Dr Keith Souter writes: Egg consumption is a good example. At one time people were advised to restrict their egg intake to four a week or even avoid them.
Not long ago because cholesterol is associated with increased risk of heart attacks and strokes it was considered logical to think that eggs were bad for you, since egg yolks are high in cholesterol.
The reasoning was that since cholesterol in the blood is a risk factor, one should avoid cholesterol in the diet.
Since then research has shown that most of the cholesterol in the body is made inside the body by the liver.
This happens because the liver is stimulated to produce cholesterol by the presence of saturated and trans fats in the diet.
The cholesterol in the diet, including from eggs does not contribute to this at all.
This has been intensively studied by Harvard University where hundreds of thousands of people have been followed up over several decades.
They have not found any higher rate of heart attacks or strokes in people who eat up to one egg a day.
Eggs won’t increase your blood cholesterol.
On the other hand, the saturated fat in butter, cheese, bacon and sausages will do.
Similarly, highly refined carbohydrates in white bread and pastries do increase the risk.
The latest research from China backs this up.
They looked at a 2018 study published in the journal Heart, which looked at half a million adults.
They found that those who ate one egg a day had a lower risk of cardiovascular disease than those who ate eggs less frequently.
This latest research aimed to find out why this could be the case.
They used targeted magnetic resonance to measure over 200 metabolites (the products of metabolism) in blood samples.
They identified 14 metabolites that are linked to heart disease.
They found that people who ate the least eggs had lower levels of beneficial or protective metabolites and higher levels of harmful ones, compared to those who ate eggs regularly.
They concluded that this explained the findings of the 2018 study.