In addition to brightening the morning and keeping us going all day, coffee has proven to have many health benefits: For one, the caffeine content is thought to increase alertness and memory in the short term – but studies show that coffee may have a long-term protective effect on the brain, too.
Drinking coffee has previously been linked to a reduced risk of Alzheimer's and Parkinson's disease, and now scientists say they might have an idea of why. It turns out that phenylindana – a chemical compound formed during the brewing process – inhibits the growth of proteins associated with degenerative brain disease. And the darker the meat, they say, the more protective compounds there are in each cup.
For new research, published at Borders in NeuroscienceResearchers at the Krembil Brain Institute in Toronto analyzed the chemical components of three different samples from Starbucks Via instant coffee: lightly roasted, dark roasted, and roasted decaffeinated black. Then they expose each sample's extract to two types of proteins – amyloid beta and tau – known as the hallmarks of Alzheimer's and Parkinson's. Research has shown that when this condition progresses, these proteins tend to form clumps (known as amyloid plaques and tau protein tangles) in the brain.
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All three coffee extracts prevent "clumping" of these proteins, suggesting that something in America's favorite morning drink might protect against disease progression. And because the researchers didn't see any difference in the usual effectiveness compared to decaffeinated coffee, they decided that it was possible not caffeine that provides this benefit.
They, however, see an inhibitory effect of more than two dark roasts compared to light roast. This makes the researchers think of phenylindana – a compound formed from acid breakdown during roasting of coffee, which is largely responsible for the bitter taste of coffee.
Phenylindanes are found in higher concentrations in coffee with longer roasting times, such as dark roasts and espresso. They have been shown to display "very strong antioxidant activity," the authors wrote in their paper, but their ability to interact with amyloid proteins and know has never been reported before.
In further laboratory studies, they found that phenylindane mixtures did prevent clumping of proteins related to disease; actually, it is only studied compounds that have an effect on both amyloid proteins and know. For tau protein, it shows a stronger inhibition rate than other compounds investigated.
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Given that both black roasted coffee extracts show a protein inhibition level that is stronger than roasted light, the authors propose that it is a phenylindhane component of coffee that is "very responsible" for this effect. (And good news for decaffeinated drinkers: Because the decafeination process occurs before roasting process, the authors assume that it has no effect on the phenylindane level.)
That doesn't mean that everyone should start drinking espresso or roasting their extra dark coffee beans, however. The research is still preliminary, according to lead author Donald Weaver, MD, co-director of the Krembil Brain Institute, and much is still unknown about how these compounds actually work in the human body. (Plus, other studies show that lighter roasts have higher levels different useful compounds, so it might still be a lottery for overall health.)
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Weaver said in a press release that he hoped that this study would lead to further studies of phenylindhane, and perhaps even for the development of drugs that could be used to treat neurodegenerative diseases. He also said he was happy to know that coffee has a good nature for you, even if there is not enough evidence to drink it solely for this reason.
"What this study is doing is taking epidemiological evidence and trying to correct it and to show that there are indeed components in coffee that are useful for counteracting cognitive decline," Weaver said. "This is interesting, but do we suggest that coffee is a medicine? Absolutely not. "
Experts say that the best way to reduce the age of your brain is to follow a healthy diet, regular exercise, and getting enough sleep. And if it turns out that a daily cup of Joe is in accordance with that plan, we are definitely all for that.
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