Longtime readers know I love coffee...
I've even touted it as the only "supplement" that I take three times a day – with a splash of real half-and-half if I can get it.
Coffee reduces the risks of some cancers, strokes, and heart disease. It also lowers your risk of dementia. And it has "everyday benefits," too, like soothing an upset stomach and alleviating migraines. Some men even report that it helps boost their sex life.
Other studies link coffee with longer lifespans, as well as a lower risk for type 2 diabetes.
However, many of these research studies are "association" studies – which show correlation between, say, coffee fighting erectile dysfunction.
We'd rather see "mechanism of action" (MOA) studies, which show how a result happens. MOA studies demonstrate the inner workings that prove causation, not just correlation. These are gold standard studies in any medical field.
That's why I'm interested in a new study out of Toronto, Canada. It's an MOA study about coffee... specifically, why the more bitter your coffee, the healthier your brain...
The researchers looked at dark and light roast coffees. They also included a dark roast decaffeinated coffee.
It's important to note that prior studies found a correlation (but not cause and effect) between drinking coffee and lower risks of Alzheimer's disease. So these researchers took coffee extracts and studied how they interacted with different compounds in the brain. That included beta-amyloid plaques and tau proteins.
These proteins are important. An Alzheimer's diagnosis has three defining characteristics...
- Memory impairment.
- Amyloid plaque buildup in the brain tissue.
- "Tangles" of phosphorylated tau proteins.
Both the amyloid plaques and the tau tangles appear on medical scans. These are the defining traits of Alzheimer's instead of less severe cases of dementia.
Researchers took six compounds from the coffees and studied how each one interacted with these proteins.
Several compounds are ones we've already seen (and written about) in different foods. Those include things like caffeic acid and quercetin. Quercetin, also found in apples, lowers blood sugar by interacting with insulin. And caffeic acid, found in wine, regulates the release of nitric oxide (NO). NO helps dilate blood vessels, an important function that allows your blood to flow slower or faster in response to things like digestion, body temperature regulation, and exercise.
But in this study, one type of compound really stood out for Alzheimer's...
Phenylindanes directly blocked the growth of both the beta-amyloid and tau proteins. This is groundbreaking because up until now, we haven't seen any extracts capable of suppressing the tau proteins.
Phenylindanes aren't the focus of many studies. But they form from the roasting process of coffee beans. The darker the roast, the more phenylindanes in the coffee. In fact, the bitter flavor you get in coffee comes from these compounds.
Even better, these compounds occur in both regular and decaffeinated coffee. So if you need to cut down caffeine for any reason, you can still get all the brain benefits from these compounds.
This latest study adds to other MOA studies on different compounds in coffee...
We know that coffee's antioxidants fight inflammation directly. Coffee stimulates the work of a key protein, nuclear factor erythroid 2-related factor 2 (Nrf2). That protein triggers the release of antioxidants from our cells. And antioxidants directly fight damaging particles called free radicals to reduce inflammation.
We also know that caffeine blocks adenosine receptors. Adenosine is a neurotransmitter in our brains that sends signals to our body. Its primary role is to signal when we need sleep. This is why coffee keeps us awake (and decaf doesn't). Researchers believe this pathway might also explain why caffeine helps alleviate migraines.
So, if you haven't warmed up to the idea of drinking coffee, now's the time to reconsider. As I mentioned, I have about three cups a day. Adding a little milk is fine, but skip the sugar.
What We're Reading...
- Did you miss it? Our in-depth article on coffee – the supplement I take three times a day.
- Something different: Do we really need a powerful new opioid?
Here's to our health, wealth, and a great retirement,
Dr. David Eifrig and the Health & Wealth Bulletin Research Team
November 13, 2018