Good News – Cholesterol Is Healthy Again
Did you hear the good news? Apparently it’s safe to eat eggs again because cholesterol is no longer considered “a nutrient of concern”! Hooray! Did you just roll your eyes in annoyance? If so, I can’t say I blame you. We’ve been fed flip-flopping dietary advice for the past several decades about whether or not the cholesterol in foods like eggs is healthy, so why is this any different? The reason this news is making big headlines is because the statement that “cholesterol is not considered a nutrient of concern for overconsumption” is not coming from the results of yet another biased study, this time it came straight from the big dogs – the Dietary Guidelines Advisory Committee at their December 15, 2014 meeting.
Will the Government Have a Change of Heart about Cholesterol?
The Dietary Guidelines Advisory Committee (DGAC) is a panel of “nationally recognized experts in the field of nutrition and health” who are appointed by the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA). As the nation’s top scientific advisory panel, the job of the DGAC is to review the current scientific and medical literature, and suggest updates for the next edition of the Dietary Guidelines for Americans, which have been revised every 5 years since their first publication in 1980 (last update was in 2010). As reported by the Washington Post, the DGAC laid out the cholesterol decision in December, at their final meeting before submitting the official report with recommendations that will serve as the basis for the next edition of the Dietary Guidelines, which are due to be released later this year (2015). It’s worthwhile to note however (before we all get too eggcited), that there have been instances where the DGAC’s recommendations did not appear in the updated government guidelines.
Why You Should Care about The Dietary Guidelines
The Dietary Guidelines for Americans are pretty darn important, whether or not you know what they are. They form the basis for Federal recommendations to the general public about what Americans should be eating and feeding their children. They determine what nutrition information is taught in schools and outreach programs, they’re used to determine the content of school lunches and food assistance programs, as well as affecting how food manufacturers are able to advertise their products. So the recommendation from the DGAC to drop the caution against eating cholesterol-rich foods is, well, a pretty big deal! Especially when you consider that we have been given the advice to restrict dietary cholesterol in our diets to prevent heart disease for nearly 50 years.
Why Did Cholesterol Get Such a Bad Reputation?
I’m going to simplify this story, but check my references at the end of this post for links that paint the full picture. Once upon a time in the 1950s, researchers were learning about cholesterol by studying it in test tubes and in animals. One of the researchers, the infamous Dr. Ancel Keys, had an idea that to this day continues to dictate the way our medical system views and treats cholesterol and cardiovascular disease (CVD). Ancel Keys’ idea came to be known as the diet-heart hypothesis, which suggests that eating cholesterol-rich foods (like egg yolks) will raise blood cholesterol levels, and cause heart disease. From this notion the lipid hypothesis was born, which suggests that increased levels of cholesterol in the blood will increase a person’s risk for heart disease, and by reducing blood cholesterol levels, we will reduce CVD. These hypotheses were met with a lot of initial skepticism from the scientific and medical communities, but for one reason or another, they prevailed as ‘truth’ and that is how cholesterol came to be the bad guy.
In 1961 the American Heart Association (for whom Ancel Keys served as a nutrition committee board member) published the first-ever guidelines for U.S. citizens targeting dietary cholesterol and high blood cholesterol as risk factors for CVD. The USDA followed suit in 1980 with its publication of the first Dietary Guidelines for Americans. Since then, the government and the American Heart Association (AHA) have continued to recommend a low cholesterol diet to prevent CVD, based on the assumptions that the lipid and diet-heart hypotheses are correct. The current recommendations according to the AHA, and also as set forth in the 2010 Dietary Guidelines for American adults, are to keep dietary cholesterol under 300 mg/day. To put this into perspective, one egg contains about 200 mg of cholesterol alone.
Turns Out Cholesterol is Not the Bad Guy
Well as it turns out, both the diet-heart hypothesis and the lipid hypothesis are pretty much totally wrong. In fact, we’ve known for quite some time that cholesterol doesn’t cause heart disease, but it’s difficult to admit something of that caliber once the entire world has been fooled into believing it for several decades. Not to mention the gazillions of dollars that have gone into research and education and medicine in a failing attempt to control CVD by restricting cholesterol…heart disease continues to be the leading cause of death in the U.S. and globally, claiming more than 17 million lives per year.
Well nobody likes to admit they are wrong, but the reality is that we now have long-term, statistically-significant studies demonstrating that dietary cholesterol intake is not correlated with CVD, such as the Framingham Heart Study. We have also debunked the notion that eating cholesterol-rich foods will significantly raise blood cholesterol levels to the point of disease. It is well understood that only 25% of the cholesterol in our bloodstream comes from diet, and the majority (75%) is produced naturally by the liver and other cells of the body. We also know that simply lowering blood cholesterol levels isn’t going to ward off CVD. In fact, it has been demonstrated that populations with the highest blood cholesterol levels have some of the lowest rates of heart disease AND populations with the lowest cholesterol levels have some of the highest rates of heart disease in the world. (Take a moment to meditate on that last sentence…it says a lot!) In light of the reality that neither blood nor dietary cholesterol increase a person’s risk for CVD as was previously believed, it makes no sense whatsoever to continue restricting dietary cholesterol in an effort to prevent heart disease. After 35 years of Dietary Guidelines advising Americans to restrict cholesterol in our diets, it appears that the “experts” finally agree!
Steve Nissen, chair of cardiovascular medicine at the Cleveland Clinic explained in USA Today that “We got the dietary guidelines wrong. They’ve been wrong for decades.” As reported in the Washington Post, Dr. Robert Eckel (former AHA president) admits that “Looking back at the literature, we just couldn’t see the kind of science that would support dietary restrictions” of cholesterol. Eckel goes on to explain that the current recommendation of limiting dietary cholesterol to 300 mg/day is “just one of those things that gets carried forward and carried forward even though the evidence is minimal.” In fact, even ol’ Ancel Keys seemed to understand the obvious 60 years ago when he stated in his paper The relationship of the diet to the development of atherosclerosis in man that “The evidence—both from experiments and from field surveys—indicates that the cholesterol content, per se, of all natural diets has no significant effect on either the serum cholesterol level or the development of atherosclerosis in man.”
Ode to Cholesterol
After saying such horrible things about cholesterol for the past half-century, it seems fitting that we should pay tribute to the life-sustaining molecule that cholesterol actually is! Despite it’s long-standing bad reputation, cholesterol plays a number of super important roles in the body, including (but not limited to):
- The production of steroid hormones (i.e. progesterone, corticosteroids like cortisol, aldosterone, etc.)
- The production of sex hormones (estrogen and testosterone)
- Precursor to Vitamin D
- Precursor to bile acids, which are necessary for fat digestion/absorption
- All cellular membranes are made from cholesterol, which is essential for their structure and function. The outer mitochondrial membrane also contains cholesterol (the mitochondria in your cells turn your food into energy).
- The nervous system needs cholesterol – the myelin sheath that coats nerves in the brain and central nervous system is rich in cholesterol, and increases the conduction speed of nervous system signals.
- Cholesterol plays a major role in our inflammatory response
- Cholesterol is linked to mental health, and about 25% of the body’s cholesterol is made in the brain.
- Cholesterol plays important roles in intracellular transport and cellular communication.
- Cholesterol is absolutely essential for life, and virtually every cell in the human body (animals too!) can and does synthesize cholesterol.
- Every cell in your body (especially cells of the liver, intestine, adrenal glands, and reproductive tissues) produces cholesterol to maintain adequate blood levels which are required for survival.
So What Really Causes Heart Disease?
Unfortunately, the long-ago disproven lipid and diet-heart hypotheses are still accepted as truth by most medical professionals and the public at large, and popular treatments to lower cholesterol levels via statin therapy are based on these outdated hypotheses. It is well established that the build-up of plaque within artery walls (known as atherosclerosis) narrows the diameter of arteries, restricts blood flow, damages artery walls, and predisposes to heart disease and stroke. According to the American Heart Association, the causes of atherosclerosis remain poorly understood, however our most current research suggests that factors such as inflammation and oxidative stress are likely the major culprits when it comes to damaging the arterial walls and instigating heart disease. I’ll get into the nitty gritty details about what causes inflammation and oxidative stress in a future blog post, but it’s important to understand that these factors are largely influenced by diet and lifestyle. If you’re reading this blog post, I’m gonna guess that you’re probably already living a somewhat anti-inflammatory lifestyle, and if you’re on a carb-conscientious Paleo diet, exercising moderately, and doing your best to manage stress, then you’re on the right track to minimizing atherosclerosis, and keeping your ticker ticking strong and loving long. I should mention however, that the increase in carbohydrate intake in the 1960s (which resulted from recommendations to lower dietary fat and cholesterol) is now thought to be a big player in the current heart disease epidemic. Now there’s some low carb food for thought!
I realize this is a confusing topic, especially because it’s the exact opposite of what most of us have been told our entire lives about cholesterol. Hopefully this article has helped to clear up some of the confusion, and possibly even given you a ‘change of heart’ about cholesterol. So go ahead and have yourself an egg… or three, knowing in your heart, that it’s okay now because the government says so. Haha! Just kidding (they haven’t agreed to anything yet), but seriously, yolk up yo! :-)
In good health,
Kinsey Jackson, MS, CNS®
- Taubes, G. Good Calories, Bad Calories
- Devlin, T.M. Textbook of Biochemistry with Clinical Correlations (7th ed.)