Monday, July 13, 2009

Caffeine & Your Brain

Mark Webber has just won the German Grand Prix in a Red Bull sponsored car. Red Bull was one of the first “energy” drinks on the market, laden with caffeine at 80mg of caffeine per 250mL can, about the amount found in a strong cup of coffee. Other caffeine sources are tea and anything with guarana. There is a small amount of caffeine in cocoa and chocolate too.

That morning kick
Caffeinated drinks are the most popular way to start the day in the Western world. Around 2002 there was the first appearance of a study linking caffeine to Alzheimer’s Disease. The surprise was the link was that **too little** caffeine increased the risk of dementia. In the following years there has been much more research showing that caffeine lowered the chance of losing your marbles.

Caffeine & dementia
In Alzheimer’s there is a build-up of beta amyloid proteins in the brain that disrupt memory. In mice, caffeine halts the formation of this nasty protein. Caffeine is also anti-inflammatory, helping to protect the brain further as Alzheimer’s is an inflammatory disease of the brain. That may help explain the results of two recent studies.

A European study tracked 676 men, aged 70-90 years, for over 10 years while assessing their cognitive decline. The lowest decline in brain function was observed in the men drinking 3 cups of coffee a day. Those with the greatest decline were the non-coffee drinkers and those drinking more than 4 cups a day. In fact, if you didn’t drink coffee then your brain went downhill four times quicker than if you had three cups a day. I bet nobody would have predicted that last century.

That’s good news for blokes, but can it apply to women too? A more recent European study of 875 women and 534 men, aged 65-79 years, also found a strong correlation between coffee consumption and dementia in both the men and women. Moderate coffee drinkers reduced their risk of dementia by two-thirds compared to non-drinkers after 21 years of follow-up. What is moderate coffee drinking? Between 3-5 cups a day.

The dose makes the poison
The single most difficult concept to get across to the media and the public is the concept of hormosis, that is, health is not a linear model, it is usually a J or U-shaped curve. We have spoken about this before with alcohol – there is a healthy level of drinking (1-2 standard drinks a day max) either side of which there is less benefit, or a negative effect with heavy drinking (4+ standard drinks a day). The J-shaped curve seems to apply to caffeine too. The least risk of dementia is for 3-5 cups a day, either side of which there appears to be little benefit.

What does it all mean?
The researchers aren’t sure if it is the caffeine alone that works or if other compounds in coffee help, as coffee has anti-oxidant phenolics and any combination of these could be offering protection to the brain. Coffee drinkers have a reduced risk of Parkinson’s Disease and type 2 diabetes as well, but no-one is too sure why. Apart from being anti-inflammatory, caffeine has magnesium that makes insulin more sensitive, reducing diabetes and in turn reducing the risk of dementia. Who knows, but the future may have coffee, or even Red Bull, recommended as a health drink!

While it all looks promising for enjoying a modest amount of coffee, I can’t get too enthused because I don’t drink coffee and the dementia story doesn’t apply for us tea drinkers.

References: European Journal of Clinical Nutrition 2007; 61: 226-232 / Journal of Alzheimer’s Disease 2009; 16: 85-91


Bas and Renee said...

And this isn't enough research to sway you to becoming a coffee drinker? I'm a tea drinker myself but will be less likely to turn down a coffee when offered I think!

Cindy Williams said...

I love coffee but it doesn't love me! Too much makes my knuckle swell with arthritis. If I cut the coffee, the swelling goes! Perhaps it's true that 'one man's meat is another man's poison'. There's a few studies on the link between coffee and arthritis which I have written about. As for my brain... let's hope all those antioxidants in tea are doing it some good!