By Alexandra Thompson Senior Health Reporter For Mailonline
Published: 10:03 BST, 23 July 2019 | Updated: 10:19 BST, 23 July 2019
The loss of a single gene up to three million years ago may explain why humans are at a greater risk of heart disease.
A decade ago scientists discovered homo sapiens are virtually the only animals to suffer heart attacks as a result of plaque accumulating in the arteries.
Our ancestors are thought to have passed down a mutation in the gene CMAH, which has left us unable to produce the sugar molecule Neu5Gc.
When scientists 'knocked out' CMAH in mice, the rodents' arteries 'furred up' almost twice as much as the unmodified animals' blood vessels.
Genetic mutation millions of years ago may explain why humans suffer heart attacks (stock)
The research was carried out by the University of California, San Diego, and led by Dr Ajit Varki, distinguished professor of medicine, and cellular and molecular medicine.
One in four deaths in the US and UK occur due to cardiovascular diseases like heart attacks or strokes, statistics show.
Atherosclerosis is a leading cause of these disorders. It is defined as the build of plaque in the arteries, which restricts blood flow to the major organs.
Obesity, smoking and inactivity all raise the risk of atherosclerosis.
However, around 15 per cent of first-time heart disease cases that come on due to atherosclerosis have no obvious cause.
The San Diego scientists were the first to note humans are the only animals to suffer atherosclerosis-related heart attacks.
'That’s always been a puzzle,' Professor Varki said.