Lifestyle & Heart Health: Important 2009 Studies

January 4, 2009 Dallas, TX - The American Heart Association (AHA) chooses important 2009 research papers on heart health and lifestyle choices. One provides insights into obesity prevention and the "best diets." The other cautions that cardiovascular risk-factor control isn't just for older people. A third reviews the significant role of laws restricting smoking in public places to sharply lower the incidence of hospital admissions for heart attacks.

These selections emerged from a process led by the AHA immediate past president, president and president-elect. The choices were based on nominations from the organization's scientific councils. The chairs of the councils had been charged with recommending the year's "most meritorious, most substantial, most significant" papers in cardiovascular medicine, according to AHA current president Dr Clyde W Yancy (Baylor University Medical Center, Dallas, TX). Several of the studies in the final cut, he told heartwire, had been backed by multiple scientific councils.

No Best Diet

In a randomized comparison in more than 800 overweight adults of four "reduced-calorie" dietary interventions consisting of fat, protein, and carbohydrate intake in different proportions, such as 40%, 15%, and 45%, respectively, or 20%, 25%, 55%, respectively(1).

Participants lost about the same amount of weight over six months, an average of 6 kg, regardless of which group they were in; in general, metabolic risk factors also improved in all four groups.

In its coverage when the study was published, Dr Robert Eckel (University of Colorado Health Sciences Center, Denver) stated that the study affirms that people who are successful at losing weight are those who stick to a specific program. "Ownership, by the patient, of the weight-loss program is what proves successful, not the type of diet you chose," he said.

It really dismissed the notion that there's something clever about weight loss, showing that it really is about calorie consumption. "We all thought the statement made in that study was pretty profound," Yancy said. "It really dismissed the notion that there's something clever about weight loss, and that it really is about calorie consumption or, to make it even more straightforward, portion control. You can spend a lot of time wringing your hands about which diet and the composition of which diet, but it really is a simple equation of calories in and calories out."

Another analysis based on multiple studies that together indicated a 17% drop in estimated one-year risk of hospital admissions for acute MI in North American and European communities that adopted strong laws restricting smoking in public places, compared with rates in those communities before implementation of the restrictions (2). The risk declined steadily with increasing follow-up time.

And a combined analysis from the Coronary Artery Risk Development in Young Adults (CARDIA) study and Multi-Ethnic Study of Atherosclerosis (MESA) suggested that young adults with a low risk of developing heart disease over the short term (within 10 years) by conventional measures can be classified into high- and low-lifetime-risk groups [4]. Those with low short-term but high long-term risk were described as having a greater degree of atherosclerotic disease progression (3).

"This study is an important look at how the presence of risk factors early in life can be crucial to the lifetime risk of cardiovascular disease," according to the AHA. In its coverage of the analysis, heartwire quoted lead author Dr Jarett Berry (University of Texas Southwestern, Dallas), who said that even at younger ages, less than 50 years, "the clock is ticking" for many adults who are unaware that they already have progressive atherosclerosis.

Kardea Nutrition Serious Nutrition for Cardiovascular Health

Reference

(1)Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med 2009; 360:859-873.

(2)Lightwood JM, Glantz SA. Declines in acute myocardial infarction after smoke-free laws and individual risk attributable to secondhand smoke. Circulation 2009; 120:1373-1379.

(3)Berry JD, Liu K, Folsom AR, et al. Prevalence and progression of subclinical atherosclerosis in younger adults with low short-term but high lifetime estimated risk for cardiovascular disease: the Coronary Artery Risk Development in Young Adults study and Multi-ethnic Study of Atherosclerosis. Circulation 2009; 119:382-386.