Researchers with the University of Nevada–Reno have found yet another reason why people shouldn’t eat animal-derived foods: At some point in human evolution, a gene—known as CMAH—that allows for the synthesis of a certain type of sugar that’s found in red meat, fish, and dairy “products” went missing. So when humans eat these foods, their bodies have an adverse reaction to the toxic sugar, and this can cause inflammation, arthritis, and cancer.

Phys.org explains the issue in more detail, but it sounds fairly simple: There’s a cancer-causing sugar in certain animal-derived foods, including caviar, and humans would be wise to avoid it.

We’re simply not meant to eat meat. The human body evolved to eat only plants—now, it’s time for our behavior to catch up.

Many biologists believe that our bodies are best suited to eating vegan. Unlike true carnivorous animals—who have claws, a short digestive tract, and long, curved fangs—humans have flat, flexible nails; a long digestive tract; flat molars; and two tiny canine teeth that are better for biting into fruits than tearing through tough hides.

Besides, meat, eggs, and dairy “products” contain cholesterol, saturated fat, and concentrated protein—all of which contribute to an increased risk of suffering from heart disease, diabetes, strokes, and other common chronic illnesses. The consumption of too much animal protein can even cause osteoporosis and contribute to kidney failure.

As Dr. William C. Roberts, the editor of the American Journal of Cardiology, says, “[A]lthough we think we are … and we act as if we are … human beings are not natural carnivores. When we kill animals to eat them, they end up killing us because their flesh, which contains cholesterol and saturated fat, was never intended for human beings, who are natural herbivores.”

Fortunately, there are plenty of animal-free foods to eat. PETA has hundreds of free vegan recipes and product suggestions, including Cavi-art, a plant-derived version of caviar that doesn’t include the carcinogenic sugar. So encourage everyone you know to evolve and go vegan!