A chemical found in red meat helps explain why eating too much steak, mince and bacon is bad for the heart.
A study in the journal Nature Medicine showed that carnitine in red meat was broken down by bacteria in the gut.
This kicked off a chain of events that resulted in higher levels of cholesterol and an increased risk of heart disease.
Dieticians warned there may be a risk to people taking carnitine supplements.
There has been a wealth of studies suggesting that regularly eating red meat may be damaging to health.
Saturated fat and the way processed meat is preserved are thought to contribute to heart problems. However, this was not thought to be the whole story.
I would strongly recommend that unless you’re a vegetarian or vegan, there is a potential risk from taking L-carnitine, lecithin, choline or betaine supplements in an attempt to ward off cognitive decline or improve fat metabolism ”
“The cholesterol and saturated fat content of lean red meat is not that high, there’s something else contributing to increases in cardiovascular risk,” lead researcher Dr Stanley Hazen told the BBC.
Experiments on mice and people showed that bacteria in the gut could eat carnitine.
Carnitine was broken down into a gas, which was converted in the liver to a chemical called TMAO.
In the study, TMAO was strongly linked with the build-up of fatty deposits in blood vessels, which can lead to heart disease and death.
Dr Hazen, from the Cleveland Clinic, said TMAO was often ignored: “It may be a waste product but it is significantly influencing cholesterol metabolism and the net effect leads to an accumulation of cholesterol.
“The findings support the idea that less red meat is better.
As told in an interview with BBC, Stanley Hazen, before he ate red meat five times a week, but now – no more than once every two weeks.
Vegetarians naturally have fewer bacteria which are able to break down carnitine than meat-eaters.
Scientists suggest that the consumption of probiotic yogurt is improving the balance of intestinal flora, reducing the amount of bacteria that feed on carnitine.
According to Dr. Hazen, this can help reduce the risk of cardiovascular disease through the consumption of red meat.
British doctors recommend limiting the consumption of meat 70 grams, which are somewhere about two slices of bacon per day.
People who love sausage, also eat fewer fruits and vegetables and more likely to smoke, and all these affect on the overall results