For a long time, the prevailing nutritional advice was to avoid foods containing cholesterol to keep the heart strong and healthy.
Cholesterol is a fatty substance that can build up and damage the blood vessels that supply the heart, and is found in animal products such as meat and, most famously, egg yolks.
For this reason, it was long thought that too many eggs per day could increase the risk of heart attacks and strokes.
But experts have now refuted claims that high-cholesterol foods are actually bad for our cholesterol levels.
They say favorites like steak and liver – two foods with the highest cholesterol levels – have little direct impact on the amount of the substance that builds up in our bodies.
Instead, they say the biggest influence on blood cholesterol levels is the mix of fats and carbohydrates in your diet – not the amount of cholesterol you eat.
High cholesterol occurs when there are too many fatty deposits, called lipids, in the blood. This can make it difficult for blood to flow through the arteries and travel to vital organs such as the heart and brain
Saturated fats in the diet, as well as obesity, stimulate cholesterol production in the liver. Typically, the higher the cholesterol level in the blood, the greater the risk of heart attacks and strokes.
Foods high in saturated fats include bacon, sausage, butter, cheese, red meat and fried foods.
Meanwhile, certain foods can help remove artery-clogging ‘bad’ cholesterol (LDL) from the body, such as fiber-rich barley and oats, beans and nuts.
The map shows the concentrations of provinces with the highest cholesterol prevalence. Health officials typically advise people to limit their intake of fatty foods, which can affect the amount of cholesterol the body produces
A lot has changed in recent decades in terms of dietary guidelines and rules for healthy eating.
Rather than focusing on a specific nutrient, dietitians pay more attention to the quality of our diets in general.
Dr. Walter Willett, nutrition researcher at Harvard University, said: ‘Cholesterol from food does not increase cholesterol levels in the blood much. It is not that there is no effect on blood cholesterol levels; there is a small effect.
‘It can increase both good and bad cholesterol in the blood, so that makes it more complicated. That’s why we need to look at the whole food, not just the cholesterol content.’
Nutrition science has changed in recent years as more and more experts and scientists recognize that blood cholesterol levels are largely determined by the amount of fats and carbohydrates in the diet, and not by dietary cholesterol such as that found in eggs.
Dr. Francisco Lopez-Jimenez, a cardiologist based in Minnesota, shared Mayo Clinic: ‘Although some studies have found a link between eating eggs and heart disease, there may be other reasons for these findings.
‘The foods that people typically eat with eggs, such as bacon, sausage and ham, could contribute more to increasing the risk of cardiovascular disease than eggs. “In addition, the way eggs and other foods are cooked – especially if they are fried in oil or butter – could play a bigger role in the increased risk of heart disease than the eggs themselves.”
Cholesterol has long been neglected in the American diet, having been specifically addressed in the 1960s when it appeared in guidelines developed by the American Heart Association.
But since then, more research has come to light that has turned the conventional wisdom on its head.
Diet affects only about 20 to 30 percent of the cholesterol in your blood.
Most of it is produced in the liver and supports crucial body processes, including strengthening the protective membranes around cells, making hormones and digesting food.
Too much of the ‘bad’ LDL cholesterol can build up in the blood vessels.
Over time, the waxy substance can block blood flow and harden arteries, significantly increasing the risk of heart attack and stroke.
The ‘good’ HDL cholesterol absorbs the bad kind in the blood and returns it to the liver for disposal.
In 2019, the American Heart Association changed its recommendations for dietary cholesterol, eliminating limits above 300 milligrams per day.
The latest advice states that studies have generally not shown a link between dietary cholesterol and cardiovascular risk.