London: For those who have been avoiding fatty foods to take care of your heart, here’s a word of warning.
A new study has found that a low-fat diet may not protect against heart disease unless you eat ‘good fats’ too.
In one of the largest studies of heart disease ever, scientists at the University of Cambridge examined the diets of 25,000 people of Britain aged between 40 and 79.
The researchers found that those people who ate foods rich in omega 6 – a fatty acid present in vegetable oils, nuts and seeds – significantly reduced their risk of heart problems.
But those who had simply cut their intake of unhealthy saturated fat were not able to reduce their risk to the same extent.
The researchers suggest the ‘balance of fats’ in our diets could be the key to preventing coronary heart disease, which is the UK’s biggest killer.
They say the current advice to reduce saturated fat in our diets is right, but ‘inconsistent’, because it does not tell people what to replace it with.
In the study, those at the highest risk of heart disease – who ate a lot of saturated fat and little omega 6 – were around 50 percent more likely to suffer from it than those at lowest risk. This was regardless of other major risk factors such as obesity and smoking.
“It is not as simple as fat is bad for heart disease,” the Daily Mail quoted Professor Kay-Tee Khaw, lead author of the study, as saying.
“We found you have to replace saturated fat with polyunsaturated fatty acids to reduce the risk. We measured 20 types of fatty acid in the blood, which was not possible to do in the past, to get a much more accurate picture of people’s diets.
“We did find an association between coronary heart disease with certain fatty acids, but the association was much stronger when we looked at the relationship between different fats,” Khaw said.
Saturated fats are found in foods such as cheese, cakes and biscuits. Too much can raise cholesterol levels in the blood, which increases the risk of heart disease.
The NHS recommends a man should eat no more than 30g per day and a woman no more than 20g.
Most people eat around 20 percent too much. Professor Khaw said their results ‘add to the accumulating evidence’ that substituting saturated fat with omega 6 benefits the heart.
It is found in avocados, eggs and poultry as well as sunflower and corn oil.
In the study, the professor added that there was potential to learn a lot more about how genetic factors affect the way different fats are metabolised.
Other fats – such as omega 3, found in fish oils, and monounsaturated fat, found in olive oil – did not appear to affect coronary heart disease, but are widely thought to be good for other conditions.
The study was published in the journal PLoS Medicine.