Junkfood Science: What do healthy eating and lifestyles have in common with woo?

January 18, 2009

What do healthy eating and lifestyles have in common with woo?

A courageous article appeared in the Journal of the American Medical Association on Wednesday. It was momentous because it may be the first article in a mainstream medical journal to expose the similarities between the promotion of healthy diet and lifestyle modifications for the prevention of heart disease and premature death, and pseudoscience and alternative modalities.

This is one medical article we won’t see reported by the media.

Staff writer, Mike Mitka, made his article more powerful by letting the facts and the researchers’ own words speak for themselves. The obvious parallel was made evident without any commentary needed on his part.

In “Lifestyle Modification and Heart Disease — Researchers Not Deterred by Trials Showing No Benefit,” Mitka reported on the latest Scientific Sessions of the American Heart Association. The findings from two major clinical trials testing the effects of lifestyle modifications for the primary and secondary prevention of cardiovascular events and in reducing premature deaths from all causes were presented. The emphasis and significance of his article, though, was not in the studies themselves, but in the discussions of lifestyle medicine that followed.

Both major trials “failed to achieve their primary endpoints, which were to lower levels of low-density lipoprotein cholesterol (LDL-C) and mortality and hospitalization,” he said. But the researchers “are still calling their studies successful.”

Reject, ignore and explain away evidence

Note: One of the earmarks of pseudoscience is that it rejects or explains away data that doesn’t support its position. Regardless of how large the body of evidence, no evidence is ever capable of contradicting its position, as UK Skeptics explained. “Pseudoscientific ideas are sometimes driven by cultural or ideological reasons, but very often they're driven by commercial goals,” they wrote.

Unlike science, in pseudoscience, “failures are ignored, excused, hidden, lied about, discounted, explained away, rationalized, forgotten, avoided at all costs.” said Rory Coker, Ph.D., physics professor at the University of Texas at Austin.

The first study Mitka described was the randomized controlled clinical trial called FIT Heart (a Family-Based Intervention Trial to Improve Heart Health). This study had enrolled 501 healthy adults who were family members of patients hospitalized for an acute cardiovascular event. The New York cardiologists wanted to see if a life-threatening incident could provide a ‘teachable moment” and motivate family members to adopt healthy lifestyle changes that would reduce their LDL-cholesterol levels.

Overview: The study participants were randomized to a control group or a behavioral intervention group that received intense education from a master’s level health educator, utilizing stages of change theory. This healthy lifestyle program followed current government preventive guidelines and recommendations of the American Heart Association. It focused on avoiding foods with saturated fat, cholesterol, partially hydrogenated fats, transfats and refined sugars; and recommended five daily servings of fruits and vegetables and foods high in fiber. The intervention group was encouraged to engage in 30-60 minutes of moderate physical activity a day and smokers to stop smoking and participate in a hospital-based smoking cessation program. The participants met with the educator five times during the first 9 months, and had two validated dietary assessments done and serial cholesterol levels drawn.

As Mitka said, at the one-year follow-up, the investigators found no difference in the cholesterol levels between the intense behavioral intervention and control groups. These popular cardiac "risk factors," as countless other clinical studies have shown, are not measures of diet or behavior.

The FIT-Heart study’s lead author, Lori Mosca, M.D., MPH, Ph.D., acknowledged the failure of lifestyle modifications in reducing their primary endpoints, said Mitka. However, she claimed that the trial was successful for helping a special intervention group to maintain a “healthier” diet and exercise more, he reported. The study had motivated people “to make lifestyle changes,” Dr. Mosca said. While the healthy diet and lifestyle changes may not help individuals, said Dr. Mosca, the trial helped make people “aware that they had risk factors for cardiovascular disease.”

The second clinical trial was the HF-ACTION (Heart Failure: a Controlled Trial Investigating Outcomes of Exercise Training) to see whether patients with heart failure participating in a highly structured exercise program, in addition to usual care, would have a lower all-cause mortality and hospitalizations.

Overview: The participants randomized to the exercise group attended 36 supervised exercise training sessions, as well as home-based exercise, then transitioned to solely home exercise returning every 3 months to reinforce their exercise routines. After 2.5 years, there was no difference between the intense exercisers and control group in all-cause mortality or hospitalizations.

HF-ACTION’s lead investigator, Christopher M. O’Connor, M.D., also admitted this trial failed to show a benefit in meeting its primary endpoint (all-cause mortality or hospitalizations). A secondary analysis, after adjusting for prognosis-related conditions such as severity of illness, reported a 15% relative risk reduction in the secondary surrogate endpoints, cardiovascular-related mortality and hospitalizations — but there was still no change in all-cause mortality rate after 3 years compared to the control group. Mitka reported that, despite the trial’s failure, the author said these results still had benefit in the clinical setting because doctors can tell patients that exercise training appears safe.

Another way of knowing — an alternative paradigm

Mitka’s brilliant writing then made the most powerful analogy of all. The investigators of both of these major lifestyle trials explained away the null results in lifestyle trials, as others have done, by using one of the oldest claims of alternative modalities: that the scientific process cannot be applied to their modality and that their interventions cannot be tested using randomized controlled clinical trials.

Déjà vu. As we read last year, Edzard Ernst, M.D., Ph.D., described the pseudoscientific claims popularly used by proponents of alternative modalities (CAM) who call for a paradigm shift and mislead the public. This “tends to be used by proponents of CM whenever the data fail to show what they had hoped for,” he wrote in a recent article in the British Medical Journal Clinical Evidence. He went on to explain:

Many enthusiasts claim that the standard of evidence in CM must be different from that in mainstream health care, and they use a range of arguments to support their view: “My therapy is holistic, individualised, complex, etc; conventional outcome measures do not capture the subtle effects generated by CM; randomisation has detrimental effects that neutralise those of my treatment; and clinical trials tell us nothing about individuals”, for example. On closer inspection, these notions turn out to be pseudo-arguments, and it is tedious to argue against them (although a full discussion has been published). Suffice to say that, after years of debate, I have reached the conclusion that those who hold such views are either deliberately trying to mislead, or are not fully informed as to what a clinical trial can and cannot achieve

It is time for the tricks to stop, and for the real treatments to take priority. The same scientific standards, evaluation and regulation should be applied to all types of medicine.

As Mitka reported, the HF-ACTION study’s null results were rationalized away by Dr. O’Connor who said:

… that clinical trials involving exercise or lifestyle modification are not like drug trials, in which a primary end point tends to show in a black-and-white fashion whether a medication does what it is intended to do. “The problem is that people view trial results in a dichotomous fashion; they should review results in a continuous fashion,” O’Connor said. “A trial is not negative or positive; it is on a continuum… and [HF-ACTION] fell into the modestly beneficial category… We believe [exercise training] improves outcome to a modest degree.”

Dr. Mosca also claimed that lifestyle interventions couldn’t be tested using the scientific research model that’s used to demonstrate whether every other medical intervention improves patient outcomes, said Mitka:

Mosca said those who argue that these trials suggest a minimal or lack of benefit for lifestyle modification and exercise for primary and secondary prevention of cardiovascular events are wrong because they fail to understand that lifestyle research does not fit easily into the standard scientific research model. “Lifestyle needs to be tested using a different paradigm, with multiple outcomes that show benefit,” said Mosca. But investigators studying lifestyle change as an intervention are pushed “to fit it into a model in which we can only have one outcome,” she noted...

But what we really wanted to do was see if we could improve lifestyle,” Mosca said… I don’t want to have another reason for people to not change their lifestyles.”

So, cardiologists at this latest Scientific Session admitted that healthy lifestyle modifications have little to no effect on reducing premature deaths from all causes or in reducing hospitalizations, but it didn’t matter because it’s really about getting people to change their lifestyles.

Trial evidence to date

Perhaps, it’s little wonder, then, that the results of every major randomized, controlled clinical trial of healthy eating and lifestyles to date have been ignored, downplayed, or explained away... or their benefits greatly overstated. As incredible as it seems, they have failed to demonstrate significant benefit in preventing chronic diseases of old age, like the big three diabetes, heart disease or cancers, or in living longer. Nor has any healthy eating intervention been credibly shown to give everyone a government-approved BMI.

Remember the Woman’s Health Initiative Dietary Modification Trial, for instance? It was designed as the largest, longest and most expensive randomized controlled diet trial in the history of our country and was to finally prove the government’s “healthy” eating dietary guidelines for the prevention of chronic diseases and weight loss. After eight years of intensive interventions, there were no real differences in the incidences of more than 30 cancers, heart attacks or strokes, diabetes, weight, or all-cause mortality among those who followed a restrictive “healthy” diet and the control group who ate whatever they chose.

The preventive health movement has become a major industry, though, and the healthy eating and lifestyle ideology has been an easy one to sell. Just like alternative modalities, everyone wants to believe in a simple magical solution that can keep them well. Various dietary ideologies have come and gone through much of human history, all giving food more power than the evidence supports. But, beyond preventing deficiencies, which is easily achieved for most people by eating an unrestricted and varied diet, food is primarily sustenance, not magic. Humans around the world have eaten very differently, with no one food or way of eating itself related to longer life.

Correlations between diets and health outcomes in epidemiological studies are easy to mistake as showing causations, but foods are most often markers for the real factors in health, like economic prosperity or genetics. Hence, the importance of testing hypotheses using randomized controlled clinical trials and measuring hard clinical outcomes, like all-cause mortality, rather than surrogate endpoints.

Science versus ideologies

Mr. Mitka closed his article reporting a final claim used by healthy lifestyle advocates — one that most separates science from an ideology or things people simply believe.

He quoted Steven H. Woolf, MD, MPH, a professor at Virginia Commonwealth University in Richmond and proponent of lifestyle changes with Partnership for Prevention who agreed with Dr. Mosca. Dr. Woolf pointed to tobacco, lack of physical activity and obesity. We know “those behaviors are the leading drivers of death in our country,” he said. "In my view," he said, "we don’t need to prove that in subsequent trials."

Science, once again, proves very inconvenient to ideologies.

© 2009 Sandy Szwarc

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