The Dean Ornish HDL-ain't-nothin-but-a-garbage-truck rag
I feel about Dean Ornish the same way as one of my favorite philosophers, David Stove (1927-1994), must have felt about his own philosophy department at the University of Sydney when he wrote about it thusly:
[It] is a disaster area, and not one of the merely passive kind, like a bombed building, or an area that has been flooded. It is the active kind, like a badly leaking nuclear reactor, or an outbreak of foot-and-mouth disease in cattle.
And like some kind of a toxic spill, Dr. Dean Ornish is there emitting effusions of imbecilities into the airwaves year after year, polluting the minds of those gullible enough to listen.
His latest screed is a ‘fact’ sheet written in response to a presentation that was made November 9, 2003 at one of the scientific sessions of the meeting of the American Heart Association. The presentation was ultimately written up as a paper and published in JAMA in January 2005. Why Ornish is just now getting around to attacking this paper I haven’t a clue.
Let’s first go through this study; then we’ll take a look at what has got Ornish’s panties in a wad. Finally, we’ll deal with his ‘fact’ sheet.
The paper entitled Comparison of the Atkins, Ornish, Weight Watchers, and Zone Diets for Weight Loss and Heart Disease Risk Reduction is another one of those studies not really worth the paper they’re written on because of fatal flaws in both the data collection and the study design.
The researchers recruited 160 people from newspaper ads and local TV news blurbs. These subjects were randomly assigned to one of the four following programs: the Atkins diet, the Ornish diet, the Zone diet, or Weight Watchers. Each group of 40 subjects underwent what the researchers referred to as “maximum effort,” which amounted to the following intervention:
A single team composed of a dietitian and physician administered diet-specific advice to each group, meeting for 1 hour on 4 occasions during the first 2 months of the study. At the first meeting, the team revealed the diet assignment and provided the corresponding rationale, written materials, and official diet cookbook. Subsequent meetings aimed to maximize adherence by reinforcing positive dietary changes and addressing barriers to adherence.
The Atkins diet group aimed for less than 20 g of carbohydrate daily, with a gradual increase toward 50 g daily. The Zone group aimed for a 40-30-30 balance of percentage calories from carbohydrate, fat, and protein, respectively. The Weight Watchers group aimed to keep total daily “points” in a range determined by current weight. Each “point” was roughly 50 calories, and most participants aimed for 24 to 32 points daily. Lists provided by the Weight Watchers Corporation determined point values of common foods. The Ornish group aimed for a vegetarian diet containing 10% of calories from fat.
In an effort to isolate the effects of the dietary component of each plan, we standardized recommendations pertaining to supplements, exercise, and external support. We encouraged all participants to take a nonprescription multivitamin daily, obtain at least 60 minutes of exercise weekly, and avoid commercial support services. To approximate the realistic long-term sustainability of each diet, we asked participants to follow their dietary assignment to the best of their ability until their 2-month assessment, after which time we encouraged them to follow their assigned diet according to their own self-determined interest level.
Basically here is what happened. The researchers recruited people from the greater Boston area who were overweight and wanted to participate in a weight-loss study. Each person was put in with a group of 39 other people and on the first day were informed which diet they were to go on. The subjects attended three more meetings of about an hour each over the next two months, and were then told to go an do their best and to come back in ten months.
What were the results? Pretty much what you would expect with this level of effort and attention. About half of the subjects dropped out, and the ones who stayed in were lax, to say the least, in following their specific program. After the two months of “maximum effort” the subjects in the Atkins group were eating fewer carbs, the ones in the Ornish group were eating less fat, and the ones in the other two groups were in between. At the end of the year, the groups were pretty much indistinguishable in terms of their diet. For example, subjects in the Atkins group were eating an average of 190 grams of carbohydrate and about 80 grams of fat while those in the Ornish group were eating 218 grams of carbohydrates and 64 grams of fat (21 grams of which were saturated fat, an absolute no no on the Ornish program). So the low-carbers weren’t low-carbing and the low-fatters weren’t low-fatting.
Those subjects who remained in the study were evaluated at the end of the first two months, at six months and at the end of the year. Researchers evaluated a number of lab values at these milestones looking for differences between the groups. What they found was that there was very little difference, which isn’t surprising since most of the subjects went off their assigned diet and kind of tended back toward what they were eating at the beginning of the study. There were some slight differences, however, and it was one of these differences that stuck in Ornish’s craw.
Turns out that the dieters in the Ornish group dropped their levels of HDL-cholesterol, the so-called ‘good’ cholesterol, whereas it went up or stayed the same in the other groups. We’ll consider the HDL issue shortly, but first let’s look at the fatal flaw in this study.
All the subjects who were recruited were obese. They had BMIs of 35 and weight about 220 pounds on average. To determine their baseline diets the subjects were asked to complete 3-day food records at the start of the study. As reported by these subjects, their intake at the start of the study when they weren’t actively dieting was around 1950 calories. I can tell you from long experience that people weighing 220 pounds and who aren’t dieting consume one hell of a lot more than 1950 calories a day. If you run 220 pounds through one of the equations commonly used to calculate energy expenditure you will discover that these subjects require somewhere in the range of 2900 calories per day just to maintain their body weight. At the caloric intake they reported at the start of the program, they would be in an almost 1000 calorie per day deficit. What does it all mean? It means that the recording of the diets of these subjects was totally unreliable. And if it was this unreliable at the start, who can say whether or not it remained unreliable throughout. If the macronutrients were analyzed based on the reporting of these subjects, then those figures were totally unreliable as well.
As you might expect, all the lab parameters were pretty much the same between all the groups. There were no statistical differences between total/HDL cholesterol, insulin, and C-reactive protein and no significant effects on blood pressure or glucose. What can be pretty much concluded from this sorry study is that if people don’t follow any kind of a diet, nothing much changes. Despite the fact that the study was a major bust in terms of data, there was one difference between the groups: the subjects on the Ornish diet dropped their HDL levels significanlty, which brings us to his ‘fact’ sheet.
The ‘fact’ sheet, which can be read in it’s entirety by clicking here may contain a few facts, but any hard facts it does contain are soon dissolved in a strong solution of total nonsense. The fact that WebMD chose to publish this nonsense should tell you all you need to know about that outfit.
He starts by showing all the positive findings of the study in regards to his program. Unfortunately, most of these statements are not backed up by the study. He then gets to the real problem with this study as he sees it:
The authors reported that “all but the Ornish diet resulted in significant reductions in the Framingham risk score.” However, this finding is very misleading.
The Framingham risk score is a system developed by the people in charge of the long-running Framingham study and is calculated to a great extent by total cholesterol and HDL-cholesterol levels. In this scoring system anything that lowers HDL levels increases the risk for heart disease. Total cholesterol levels fell in all the groups in the above study and HDL levels increased in all the groups except for the Ornish group in which HDL levels dropped. As a consequence, according to the Framingham score, the subjects on the Ornish diet increased their risk for heart disease, which does not set well with Dr. Ornish who has built his reputation on the fact that his program protects against and even reverses heart disease.
Like a politician caught with his hand in the till, Ornish comes up with this convoluted explanation of why all the rules don’t apply to him or his program. He has this to say about the HDL levels falling in the group on his diet:
What does this mean? Your body makes HDL to remove excessive fat and cholesterol in your diet, like a garbage truck. Most Americans consume a diet high in saturated fat and cholesterol, so those with higher HDL levels are at lower risk for heart disease since they will be more efficient at metabolizing and removing excessive saturated fat and cholesterol. In other words, those with higher HDL levels have more garbage trucks (HDL) to get rid of the garbage (excessive fat and cholesterol).
However, when someone on a high-fat, high-cholesterol diet changes to a healthy low fat, low-cholesterol diet, their HDL levels may not increase or even decrease because there is less need for it. When you have less garbage, you need fewer garbage trucks to remove it, so a reduction in HDL on a low-fat diet is not harmful.
In contrast, someone who increases the amount of fat and cholesterol in their diet (e.g., an Atkins diet) may increase their HDL because their body is trying to get rid of the extra garbage (fat and cholesterol) by increasing the number of available garbage trucks (HDL). For example, eating a stick of butter will raise HDL in those who are able to do so, but that does not mean that butter is good for your heart.
Interesting, but just like the famous “I did not have sex with that woman, Ms. Lewinsky” speech, it’s a bunch of smoke and mirrors. And it doesn’t even make sense, but that is never a problem for Dr. Ornish.
HDL does indeed scavenge cholesterol from the tissues and transport it to the liver where it is then repackaged and sent back out to the tissues or is discharged into the GI tract through the bile. The cholesterol in the bile is then reabsorbed into the liver, repackaged and sent back out to the tissues. Here is where the Ornish analogy to the garbage truck breaks down. His terminology implies that the cholesterol is taken to the ‘dump’ where it is deposited never to be seen again. In actuality, using his terms, what happens is that the garbage trucks take the garbage (cholesterol) to the dump and other trucks pick it up and bring it back. So, if you’ve got fewer garbage trucks hauling it to the dump, you need fewer to bring it back.
Because it doesn’t really make sense that years of natural selection would have designed a system to act this way–taking it away and bringing it back to no useful purpose–researchers have suspected that there is much more to HDL than simply the cholesterol-scavenging aspects. And sure enough, there are.
HDL acts as an anti-inflammatory agent and an antioxidant. It binds harmful substances in the blood, stimulates endothelial cell movement, decreases multiple clotting functions, protects red blood cells, stimulates the synthesis of prostacyclin (an important substance involved in arterial relaxation), and increases the half life in the circulation of this prostacyclin. HDL reduces growth factor synthesis in the vascular smooth muscle cells, stimulates the production of nitric oxide, modulates endothelial function and is antithrombotic. All in all, HDL is something you want more of, Dean Ornish’s talk of needing fewer garbage trucks notwithstanding.
As to the idea that lower HDL levels are a function of having less ‘garbage’ to cart away, recent studies show that people with hyperinsulinemia apparently destroy their own HDL particles at greater rates than those with normal insulin levels, leading to lower blood amounts. Apparently people have lower HDL levels because they have an underlying problem, not because they have less ‘garbage’ to haul away. And any way you want to cut it, the Ornish diet lowers HDL levels. Not only did the study detailed above show this HDL lowering effect, his own published studies show it as well.
But our Dean doesn’t let a little thing like the facts stop him. Not on your life. He ends his ‘fact’ sheet by explaining the fall in HLD levels seen on his program with the same faulty argument that he has used forever:
At best, HDL is only a risk factor for heart disease. In our studies over the past 25 years, we used actual measures of heart disease to see what happened to patients with severe coronary heart disease who consumed a low-fat, whole foods diet [my italics]. They showed reversal of their heart disease using state-of-the-art measures such as quantitative coronary arteriography, cardiac PET scans, thallium scans, and radionuclide ventriculography in randomized controlled trials published in leading peer-reviewed journals. Also, there were 2.5 times fewer cardiac events in these patients. LDL decreased by 40% on average after one year and HDL decreased by 9%, yet these patients showed clear reversal of their heart disease in every way we could measure.
I posted on this very subject a few days ago. All the published studies he refers to are with subjects who are following his program, which comprises four parts: stress management and meditation, smoking cessation, exercise, and a low-fat, vegetarian diet. As I pointed out in my earlier post meditation and stress reduction reduce the incidence and severity of heart disease all by themselves as does exercise and stopping smoking. Ornish tries to pin whatever success his patients have on his program to the diet, when there are three other components that have been shown to reduce heart disease that he tries to sweep under the rug.
We can turn Australian philosopher Stove’s words on Ornish and his idiotic arguments once again:
How did an argument so easily answered ever impose itself upon intelligent people? Easily. It was simply a matter of ensuring…a one-sided diet of examples.