Researchers nix low-carb diet

December 14, 2007

For most of the past decade, there was much hubbub about the Atkins and Zone diets. Both focus on quick, effective ways to lose weight through high-protein and low-carbohydrate foods. Today, many still swear by them.

However, research on these diets has been limited, if nonexistent – until now. ASU scientists from the departments of Nutrition and Exercise and Wellness, along with other colleagues, have been studying the diets since 2005, and find many biomarkers being negatively affected by the severely low-carbohydrate intake. Download Full Image

ASU researchers Carol Johnston and Pamela Swan, along with collaborators Sherrie Tjonn and Andrea White, both registered dieticians, and Barry Sears of the Inflammation Research Foundation and creator of the Zone diet, have published three papers during the last two years, appearing in Osteoporosis International, the American Journal of Clinical Nutrition and, most recently, in the Journal of the American Dietetic Association.

The biggest difference in these types of diets is the amount of carbohydrate prescribed. The Atkins diet entails very low carbohydrate – less than 20 grams daily – whereas the Zone promotes a more moderate intake of carbohydrates – up to 180 grams daily.

“The downside of severely low carbohydrate intake is that dieters go into what’s called ketosis, or the inefficiency of the body to oxidize fat,” says Johnston, chair and professor in the Department of Nutrition, School of Applied Arts and Sciences.

The term used to describe diets that produce this biological effect is ketogenic; hence, Atkins is a ketogenic, low-carbohydrate (KLC) diet, and the Zone diet is considered a nonketogenic, low-carbohydrate (NLC) diet.

With these studies, their research uncovered that the ketogenic diet may increase bone loss because of an increase in acid in the body and not enough intake of alkalizing minerals, such as potassium, to neutralize this effect. In addition, a higher percentage of calcium was found in the urine of those on the KLC diet, leading the researchers to believe that the bones are “leaching” calcium.

“The public should realize that these diets have differing effects on biomarkers,” Johnston says. “Diets that severely restrict carbohydrates, particularly potassium-rich fruits and vegetables, may have deleterious effects on bones.”

Another study by these researchers looked at the metabolic advantage of one diet over the other. They found that the reduction in fat loss and weight loss was about the same for both diets over a six-week trial. In addition, body mass index was significantly lower after six weeks in both diet groups. However, those following the KLC diet experienced a greater increase in LDL cholesterol than those following the NLC diet. HDL cholesterol did not seem to be significantly affected.

“With a higher fat concentration with the KLC diet, the increase in the LDL cholesterol is not really that surprising,” Johnston says.

They also note that dieters on the NLC diet versus the KLC diet experienced more energy. Their most recent article, published in October, explains that the body needs carbohydrates for energy, so for those individuals who are taking in an extremely low amount of carbohydrates and only receiving energy from protein, intense exercise is harming their bodies more than it’s helping. Without adequate amounts of carbohydrate stores, or glycogen, muscles rapidly fatigue during sustained exercise.

“And because there is an overall lack of energy, the KLC diets actually may thwart attempts to combine diet modifications with increased physical activity,” says Swan, acting chair and associate professor in ASU’s Department of Exercise and Wellness, School of Applied Arts and Sciences.

The researchers note that when a person’s body is not getting the nutrients it needs to function, that person’s body goes into a state of stress, which causes systematic inflammation.

“120 grams of carbohydrates is enough for an average person who does moderate exercise, but endurance athletes should eat more carbs, especially for long bouts of exercise, like a marathon,” Swan says.

“The KLC diets restrict carbohydrates too much; at minimum, carbohydrate intake should be moderate,” Johnston adds.

All the research was supported by a grant from the Inflammation Research Foundation.

ASU paves way for bioscience education

December 14, 2007

To help meet the need of Arizona’s booming bioscience sector and create the next generation of highly skilled, interdisciplinary scientists, the Arizona Board of Regents recently approved an innovative ASU graduate degree in biological design.

The biological design doctoral program seeks to attract and train new scientific talent to use an outcome-driven, interdisciplinary approach in solving major global challenges in human health and the environment. The program is a collaboration between ASU’s Biodesign Institute, the Ira A. Fulton School of Engineering, and the College of Liberal Arts and Sciences. Download Full Image

“The challenges for the next generation of scientists are more complex and inter-related than ever before,” explains Biodesign Institute researcher Neal Woodbury, who directs the institute’s Center for BioOptical Nanotechnology and is a professor in the College of Liberal Arts and Sciences. “Problems as seemingly unrelated as global pandemics, the need for better medical diagnostics and environmental deterioration all stand to benefit from a convergence of technologies from multiple fields of science. Our goal is to teach students to work in interdisciplinary teams that focus on solving a large-scale problem, rather than working independently on an isolated piece of that problem, which is the more traditional approach.”

The new program reflects ASU’s commitment to “use-inspired” research, one of seven imperatives outlined in 2002 by ASU President Michael Crow as part of the university’s 10-year strategic plan.

An executive committee including individuals from across ASU’s bioscience, engineering, informatics and mathematics academic units spearheaded the effort to create the new doctoral program.

According to electrical engineering professor Trevor Thornton, a member of the biological design doctoral graduate program’s executive committee, the main challenge was designing a curriculum to meet the mission of multidisciplinary, solution-driven research.

“An undergraduate curriculum allows a student to gain mastery of an individual discipline,” Thornton says. “The biological design Ph.D. program will allow students to apply their core expertise to multidisciplinary projects while providing them with the skills they need to work with scientists and engineers from other disciplines.”

The doctoral program consists of a two-semester core course sequence to provide training in bio-related areas. There, doctoral candidates will receive intensive training in all the relevant biology-related areas (including biophysics, biomedical engineering, biochemistry and molecular biology) combined with emergent disciplines, including synthetic biology, systems biology, artificial tissues and drug development.

More than 100 ASU participating faculty will be eligible to mentor students in the program. Initially, 15 students will be recruited each year, generating a total student enrollment of around 60 students by the fourth year.

Science is in the midst of a profound transformation, with increasingly complex data sets and problems requiring a large, interdisciplinary team approach combining the biological sciences, physical sciences, engineering and computing. Arizona has been on the fast track in creating a collaborative environment for success.

To catalyze Arizona efforts, the state heavily invested in advancing its research portfolio at its universities with more than $400 million in capital improvements including: ASU’s Biodesign Institute and Interdisciplinary Science and Technical Buildings (I, II, III); the University of

Arizona’s BIO5; the expansion of the University of Arizona College of Medicine – Phoenix in partnership with Arizona State University; and the new Arizona Biomedical Collaborative building, home of ASU’s School of Biomedical Informatics.

These significant investments have been matched by the recruitment of top scientific talent to fill the research space and jump-start new statewide scientific initiatives. A report from the nonprofit Flinn Foundation assessing education needs in the bioscience arena notes that bioscience and high-tech organizations statewide are increasingly dependent on students trained in interdisciplinary, use-inspired science for expansion, growth and economic success.

“We will put great emphasis on individual mentoring of the students,” says Stephen Albert Johnston, a faculty member in the School of Life Sciences within the College of Liberal Arts and director of the Center for Innovations in Medicine at the Biodesign Institute. “We want their time with the program to be effective – and, therefore, I expect most students to finish in four to five years.”

Students will explore interdisciplinary areas of greatest interest and have a large impact in topics such as biofuels, nanoscience, human-computer interfaces, personalized medicine and infectious disease. Students will have an almost unlimited menu of courses to take from academic units in science and engineering, as well as appropriate training courses in law, policy, sociology and business. This will serve to create a highly flexible degree program focused on preparing student for interdisciplinary careers in science and engineering or the application of science and engineering fundamentals to commercial, legal, political or social realms.

Students will receive a highly competitive stipend, plus full tuition reimbursement and health care benefits.

The program is supported by state funds from the Technology Research Infrastructure Fund, Science Foundation Arizona, and individual investigator research grants.

The deadline for applicants to the fall 2008 program is Jan. 1.

For more information and to apply online, visit the Web site">">

Joe Caspermeyer

Manager (natural sciences), Media Relations & Strategic Communications