The Yolk is Back in Town: Does Cholesterol Still Matter?

by Ally Gallop, BSc, RDN, CDE

Cherry picking through the Dietary Guidelines Advisory Committee’s (DGAC) February report is a nutrition communicator’s nightmare. Though the report is 571 pages deep, media headlines repeatedly echo the lack of a recommendation surrounding a seemingly new leniency towards cholesterol. This year, the DGAC points to inadequate evidence linking high dietary cholesterol to high serum cholesterol. So what changed? And why should we, as nutrition communicators, care?

The 2015 DGAC’s report recommends withdrawing cholesterol’s longstanding upper limit of 300 milligrams (mg) per day when updating the 2015 dietary guidelines set to occur later this year. Since the federal government’s dietary guidelines were first officially released in 1980, there has always been a focus on cholesterol and saturated fat. The initial guidelines stated to “avoid too much fat, saturated fat, and cholesterol.” It took until the fourth version in 1995 to place a hard number on cholesterol: 300 mg daily for the general population. A stricter 200 mg was advised for those with high cholesterol, at risk of cardiovascular disease (CVD), or diabetes. It also took until 1990 for specific limits on saturated fat to be made: less than 10% total caloric intake from saturated fat (the 2010 goal is now less than 7%).

So how did eggs become roped into this? In the 1950s, egg consumption averaged 374 per year or roughly a daily egg. With 186 mg cholesterol and 1.6 grams saturated fat per large egg, this dietary staple was a clear target. At the time, dietary cholesterol was thought to increase LDL (the “bad” cholesterol”) and one’s risk of CVD. Fast-forward to the 1990s and consumption plummeted to 236 (0.6 eggs per day). Even with this reduction, CVD remains the leading cause of death for both men and women. Marion Nestle relates this to poor communication with the public. Assumptions that Americans would adopt these dietary restrictions by replacing butter, beef, and cheese “with healthy fruits and vegetables… was naïve.” Americans were eating more refined carbohydrates, sugar, and sweeteners, items known to contribute to excess body weight, increased LDL, type 2 diabetes, and CVD risk.

Yet as far back as the 1990’s, experts began to learn that eating cholesterol does not necessarily parallel large increases in one’s risk of CVD. In 1999, the Journal of the American Medical Association found that despite an egg’s cholesterol, daily consumption did not increase one’s risk. Harvard’s School of Public Health’s Walter Willett has voiced how although this recommendation was initially based on well-intentioned theory, it stuck around due to inertia. The restriction was based on and supported by short-term studies with no consistent, hard, and direct evidence

So too, agreed the joint American Heart Association-American College of Cardiology task force in 2013 when it reported that cholesterol’s initial strict limit was based on studies too broad to find a direct link. Even so, the United States remains the only country to include a cholesterol limit within its dietary guidelines.

Adding to the complexity, cholesterol is produced by the liver having multiple roles throughout the body. It’s necessary for the production of steroid hormones, is present within the membrane of every cell, and is a requirement for fat absorption due to its role as a precursor for bile acids. In fact, the liver produces upwards of 85% of the body’s total cholesterol levels. Additionally, Willett shares how “It has become clear that eggs raise both LDL and HDL [the “good” cholesterol], so the impact on heart disease is less clear, and of course eggs contain much more than cholesterol.” And so they do. Eggs improve our:

  • Eyes: due to the antioxidants lutein and zeaxanthin, which help prevent macular degeneration
  • Brain: dietary choline is hard to come by, so eggs are a unique source
  • Muscles: there’s a reason why this high quality protein is rampant in a weight lifter’s diet
  • Satiety: the protein keeps us feeling full for longer, thereby being a useful addition to weight loss and maintenance eating patterns

But guess what? Your dietary advice hasn’t really changed.

The implications surrounding food communicators involve the public’s perception that nutritionists are forever changing their minds as to what’s healthy and what’s not. But taken together with saturated fat, the recommendations don’t really change.

The USDA and the Department of Health and Human Services will be responsible for updating the forthcoming dietary guidelines. If they adopt the DGAC’s recommendations, no longer having a guideline does not mean that foods containing cholesterol should be consumed without restraint. The vehicle that cholesterol is carried in still matters. As mentioned, cholesterol tends to coincide with saturated fat and exists primarily in animal foods, to which the DGAC continues to recommend restricting to no more than 7% of all calories. For instance, items with both high cholesterol and saturated fat include cheese and other high-fat dairy products; pizza; and many cuts of beef, pork, and poultry (with the skin).

In defense of the DGAC, Tufts own Dr. Alice Lichtenstein reports how the average American now consumes between 250 and 350 mg daily. Among other pertinent dietary factors, focusing on cholesterol is no longer of dire concern for the DGAC. However, although dietary cholesterol may not be of concern to the committee, saturated fat still is.

Rather than focusing on specific nutrients, its not enough for food communicators to solely depend on moderation and the importance of whole foods and diets when counseling patients. From experience, they want specific answers. So here’s what you need to know:

  • In 2012 3% of Americans had diabetes, another 86 million were in the prediabetic state, and 1.7 million new cases were diagnosed. In total, 85.6 million Americans suffer from CVD or the aftermath of stroke. Acknowledging that the dietary guidelines are intended for the general population, with numbers this large nutrition communicators need to avoid making broad strokes when advising the public.
  • A daily egg is fine, except for those with diabetes* who should limit their intake to no more than three yolks per week.
  • For those with or at risk for CVD and/or diabetes, continue with a 200 mg restriction.
  • Remain conservative with foods high in saturated fat. For instance, avoid 3-egg omelets with a side of bacon and sausage.
  • Opt for high-fiber foods and whole grains, since refined carbohydrates can lower HDL (nay) and fiber can help lower LDL (yay!).
  • For those pregnant or immune-compromised, cook eggs fully.

Remember that as of 2012 9.3% of Americans had diabetes, another 1.7 million new cases were diagnosed, and 86 million were in the prediabetic state. In total, 85.6 million Americans suffer from CVD or the aftermath of stroke. Acknowledging that the dietary guidelines are intended for the general public as a preventative health measure, with numbers this large nutrition communicators need to avoid making broad strokes when advising the public.

And ultimately, Dr. Lichtenstein reminds us how “all bets are off as to what the 2015 [dietary guidelines] will be.” Only time will tell if the 300 mg restriction lives on.

Want to have input on the 2015 dietary guidelines? The public comment period was recently extended until May 8, 2015. Click here to have your voice heard.

Ally Gallop, BSc, RD, CDE is studying towards an MS/MPH focusing in nutrition communication and behavior change. Her favorite egg dish is a scrambled egg, avocado, black beans, sweet potatoes, and Sriracha sauce.

The Friedman Sprout is a monthly student run newspaper that aims to serve the student population at the Friedman School of Nutrition Science and Policy, prospective students, and alumni. Our mission is to report on newsworthy information that affects the Friedman community including nutrition research, food policy, internship and volunteer opportunities, as well as school events. Our editorial slant is that of sustainability in food and nutrition.

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