline and then again on up to seven different occasions across a 10-year period.
Throughout the 10 years, a subset of participants also underwent multiple magnetic resonance imaging (MRI) scans to measure brain volume changes and Positron Emission Tomography (PET) scans to assess Aβ-amyloid accumulation. These scans were also taken on up to seven different occasions.
The findings revealed that the participants who drank more coffee showed slower cognitive decline throughout the 10 years in the domains of executive function and attention. They also showed slower decline according to the AIBL PACC. Participants who drank more coffee were also less likely to transition from their “cognitively normal” status at baseline to a “mild cognitive impairment” or “AD” status throughout the study period.
An analysis of the PET scans further revealed that drinking more coffee was associated with slower Aβ-amyloid accumulation in the brain and a lower risk of reaching “moderate”, “high”, or “very high” Aβ-amyloid burden status. The MRI scans revealed that coffee intake was not related to brain volume atrophy.
These results suggest that coffee intake might protect against cognitive decline by slowing down the build-up of Aβ-amyloid in the brain, and improving “the associated neurotoxicity from Aβ-amyloid-mediated oxidative stress and inflammatory processes.” These results suggest that habitual coffee intake might serve as a lifestyle factor that can delay the onset of Alzheimer’s.
“Our estimates suggest that if the average cup of coffee made at home is 240 g, increasing intake from one to two cups per day could provide up to 8% decrease in executive function decline over an 18-month period, and up to 5% decrease in cerebral Aβ-amyloid (the sticky protein that clumps together in the brain, killing neurons, in Alzheimer’s disease) accumulation over the same time period,” Gardener told PsyPost. “However, finding a maximum number of beneficial cups of coffee is a question for future research which we were not able to identify in the current study. Unfortunately, there will be a limit whereby more cups will not produce any further positive effects.”
“Any future recommendations would also have to be personalized to the individual taking into consideration any other medical conditions they have that may make increasing coffee consumption not advisable,” Gardener added.
The researchers also noted that additional evidence from longitudinal intervention studies would be needed to corroborate these findings. While the study authors say it is unclear which coffee ingredient is responsible for these neuroprotective effects, they suggest that the answer may be more than caffeine. For example, a study in rats found evidence of neuroprotective benefits from a component of coffee called Eicosanoyl-5-hydroxytryptamide (EHT).
“Additional studies with participants followed for 10+ years in a range of different groups of participants, and intervention studies where participants are assigned a specific amount and type of coffee to drink are required to validate our findings and confirm our preliminary findings,” Gardener explained.
“Our study did not have data on mid-life coffee consumption, consequently potential positive or negative effects of coffee intake at midlife cannot be assessed in the current study. It was also not possible for us to determine the potential consequences of varying methods of coffee preparation (e.g., decaffeinated coffee, brewing method, with or without milk or sugar etc.) on the associations observed, so these are both major methodological points to include in future research.”
The study, “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”, was authored by Samantha L. Gardener, Stephanie R. Rainey-Smith, Victor L. Villemagne, Jurgen Fripp, Vincent Doré, Pierrick Bourgeat, Kevin Taddei, Christopher Fowler, Colin L. Masters, Paul Maruff, Christopher C. Rowe, David Ames, Ralph N. Martins, and the AIBL Investigators.