January 2016

The Great Cholesterol Myth

 

Long-standing dietary advice has told us to reduce cholesterol intake, but a closer look suggests this advice may be misguided.  Learn more about the history of this information, studies surrounding cholesterol’s effects on heart health and how to protect your heart.

 

In 1953, a young biologist named Ancel Keys proposed the then-radical theory that heart disease was caused by consuming too much fat in the diet.  It’s difficult to imagine that this theory was radical given how widespread its acceptance is today, but at the time the prevailing belief was that diet had little to do with heart disease.  However, Keys believed he was on to something.  Previous research showed that when you fed rabbits large amounts of cholesterol, their arteries were filled with cholesterol-laden plaque.  Never mind the inconvenient fact that rabbits are herbivores and the amount of cholesterol in their diets is pretty close to zero.  And that other animals, such as rats and baboons, do not react in the same way as rabbits to a high-cholesterol diet; they metabolize cholesterol very differently.

 

The recommendation to eat “no more than 300 mg of cholesterol” a day remains the standard dietary advice of every major health organization to this day.  Because fat in the diet and cholesterol in the blood were believed to be linked, Keys began to investigate dietary fat and its connection to heart disease.  He looked at data on fat consumption and heart disease from various countries and published the results in his famous Seven Countries Study, which supposedly demonstrated a clear link between the amount of dietary fat consumed and the incidence of heart disease.  Those countries eating the most fat also had the highest rates of heart disease.  Sounds like an open-and-shut case against dietary fat, doesn’t it?  Except it was anything but: Keys had available to him reliable food consumption data from 22 countries, but he used only seven.  By hand-selecting the seven countries that supported his preconceived hypothesis, Keys was able to make a convincing case that there was a direct connection between fat consumption and heart disease.  The fact that Keys chose to include only seven countries and ignored the other 15 didn’t go unnoticed.  Many researchers criticized Keys for conveniently omitting data that didn’t support his theory.  When analyzing the data from all 22 countries, researchers found that the correlation between fat, cholesterol and heart disease vanished.

The Seven Countries study is the cornerstone of current cholesterol and fat recommendations and official government policy, so it’s worth examining.  Keys examined fat consumption in seven countries: Italy, Greece, the former Yugoslavia, the Netherlands, Finland, the United States and Japan.  It hardly went unnoticed that Keys chose only the countries that fit his hypothesis.  In fact, British physician Malcolm Kendrick used the same data available to Keys and quickly discovered that if you simply chose different countries, you could easily prove that the more saturated fat and cholesterol people consumed, the lower their risk of heart disease.  Yet Dr. John Yudkin (The University of London) found that, in some countries, the intake of fat was virtually the same, but the rates of cardiovascular disease were vastly different.  For example, Finland had a high per capita fat intake and a high rate of heart disease.  But the people of West Germany ate the same high fat diet, yet they had one-third the rate of heart disease seen in Finland.  In addition, the Netherlands and Switzerland had only one-third the rate of heart disease seen in Finland, even though the Dutch and Swedes consumed even more fat than the Finns.

 

Cherry-picking the countries that proved the theory was only one of the many problems with the Seven Countries Study.  There were also tremendous variations in heart mortality within these countries, even though saturated fat consumption was identical.  How did Keys explain these facts, which were clearly present in his data?   He didn’t.  He ignored them.  And then he managed to get his theories officially incorporated into the 1960 AHA dietary guidelines, where they have influenced government policy on heart disease, fat consumption and cholesterol for decades. 

 

So: how has this advice worked out?  The largest study (Women’s Health Initiative) ever to ask whether a low-fat diet reduces the risk of getting cancer or heart disease has found that a low-fat diet has NO effect.  Yet these questionable findings didn’t stop the cholesterol-lowering, fat-avoiding juggernaut that continues to this day. 

 

One of the most respected researchers in the world, Michel de Lorgeril, a French cardiologist, has authored dozens of papers in peer-reviewed journals and was the lead researcher for the Lyon Heart Study, a 1999 study on the cardiovascular effects of a Mediterranean-style diet.  The following quote comes from his only book written in English: “We can summarize in one sentence: Cholesterol is harmless.”

 

So now where do we go?  Back to Dr. Yudkin, who examined Keys’ Seven Countries Study.  Dr. Yudkin looked at different types of fats.  He even looked at the roles of carbohydrates and protein, and instead of confirming Keys’ hypothesis, Yudkin’s much more comprehensive data showed that the single dietary factor that had the strongest association with coronary heart disease was..wait for it.. sugar and other concentrated sweeteners.   The way all types of sugar damage the heart can be directly related to insulin resistance, or pre-diabetes.  Further, the culprit is fructose, not glucose.  Research has shown that fructose is seven times more likely to form artery-damaging glycation end products.  Fructose is metabolized by the body like fat, and it turns into fat (triglycerides) almost immediately.  Fructose is the major cause of fat accumulation in the liver, a condition called fatty liver.  And there is a direct link between fatty liver and insulin resistance, or pre-diabetes.

 

**One important caveat: Fructose found in whole foods such as fruits is a different story.  There is not all that much fructose in an apple, for example, and the apple comes with a hefty dose of fiber, which slows the rate of carbohydrate absorption and reduces insulin response.  But fructose as an added ingredient (which you will find on the food label in the list of ingredients), concentrated into a syrup, and then inserted into practically every food we buy at the supermarket (bread, pretzels, cereals, crackers), well that’s a different story.  Since the introduction of high-fructose corn syrup into our food supply in the 1970’s, our fructose consumption has sky-rocketed.  As Dr. Robert Lustig (“Sugar: The Bitter Truth”) points out, the percentage of calories from fat in the American diet  has gone down at the same time that fructose consumption has skyrocketed, along with heart disease, diabetes, obesity and hypertension.  Coincidence?   Don’t think so.

 

Metabolic syndrome is a collection of symptoms: high triglycerides, abdominal fat, hypertension and insulin resistance that seriously increases the risk for heart disease.  In humans, a high-fructose diet raises the triglycerides almost instantly; the rest of the symptoms associated with metabolic syndrome take longer to develop, but they develop, nonetheless.

In summary, the case against fructose consumption as a key factor in the development of heart disease seems to be far more cogent than the case against fat.  It’s also worth pointing out that every single bad thing fructose does to increase our risk for heart disease (and it does a lot!) has virtually nothing to do with elevated cholesterol.  The fact is that sugar is far more damaging to the heart than either fat or cholesterol, but that has never stopped the diet establishment from continuing to stick to its story that fat and cholesterol are what we ought to be worried about.

 

Jonny Bowden and Stephen Sinatra

**Consult with your physician or Registered Dietitian about your personal risk for heart disease.

 

EAT FOR HEART HEALTH

 

Eliminate These Foods

• High-fructose corn syrup, fructose (as an added ingredient) and soda
• Processed carbohydrates (white bread, white pasta, crackers and white rice)
• Trans-fats (partially hydrogenated oils), corn and vegetable oil
• Processed meats such as bacon, ham, hot dogs, bratwurst and most sausages

 

Eat More of These Foods

• Vegetables
• Wild salmon
• Berries and cherries
• Grass-fed meat
• Nuts
• Beans
• Dark chocolate
• Garlic and turmeric
• Pomegranate juice, green tea, red wine
• Extra virgin olive oil

Make These Changes to Reduce Lifestyle Stress

• Meditate or practice deep breathing
• Express your emotions
• Play
• Cultivate intimacy and pleasure
• And most of all: enjoy your life!!

 

Good to Know:  If you doctor is concerned about your cholesterol levels, ask about the following tests, which are far more important than the standard test for cholesterol:

LDL Particle Size: Measures whether your LDL particles are mostly type A, the large, fluffy, benign kind, or mostly type B, the small, dense kind that cause inflammation (one common test is the NMR LipoProfile; others include the Lipoprint, Berkeley, VAP and LPP).

hs-CRP: Measures CRP, a marker for inflammation directly associated with cardiovascular health; an optimal level is less than 0.8 mg/dL.

Fibrinogen: Measures the levels of a protein that determine blood’s ability to clot properly, normal levels are between 200-400 mg/dL.

Serum Ferritin (Iron): Test for iron overload, which can contribute to heart disease; optimal levels are less than 80 mg/dL for women and less than 90 mg/dL for men.

Lp(a): Elevated Lp (a) levels are a very serious risk factor for heart attacks

Homocysteine: Elevated levels strongly predict first and recurring cardiovascular incidents; optimal levels are between 7 and 9 umol/L.

Interleukin-6: Elevated levels are a precursor to elevated CRP levels; optimal levels are between 0.0 and 12.0 pg/mL

Coronary Calcium Scan: Measures coronary calcification; a score of about 400 is considered extensive and a risk factor for coronary events.

 

 

**The Framingham Heart Study**

One study often mentioned by the defenders of the cholesterol theory is the Framingham Heart Study.  Retrospective review of these data (the study started back in 1948) revealed that those subjects with high cholesterol lived just as long as those who had low cholesterol.   In fact, heart disease struck individuals with cholesterol levels as low as 150 mg/dL.  In short, with regard to the study subjects, the more saturated fat one ate, the more cholesterol one ate, the lower the person’s cholesterol.  People who ate the most cholesterol, the most saturated fat and ate the most calories weighed the least and were the most physically active.