Warnings against eating foods high in cholesterol, like eggs or shrimp, have been a mainstay of dietary recommendations for decades. That could change if the scientific advisory panel for the 2015 iteration of the Dietary Guidelines for Americans has its say.
A summary of the committee’s December 2014 meeting says “Cholesterol is not considered a nutrient of concern for overconsumption.” Translation: You don’t need to worry about cholesterol in your food.
Why not? There’s a growing consensus among nutrition scientists that cholesterol in food has little effect on the amount of cholesterol in the bloodstream. And that’s the cholesterol that matters.
Nutrition experts like Dr. Walter C. Willett, chair of the Department of Nutrition at Harvard School of Public Health, called the plan a reasonable move. Dr. Steven Nissen, chair of cardiovascular medicine at the Cleveland Clinic, told USA Today “It’s the right decision. We got the dietary guidelines wrong.”
Keep in mind that this isn’t a done deal. The panel, which is formally known as the 2015 Dietary Guidelines Advisory Committee, makes recommendations for the next guidelines update, but these recommendations aren’t always followed.
The cholesterol connection
Cholesterol has a bad reputation, its name linked to heart attacks, strokes, and other types of cardiovascular disease. Yet cholesterol is as necessary for human health as water or air.
Cholesterol is a type of fat, or lipid. It is an essential building block for cell membranes and other crucial structures. It is needed to form the protective sheath that surrounds nerve fibers. The body uses cholesterol to make hormones such as testosterone and estrogen, the bile acids we need to digest and absorb fats, and vitamin D.
Cholesterol is so important that your liver and intestines make it day and night from fats, sugars, and proteins. In the average person, the body’s production of cholesterol far outstrips any contribution from cholesterol in food.
Why is blood cholesterol a concern? Too much of it, especially in the wrong kind of particle, can cause trouble inside blood vessels (see “From cholesterol to crisis” below). Harmful low-density lipoprotein (LDL) particles ferry cholesterol to artery walls. Protective high-density lipoprotein (HDL) particles pull cholesterol out of circulation and deliver it to the liver for destruction.
Doing away with the beware-cholesterol-in-food warning would simplify the art of choosing healthy foods. And it would let people enjoy foods that contain higher amounts of cholesterol, such as eggs, shrimp, and lobster, without worrying about it. A better focus is on reducing saturated fat and trans fat in the diet, which play greater roles in damaging blood vessels than dietary cholesterol.
Science, including nutrition science, is a process of change. New findings emerge that nudge aside old thinking and prompt new recommendations. That’s easy for someone like me to say, since I closely follow nutrition science and research and understand how they work. But for folks who don’t, a change in the recommendations about cholesterol in food is likely to be seen as another dietary flip-flop and undermine confidence in what’s known about healthy eating.
Image from Managing Your Cholesterol, a Special Health Report from Harvard Medical School