One-third of global deaths are due to cardiovascular disease caused by atherosclerosis, when arteries are clogged with fat deposits. Although it’s common for humans to experience heart attacks, the same event is rare in mammals. Now, researchers believe that they understand why.
Risk factors for cardiovascular disease in humans can include age, hypertension, obesity, smoking, blood cholesterol and inactivity. However, in 15% of cardiovascular events caused by atherosclerosis, none of these risk factors is at hand.
Researchers think that there was the loss of a single gene, CMAH, in human ancestors between 2 million and 3 million years ago, leading to a higher risk of cardiovascular disease. This gene included a sialic acid sugar molecule called Neu5Gc. Apes and chimps have maintained this gene and molecule over time.
In a new study, mice were modified to be similarly deficient in this molecule, which caused a twofold increase in atherosclerosis.
Even though humans lack this gene and the Neu5Gc molecule within it, those who regularly eat red meat are exposed to it. Consuming it as a byproduct of red meat causes the human body to react with an immune response as well as chronic inflammation.
Read full, original post: Evolution may be why humans are prone to heart attacks, study says