The American Heart Association made a big splash recently by declaring that, by gosh, they’ve been right all along: saturated fats DO cause heart disease, so consuming coconut oil and other sources of saturated fat is a bad idea. We should all be consuming vegetable oils instead to lower our cholesterol and prevent heart disease.
Here’s a quote from Dr. Frank Sacks, the lead author of the AHA’s report:
“We want to set the record straight on why well-conducted scientific research overwhelmingly supports limiting saturated fat in the diet to prevent diseases of the heart and blood vessels.”
In a post last week, I pointed out that the American Heart Association’s very existence depends on people believing saturated fat and cholesterol are deadly. The AHA receives hundreds of millions of dollars in donations and licensing fees from Big Pharma and the makers of low-fat foods. If the Diet-Heart Hypothesis ever dies, so does the American Heart Association.
I also pointed out that Dr. Sacks once headed the AHA’s Nutrition Committee – which means he was given the task of determining if the advice he’s been peddling is correct. If the AHA wanted an objective report, they wouldn’t assign it to someone who would be committing professional suicide if he came to any other conclusion.
Gary Taubes wrote a detailed critique of the AHA’s report. The brief version is that Sacks and the other researchers engaged in rather creative cherry-picking. Somehow, in their objective search for scientific truth, they managed to exclude all but four clinical studies … and wouldn’t you know it, those four studies just happened to support the AHA’s position on saturated fats.
Taubes pointed out the flaws in those four studies. I don’t want to cover the same ground here. Instead, we’ll look at some contrary evidence Dr. Sacks chose to ignore. But first, here’s the abstract from the AHA report:
Prospective observational studies in many populations showed that lower intake of saturated fat coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of CVD and of other major causes of death and all-cause mortality. In contrast, replacement of saturated fat with mostly refined carbohydrates and sugars is not associated with lower rates of CVD and did not reduce CVD in clinical trials. Replacement of saturated with unsaturated fats lowers low-density lipoprotein cholesterol, a cause of atherosclerosis, linking biological evidence with incidence of CVD in populations and in clinical trials. Taking into consideration the totality of the scientific evidence, satisfying rigorous criteria for causality, we conclude strongly that lowering intake of saturated fat and replacing it with unsaturated fats, especially polyunsaturated fats, will lower the incidence of CVD.
“Taking into consideration the totality of the scientific evidence … “
Heck, I thought I was the comedian. That statement is just plain funny. Sacks and the other researchers didn’t consider anything close to the totality of the evidence.
Here are some quotes from a study titled Serum Cholesterol and Atherosclerosis in Man. (Sorry, all I have is a PDF in my files, not a link I can share.)
No correlation between the two could be found between the two, indicating that, when the age factor was removed, the positive correlation between aortic atherosclerosis and serum total cholesterol was statistically insignificant.
The points were scattered at random, showing there is no correlation between the serum total cholesterol and the amount and severity of aortic atherosclerosis.
Now for the punchline … that study was published in 1961 by the American Heart Association. Yup, their own study concluded that higher cholesterol doesn’t mean more heart disease.
And here’s a quote from one of the many analyses of data gathered from the long-running Framingham study:
After age 50 years there is no increased overall mortality with either high or low serum cholesterol levels. There is a direct association between falling cholesterol levels over the first 14 years and mortality over the following 18 years (11% overall and 14% CVD death rate increase per 1 mg/dL per year drop in cholesterol levels).
Got that? For each one-point drop in cholesterol, there was a 14% increase in cardiovascular death. Boy, doesn’t that make you want to run out and drink a Crestor cocktail?
Ah, but wait! Faced with such contrary evidence, the lipophobes later decided that it’s really the LDL cholesterol that matters, ya see. That’s the bad stuff. Keep that LDL level down to avoid heart disease.
Once again, we can cite the AHA’s own data to dispute that one. A nationwide study conducted by UCLA showed that 72.1% of people hospitalized for a heart attack had LDL levels below 130 – the supposed safe range for LDL. Here’s what the average lipid values were among the heart-attack patients:
Low total cholesterol and low LDL on average. (But please note they had high triglycerides and low HDL. A low-carb, high-fat diet lowers triglycerides and raises HDL.)
Looking at the data another way, we can say that only 27.9% of heart-attack victims had the “high” LDL levels that the American Heart Association tells us to avoid. But to know if that’s a meaningful figure, we also have to know what percentage of the population has high LDL. After all, if only 15% of Americans have high LDL but account for nearly 28% of heart attacks, we’d have to conclude the AHA has a point.
While writing a post in 2010 on that topic, I looked up some data on the AHA website. According to their own figures, 32.6% of Americans over age 20 have LDL levels above 130. So putting two and two together, here’s what we get:
People with “high” LDL make up 32.6% of the population, but account for just 27.9% of the heart attacks.
For those of you who prefer pictures, here’s a chart of some data taken from a 2002 National Institutes of Health report. The green bars represent the distribution of LDL levels among people in the 55-74 age group. The red bars represent the distribution of LDL levels among people in that group who have heart disease.
Text in the chart is small and difficult to read, but it tells us the average LDL level in that age group is 137.5. The average LDL level among people with heart disease in that age group is 104.9.
In other words, data from both the American Heart Association and the National Institutes of Health tell us that people with “high” LDL are under-represented among victims of heart disease.
If LDL is the “bad” cholesterol that causes heart disease, how can that possibly be true? Shouldn’t the fact that people with low LDL make up a disproportionate share of heart-attack victims be considered in the “totality of the scientific evidence”?
The AHA’s own data also show that among black, white and Hispanic men in America, Hispanics are the most likely to have “high” LDL – 42.7%, compared to 31.5% among white men. And yet the rate of heart disease among Hispanic men is 5.3%, compared to 9.4% among white men.
Among black, white and Hispanic women in America, blacks are the least likely to have “high” LDL. They also have the highest rate of heart disease. Once again, if LDL is the “bad” cholesterol that causes heart disease, how can that possibly be true? Shouldn’t these figures (found on the AHA’s own site) be considered in the “totality of the scientific evidence”?
Yes, I’m sure that in his effort to prove he’s been right all along, Dr. Sacks managed to pluck some studies in which high LDL was correlated with heart disease. I’m also sure I don’t care. Good scientists don’t cherry-pick. They don’t ignore or dismiss contrary evidence. And if we’re looking at the correlations (or lack of) between cholesterol levels and heart disease, there’s plenty of contrary evidence.
Here’s yet another example, from a study titled Lipids and All-Cause Mortality among Older Adults:
The results indicate higher mortality among older people with lower levels of total cholesterol.
Higher mortality among older folks with lower cholesterol? Whoops.
Furthermore, they show no association between all-cause mortality and hypercholesterolemia, high LDL, low HDL, hypertriglyceridemia, and high non-HDL in this group of older adults.
Nothing. No significant correlations at all for any measure of cholesterol. This was a study of 800 people that lasted 12 years. Shouldn’t it be considered in the “totality of the scientific evidence”?
But so far, we’ve been talking about observational studies. Dr. Sacks assures us the clinical studies provide “overwhelming” evidence that the American Heart Association is absolutely, positively correct in telling people to avoid saturated fats and switch to vegetable fats instead.
As a reminder, here’s what the AHA recommends:
Use these oils instead of solid fats (including butter, shortening, lard and hard stick margarine) and tropical oils (including palm and coconut oil), which can have a lot of saturated fat.
Here’s an alphabetical list of common cooking oils that contain more of the “better-for-you” fats and less saturated fat.
So skip that butter and switch to vegetable oils, folks. The American Heart Association says so.
Elsewhere on the site, the AHA tells us to choose skim or 1% fat dairy products. Saturated fat from dairy products will kill you, ya see. But is that what the science shows? Hardly.
A study titled Biomarkers of dairy intake and the risk of heart disease wasn’t exactly a clinical study, but it doesn’t suffer from the usual weaknesses of observational studies, either. The reason? The researchers didn’t rely solely on food questionnaires to determine what people eat. They directly measured biological markers of dairy fat in body-fat tissue, so they knew how much dairy fat people had consumed. Then they looked at rates of heart disease. Here are the results:
Dairy product intake as assessed by adipose tissue and by FFQ is not associated with a linear increase in the risk of MI in the study population.
People eating more dairy fat didn’t have more heart disease. In fact, as dairy-fat consumption went up, the researchers noticed a possible “protective” effect. So to avoid risking their future funding, they added this to their conclusions:
It is possible that the adverse effect of saturated fat in dairy products on cardiovascular health is offset by presence of beneficial nutrients.
Riiiiight. I guess when you skim away the deadly saturated fat from dairy products, you accidentally drop in beneficial nutrients.
Anyway, this is just one of several studies in which saturated dairy fats were NOT linked to heart disease. Same goes for saturated fats in general.
Dr. Sacks has an answer for those studies, however. It goes something like this:
Well, sure, in some studies people who ate less saturated fat didn’t have lower rates of heart disease. But that’s because they replaced the saturated fats with sugars and other processed carbohydrates that are really, really bad. [Note to American Heart Association: that’s what happens when you tell people to stop eating bacon and eggs, then put your seal of approval on boxes of Cocoa Puffs.] To really get the benefit of cutting back on saturated fat, you have to replace it with the good fats recommended by the AHA.
In several online articles, Dr. Sacks was quoted as saying he just can’t imagine why anyone would think coconut oil is healthy. After all, there are no clinical studies showing the benefits of coconut oil.
Since the American Heart Association recommends replacing butter and lard with soybean oil, corn oil or safflower oil, we must assume (if Dr. Sacks is being consistent) those oils have been tested in clinical studies.
And by gosh, they have.
In a clinical trial conducted in 1968, researchers had about 200 men switch from saturated fats to soybean oil, while a control group stuck to their normal diet. Men in both groups had survived a heart attack. By the end of the study some years later, average cholesterol levels in the soybean group dropped from 273 to 213.
A sixty-point drop! Wow, Dr. Sacks is right! Switching to a polyunsaturated oil will lower your cholesterol!
And here are the results from that study:
The total number of men who had a major relapse at any time in the trial was 45 in the test group and 51 in the controls; of these major relapses 25 in each group were fatal. None of the differences found is significant. Relapses were not related to initial cholesterol level, to change in cholesterol level during the trial, nor, in any consistent way, to observance of the dietary regimen. The results are compared with those from a similar trial in Oslo. There is no evidence from the London trial that the relapse-rate in myocardial infarction is materially affected by the unsaturated fat content of the diet used.
A huge drop in cholesterol, but no significant difference in heart attacks. Somehow, this trial didn’t make the cut when Sacks was looking at the totality of the evidence.
In another study conducted in 1965, researchers set out to test the benefits of replacing saturated animal fats with olive oil or corn oil. Here’s what happened:
Eighty patients with ischaemic heart disease were allocated randomly to three treatment groups. The first was a control group. The second received a supplement of olive oil with restriction of animal fat. The third received corn oil with restriction of animal fat. The serum-cholesterol levels fell in the corn-oil group, but by the end of two years the proportions of patients remaining alive and free of reinfarction (fatal or non-fatal) were 75%, 57%, and 52% in the three groups respectively.
Let me clarify in case your brain is getting tired by this point: in the group that continued eating animal fats, 75% were alive at the end of the study. In the group that switched to olive oil, only 57% were still alive. In the group that switched to corn oil, only 52% were still alive.
A study conducted (and apparently buried) by Ancel Keys in the 1960s was recently rediscovered. Here’s what The Washington Post had to say about it:
It was one of the largest, most rigorous experiments ever conducted on an important diet question: How do fatty foods affect our health? Yet it took more than 40 years — that is, until today — for a clear picture of the results to reach the public.
One of the largest and most rigorous experiments ever. For some reason, it didn’t make the cut when Dr. Sacks went looking for the totality of the evidence. Here’s why:
The story begins in the late 1960s and early ’70s, when researchers in Minnesota engaged thousands of institutionalized mental patients to compare the effects of two diets. One group of patients was fed a diet intended to lower blood cholesterol and reduce heart disease. It contained less saturated fat, less cholesterol and more vegetable oil. The other group was fed a more typical American diet.
Today, the principles of that special diet — less saturated fat, more vegetable oils — are recommended by the Dietary Guidelines for Americans, the government’s official diet advice book. Yet the fuller accounting of the Minnesota data indicates that the advice is, at best, unsupported by the massive trial. In fact, it appears to show just the opposite: Patients who lowered their cholesterol, presumably because of the special diet, actually suffered more heart-related deaths than those who did not.
And finally, another study conducted in the 1960s and 1970s was also recently rediscovered. In the Sydney Diet Heart Study, researchers had more than 200 men replace animal fats with safflower oil. The control group of more than 200 men continued eating their normal diet. Here are the results:
In this cohort, substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit. These findings could have important implications for worldwide dietary advice to substitute omega 6 linoleic acid, or polyunsaturated fats in general, for saturated fats.
Well, yes, these findings should affect the worldwide dietary advice to substitute polyunsaturated fats for saturated fats. Unfortunately, much of that worldwide advice originated with the American Heart Association, which can’t possibly admit to being wrong.
Most of the major media outlets dutifully reported the AHA’s recent (ahem) “findings” as if the AHA is a neutral observer and reporter of the science. Perhaps they were at one time, but certainly not now. When an organization’s very existence depends on a single hypothesis being true, they cannot possibly be trusted to objectively evaluate that hypothesis or any competing hypothesis. All they can do is declare themselves correct, no matter what the evidence.
So that’s what happened. They declared themselves correct. The “presidential advisory” report is cherry-picked garbage, Sacks still sucks, and the American Heart Association is still crazy after all these years.