This article was published in the August/September 2010 Wedge newsletter. The following information may be outdated.

Don't be Afraid of Cholesterol

By Jennette Turner

Studies have yet to peg high cholesterol as a cause of heart disease, or prove that lowering one's cholesterol lowers the risk. Still, cholesterol has been blamed for our nation's high rates of heart disease for the past several decades; and still, medical establishments, pharmaceutical companies and processed food industries are admonishing Americans to reduce our consumption of dietary cholesterol and advising us to take statin drugs when our cholesterol levels are "too high."

Predictably, heart disease rates have not decreased. And medicine is now concluding that if lowering cholesterol did not work, it must mean levels need to be lowered even further.

There have always been doctors and scientists who disagreed with this cholesterol hypothesis and worked to propose alternate theories, but dissent often resulted in the blacklisting of researchers or the discontinuation of their funding. Over the past 10 years, however, the accumulated evidence has overwhelmingly shown cholesterol is not the villain it was made out to be.

Voices from the "alternative" health care movement, including Dr. Joseph Mercola and the Weston A. Price Foundation, were among the first to provide opposing views about heart disease. Now, popular books such as Gary Taubes' "Good Calories, Bad Calories" have brought the issue into the mainstream.

Cholesterol is a natural substance found in every single one of the body's cells, not an evil to be eradicated. Our bodies make around 80% of the cholesterol we need; the rest must come from our diets, where it is found only in animal products like eggs, dairy and meat.

Here are some of the ways cholesterol functions in the human body:

It maintains the stability, integrity and fluidity of cell membranes and facilitates communication between cells (including cells in the brain)
It is a precursor for bile acids and salts, which assist in the digestion of fats, and helps strengthen the lining of the gut (this is why low cholesterol diets are a risk factor for irritable bowel syndrome, colitis and other digestive discomforts)
It is the body's basic repair substance, assisting in the replacement of old or damaged cells and used throughout the body (including the arteries) for healing
It is the "mother of all hormones": all our steroid hormones (including glucocorticoids, which help regulate blood sugar, and DHEA, the "youth" hormone), stress hormones (including adrenaline and cortisol) and sex hormones (including estrogen, progesterone and testosterone) are made from cholesterol

The brain is a particularly cholesterol-dependent organ. It makes up only 2% of body weight, yet it contains 25% of the body's cholesterol. Our ability to think, reason and learn is a result of the "plasticity" of our brains, or the way the brain constantly forms new connections (know as "synapses") between neurons. The ability of cells to make these connections is dependent on a limiting factor: cholesterol. Low cholesterol levels have shown an increased risk for memory loss and other cognitive dysfunction, and are linked to mental illness, depression, anxiety, violence, aggression and suicide.

If we don't have enough cholesterol, our bodies will divert cholesterol from the endocrine system to use for brain function. This can put our bodies into a state of hormonal upheaval and leave us vulnerable to a host of problems such as diabetes, heart disease, adrenal and thyroid disorders, chronic fatigue and infertility.

When Harvard researchers found an association between low-fat dairy foods and infertility, doctors began recommending full-fat dairy to infertile women—with the disclaimer that they should return to low-fat foods after conception. This implies a woman's reproductive health is somehow separate from her overall health. It also begs the question: is a diet that reduces fertility healthful for anyone?

In addition to cholesterol's unique individual functions, it also affects other important factors in our health. For example, cholesterol is required for our bodies to make Vitamin D, a fat-soluble vitamin that assists in the metabolism of minerals. D is required for the growth and repair of bone tissue, protects our bodies from cancer, supports cardiovascular health and strengthens the immune system. Vitamin D also helps our bodies regulate insulin and promotes mental health.

Our bodies can make Vitamin D from cholesterol when we are exposed to UVB sunlight, the availability of which depends on the angle of the sun (making Vitamin D synthesis impossible for much of the year in Northern climates like Minnesota). In the summer, UVB rays are primarily present during "peak" hours— the work day for most people. It is also important to note that sunscreen prevents us from being able to convert cholesterol into Vitamin D. Bottom line: most people cannot count on the sun to supply them with all the Vitamin D they need.

We need to obtain Vitamin D from food. It is found with cholesterol, and only in animal fats: full-fat dairy and butter, pork, lamb, liver and fatty fish. With the exception of fish, these are foods we have been warned about, even as our rates of diabetes, cancer, heart disease, depression and osteoporosis (all related to D deficiency) climb ever higher.

Analyses like the above make clear our whole bodies depend on cholesterol. The misguided focus on lowering blood cholesterol levels has been damaging to the physical and mental health of many people. We are fortunate to be able to repair the damage by easily managed (and delicious) changes. Start with eggs for breakfast; put butter or ghee on your vegetables; and, if you eat dairy products, enjoy the full-fat varieties. Try some of the Wedge's nitrate-free bacon—it is BLT season, after all. Eat real food, including red meats, liver and seafood, without guilt. Human beings evolved eating animal foods, and animal fats, and they support our health.

The reasons why the cholesterol theory came to be accepted as fact are complicated and involve political as well as medical motivations. For a thorough examination of ways the pharmaceutical and food industries have influenced consumers, doctors and government agencies that provide health recommendations, I highly suggest Marion Nestle's Food Politics (University of California ©2002) and Overdosed America, by Dr. Jon Abramson (HarperCollins ©2004).

Learn more about cholesterol and hormones in Jennette's lecture Building Fertility with Nutrition at the Wedge in September. See class schedule in this issue for details.

Resources:

J.A. Alvarez and A. Ashraf, "Role of Vitamin D in Insulin Secretion and Insulin Sensitivity for Glucose Homeostasis." International Journal of Endocrinology, vol. 2010 (Article ID 351385)

B.A. Barres and S.J. Smith, "Cholesterol – Making or Breaking the Synapse." Science Magazine, vol. 294: Nov. 2001

Dr. John Cannell, M.D., "Understanding Vitamin D Cholecalciferol." Vitamin D Council website
J.E. Chavarro et al, "A Prospective Study of Dairy Foods Intake and Anovulatory Infertility." Human Reproduction, 22(12): December, 2007

C.F. Garland et al, "The Role of Vitamin D in Cancer Prevention." American Journal of Public Health, 96 (2): February 2006