Nutritional guidelines and recommendations are constantly changing in the light of new research. It can be difficult to keep up with which foods are healthy and which aren’t. Here we look at five foods that have gone through the cycle of being the villains of nutritional science but are now, based on some old and some new science, apparently okay to eat again.
For a long time, eggs were thought to be bad for your heart. A large egg contains a hefty 185mg of cholesterol. Dietary cholesterol was believed to contribute to high blood cholesterol levels. But for the last 20 years, nutrition and medical research has shown repeatedly that at normal intakes dietary cholesterol has very little influence on a person’s blood cholesterol levels.
Although it’s taken a while, nutrition experts are now correcting the record for eggs and other foods that contain cholesterol (such as chicken liver and shellfish) by removing it as a nutrient of concern from dietary guidelines. Eggs are an excellent source of protein, healthy fats, and several vitamins and minerals. (Watch: A simple, delicious green smoothie recipe. Post continues after video.)
2. Fat spreads
The story of fat spreads, such as margarine and butter, is probably one of the most confusing stories in nutrition. The origin of margarine, which is made from vegetable fat, dates back to the mid-1800s. Since that time, margarine has replaced butter as the fat spread of choice in most developed countries. This switch was driven by the lower price of margarine compared with butter as well as recommendations from health professionals to eat less saturated fat in order to prevent coronary heart disease (CHD).
While this switch away from saturated fats began to show reduced CHD incidence in the population, researchers also identified an independent link between trans fat (a fat produced when partially hydrogenating vegetable fats to make margarines) intake and CHD. Since this link between trans fat and CHD was confirmed by multiple studies regulatory agencies around the world have sought to eliminate trans fats from the diet.