Research on Carbohydrates and Diet

Recently, the role that carbohydrates play in the diet has been the subject of much debate, the result of the new popularity of low-carbohydrate fad diets.  Below, Barilla has collected summaries of recent scientific research into low-carb diets and their effectiveness. For more information about pasta and how it can be part of a healthy diet please visit the Healthy Eating section of this Barilla's site. 

Efficacy and Safety of Low-Carbohydrate Diets: A Systematic Review
Journal of the American Medical Association
April 9, 2003
A systematic review of studies published between 1966 and February 2003 on the safety and efficacy of low-carbohydrate diets finds insufficient evidence to recommend or advise against the use of such diets, and that weight loss was associated with length of diet, pre-diet weight, and the number of calories consumed, but not reduced carbohydrate content.
Bravata DM, Sanders L, Huang J, Krumholz HM, Olkin I, Gardner CD, Bravata DM. Efficacy and safety of low-carbohydrate diets: a systematic review. JAMA. 2003 Apr 9;289(14):1837-50.

A Randomized Trial of a Low-Carbohydrate Diet for Obesity
New England Journal of Medicine
May 22, 2003
The low-carbohydrate diet produced a greater weight loss (absolute difference, approximately 4 percent) than did the conventional diet for the first six months, but the differences were not significant at one year. The low-carbohydrate diet was associated with a greater improvement in some risk factors for coronary heart disease. Adherence was poor and attrition was high in both groups. Longer and larger studies are required to determine the long-term safety and efficacy of low-carbohydrate, high-protein, high-fat diets.
Foster GD, Wyatt HR, Hill JO, McGuckin BG, Brill C, Mohammed BS, Szapary PO, Rader DJ, Edman JS, Klein S. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med. 2003 May 22;348(21):2082-90.

A Low-Carbohydrate as Compared with a Low-Fat Diet in Severe Obesity
New England Journal of Medicine
May 22, 2003
Severely obese subjects with a high prevalence of diabetes or the metabolic syndrome lost more weight during six months on a carbohydrate-restricted diet than on a calorie- and fat-restricted diet, with a relative improvement in insulin sensitivity and triglyceride levels, even after adjustment for the amount of weight lost.  This finding should be interpreted with caution, given the small magnitude of overall and between-group differences in weight loss in these markedly obese subjects and the short duration of the study.  Future studies evaluating long-term cardiovascular outcomes are needed before a carbohydrate-restricted diet can be endorsed.
Samaha FF, Iqbal N, Seshadri P, Chicano KL, Daily DA, McGrory J, Williams T, Williams M, Gracely EJ, Stern L.  A low-carbohydrate as compared with a low-fat diet in severe obesity
N Engl J Med. 2003 May 22;348(21):2074-81.

Carbs are essential for effective dieting and good mood
MIT Clinical Research Center
Judith Wurtman, director of the Program in Women's Health at Clinical Research Center at the Massachusetts Institute of Technology, and her colleagues have found that when you stop eating carbohydrates, your brain stops regulating serotonin, a chemical that elevates mood and suppresses appetite. And only carbohydrate consumption naturally stimulates production of serotonin.
More information at: http://web.mit.edu/newsoffice/nr/2004/carbs.html

The Glycemic Index: Physiological Mechanisms Relating to Obesity, Diabetes, and Cardiovascular Disease
Journal of the American Medical Association
May 8, 2002
Several dozen studies have described significant improvements in diabetes, obesity, or cardiovascular disease among subjects consuming low-vs. high-glycemic-index diets.  The purpose of this review was to examine the physiological effects of the glycemic index and the relevance of these effects in preventing and treating obesity, diabetes, and cardiovascular disease.  The study concludes that the concept of glycemic index may be complex from a food science perspective, but its public health application is simple: increase consumption of fruits, vegetables, and legumes; choose grain products processed according to traditional rather than modern methods (e.g., pasta, stone-ground breads, old-fashioned oatmeal); and limit intake of potatoes and concentrated sugar.  Despite areas of continuing controversy, it would be prudent to use glycemic index as a qualitative guide for food selection because of its health benefits and lack of adverse effects.
Ludwig DS. The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. JAMA. 2002 May 8;287(18):2414-23.

Modification of Dietary Habits (Mediterranean Diet) and Cancer Mortality in a Southern Italian Village from 1960 to 1996
Journal of the New York Academy of Sciences
1999
A 2001 study examined changes in diet in among the people of Nicotera, a village in southern Italy whose 1960s’s food patterns had factored in to the development of the Mediterranean Diet Pyramid.  The study found a strong correlation between decreased pasta and bread consumption (down 20%) and increased risk of colon and breast cancer.
de Lorenzo A, Andreoli A, Sorge RP, Iacopino L, Montagna S, Promenzio L, Serrano P. Modification of dietary habits (Mediterranean diet) and cancer mortality in a southern Italian village from 1960 to 1996. Ann N Y Acad Sci. 1999;889:224-9.

Adherence to a Mediterranean Diet and Survival in a Greek Population
New England Journal of Medicine
June 26, 2003
This study confirmed the health benefits of the Mediterranean diet, but was not able to determine which food groups were the primary contributors to this benefit.  The study concluded that following the overall Mediterranean diet significantly reduces the risk of death from cancer and coronary heart disease. 
Trichopoulou A, Costacou T, Bamia C, Trichopoulos D. Adherence to a Mediterranean diet and survival in a Greek population.  N Engl J Med. 2003 Jun 26;348(26):2599-608.

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