Dean Ornish, M.D.

I’m glad to see that my recent column sparked a lively debate, as understanding different perspectives brings us closer to what is true. However, given the level of anger, misunderstanding, and ad hominem attacks in many of the posts, one might think I’d written an article entitled, “Why the Atkins Diet Causes High Gasoline Prices” instead of an essay describing common ground among different diets.

At a time when our country is more balkanized and polarized than ever, it’s important that we look for ways to come together when possible. To say that there is a convergence of dietary recommendations does not mean that we all agree on everything; clearly, important differences remain. The Atkins diet, Mediterranean diet, and low-fat diets all have some benefits. No one has a monopoly on truth, and we can all learn from each other.

Several people wrote about my statement that patients in the recent NEJM study were counseled to choose vegetarian sources of protein and fat. As one wrote, “Dr. Ornish states that this study was of a ‘vegetarian Atkins diet’. That’s absolutely false, and I’m very surprised someone that claims his credentials would make such a purposeful mis statement.”

I didn’t make this up. In the NEJM study, the authors wrote in the Methods section, “the participants were counseled to choose vegetarian sources of fat and protein and to avoid trans fats.” If the lead author is now saying in an email to one of the bloggers that “Our low-carb diet was based on Atkins, the participants read the book and the recipes were more or less comparable to what you know in the states. Beef is the main red meat,” then it’s hard for me to understand why patients in the study were counseled to choose vegetarian sources of fat and protein. What were they thinking? I wonder why the journal article did not describe the types of foods that patients reported consuming since it’s a major focus of the intervention.

Also, those on the “low-fat” diet in this study decreased their total fat intake from 31.4 percent to 30.0 percent, hardly at all. Other studies have shown that this trivial reduction in total fat has virtually no effect on LDL-cholesterol, and that’s what this study found as well. In contrast, we found a 40% average reduction in LDL-cholesterol after one year in a randomized controlled trial published in the Journal of the American Medical Association when people reduced dietary fat to 10 percent of calories, without cholesterol-lowering drugs—and they reversed their coronary heart disease, which I’ll describe more later. A 40 percent reduction in LDL is comparable to the effects of statin drugs like Lipitor but without the costs and side-effects. No study of the Atkins diet has ever reported reductions in LDL to this degree.

Gary Taubes wrote in TierneyLab (July 21) that the NEJM study validates that saturated fat is not harmful because the intake of saturated fat was higher in the Atkins group yet their LDL cholesterol decreased. “How can saturated fat be bad for us if a high saturated fat diet lowers LDL at least as well as a diet that has 20 to 25 percent less saturated fat?”

Let’s examine the data. Saturated fat intake was essentially unchanged (approximately 10% of calories) in both the “low-fat” and Mediterranean diet groups during the study and increased from only 10% to 12.2% in the Atkins group. While this may have been statistically significant and may technically be 20-25% more, the actual amount of saturated fat increased from an average of only 0.3 to 0.7 grams of saturated fat per day. Increasing saturated fat intake by less than one gram per day is not clinically meaningful and hardly validates Mr. Taubes’ assertion.

Also, during the first six months of the study, when people were following the strictest phase of the Atkins diet (only 20 grams of carbohydrates per day), LDL-cholesterol actually increased, whereas it decreased on both the “low-fat” and Mediterranean diets.

I agree with Mr. Taubes when he said in an earlier TierneyLab (July 24) “It would also be great to have studies that looked at heart disease endpoints” and not just risk factors such as cholesterol levels.

Let’s start with the science. Unfortunately, there have been only two published peer-reviewed studies examining what happens to measures of cardiovascular health in those who begin consuming an Atkins diet. (I had nothing to do with either study and did not even know about these until they were published.)

In the first study, blood flow to the heart worsened on an Atkins diet but improved on a very low-fat, whole foods diet when blood flow to the heart was actually measured.

In the second study, the Atkins, Ornish, and South Beach diets were tested in a randomized and counterbalanced crossover study. Blood flow and arterial health (endothelial function) were measured using brachial artery reactivity testing (BART), also known as flow-mediated vasodilation, a well-accepted direct measure of arterial health and a validated predictor of cardiovascular events. Blood flow worsened on the Atkins diet, and there was a significant inverse correlation between intake of saturated fat and total fat and worsening of blood flow.

Now, I would be the first to acknowledge that neither of these studies is definitive, and both have significant methodological limitations. However, before anyone else posts that the Atkins diet has been scientifically proven to reverse heart disease, as Dr. Atkins often claimed in my frequent debates with him, let’s be clear that there is not a single published peer-reviewed study proving this to be true that examined measures of cardiovascular health rather than only risk factors such as changes in cholesterol levels.

And if Mr. Taubes believes, as he was quoted in the TierneyLab on July 24, that “It’s also true that I don’t think that LDL is a particularly meaningful predictor of heart disease risk, and I think total cholesterol is meaningless,” then why do he and others claim that the Atkins diet is better for your heart because of its effects on blood cholesterol levels? Or does he believe that HDL and triglycerides are valid predictors (because they seem to improve on an Atkins diet—more on this later) but LDL and total cholesterol (which do not improve on an Atkins diet) are not? How convenient.

The burden of proof is on the advocates of high-protein diets to show that an Atkins diet is beneficial to those with heart disease before claiming that it is, especially given the large amount of data from other epidemiological studies, animal research, and randomized controlled trials in humans linking the intake of a diet high in animal fat and protein with the incidence of coronary heart disease and other chronic illnesses. There is not space here to describe these studies in detail, but this evidence is summarized in my newest book, The Spectrum.

In contrast, there is scientific evidence, published in the leading peer-reviewed journals, that a very low-fat, whole-foods, plant-based diet can significantly reduce LDL-cholesterol levels and can reverse the progression of coronary heart disease.

My colleagues and I at the non-profit Preventive Medicine Research Institute and the University of California, San Francisco, have studied for more than three decades the effects of diets much lower in fat than the one used in NEJM study as well as lower in refined carbohydrates and higher in fruits, vegetables, whole grains, legumes, and soy products.

Using state-of-the-art measures, in a series of randomized controlled trials, we found that this diet (plus moderate exercise and stress management techniques) caused reversal of coronary heart disease after only one month, even more reversal after one year, and still more improvement after five years. There were also 2½ times fewer cardiac events such as heart attacks, bypass surgery operations, angioplasties, and hospital admissions. We found that 99 percent of patients on our program were able to stop or reverse the progression of their heart disease.

In a more recent randomized controlled trial, we also found that this nutrition and lifestyle program could stop or even reverse the progression of early prostate cancer.

It is true that in addition to changing diet, patients were asked to walk moderately and to practice stress management techniques such as meditation. However, in both the coronary heart disease and prostate cancer studies, we found a significant correlation between adherence to the dietary recommendations and changes in the disease state. There was a statistically significant “dose-response” relationship between the degree of dietary change and degree of improvement in both heart disease and prostate cancer.

In our new study, published in the Proceedings of the National Academy of Sciences, showed that these diet and lifestyle changes caused beneficial changes in gene expression in over 500 genes in just three months—“turning on” (upregulating) disease-preventing genes and “turning off” (downregulating) genes that promote heart disease, cancer, and other illnesses as well as downregulating genes that promote inflammation and oxidative stress.

This week, The Lancet Oncology, the leading cancer journal, published our new study showing, for the first time, that these diet and lifestyle changes significantly increases telomerase and, thus, telomere length. Telomeres are the ends of chromosomes that control how long we live. As your telomeres get longer, your life gets longer. This is the first time that any intervention, even drugs, has been shown to significantly increase telomerase.

Studies by other investigators have also found that lowering LDL-cholesterol with very low-fat diets and/or cholesterol-lowering drugs can reverse the progression of coronary heart disease.

For example, a study by a group of German scientists found that a 20 percent fat diet plus exercise caused regression (reversal) of heart disease in almost 40 percent of patients. In our research, we found that 82 percent of patients showed regression, but they made bigger changes in diet. A study from the University of Texas found that the more people with heart disease reduced their cholesterol levels, the more improvement they measured in blood flow to the heart, heart attacks, bypass surgery, angioplasty, and deaths from heart disease.

A 5-year study directed by Dr. Caldwell Esselstyn, Jr., at The Cleveland Clinic found that a 10% fat plant-based diet plus cholesterol-lowering drugs showed similar findings. Their cholesterol levels fell significantly, they experienced no new coronary events, and angiography showed that their disease had stabilized and in some cases selectively reversed.

Now, it is true that these are relatively small studies. However, there is an erroneous belief that larger studies are more valid than smaller ones. In a larger study, smaller changes may be statistically significant that are clinically irrelevant. Smaller studies require larger and more consistent changes than larger studies to be statistically significant. Judging the quality of a clinical study solely by the number of patients is somewhat akin to judging the merits of a book only by the number of pages or a symphony by the number of notes. Also, smaller studies enable investigators to achieve higher levels of dietary adherence.

Also, we replicated these findings in over 3,000 patients in three larger demonstration projects, including one with Medicare. These data were peer reviewed in an all-day hearing at the CMS headquarters in Baltimore with a panel of experts convened by Medicare, which is why Medicare is now covering intensive lifestyle programs for reversing heart disease such as this one.

Triglycerides decrease on diets that reduce the intake of refined carbohydrates, which both Dr. Atkins and I agreed about, and triglycerides decrease on both Atkins and Ornish diets if people are mindful about reducing the intake of refined carbohydrates.

It is true that HDL-cholesterol levels increase on an Atkins diet. As I have written about before, there is tremendous confusion about what HDL does among both health professionals as well as in the general public. There is often a simplistic view that HDL is good, so that anything that raises HDL is good for you, and anything that lowers it is bad for you. This is not true.

Your body makes HDL to remove excessive cholesterol from your blood and tissues, a process known as “reverse cholesterol transport.” Think of HDL as the garbage trucks of your body. HDL transports cholesterol back to your liver where it is metabolized and removed from your body. Your body’s ability to make more garbage trucks (i.e., raise your HDL) is, in part, genetically determined. Some people can make more garbage trucks than others.

Most Americans eat a diet that’s relatively high in saturated fat and cholesterol—i.e., a lot of “garbage.” Those people who have a lot of garbage trucks—in other words, who have high HDL levels—are more efficient at getting rid of extra fat and cholesterol in their diet. As a result, they have a lower risk of a heart attack or stroke than those who eat a high-fat, high-cholesterol diet who have lower HDL levels. However, the relationship of HDL to risk of heart disease and stroke assumes that people are not changing their diet.

Not everything that raises HDL is good for you. For example, if you increase the amount of fat and cholesterol in your diet (e.g., an Atkins diet), you may increase your HDL because your body is trying to get rid of the extra “garbage” (fat and cholesterol) by increasing the number of available garbage trucks (HDL) if you are genetically able to do so. 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. It isn’t.

After spending almost a billion dollars, Pfizer discontinued a study of its drug, Torcetrapib. It was designed to prevent heart attacks by raising HDL-cholesterol. Midway through the study, researchers found that this new drug actually increased the risk of a heart attack, so they had to stop the study and take the drug off the market. This drug raised HDL by interfering with reverse cholesterol transport, causing HDL to build up. It’s like having a traffic jam of garbage trucks—more trucks, but they don’t work as well.

Not everything that lowers HDL is bad for you. If you change from a high-fat, high-cholesterol diet to a healthy low fat, low-cholesterol diet, your HDL levels may stay the same or even decrease because there is less need for it. When you have less garbage, you need fewer garbage trucks to remove it, so your body may make less HDL. Thus, a reduction in HDL on a low-fat diet is not harmful.

We know this is true because instead of just measuring risk factors like HDL, as I described earlier, we measured what actually happens to the progression of coronary heart disease in people who went on diets that were very low in “garbage”—i.e., very low in cholesterol, saturated fat, total fat, and refined carbohydrates and high in fruits, vegetables, whole grains, legumes, and soy products.

Their HDL levels came down by 9 percent after one year, but their LDL (“bad”) cholesterol levels came down even more, by an average of 40 percent. None of these patients was taking cholesterol-lowering drugs. As mentioned above, even though their HDL levels decreased, these patients showed reversal of their heart disease using state-of-the-art measures.

A low HDL in the context of a healthy low-fat diet has a very different prognostic significance than a low HDL in someone eating a high-fat, high-cholesterol diet. People living in countries such as Asia that consume a low-fat diet have low HDL levels yet among the lowest rates of heart disease in the world.

I want to emphasize that it’s not just the amount of fat in your diet that determines how it affects your heart. If you eat a very low-fat diet that’s high in refined carbohydrates such as sugar and other concentrated sweeteners, white flour, white rice, pasta, and so on, then this may actually worsen your risk of cardiovascular disease as well as cause weight gain. It’s not surprising to me that many people lose weight on an Atkins diet, since Americans eat way too many refined carbohydrates.

However, you can lose even more weight by reducing both refined carbohydrates and fat and replacing refined carbohydrates with good carbs rather than animal protein. We reported in a randomized, controlled clinical trial published in the Journal of the American Medical Association a 24-pound weight loss after one year and 13-pound average weight loss after 5 years in a group of men and women, much more than the 10 pounds lost in the NEJM study. 

Replacing refined carbohydrates with unrefined carbohydrates such as fruits, vegetables, and whole grains is more healthful than replacing refined carbohydrates with bacon and sausage. For example, in the Harvard Nurses’ Health Study of over 75,000 women, researchers found a strong inverse relationship between intake of whole grains and the risk of developing coronary heart disease.

What you include in your diet is as important as what you exclude. There are at least 100,000 substances in certain foods that have powerful anti-cancer, anti-heart-disease and anti-aging properties. These include phytochemicals, bioflavonoids, carotenoids, retinols, isoflavones, genistein, lycopene, polyphenols, sulforaphanes, and so on. Where do you find these potent substances? With few exceptions, these protective factors are found in fruits, vegetables, whole grains, legumes, soy products and in some fish. These are rich in good carbs, good fats, good proteins and other protective substances.

An optimal diet is low in refined carbohydrates as Atkins indicated, includes omega 3 fatty acids as in the Mediterranean diet, and is low in saturated fat and trans fats and high in fruits, vegetables, unrefined carbohydrates, legumes, and soy products as I have been recommending.

Not everyone needs to follow a plant-based diet with only 10% of calories from fat. As I describe in my book, The Spectrum, it’s now possible to personalize a way of eating that combines the best aspects of each approach tailored to a person’s own needs, genes, and preferences. How much you need to change your diet depends on what you’re trying to accomplish. If you are trying to reverse heart disease, prostate cancer, or diabetes—the “pound of cure”—then you probably need to make bigger changes than someone who is just trying to lose a few pounds or lower their cholesterol level a few points.

Sometimes it’s good to be a contrarian—just about everything that my colleagues and I have proven in the past 30 years of research was once thought to have been impossible—but it’s important not to tell people what they may want to hear—“meat and butter are good for your heart”—when the science does not support it. I sometimes eat foods that may not be very healthful for me, but I don’t fool myself into believing that they are.

I welcome any constructive comments from TierneyLab readers. Thank you.