Focus on Research
Penn State Intercom......August 23, 2001

Nuts cut coronary
heart disease risk

By Barbara Hale
Public Information

In the most comprehensive review yet of the available epidemiological and clinical evidence, University researchers have concluded that eating tree nuts or peanuts can have a strong protective effect against coronary heart disease.

Penny Kris-Etherton, distinguished professor of nutrition and lead author of the review, said, "To date, five large epidemiologic studies and 11 clinical studies have demonstrated that frequent consumption of nuts decreases the risk of coronary heart disease."

The most improvement comes with adding very small amounts of nuts -- an ounce, or about three to four tablespoons, five or more times a week.

"However, you can't simply add nuts, nut butters or nut oils to your usual diet without making some adjustments," Kris-Etherton said. "You have to replace some of the calories you usually consume with nuts and substitute the unsaturated fat in nuts for some of the saturated fat in your diet."

The study co-authors are Guixiang Zhao, a doctoral candidate and a Kligman Scholar in Nutrition; Amy E. Binkoski, doctoral candidate in the Life Sciences Consortium; Stacie M. Coval, master's degree candidate; and Terry Etherton, distinguished professor and head of the dairy and animal sciences department.

The researcher's review of the existing published epidemiologic studies shows that consuming 1 ounce of nuts more than five times a week can result in a 25-to-39 percent reduction in coronary heart disease risk among people whose characteristics match those of the general adult U.S. population.

Among the nuts consumed by the people who took part in the epidemiologic studies were almonds, brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pistachios and walnuts, as well as peanuts. However, the effects of specific nuts on coronary heart disease risk were not evaluated in these studies due to difficulties in classifying consumption patterns of specific nuts and because of the small number of cases in each category. In typical American diets, peanuts account for approximately half of all nuts consumed.

The 11 clinical studies reviewed by the researchers focused on the blood cholesterol-lowering effects of nuts. Collectively, these studies showed that including nuts in a blood cholesterol-lowering diet has favorable effects.

Calculations conducted by the researchers using the published data suggest that nuts may contain other cholesterol-lowering constituents, but studies are needed to corroborate this. Nuts studied in clinical investigations included walnuts, almonds, macadamia nuts, pecans, pistachio nuts and peanuts.

Nuts are a rich source of unsaturated fatty acids, the "good" fats, and are low in saturated fatty acids, the "bad" fats. However, the researchers concluded that the fatty acid profile of nuts contributes to only part of the total reduction in coronary heart disease risk.

Kris-Etherton noted that dietary guidance on fats has changed in recent years from removing or drastically restricting fats to substituting and replacing them with heart healthy alternatives. For example, she said, "you can cut back a little on margarine and add a small amount of slivered almonds on green beans. You can flavor a salad with a few walnuts and use less dressing. Or, you could use peanut butter instead of full fat cream cheese on a bagel."

Internet a good tool
for market research

By Barbara Hale
Public Information

Consumers can look forward to kinder, gentler market survey techniques -- and fewer of those annoying phone calls -- if market researchers take heed to recent findings about ways to use the Internet.

Frank E. Ritter, associate professor of information science and technology, said, "Our research shows that it is possible to use the Internet to perform a wide range of useful and accurate surveys without spamming, without being intrusive and in a manner that facilitates communication."

Tanya L. Cheyne, Ritter's former student at the School of Psychology at the University of Nottingham, England, conducted the research as part of her thesis requirements. Ritter joined the School of Information Sciences and Technology in 1999 and was a faculty member at Nottingham when the study was conducted.

The researchers used a survey on mobile phones as their test case. They advertised the survey in newsgroups and placed banner ads on Web pages where the target groups were most likely to be found. The survey also was included in three Internet search engine databases.

Search engines produced the greatest number of responses, 750, over the first 30 days. Forty percent of the responders were over the age of 40, an age group comprising less than 10 percent of the respondents from the banner ads and newsgroups. Only 1 percent was a UK resident, whereas newsgroups and banner ads on Web sites produced yields of 18 percent and 10.5 percent UK residents respectively.

Banner ads on Web sites also offer a significant targeting opportunity. While fewer people, 225, responded, they were from the targeted groups. However, the researchers warned, "It is important to check where banners will be placed and to determine whether the site's audience fulfills the respondent profile. Banner advertisements have little space to explain to potential respondents anything about the survey. To attract respondents with specific characteristics, it useful to mention an incentive that appeals to them directly."

The researchers do not recommend newsgroups to solicit responses. Response rates were far less than the 2 percent found with more traditional methods.

"Internet users are typically resistant to being used for the practice of completely self-serving commercial activity, including performing market research," the researchers noted. "Reputable firms will keep in mind that the recipient must pay to receive what to them is junk mail."  

Birds of a feather may not
roost in same family tree

A comprehensive analysis of the genes of aquatic birds has revealed a family tree dramatically different from traditional relationship groupings based on the birds' body structure, according to new research.

The most startling and unexpected finding of the study is that the closest living relative of the elegant flamingo, with its long legs built for wading, is not another long-legged species of wading bird but the squat grebe, with its short legs built for diving. The two species, whose genes surprisingly are more similar to each other's than to those of any other bird, otherwise show no outward resemblance, according to Blair Hedges, an evolutionary biologist.

Hedges leads one of the two research groups that collaborated on the study by separately performing two different kinds of genetic analyses using DNA samples obtained from separate sources. The other group is led by John A. W. Kirsch, professor of zoology and director of the Zoological Museum at the University of Wisconsin.

For the full story, see http://www.science.psu.edu/alert/Hedges7-2001.htm

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