In contrast to all other animals, people unfortunately have a tendency to contract heart attacks that have no obvious cause. According to a recent study in the Proceedings of the National Academy of Sciences, this nasty ticker malfunction can all be traced back to a single gene that was deactivated in humans from 2 to 3 million years ago due to a mutation in one of our ancestors.
Atherosclerosis is a form of cardiovascular disease characterized by arterial obstruction that is the leading cause of human death worldwide and causes around one-third of all deaths. In many cases, it is triggered by factors such as obesity, high blood pressure, smoking and blood cholesterol, although about 1
These sudden, unexplained heart attacks occur in all other species, including many of our closest relatives, such as chimpanzees, they practically do not exist. And the reason for this seems to be a single sugar molecule called Neu5Gc, which is on the cell surface of all animals except humans.
The gene coding for Neu5Gc is called CMAH and seems to have been deactivated a few million years ago by one of our early ancestors. One theory suggests that the elimination of Neu5Gc was an evolutionary response to a specific form of malaria that attached to the molecule to infect monkeys.
To date, modern humans are immune to certain strains of malaria, the chimpanzees and other monkeys are vulnerable, but the results of this latest research show how much the price we have to pay for our resistance to the disease.
The authors of the study deactivated the CMAH gene in laboratory mice due to a lack of Neu5Gc. Compared to normal mice, these rodents were 1.9 times more likely to suffer from arteriosclerosis.
The mutant mice got worse when they were fed a diet high in red meat. a fold increase in atherosclerosis compared to normal mice. This is because red meat contains a high level of Neu5Gc, which triggers an immune response called xenosialitis, in which antibodies that are supposed to recognize and destroy Neu5Gc trigger an inflammatory process that appears to involve a risk of heart attack.
these results seem to indicate that eating too much red meat significantly increases the risk of cardiovascular disease, but non-smoking super-fit vegetarians are also genetically motivated to kick in the bucket for no apparent reason.