Carol Johnston, Ph.D., R.D. Professor

B.S., University of Michigan
M.A., University of Texas, Austin Ph.D., University of Texas, Austin

Phone: (480) 727-1713
Office: Health Sciences Center (HSC), Rm. 1403
E-mail: carol.johnston@asu.edu

BIOGRAPHY

Dr. Johnston, Professor and Chair, has been a member of the nutrition faculty at Arizona State University since 1986.  She received her BS in nutrition from the University of Michigan, Ann Arbor and her MS in nutrition and PhD in biological sciences from the University of Texas, Austin. She is a registered dietitian (RD) and a certified nutrition specialist (CNS). She teaches both undergraduate and graduate courses and has an active research program. She has published over 80 research articles and book chapters on topics ranging from the effects of vitamin C nutriture on health and disease to the efficacy of high-protein diets for weight loss and the use of vinegar to help manage blood glucose levels in diabetics. She is an expert in vitamin C metabolism and testified before the Panel on Antioxidants and Related Compounds of the Food and Nutrition Board of the Institute of Medicine regarding the safety of high-dose vitamin C. She is an elected member of the 2005-2010 Dietary Supplements- Non-Botanicals Expert Committee of the U.S. Pharmacopoeia, and she is a member of the Board of Directors of the American College of Nutrition. She received the 2004 Grace A. Goldsmith Award from the American College of Nutrition in recognition of her research that has advanced the knowledge and application of nutrition to the prevention and treatment of disease. She received the 2000 Outstanding Teaching Award from the College of Liberal Arts and Sciences Alumni Association, Arizona State University.

CURRENT RESEARCH INTERESTS

• Vitamin C: relationships with adiposity
• Vinegar: antiglycemic effects in healthy adults and individuals with type 2 diabetes
• Vegetarian diets
• Low carbohydrate diets

RECENT PUBLICATIONS

Book chapters

Johnston CS, Steinberg FM, Rucker RB. Ascorbic Acid. In: Handbook of Vitamins, 4 th ed. Marcel Dekker, Inc: New York, In Press.

Johnston CS. Vitamin C. In: Present Knowledge in Nutrition, 9 th ed. (eds. Bowman BA, Russell RM) ILSI Press: Washington, DC, 2006.

Johnston CS. Orange juice: Are the health benefits of oranges lost during processing? In: Beverage Impacts on Health and Nutrition. (eds. Wilson T, Temple NJ) Humana Press; Totowa NJ. 2003

Johnston CS. Potential adverse effects of vitamins C and E. In: The Antioxidant Vitamins C and E. (eds Packer L, Traber MG, Kraemer K, Frei B) AOCS Press: Champaign IL. 2002.

Johnston CS. Vitamin C. In: Present Knowledge in Nutrition, 8 th ed. (eds. Bowman BA, Russell RM) ILSI Press: Washington, DC, 2001.

Johnston CS, Steinberg FM, Rucker RB. Ascorbic Acid. In: Handbook of Vitamins, 3 rd ed. (eds. Rucker RB, Suttie JW, McCormick DB, Machlin LJ) Marcel Dekker, Inc: New York, 2001.

Refereed articles

Johnston CS, Beezhold BL, Mostow B, Swan PD. Plasma vitamin C is inversely related to body mass index and waist circumference but not to plasma adiponectin in non-smoking adults Journal of Nutrition 2007 In press

Winham D, Hutchins, AM, Johnston CS. Pinto bean consumption reduces biomarkers for heart disease risk. the Journal of the American College of Nutrition.  In Press.

Johnston CS, Tjonn SL, Swan PD, White AM, Hutchins H, Sears B. Benefits of ketogenic diets (letter reply). American Journal of Clinical Nutrition. 2007;85:239-40.

Kleiner RE, Hutchins AM, Johnston CS, Swan PD. Effects of an 8-week high protein or high carbohydrate diet in adults with hyperinsulinemia. Medscape General Medicine. 2006;8(4).

Johnston CS, Tjonn SL, Swan PD, White AM, Sears B. Low-carbohydrate, high-protein diets that restrict potassium-rich fruits and vegetables promote calciuria. Osteoporosis International. 2006;17:1820-21.

Johnston CS. Metabolic advantage of low-carbohydrate diets (letter reply). Journal of the American College of Nutrition 2006;25:436

Johnston CS, Corte C, Swan PD. Marginal vitamin C status is associated with reduced fat oxidation during submaximal exercise in young adults. Nutrition and Metabolism 2006;3:35

Johnston CS, Gaas CA. Vinegar: Medicinal uses and antiglycemic effect. Medscape General Medicine. 2006;8:61.

Johnston CS., Tjonn SL, Swan PD, White A, Hutchins H, Sears B. Ketogenic low-carbohydrate diets have no metabolic advantage as compared to non-ketogenic low-carbohydrate diets. American Journal of Clinical Nutrition 2006;83:1055-1061.

Benyshek D, Johnston C, Martin J. Glucose metabolism is altered in the adequately-nourished grand-offspring (F3 generation) of rats malnourished in utero. Diabetologia 2006;49:1117-1119.

Winham DM, Johnston CS, Rhoda KM. Maternal weight gain is associated with infant insulin concentrations during the first year of life. Diabetes Care. 2006;29:949.

Johnston CS, Buller AJ. Vinegar and peanut products as complementary foods to reduce postprandial glycemia. Journal of the American Dietetic Association. 2005;105:1939-1942.

Johnston CS. Uncle Sam's Diet Sensation: MyPyramid -- An Overview and Commentary. Medscape General Medicine. 2005;7:78. 

Hutchins AM, McIver IE, Johnston CS. Soy isoflavone and ascorbic acid supplementation alone or in combination minimally affect plasma lipid peroxides in healthy postmenopausal women. Journal of the American Dietetic Association. 2005;105:1134-1137.

Hutchins AM, McIver IE, Johnston CS. Hypertensive crisis associated with high dose soy isoflavone supplementation in a post-menopausal woman: a case report BMC Women's Health 2005, 5:9 

Johnston CS. Strategies for healthy weight loss: from vitamin C to the glycemic index. Journal of the American College of Nutrition. 2005:24:158-165.

Hathcock JN, Dickinson A, Azzi A, Blumberg J, Frei B, Johnston CS, Packer L, Parthasarathy S, Traber MG. Potential harm of vitamin E supplementation (letter reply). American Journal of Clinical Nutrition. 2005;81:1142-1143.

Hathcock JN, Dickinson A, Azzi A, Blumberg J, Bray T, Frei B, Jialal I, Johnston CS, Kelly FJ, Kraemer Klaus, Packer L, Parthasarathy S, Sies H, Traber MG. Vitamins E and C – safe within broad ranges of intakes. American Journal of Clinical Nutrition. 2005;81:736-745..

Hampl JS, Levinson SL, Garcia LW, Johnston CS. Project GLEAN: Evaluation of a school-based, gleaned-food distribution program. J Sustain Agr. 2004;25:5-15.

Hampl JS, Taylor CA, Johnston CS. Vitamin C Deficiency and Depletion in the United States: The Third National Health and Nutrition Examination Survey, 1988 to 1994. American Journal of Public Health. 2004;94:870-875.

Benyshek DC, Johnston CS, Martin JF. Post-natal diet determines insulin resistance in fetally malnourished, low birthweight rats (F1) but diet does not modify the insulin resistance of their offspring (F2). Life Sciences. 2004;74:3033-3041.

Johnston CS, Tjonn SL, Swan PD. High-protein, low-fat diets are effective for weight loss and favorably alter biomarkers in healthy adults. Journal of Nutrition 2004; 134:586-91.

Johnston CS, Kim CM, Buller AJ. Vinegar improves insulin sensitivity to a high carbohydrate meal in subjects with insulin resistance or type 2 diabetes mellitus. Diabetes Care 2004;27:281-282.

Johnston CS, Dancho CL, Strong GM. Orange juice ingestion and supplemental vitamin C are equally effective a reducing plasma lipid peroxidation in healthy adult women. Journal of the American College of Nutrition 2003;22:519-523.

Huso ME, Hampl JS, Johnston CS, Swan PD. Creatine supplementation influences substrate utilization at rest. Journal of Applied Physiology. 2002;93:2018-2022.

Venti CA , Johnston CS. Modified Food Guide Pyramid for Lactovegetarians and vegans. Journal of Nutrition. 2002;132:1050-1054.

Johnston CS, Bowling DL. Bioavailability of oxidized vitamin C (dehydroascorbic acid). Journal of the American Dietetic Association. (letter) 2002;102:1224-1225.

Johnston CS, Day CS, Swan PD. Post-prandial thermogenesis is increased 100% on a high-protein, low-fat diet versus a high-carbohydrate, low-fat diet in healthy, young women. Journal of the American College of Nutrition. 2002;21:55-61.

Johnston CS, Bowling DL. Stability of ascorbic acid in commercially available orange juices. Journal of the American Dietetic Association. 2002;102:525-529.

Benyshek DC , Martin JF, Johnston CS. A reconsideration of the origins of the type 2 diabetes epidemic among Native Americans and the implications for community-based interventions. Medical Anthropology 2001;20:25-64.

Johnston CS, Cox SK. Plasma-saturating intakes of vitamin C confer maximal antioxidant protection to plasma. Journal of the American College of Nutrition. 2001;20:623-627.

Johnston CS, Taylor CA, Hampl JS. More Americans are eating ‘5 A Day’ but intakes of dark green and cruciferous vegetables remain low. Journal of Nutrition. 2000:130:1063-1067.

Taylor CA, Hampl JS, Johnston CS. Low intakes of vegetables and fruits, especially citrus fruits, lead to inadequate vitamin C intakes among adults. European Journal of Clinical Nutrition. 2000;54:573-578..

Martin JF, Johnston CS, Han T, Benyshek DC. Nutritional origins of insulin resistance: an animal model for diabetes-prone populations. Journal of Nutrition. 2000;130:741-744.

Johnston CS, Monte WC. Infant formula ingestion is associated with the development of diabetes in the BB/Wor rat. Life Sciences. 2000;66:1501-1507.

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