What Cholesterol Myth?
There’s some people out there, smart ones even, who don’t believe that elevated cholesterol levels are dangerous for your health. One reader recently read The Cholesterol Myth by U. Ravnskov, MD, PhD and wrote to ask my opinion on his anti-cholesterol rhetoric. Is the whole cholesterol thing a scam, a phony issue, a myth?
The mainstream story goes like this: Animal products and some tropical oils have high levels of saturated fat. Eating a lot of saturated fat increases blood cholesterol levels. Having elevated blood cholesterol increases the chance of dying from a heart attack.
But, well, does it? Does eating saturated fat in the form of meat and whole milk and cheese and eggs and all that other good stuff really lead to heart attacks? Ravnskov’s point is that there is surprisingly little support from good randomized and controlled clinical trials to prove it.
But since Ravnskov stepped down from his soapbox there’s been some new evidence supporting the role of dietary intake of saturated fat (and that means cholesterol as the body sees it) in the development of heart disease. A Harvard study reviewed the literature to date (as of June, 2009) and pooled the existing research to look for an overall effect of replacing saturated fat with poly-unsaturated fat in the form of vegetable and fish oils.
They found that people who replaced saturated fat in their diets with poly-unsaturated fat had a 19% reduced risk of heart disease troubles like heart attacks. For each 5% energy increase of poly-unsaturated fat in the diet substituting for saturated fat, there was a 10% reduction in risk. It was “dose dependent” so a little reduction of saturated fat helped a little and a big reduction helped a lot. The longer people stuck to the diet change, the greater the benefit that was seen.
The risk of heart disease was reduced by 24% for each 1 mmol/l reduction in total cholesterol. This finding is consistent with results of observational studies of total cholesterol levels and the risk of heart disease.
The Harvard review provides proof from randomized, controlled clinical trials – the gold standard for medical evidence – that reducing saturated fat in the diet (and thus cholesterol) and replacing it with poly-unsaturated fat reduces heart attacks. It’s not a myth.
And nobody’s talking drugs here. This is about diet. It’s about what you put into your body.
But there’s one caveat. Because the trials included in this study looked only at replacing saturated with poly-unsaturated fat, it’s not possible from this evidence alone to distinguish between the benefits of reducing saturated fat and the benefits of increasing poly-unsaturated fat. It’s likely they work in concert.
Other studies looking at replacing saturated fat with carbohydrates weren’t so supportive. This may be because of the choice of carb. If participants were eating more refined grains and sugar, then the inflammatory condition inspired by their choices may have counterbalanced any beneficial effect of lowering saturated fat. We know that fructose without fiber (Dr. Lustig’s poison without its antidote) increases triglycerides and the small, dense (ie dangerous) form of LDL. That small form of LDL is what climbs up under the lining of blood vessel walls and forms atherosclerotic plaques of cholesterol that eventually rupture causing a heart attack.
One point to remember is that the studies in the Harvard review didn’t differentiate between omega-6 and omega-3 poly-unsaturated fats. The latter is protective against heart disease while the former is of questionable merit. Could it be that using oils like canola that have higher levels of omega-3 rather than something like lard, which is predominately saturated fat, is really what matters? Is it not the reduction of saturated fat but rather the addition of omega-3? Again, I think it’s a concerted effort of both together. Those saturated fat calories have to be replaced with something – might as well be healthy, protective fats instead of sugar, white bread, hydrogenated oils and junk food.
My take is that we should be eating less saturated fat and cholesterol, and that means less animal fat. All saturated fat isn’t the same though, and saturated fat from plant sources, like coconuts, is better than animal sources because it contains primarily medium chain fatty acids rather than long ones. The Yogis may have had this one right, too. In the old Hatha Yoga Pradipka, the gurus recommended that aspirants not eat “fish, goat, or other meat” and not consume “oil.” (I:59) On the other hand, they did promote coconuts – and even minimal amounts of dairy products for a Yoga diet. (I:62)
While the latter may seem a contradiction, I believe this should be taken within the context of moderation. We need fat. We need cholesterol. They’re paramount to proper bodily functioning. But as with so many things, the middle path of moderation is the key. We have to find the right balance.
The American Heart Association (AHA) agrees, too. They don’t recommend no saturated fat, but rather that the intake is less than 10% of dietary energy for those without heart disease or diabetes. It drops to a recommended 7% of the diet with those conditions.
What’s 10%? If a normal diet is 2000 calories, then 10% is 200 calories.
A large egg contains 1.5 grams of saturated fat, and at 9 calories per gram, that’s 13.5 calories from saturated fat. (It also contains about 200 grams of cholesterol, so within the <300 grams of actual cholesterol per day recommended by the AHA.)
If you cook the egg in 2 tablespoons of canola oil, that’s another 2 grams of saturated fat. (Canola oil is primarily poly-unsaturated with a high level of healthy omega-3.) So if you fry an egg (okay, I recommend boiling, but…) in canola oil, you’ll get another 18 calories for a total of 31.5 calories of saturated fat from an egg sandwich for breakfast. And that’s less than a quarter of the 200 calories advocated by the AHA.
And what if you cook it in butter? (gasp!) If you use two tablespoons of butter, that’s 14 grams, so another 126 calories from saturated fat. One egg cooked in two tablespoons of butter provides 140 calories from saturated fat, well within the dietary guidelines for cholesterol provided by the AHA. That means, of course, little dairy, meat products or other forms of saturated fat for the rest of the day.
And that’s the problem. Most people would not only eat bacon or sausage with that fried egg, but they might also include a glass of milk or cream in their coffee. Then they would butter their toast. And then they would have cheese for lunch – on top of their hamburger. And then have pot roast for supper. (Yes, SUPPER. I’m from the rural Midwest where we also warsh our clothes rather than wash them.)
If you’re considering following Dr. Ornish’s low-fat diet (which I highly recommend) because you have known cholesterol deposits in your blood vessels and heart disease, then the AHA guidelines for the average well person are too high. As noted in my last post, it’s Ornish’s cure-with-diet-and-no-drugs program that has reversed the build-up of cholesterol in the arteries of the heart – and decreased heart attacks, hospitalizations, and angioplasties by 2.5 times! It’s those gnarly cholesterol build-ups that destabilize and rupture in a heart attack.
Cholesterol is not the entire answer. It’s not that simple. The human body is complex. Some people have stable cholesterol plaques that never rupture. What makes them rupture? That’s a whole different topic. The point is that when they’re there, that other thing that makes them rupture comes along and ruptures them. And if they’re not present within the blood vessel wall to rupture, then that other thing can’t do so much damage.
Bottom line:
Limit intake of saturated fat, which the body sees as cholesterol, from animal products like meat, milk, cheese and butter. Most people should strive for obtaining only 10% of their calories from animal sources.
Replace most animal fats with olive oil and canola oil.
Avoid hydrogenated fat, partially hydrogenated fat, and trans fat like the plague. They increase LDL cholesterol and reduce HDL cholesterol levels in the blood and lead to disease-causing inflammation – provoking heart attacks from two angles. That means no commercially prepared cookies, crackers,and other baked goods, commercially prepared fried foods, and most margarines.
In the next post, I’ll go over, point-by-point, the “facts” Dr. Ravnskov presents on his website.
References:
Mozffarian D, Micha R, Wallace S. Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLoS Med. 2010 Mar 23;7(3):e1000252.
American Heart Association Dietary Guidelines: Revision 2000
NIH’s National Cholesterol Education Program: Third Report
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Loved the article! Balance balance balance – in all things
lol “supper” and “warshing” clothes – seems mid-westerners and east-tennesseans speak the same language
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