About every five years, the U.S. departments of Agriculture and Health and Human Services revise their dietary guidelines for Americans. The document affects everything from school lunch decisions to health advice from your doctor. The new 2015 report was released last week, and the committee of health experts behind it has indicated it will no longer recommend limiting dietary cholesterol intake.
Q: Why is the committee removing guidance to limit cholesterol intake?
A: The report states that "available evidence shows no appreciable relationship between consumption of dietary cholesterol and serum cholesterol." For most researchers who have studied the link between dietary cholesterol and its effect on blood cholesterol, this change is no surprise and is long overdue. It has been known for about 50 years that dietary cholesterol has little or no impact on blood cholesterol levels in the vast majority of people. So, a focus on avoiding high-cholesterol foods like eggs, shrimp, etc. was misguided from the beginning.
Of course, high blood cholesterol is linked to increased risk of cardiovascular disease, heart attacks and strokes. However, even this relationship is not a simple one. Some people with high blood cholesterol don’t get cardiovascular disease, and some people with low blood cholesterol die of heart attacks.
Cholesterol is an important chemical that the body uses to synthesize estrogen, testosterone and vitamin D, among other things. It is so important that the body makes much more cholesterol daily than a person typically consumes. When cholesterol is in the diet, the body makes less and, therefore, the change in blood cholesterol levels is minimal.
Eggs have been the most maligned high-cholesterol food, and, because of that, people who avoid eggs have been missing a good, low-calorie source of high-quality protein and B vitamins. It also is a major source of choline and biotin, two nutrients commonly underconsumed.
Q: What other changes were suggested?
A: The committee recommends reducing consumption of red meat — not just the higher-fat meats. However, the report does not clarify how much red meat is too much. The report does say in a footnote that "lean meats can be a part of a healthy dietary pattern."
Q: What is the potential impact of reducing meat consumption on human health in the United States?
A: Reducing meat intake, especially red meat, decreases two nutrients of great concern: iron and zinc. Iron, in particular, is the most common nutrient deficiency in the U.S. and the world, especially for women.
The Institute of Medicine’s recommended iron intake is based on dietary patterns that include the "heme" form of iron primarily found in red meat. For vegetarian diets, the institute recommends an 80 percent increase in daily dietary iron intake to make up for the limited absorption of iron from this type of diet.
After the McGovern Report in 1977 established the first U.S. dietary recommendations, University of Wisconsin professor Alfred Harper wrote numerous articles on how these recommendations would decrease the health of the nation, including the negative effect on women’s iron status. Harper’s predictions were followed by a steady decline in the health of the United States when compared with other countries.
How much further will the United States slide with anti-meat recommendations?
Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dobbs also works with University Health Services.