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May 2008- Research Behind the News
practice applications
RESEARCH BEHIND THE NEWS
The following capsule news summaries reflect emerging areas of research that will likely capture the attention of various media and news outlets. These capsule reviews are derived from the New in Review section of the Journal on page 891.
Berry Healthy!
I
f red wine and chocolate do not agree with you, consider a diet rich in berries. Previous studies involving polyphenol-rich foods such as red wine, cocoa, and tea have revealed evidence of their cardiovascular benefits. In a new study from Finland, published in the February 2008 issue of the American Journal of Clinical Nutrition, researchers analyzed the impact of introducing polyphenolrich berries into the diets of a group of middle-aged men and women with existing cardiovascular risk factors. Seventy-two subjects volunteered for the trial and were randomly assigned to consume a moderate amount of
berries or control products for 8 weeks. The berry group consumed 100 g of whole bilberries (sometimes called European blueberries) and 50 g of lingonberry-rich nectar every other day. (Lingonberries are similar to small cranberries.) In addition, the berry group consumed 100 g of puree of black currants or strawberries, and a juice of raspberry and chokeberry on the other days. At the end of the 2-month period, researchers found that levels of high-density lipoprotein (HDL) cholesterol rose significantly by 5.2% in the berry group compared to 0.6% in the control group. Systolic blood pressure was slightly reduced
in the berry group (1.5 mm Hg). Finally, platelet function, assessed through a platelet function analyzer, was inhibited in the berry group. Bottom Line: The researchers conclude: “We found favorable changes in platelet function, blood pressure, and HDL cholesterol after the consumption of berries for two months. The findings are important, because they may partly explain the CVD [cardiovascular disease]-protective role of a diet rich in fruit and vegetables. Other types of studies are now warranted to identify the compound and mechanisms that are responsible for the observed effects.”
A Diet for Fertility?
F
or some women, treating infertility can begin in a very different kind of laboratory—their own kitchen, according to the results of a study published in the February 2008 issue of the American Journal of Obstetrics & Gynecology. Researchers from the Harvard School of Public Health in Boston surveyed the diets of 18,555 married females (from the Nurses Health Study II) and followed the subjects over an 8-year period as they attempted pregnancy or became pregnant. A total of 3,430 reports of
infertility were reported, and 438 of these were incident reports of ovulatory infertility. High intake of animal protein (including chicken and red meat) seemed to indicate increased risk of infertility, while high intake of vegetable proteins (beans and nuts) lowered the risk of infertility. The risk of ovulatory infertility was 50% lower in women who consumed 5% of total energy intake as vegetable rather than animal protein. Bottom Line: “We prospectively evaluated the association between
protein intake and ovulation infertility in a cohort of healthy women and found that consuming animal protein was associated with an increased risk of this condition,” write the researchers. “Furthermore, we found that consuming vegetable protein instead of carbohydrates or animal protein was associated with a substantially lower risk of ovulation infertility. These findings are in agreement with previous studies measuring the effect of diet on ovulatory function in animals.”
Eating Out Doesn’t Have to Mean Pigging Out f you’re worried about your weight, try moving to an area teeming with restaurant options. According to findings reported in the February 2008 issue of the American Journal of Preventative Medicine, generally speaking, the more restaurants in an area, the better the population’s weight status. Individual data for 714,054 individuals from the 20022006 Behavioral Risk Factor Surveillance System (BRFSS), an annual telephone health survey, was examined alongside restaurant data from
I
766
Journal of the AMERICAN DIETETIC ASSOCIATION
the 2002 US Economic Census. After linking the data, 544 counties were modeled, representing 75% of the US population for 2002. The researchers analyzed fast-food (customers pay before eating) and full-service (pay after eating) restaurant density, along with the ratio of fast-food to full-service. They discovered that a higher total restaurant density is significantly associated with lower weight status. However, a higher full-service restaurant concentration was shown to be significantly associated with
lower weight status while, in contrast, a higher fast-food density is associated with higher individual weight status. Bottom Line: The researchers note that, “This study found that the restaurant environment was independently associated with weight status, including individual-level demographic and behavioral characteristics and countylevel structural factors. In particular, the types of restaurants that are available may function as a highly salient determinant for weight outcomes.”
This article was written by Tony Peregrin, a freelance writer in Chicago, IL.
RESEARCH BEHIND THE NEWS
The following capsule news summaries reflect emerging areas of research that will likely capture the attention of various media and news outlets. These capsule reviews are derived from the New in Review section of the Journal on page 891.
Berry Healthy!
I
f red wine and chocolate do not agree with you, consider a diet rich in berries. Previous studies involving polyphenol-rich foods such as red wine, cocoa, and tea have revealed evidence of their cardiovascular benefits. In a new study from Finland, published in the February 2008 issue of the American Journal of Clinical Nutrition, researchers analyzed the impact of introducing polyphenolrich berries into the diets of a group of middle-aged men and women with existing cardiovascular risk factors. Seventy-two subjects volunteered for the trial and were randomly assigned to consume a moderate amount of
berries or control products for 8 weeks. The berry group consumed 100 g of whole bilberries (sometimes called European blueberries) and 50 g of lingonberry-rich nectar every other day. (Lingonberries are similar to small cranberries.) In addition, the berry group consumed 100 g of puree of black currants or strawberries, and a juice of raspberry and chokeberry on the other days. At the end of the 2-month period, researchers found that levels of high-density lipoprotein (HDL) cholesterol rose significantly by 5.2% in the berry group compared to 0.6% in the control group. Systolic blood pressure was slightly reduced
in the berry group (1.5 mm Hg). Finally, platelet function, assessed through a platelet function analyzer, was inhibited in the berry group. Bottom Line: The researchers conclude: “We found favorable changes in platelet function, blood pressure, and HDL cholesterol after the consumption of berries for two months. The findings are important, because they may partly explain the CVD [cardiovascular disease]-protective role of a diet rich in fruit and vegetables. Other types of studies are now warranted to identify the compound and mechanisms that are responsible for the observed effects.”
A Diet for Fertility?
F
or some women, treating infertility can begin in a very different kind of laboratory—their own kitchen, according to the results of a study published in the February 2008 issue of the American Journal of Obstetrics & Gynecology. Researchers from the Harvard School of Public Health in Boston surveyed the diets of 18,555 married females (from the Nurses Health Study II) and followed the subjects over an 8-year period as they attempted pregnancy or became pregnant. A total of 3,430 reports of
infertility were reported, and 438 of these were incident reports of ovulatory infertility. High intake of animal protein (including chicken and red meat) seemed to indicate increased risk of infertility, while high intake of vegetable proteins (beans and nuts) lowered the risk of infertility. The risk of ovulatory infertility was 50% lower in women who consumed 5% of total energy intake as vegetable rather than animal protein. Bottom Line: “We prospectively evaluated the association between
protein intake and ovulation infertility in a cohort of healthy women and found that consuming animal protein was associated with an increased risk of this condition,” write the researchers. “Furthermore, we found that consuming vegetable protein instead of carbohydrates or animal protein was associated with a substantially lower risk of ovulation infertility. These findings are in agreement with previous studies measuring the effect of diet on ovulatory function in animals.”
Eating Out Doesn’t Have to Mean Pigging Out f you’re worried about your weight, try moving to an area teeming with restaurant options. According to findings reported in the February 2008 issue of the American Journal of Preventative Medicine, generally speaking, the more restaurants in an area, the better the population’s weight status. Individual data for 714,054 individuals from the 20022006 Behavioral Risk Factor Surveillance System (BRFSS), an annual telephone health survey, was examined alongside restaurant data from
I
766
Journal of the AMERICAN DIETETIC ASSOCIATION
the 2002 US Economic Census. After linking the data, 544 counties were modeled, representing 75% of the US population for 2002. The researchers analyzed fast-food (customers pay before eating) and full-service (pay after eating) restaurant density, along with the ratio of fast-food to full-service. They discovered that a higher total restaurant density is significantly associated with lower weight status. However, a higher full-service restaurant concentration was shown to be significantly associated with
lower weight status while, in contrast, a higher fast-food density is associated with higher individual weight status. Bottom Line: The researchers note that, “This study found that the restaurant environment was independently associated with weight status, including individual-level demographic and behavioral characteristics and countylevel structural factors. In particular, the types of restaurants that are available may function as a highly salient determinant for weight outcomes.”
This article was written by Tony Peregrin, a freelance writer in Chicago, IL.