Heart Health: Do I need to eat less cholesterol?

Typically the first food items that are eliminated on a cholesterol-lowering diet are eggs and other foods rich in cholesterol.  But does eating less cholesterol help lower blood cholesterol levels and reduce the risk of heart disease?

The American Heart Association guidelines recommend that you aim to eat less than 300 milligrams of cholesterol each day.¹  Even more strict is the National Institute of Health’s Therapeutic Lifestyle Changes (“TLC”) diet, which recommends that you eat less than 200 milligrams of cholesterol per day to lower LDL cholesterol by 3-5%.²   

On the other end of the spectrum is Harvard School of Public Health, stating “for most people dietary cholesterol isn't nearly the villain it's been portrayed to be. Cholesterol in the bloodstream, specifically the bad LDL cholesterol, is what's most important. And the biggest influence on blood cholesterol level is the mix of fats and carbohydrates in your diet—not the amount of cholesterol you eat from food.”³

Clearly there are conflicting opinions about whether or not lowering the cholesterol in your diet will make a difference.  Why?  Dietary cholesterol does not have a significant impact on blood cholesterol levels and there are other more important risk factors for heart disease. 

Of the total amount of cholesterol in the body, approximately 75% is made by the liver and 25% comes from foods.  Cholesterol is critical for health; we could not survive without it.  It is important for the structural integrity of our cells, for defense against infections, for brain and nervous system tissue, digestive health, and mood.  It is so important for normal bodily functions that the level is closely regulated; if there is less cholesterol in the diet, the liver makes more and vice versa. 

According to the USDA National Nutrient Database, one extra-large egg contains 203 milligrams of cholesterol.⁴   So are eggs healthy or are they a high-cholesterol trap?  One researcher found that it depends on what the hen eats. Dr. Niva Shapira of Tel Aviv University's School of Health Professions says that all eggs are not created equal. Her research indicates that when hens are fed with a diet low in omega-6 fatty acids from a young age — feed high in wheat, barley, and milo and lower in soy, maize and sunflower, safflower, and maize oils — they produce eggs that may cause less oxidative damage to human health. This is especially important for preventing the development of plaque that could block arteries.

While most people believe that increased dietary cholesterol has a direct connection to the development of plaque in blood vessels, there are other more critical factors.  The real risk is oxidative damage, which depends on the basic vulnerability of the LDL particle (the higher the polyunsaturated fat content, the greater the risk of oxidation), antioxidant status of the cells, the amount of time the LDL particle is in the bloodstream (the shorter the better), and the cumulative exposure to factors that increase oxidative stress (smoking, stress, environmental toxins, infections, and lack of exercise.)

Eating a low cholesterol diet alone is definitely not a sure thing to decrease your risk of heart disease.  Before you give up eggs for the long-term, be sure to ask questions and learn about all of the factors that help protect you from heart disease.  It is far better to adopt a more holistic approach to your diet and lifestyle to protect your health and your life.

References:

¹ Diet and Lifestyle Recommendations.  American Heart Association website. http://www.heart.org/HEARTORG/GettingHealthy/Diet-and-Lifestyle-Recommendations_UCM_305855_Article.jsp  Accessed December 20, 2012.

² Your Guide to Lowering Your Cholesterol With TLC. U.S. Department of Health and Human Services, National Institutes of Health, National Heart, Lung, and Blood Institute.  NIH Publication No. 06-5235.  December 2005.

³ The Nutrition Source, Fats and Cholesterol.  Harvard School of Public Health website. http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-and-cholesterol/  Accessed December 20, 2012.

⁴ USDA National Nutrient Database for Standard Reference, Release 25.  United States Department of Agriculture website. http://ndb.nal.usda.gov/  Accessed December 20, 2012.