The Dietary Guidelines Advisory Committee, the panel of experts who review the Dietary Guidelines for revision every five years (published most recently in 2019), will change their recommendation about dietary cholesterol in the report they will send to the federal government in the next few weeks.
The current guidelines, and those of the past 40 years, restricted dietary cholesterol to 300 milligrams a day. For reference, an egg yolk has around 200 milligrams and a 6-ounce T-bone steak has 90 milligrams. In 2019, the American Heart Association and the American College of Cardiology dropped their advice about cholesterol as well.
True, cholesterol is a major part of the plaque that narrows the arteries in atherosclerosis, the underlying cause of heart disease and strokes, but only 20 percent of our blood cholesterol comes from diet. Our liver makes the rest. The issue is confounded because many high cholesterol foods are high in saturated fat and saturated fat and trans fat do add to blood lipid levels. Dietary cholesterol, which is found in animal-derived foods, is usually accompanied by saturated fats as in full-fat dairy products and the meat of domesticated animals. Egg yolks and crustaceans (crabs, lobsters, shrimp, and crayfish) are high in dietary cholesterol but low in saturated fat.
There really isn’t strong evidence to link high cholesterol foods with high blood cholesterol levels. Many of the major studies supporting the case were just too broad to be useful. In newer controlled clinical studies, where subjects ate a specific amount of cholesterol while their blood cholesterol was measured, there was only a slight or no increase in blood cholesterol levels. Other studies showed that eating a daily egg was not tied to more heart disease or stroke. It turns out that most of the variation in blood cholesterol levels is genetic.
Diet advice to prevent cardiovascular disease is complicated at best. As new scientific information comes to light, the recommendations change. Presently, the best advice for a healthy blood lipid profile rely on a diet abundant in soluble fibers from vegetables, legumes, whole grains, and fruit, with mono-unsaturated fats from olives, nuts and seeds, along with a restriction of added sugars, refined starches, and trans fat from processed foods. That diet fights inflammation and maintains good glucose metabolism. Eggs are fine, but not so many as to take the place of other healthy foods or lead to overweight.