
Health Science
Coffee Is Pure Poison
Coffee contains over 1,000 compounds, 70% of which are potentially carcinogenic. Yet our liver detoxifies these toxins through hormesis—a process that actually stimulates our cells.

Health Science
Coffee contains over 1,000 compounds, 70% of which are potentially carcinogenic. Yet our liver detoxifies these toxins through hormesis—a process that actually stimulates our cells.
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Yes, here at edubily we famously maintain an ambivalent relationship with coffee. That is: who doesn't enjoy coffee? Who hasn't felt coffee give them wings in the moment? We know it all.
But we also know the downsides. We've laid these out in nuanced and detailed fashion across our platforms, just recently here.
Coffee is particularly problematic for those who care about their methylation. Methylation regulates not only our gene expression (e.g., turning cancer genes on/off), but also the formation of crucial compounds (e.g., carnitine, creatine), so studies repeatedly show how important good methylation is for our energy metabolism.
The problem: compelling studies have shown that coffee inhibits methylation. This was demonstrated in one of the most famous animal models for "methylation deficiency"—the so-called Agouti mice. Interested? You can find more details in this article from us.
Bruce Ames Knows About Poisons
But actually, today's topic isn't really about coffee. At least not like this…
Rather, it's about one of the most famous biochemists of our time, Bruce Ames, who is soon to be a centenarian—that is, 100 years old. So alongside surely good genetics, he's done quite a lot right over his very long lifespan.
In any case, he was once the chief toxicologist for the United States. The famous Ames Test comes from him. In that test, poor bacteria are doused with chemicals, and then scientists examine at the genetic level how severely the bacterial DNA is altered.
A high degree of alteration—we call this mutagenicity—is not good. It can increase cancer risk in us, for example. But what does that have to do with coffee?
Is Coffee Carcinogenic – Or…?
In a famous lecture, delivered with the same sarcasm we typically use (;-), Ames let the cat out of the bag. He and his team tested thousands of substances for mutagenicity.
And they found promptly: Nearly half of all substances we humans encounter daily are potentially carcinogenic. Oh! And it doesn't matter whether they're "natural" or man-made substances. Oh!
Coffee fared particularly poorly. Roasted coffee contains well over 1,000 substances – 70% of them act as potential carcinogens. In fact, a single cup of coffee delivers roughly the same amount of toxic compounds as a year's worth of pesticide exposure. Based on estimates from around 20 years ago.
But why shouldn't all this concern us? Why hasn't anyone, presumably, ever gotten cancer from consuming enormous amounts of coffee?
Because we're not bacteria. What protects us above all is a liver. It takes in those supposed toxins and simply renders them harmless. What then enters the bloodstream is no longer disease-causing; on the contrary, it's health-promoting.
This principle is called hormesis—small amounts of "poisons" stimulate the health of our cells.
Detoxification Isn't a "Burden," It's Completely Normal
So this article isn't really about coffee at all. Rather, it's about how we're increasingly losing realistic assessments of our environment. Like an immune system that's gone completely haywire and shoots at everything, we modern people see "evil toxins" everywhere today.
Bruce Ames could only smile wearily at this. This "scaremongering" doesn't help you, and our lay assessments are often miles off the mark.
On the topic of Fukushima, for example, Ames said at the time: people shouldn't worry about it, but instead should focus on combating the often widespread folate deficiency. A folate or folic acid deficiency actually causes real DNA double-strand breaks and acts like a strong dose of radiation.
Let's be clear: "natural substances" are not inherently less harmful than classic factory-made poisons. And nature has given us, for precisely this reason, among other things a liver and two kidneys. Not to never "burden" them.
We're sticking with tea anyway.
(The basis for this article was this blog post from us.)