We read, daily it seems, of the health risks of this behavior or that dietary factor. In cardiovascular health, we've been lectured for years about the crucial importance of such risk factors as dietary salt in determining society's rate of heart attacks and strokes.

But a recent and insightful post on Junkfoodscience reported May 2nd:

"A major medical paper on primary heart disease prevention admitted that cardiovascular disease risk factors have proven useless for predicting heart disease among our population and that reducing risks factors doesn't translate into reduced clinical disease or fewer premature deaths."

Prompting author Sandy Szwarc's contrarian comments was publication of new American Heart Association Guidelines for Cardiovascular Disease Prevention in Women which expand the number of "at risk" women being urged to alter their lifestyles to reduce their likelihood of a cardiovascular event. Trouble is, Szwarc explains:

"virtually all heart disease occurs in women without 'risk factors'…these risk factors themselves are problematic … relying on them to predict who will succumb to disease or premature death is insupportable.

"A study just published in the March issue of the Journal of the American Medical Association actually tested the AHA's proposals, among men and women. The METEOR Trial was a randomized, double-blind, placebo-controlled study conducted across 61 primary care centers in the U.S. and Europe. It examined 984 adults, with an average age of 57, who were all considered to have low risk factors for heart disease based on the Framingham Risk Score. Some received the statin, rosuvastatin, and the rest a placebo and after two years the progression of atherosclerosis was assessed by carotid intima-media thicknesses, measured by ultrasound. While the statin reduced LDL-cholesterol by 49% and resulted in small reductions in intima-media thickness, there was no regression of atherosclerosis or change in clinical outcomes."

She continues to explain that NHANES data show 85% of the population has low Framingham scores for risk while 2% have high scores, yet the AHA lumps them together to urge them all to worry about their risk and undertake lifestyle changes or begin taking medications.

"In other words, these risk factors aren't very good measures and we give them more credence than the evidence can support. That doesn't mean we should run screaming into the hills, thinking we're all going die and are all at risk, but that the evidence indicates that our obsession with these popular risk factors and numbers is not especially helpful, healthful or necessary for virtually all of us."

In support of her conclusion, she cites Dr. P.K. Shah, director of cardiology at Cedars-Sinai Medical Center. Shah wrote in the Los Angeles Times on February 28, 2005: "Our traditional risk factors are very weak overall predictors of future risk." She continues:

"The World Health Organization's MONICA project , which is an impressive 10-year study that measured cardiovascular disease mortality and disease incidences and risk factors among 10 million people in 21 countries, was also not included in the AHA evidence review. This study data continues to reveal no statistical connections between reductions in standard risk factors (obesity, smoking, blood pressure or cholesterol levels) and heart disease."

She quotes "the latest Cochrane review of 39 clinical trials conducted in multiple countries over the course of three decades, just updated in August 18, 2006:"

"In many countries, there is enthusiasm for "Healthy Heart Programmes" that use counseling and educational methods to encourage people to reduce their risks for developing heart disease. These risk factors include high cholesterol, excessive salt intake, high blood pressure, excess weight, a high-fat diet, smoking, diabetes, and a sedentary lifestyle. This updated review of all relevant studies found that the approach of trying to reduce more than one risk factor - multiple risk factor intervention - advocated by these Programmes do result in small reductions in blood pressure, cholesterol, salt intake, weight loss, etc. Contrary to expectations, these lifestyle changes had little or no impact on the risk of heart attack or death...

"Recent trials examining risk factor changes have cast considerable doubt on the effectiveness of these multiple risk factor interventions....The pooled effects suggest multiple risk factor intervention has no effect on mortality....

"Risk factor changes were relatively modest, were related to the amount of pharmacological treatment used, and in some cases may have been over-estimated because of regression to the mean effects, lack of intention to treat analyses, habituation to blood pressure measurement, and use of self-reports of smoking. Interventions using personal or family counselling and education with or without pharmacological treatments appear to be more effective at achieving risk factor reduction and consequent reductions in mortality in high risk hypertensive populations. [However], the evidence suggests that such interventions have limited utility in the general population."

The salt and health debate has featured these same issues (e.g. selective citation of the medical literature, defining-down the blood pressure levels defined as "at risk" and, of course, active efforts to persuade the entire population that everyone will benefit by reducing dietary salt intakes.

Let's stick with the facts. And, if we insist on paying attention to blood pressure, for example, as a CV risk, let's also make sure we look at the mortality associated with other risk factors which are modified when salt intake is curtailed: increased insulin resistance and accelerated plasma renin activity, for two, both of which are powerful indicators of adverse CV outcomes.