Think "diet patterns," not specific foods/nutrients, to reduce CV death, study suggests
July 16, 2008 | Shelley Wood
theheart.org
Boston, MA - Health professionals providing diet advice should focus on overall eating patterns, rather than thinking of specific foods as "good" or "bad," a new analysis of the Nurses' Health Study suggests [1]. Researchers for the study say that risk of cardiac, cancer, or all-cause mortality is increased when red meat, processed meat, refined grains, French fries, and sweets form the bulk of the diet, whereas a diet made up primarily of healthier foods is associated with significant reductions in both cardiac and all-cause death.
"Nutritional recommendations to prevent chronic disease and promote longevity may need to focus on overall dietary patterns rather than individual nutrients," lead author on the study, Dr Christin Heidemann (German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany), told heartwire.
Results of the study appear in the July 15, 2008 issue of Circulation.
Heidemann and colleagues point out that most studies linking disease outcomes to diet have focused on specific dietary components or nutrients, rather than broader, more complex eating patterns.
Moreover, "most of these studies have been small and inadequately powered," Heidemann added. What's more, she noted, "A unique feature of our study is the existence of repeated dietary assessments during the follow-up—study participants completed food frequency questionnaires five times during follow-up, every two to four years, which allowed us to best represent the participants' long-term diet," she said.
Food for life
In all, Heidemann et al surveyed the eating habits of 72 113 women, who had no heart disease or cancer at baseline, then followed them from 1984 to 2002.
The authors identified two broad dietary patterns from the more than 115 foods queried in the study: one, dubbed the "prudent" diet, was made up primarily of fruit, vegetables, legumes, fish, poultry, and whole grains; the other, dubbed the "Western" diet pattern, emphasized red meat, processed meats, desserts/candy, French fries, and refined carbohydrates. In all, 6011 women died over the course of the study. After controlling for other risk factors, researchers found that greater adherence to the "prudent" diet was associated with significantly fewer deaths and all-cause deaths, as compared with low adherence to the diet. The Western diet, by contrast, was linked with increased heart, cancer, and all-cause deaths.
Multivariable* adjusted relative risk (95% CI) of death associated with highest quintile of diet adherence, vs lowest
Deaths
Prudent
p for trend
Western
p for trend
Cardiovascular
0.72 (0.60-0.87)
<0.001
1.22 (1.01-1.48)
0.009
Cancer
0.98 (0.87-1.10)
0.97
1.16 (1.03-1.30)
0.004
All
0.83 (0.76-0.90)
<0.001
1.21 (1.12-1.32)
<0.001
*Adjusted for age, follow-up, body-mass index, physical activity, smoking, hormone replacement therapy, history of hypertension, use of multivitamins, missing data, and total energy intake
To download table as a slide, click on slide logo above
Authors of the study contend that the relationship between overall eating patterns and mortality has not been adequately studied.
"These study results highlight the importance of intensifying efforts of health professionals to promote the adoption of a healthy overall diet, including high intakes of such plant foods as vegetables, fruit, legumes, and whole grains, as well as fish and poultry, and low intakes of red and processed meat, refined grains, French fries, and sweets," Heidemann emphasized to heartwire.
Asked about the lack of a significant impact on cancer deaths with the prudent diet, Heidemann pointed out that different components of the two diets may have greater effects on specific causes of death. "For example," she said, "a high consumption of fruit and vegetables, two of the main components of the prudent pattern, has been shown to be linked to a decreased risk of CVD, but the evidence from prospective studies for a reduced risk is limited for most cancer sites."
Evidence adds up
In an accompanying editorial [2], Dr Lawrence J Appel (Johns Hopkins University, Baltimore, MD) highlights the "remarkable convergence of evidence" supporting the benefits of diets that emphasize fish, whole grains, fruits, and vegetables. Not only does the prudent diet echo many of the components of the Mediterranean and DASH diets, but other longevity studies, including population-based studies of Okinawa Japanese or the Yanomami Indians, have produced similar results, despite emphasizing different components of the overall diet, Appel notes.
"Clearly, one can live long," Appel writes. "Diet matters, as do other lifestyle habits (including smoking and physical activity), environmental exposures, and genetic factors. While scientists dissect the relative contributions of these factors, it is prudent to recommend a diet rich in fruits and vegetables and reduced in saturated fat, salt, meats, refined grains, sweets, and full-fat dairy products."
Sources
Heidemann C, Schulze MB, Franco OH, et al. Dietary patterns and risk of mortality from cardiovascular disease, cancer, and all causes in a prospective cohort of women. Circulation 2008; 118:230-237.
Appel LJ. Dietary patterns and longevity: Expanding the blue zones. Circulation 2008; 118:214-215.
Related links
Lower rates of stroke, MI in women adhering to DASH-style diet long-term
[HeartWire > Cardiometabolic risk; Apr 14, 2008]
Two hamburgers, an order of fries, and the metabolic syndrome to go, please!
[HeartWire > Cardiometabolic risk; Jan 22, 2008]
Mediterranean diet beneficial in US populations, too
[HeartWire > Prevention; Dec 17, 2007]
Both Mediterranean and AHA-recommended diets reduce events post-MI
[HeartWire > Cardiometabolic risk; Mar 29, 2007]
New AHA diet recommendations also emphasize lifestyle, but focus is still mostly on trimming the fat
[HeartWire > Cardiometabolic risk; Jun 19, 2006] |
