Could caffeine save you from Alzheimer’s?

As stereotypes go, I fully live up to one of the common ones about Melburnians. I live in an inner-northern Melbourne suburb and love having caffeine in the form of a coffee. Long black for me, thanks. At least one a day is mandatory, and more often than not I’ll have three or four.

While I don’t mind being stereotyped, I do sometimes wonder if there are downsides to my having so much caffeine. Is this regime likely to lead to an adverse health outcome? According to the latest research, no. Quite the opposite in fact. Those long blacks might just be helping me to ward off Alzheimer’s disease.

The research out of France indicates a moderate amount of caffeine is associated with a reduced risk of worsening dementia. Published in the journal Alzheimer’s & Dementia, the study suggests caffeine could reduce the ‘clumping’ of proteins in the brain.

The proteins linked to Alzheimer’s and other forms of dementia are known as amyloid beta (or beta-amyloid) peptides. Clumping can occur when the ratio of one amyloid beta type, Aβ42, to another form, Aβ40, gets too low. The clumping forms what is commonly referred to as ‘brain plaque’, thought to play a central role in Alzheimer’s disease.

The caffeine ‘sweet spot’

Reading through the overview of the new study filled me with confidence – perhaps even a sense of smugness. I could now justify my inner-city caffeine-consuming lifestyle as being good for my long-term health.

Unfortunately, my smugness levels began to fall as I read on. It was the devil in the data’s detail. Yes, caffeine consumption appeared to be linked to reduction in harmful brain clumps. However, the link was specific to the level of caffeine consumed. 

Uh-oh. Were my three- or four-coffee days taking my levels too far? My first thought was ‘yes’, but after reading through the report a couple of times I was reassured. 

Those who had less caffeine had a reduced Aβ42 to Aβ40 ratio compared to those who consumed higher levels of caffeine. There was a similarly reduced ratio of Aβ42 to a form of tau protein called ptau-181, another potential Alzheimer’s indicator.

Ah, so more caffeine is better? Yes, at least in this study which, it must be said, was relatively limited. It took in 263 participants, aged over 70, subjected to a baseline clinical evaluation. A detailed food and beverage survey measuring consumption of tea/coffee, chocolate, tea, soda, etc, then followed. This was used to assess the amount of caffeine absorbed by their bodies each day.

The problem with limiting the study to participants aged over 70 is that it tells us nothing about the potential effects of earlier caffeine consumption. It suggests I should be having my long blacks later in life, but I am currently in my late 50s. Does the association hold true for people of my age and those in their 60s?

This study does not answer that question. However, it’s probably not unreasonable to assume that the effects at an earlier age could be similar. 

What defines ‘low level’?

This was another question I had in my mind when reading through this research. In this study, low level was defined as 216mg of caffeine per day. More than 216mg was defined as high. Reading this number prompted two further questions in my mind. First, why such a specific number and second, how much is 216mg in terms of cups of coffee anyway?

The answer to the first question is that 216mg was the median daily caffeine intake of the 263 participants. That means half of the participants had 216mg or less per day and the other half had more. 

As it turns out, around 216mg of caffeine is what you’ll get from two cups of coffee. A quick internet search reveals estimates of between 80mg and 120mg per cup on average. This will, of course, depend on a number of factors such as coffee type and brewing method. In general terms, though, two cups of coffee a day defines the midpoint.

It must be said that this study did not take into account a number of other potentially contributory factors. The time of day of the caffeine consumption, for example. For some an afternoon or evening intake of caffeine can cause disrupted sleep. That, on its own, has been linked to an increased risk of reduced long-term neurological function.

For the time being, I’ll continue to live my stereotypical Melbourne life and have at least two coffees daily.

Are you a coffee drinker? How many cups a day do you average? Let us know via the comments section below.

Also read: Alzheimer’s drugs: are they really game changers?

Disclaimer: This article contains general information about health issues and is not advice. For health advice, consult your medical practitioner.