Gluten sensitivity: new epidemic or new myth? David T. Nash, MD, and Amy R. Slutzky, PhD, MSLIS
Fueled in part by recent bestselling books that warn of the evils of gluten in our diets, a significant proportion of our population is now either avoiding foods that contain gluten or eliminating gluten entirely from their diets, and these numbers continue to grow. The gluten-free trend—and the accompanying multibillion-dollar industry it has created—stems from the spreading belief that eating foods containing wheat or other gluten-laden grains may not only result in weight gain and obesity, but can also lead to a laundry list of ailments ranging from depression and anxiety to arthritis and autism. One popular book contends that current recommendations for a high-grain/low-fat diet underlie much of today’s chronic health problems and that a low-carbohydrate, high-fat/cholesterol diet is ideal. Every major change in our diet carries with it the possibility of unforeseen risks. Concern about the impact of such popularized dietary recommendations on overall well-being—and on cardiovascular health in particular—warrants discussion in the medical community.
F
ueled in part by recent bestselling books—and the television talk shows and celebrity endorsements that accompany them—that warn of the evils of gluten in our diets, a significant proportion of our population is rapidly changing its eating habits. Approximately 30% of all Americans are now either avoiding foods that contain gluten or eliminating gluten entirely from their diets, and these numbers continue to grow (1). The gluten-free trend—and the accompanying multibillion-dollar industry it has created—stems from the spreading belief that eating foods containing wheat or other gluten-laden grains may not only result in weight gain and obesity, but can also lead to a laundry list of ailments ranging from depression and anxiety to arthritis and autism. In the book Grain Brain, for example, the author, David Perlmutter, lists dozens of diseases and symptoms that he believes are all related to gluten sensitivity and thus may be prevented or cured by a gluten-free diet. His list includes 38 different diseases or symptoms, including autism, infertility, and schizophrenia (p. 67) (2). He asserts that a low-carbohydrate, high-fat/cholesterol diet is ideal not just for those afflicted with celiac disease, but for most of the rest of us, as well. According to the book, “the alleged correlation between higher cholesterol and higher cardiac risk is an absolute fallacy” (p. 72), and the author entreats the reader to “start swapping out your daily Proc (Bayl Univ Med Cent) 2014;27(4):377–378
bread with butter and eggs” (p. 12). Further, he charges that our nation’s glorification of a high-grain/low-fat diet underlies today’s epidemics of obesity, memory loss, and other common chronic illnesses, all of which is supported by uninformed physicians and a rapacious drug industry. It all makes for eye-catching reading and causational rhetoric. A response is required. The declaration that a single, simple “cure” can successfully treat numerous diverse diseases and symptoms is reminiscent of the oratory of the “snake oil” merchants of generations ago. These doctor-showmen plied their craft centuries ago in the sparsely populated areas of the American frontier and were known for their elixirs or “miracle cures” (which often included alcoholic admixtures of various nostrums). Of course, this was long before the development of placebo-controlled, randomized clinical trials, which have become the mainstay of proof of efficacy and safety in our modern era of health care. According to Grain Brain, much chronic disease originates in the widespread ingestion of carbohydrates, and these foodstuff, rather than cholesterol or saturated fats, are the premier contributor to an unhealthy individual. Numerous recent studies, however, have provided high-level evidence to the contrary. A recent systematic review found several prospective cohort studies that demonstrated a relationship between consumption of saturated and trans fats and cognitive decline (3). A prospective study of a large heterogeneous population reported that a high-fat diet increases risk of specific breast cancer subtypes (4). A meta-analysis of 16 prospective cohort studies found that “higher consumption of fruit and vegetables [all containing carbohydrates] is associated with a lower risk of mortality from all causes, particularly from cardiovascular mortality” (5). Likewise, a multisite randomized controlled trial found that a low-fat, plant-based nutrition program reduced cardiovascular risk factors (6). Evidence-based findings such as these have
From State University of New York Upstate Medical University, Syracuse, New York. Corresponding author: Amy R. Slutzky, PhD, MSLIS, Health Sciences Library, SUNY Upstate Medical University, 766 Irving Avenue, Syracuse, NY 13210 (e-mail: [email protected]). Note: This article will also appear in The American Journal of Cardiology. 377
led international panels to issue guidelines that recommend minimizing intake of saturated fats and trans fats and including whole grains as a primary staple of the diet (7). Flaws in the arguments presented in the book have not entirely escaped the notice of health care professionals. Some have spoken up, calling the book “comfortably simplistic” (8), one of “brawn, not brain” (9). Others have charged the author with ignoring “the bulk of science,” exaggerating the truth, and making false assumptions (10), and have noted that the book makes claims that are contrary to “what some pretty reliable sources have to say,” referring to recommendations from the World Health Organization and Consumer Reports (11). Yet, the book remains a New York Times bestseller after 43 weeks, and sales of gluten-free products are projected to grow at an annual rate of 10.2% over each of the next 5 years (12). Every major change in our diet carries with it the possibility of unforeseen risks. Many readers—the general public, as well as medical professionals—accept what they read at first glance. Myths have been part of our medical lore for millennia (13). Those jumping on the gluten-free/high-fat bandwagon may be disappointed when their symptoms are not mitigated; more critically, they may be at increased risk for other, more dangerous ailments. At the very least, concern about the impact of encouraging a high-cholesterol, high-saturated-fat diet warrants discussion in the medical community. In short, it is time to review some of the most egregious misinformation being spread and separate some of the wheat from the chaff. Acknowledgments The authors wish to acknowledge the invaluable efforts of Jim Capodagli, MLS, and Rachel Mondo.
4.
5.
6.
7.
8.
9.
10.
11.
12. 1.
2.
3.
378
Strom S. A big bet on gluten-free. New York Times, February 17, 2014. Available at http://www.nytimes.com/2014/02/18/business/food-industry-wagers-big-on-gluten-free.html?_r=0; accessed July 30, 2014. Perlmutter D, Loberg K. Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers. New York: Little, Brown and Company, 2013. Barnard ND, Bunner AE, Agarwal U. Saturated and trans fats and dementia: A systematic review. Neurobiol Aging 2014;35:S65–73.
13.
Sieri S, Chiodini P, Agnoli C, Pala V, Berrino F, Trichopoulou A, Benetou V, Vasilopoulou E, Sánchez MJ, Chirlaque MD, Amiano P, Quirós JR, Ardanaz E, Buckland G, Masala G, Panico S, Grioni S, Sacerdote C, Tumino R, Boutron-Ruault MC, Clavel-Chapelon F, Fagherazzi G, Peeters PH, van Gils CH, Bueno-de-Mesquita HB, van Kranen HJ, Key TJ, Travis RC, Khaw KT, Wareham NJ, Kaaks R, Lukanova A, Boeing H, Schütze M, Sonestedt E, Wirfält E, Sund M, Andersson A, Chajes V, Rinaldi S, Romieu I, Weiderpass E, Skeie G, Dagrun E, Tjønneland A, Halkjær J, Overvard K, Merritt MA, Cox D, Riboli E, Krogh V. Dietary fat intake and development of specific breast cancer subtypes. J Natl Cancer Inst 2014;106(5). Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, Hu FB. Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ 2014;349:g4490. Mishra S, Xu J, Agarwal U, Gonzales J, Levin S, Barnard ND. A multicenter randomized controlled trial of a plant-based nutrition program to reduce body weight and cardiovascular risk in the corporate setting: the GEICO study. Eur J Clin Nutr 2013;67(7):718–724. Barnard ND, Bush AI, Ceccarelli A, Cooper J, de Jager CA, Erickson KI, Fraser G, Kesler S, Levin SM, Lucey B, Morris MC, Squitti R. Dietary and lifestyle guidelines for the prevention of Alzheimer’s disease. Neurobiol Aging 2014;35S2:S74–S78. Review of Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers. Publishers Weekly, September 17, 2014. Available at http://www.publishersweekly.com/9780316234801; accessed July 31, 2014. Katz DL. Brawn, brains, and grains of truth. Medscape, April 3, 2014. Available at http://www.medscape.com/viewarticle/822731; accessed July 30, 2014. McDougall JA. The smoke and mirrors behind Wheat Belly and Grain Brain. McDougall Newsletter 2014;13(1). Available at https://www.drmcdougall.com/misc/2014nl/jan/smoke.pdf; accessed July 30, 2014. Quinn B. Barbara Quinn: Pay no mind to ‘Grain Brain.’ Monterey Herald, May 27, 2014. Available at http://www.montereyherald.com/food-wine/ ci_25845018/barbara-quinn-pay-no-mind-grain-brain; accessed July 30, 2014. Markets and Markets. Gluten-free products market by type (bakery & confectionery, snacks, breakfast cereals, baking mixes & flour and meat & poultry products), sales channel (natural & conventional) & geography—global trends & forecasts to 2019. July 2014. Available at http:// www.marketsandmarkets.com/Market-Reports/gluten-free-productsmarket-738.html; accessed July 29, 2014. Nash DT, Gensini G, Simon H, Arno T, Nash SD. The Erysichthon syndrome. progression of coronary atherosclerosis and dietary hyperlipidemia. Circulation 1977;56(3):363–365.
Baylor University Medical Center Proceedings
Volume 27, Number 4
Fueled in part by recent bestselling books that warn of the evils of gluten in our diets, a significant proportion of our population is now either avoiding foods that contain gluten or eliminating gluten entirely from their diets, and these numbers continue to grow. The gluten-free trend—and the accompanying multibillion-dollar industry it has created—stems from the spreading belief that eating foods containing wheat or other gluten-laden grains may not only result in weight gain and obesity, but can also lead to a laundry list of ailments ranging from depression and anxiety to arthritis and autism. One popular book contends that current recommendations for a high-grain/low-fat diet underlie much of today’s chronic health problems and that a low-carbohydrate, high-fat/cholesterol diet is ideal. Every major change in our diet carries with it the possibility of unforeseen risks. Concern about the impact of such popularized dietary recommendations on overall well-being—and on cardiovascular health in particular—warrants discussion in the medical community.
F
ueled in part by recent bestselling books—and the television talk shows and celebrity endorsements that accompany them—that warn of the evils of gluten in our diets, a significant proportion of our population is rapidly changing its eating habits. Approximately 30% of all Americans are now either avoiding foods that contain gluten or eliminating gluten entirely from their diets, and these numbers continue to grow (1). The gluten-free trend—and the accompanying multibillion-dollar industry it has created—stems from the spreading belief that eating foods containing wheat or other gluten-laden grains may not only result in weight gain and obesity, but can also lead to a laundry list of ailments ranging from depression and anxiety to arthritis and autism. In the book Grain Brain, for example, the author, David Perlmutter, lists dozens of diseases and symptoms that he believes are all related to gluten sensitivity and thus may be prevented or cured by a gluten-free diet. His list includes 38 different diseases or symptoms, including autism, infertility, and schizophrenia (p. 67) (2). He asserts that a low-carbohydrate, high-fat/cholesterol diet is ideal not just for those afflicted with celiac disease, but for most of the rest of us, as well. According to the book, “the alleged correlation between higher cholesterol and higher cardiac risk is an absolute fallacy” (p. 72), and the author entreats the reader to “start swapping out your daily Proc (Bayl Univ Med Cent) 2014;27(4):377–378
bread with butter and eggs” (p. 12). Further, he charges that our nation’s glorification of a high-grain/low-fat diet underlies today’s epidemics of obesity, memory loss, and other common chronic illnesses, all of which is supported by uninformed physicians and a rapacious drug industry. It all makes for eye-catching reading and causational rhetoric. A response is required. The declaration that a single, simple “cure” can successfully treat numerous diverse diseases and symptoms is reminiscent of the oratory of the “snake oil” merchants of generations ago. These doctor-showmen plied their craft centuries ago in the sparsely populated areas of the American frontier and were known for their elixirs or “miracle cures” (which often included alcoholic admixtures of various nostrums). Of course, this was long before the development of placebo-controlled, randomized clinical trials, which have become the mainstay of proof of efficacy and safety in our modern era of health care. According to Grain Brain, much chronic disease originates in the widespread ingestion of carbohydrates, and these foodstuff, rather than cholesterol or saturated fats, are the premier contributor to an unhealthy individual. Numerous recent studies, however, have provided high-level evidence to the contrary. A recent systematic review found several prospective cohort studies that demonstrated a relationship between consumption of saturated and trans fats and cognitive decline (3). A prospective study of a large heterogeneous population reported that a high-fat diet increases risk of specific breast cancer subtypes (4). A meta-analysis of 16 prospective cohort studies found that “higher consumption of fruit and vegetables [all containing carbohydrates] is associated with a lower risk of mortality from all causes, particularly from cardiovascular mortality” (5). Likewise, a multisite randomized controlled trial found that a low-fat, plant-based nutrition program reduced cardiovascular risk factors (6). Evidence-based findings such as these have
From State University of New York Upstate Medical University, Syracuse, New York. Corresponding author: Amy R. Slutzky, PhD, MSLIS, Health Sciences Library, SUNY Upstate Medical University, 766 Irving Avenue, Syracuse, NY 13210 (e-mail: [email protected]). Note: This article will also appear in The American Journal of Cardiology. 377
led international panels to issue guidelines that recommend minimizing intake of saturated fats and trans fats and including whole grains as a primary staple of the diet (7). Flaws in the arguments presented in the book have not entirely escaped the notice of health care professionals. Some have spoken up, calling the book “comfortably simplistic” (8), one of “brawn, not brain” (9). Others have charged the author with ignoring “the bulk of science,” exaggerating the truth, and making false assumptions (10), and have noted that the book makes claims that are contrary to “what some pretty reliable sources have to say,” referring to recommendations from the World Health Organization and Consumer Reports (11). Yet, the book remains a New York Times bestseller after 43 weeks, and sales of gluten-free products are projected to grow at an annual rate of 10.2% over each of the next 5 years (12). Every major change in our diet carries with it the possibility of unforeseen risks. Many readers—the general public, as well as medical professionals—accept what they read at first glance. Myths have been part of our medical lore for millennia (13). Those jumping on the gluten-free/high-fat bandwagon may be disappointed when their symptoms are not mitigated; more critically, they may be at increased risk for other, more dangerous ailments. At the very least, concern about the impact of encouraging a high-cholesterol, high-saturated-fat diet warrants discussion in the medical community. In short, it is time to review some of the most egregious misinformation being spread and separate some of the wheat from the chaff. Acknowledgments The authors wish to acknowledge the invaluable efforts of Jim Capodagli, MLS, and Rachel Mondo.
4.
5.
6.
7.
8.
9.
10.
11.
12. 1.
2.
3.
378
Strom S. A big bet on gluten-free. New York Times, February 17, 2014. Available at http://www.nytimes.com/2014/02/18/business/food-industry-wagers-big-on-gluten-free.html?_r=0; accessed July 30, 2014. Perlmutter D, Loberg K. Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers. New York: Little, Brown and Company, 2013. Barnard ND, Bunner AE, Agarwal U. Saturated and trans fats and dementia: A systematic review. Neurobiol Aging 2014;35:S65–73.
13.
Sieri S, Chiodini P, Agnoli C, Pala V, Berrino F, Trichopoulou A, Benetou V, Vasilopoulou E, Sánchez MJ, Chirlaque MD, Amiano P, Quirós JR, Ardanaz E, Buckland G, Masala G, Panico S, Grioni S, Sacerdote C, Tumino R, Boutron-Ruault MC, Clavel-Chapelon F, Fagherazzi G, Peeters PH, van Gils CH, Bueno-de-Mesquita HB, van Kranen HJ, Key TJ, Travis RC, Khaw KT, Wareham NJ, Kaaks R, Lukanova A, Boeing H, Schütze M, Sonestedt E, Wirfält E, Sund M, Andersson A, Chajes V, Rinaldi S, Romieu I, Weiderpass E, Skeie G, Dagrun E, Tjønneland A, Halkjær J, Overvard K, Merritt MA, Cox D, Riboli E, Krogh V. Dietary fat intake and development of specific breast cancer subtypes. J Natl Cancer Inst 2014;106(5). Wang X, Ouyang Y, Liu J, Zhu M, Zhao G, Bao W, Hu FB. Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ 2014;349:g4490. Mishra S, Xu J, Agarwal U, Gonzales J, Levin S, Barnard ND. A multicenter randomized controlled trial of a plant-based nutrition program to reduce body weight and cardiovascular risk in the corporate setting: the GEICO study. Eur J Clin Nutr 2013;67(7):718–724. Barnard ND, Bush AI, Ceccarelli A, Cooper J, de Jager CA, Erickson KI, Fraser G, Kesler S, Levin SM, Lucey B, Morris MC, Squitti R. Dietary and lifestyle guidelines for the prevention of Alzheimer’s disease. Neurobiol Aging 2014;35S2:S74–S78. Review of Grain Brain: The Surprising Truth about Wheat, Carbs, and Sugar—Your Brain’s Silent Killers. Publishers Weekly, September 17, 2014. Available at http://www.publishersweekly.com/9780316234801; accessed July 31, 2014. Katz DL. Brawn, brains, and grains of truth. Medscape, April 3, 2014. Available at http://www.medscape.com/viewarticle/822731; accessed July 30, 2014. McDougall JA. The smoke and mirrors behind Wheat Belly and Grain Brain. McDougall Newsletter 2014;13(1). Available at https://www.drmcdougall.com/misc/2014nl/jan/smoke.pdf; accessed July 30, 2014. Quinn B. Barbara Quinn: Pay no mind to ‘Grain Brain.’ Monterey Herald, May 27, 2014. Available at http://www.montereyherald.com/food-wine/ ci_25845018/barbara-quinn-pay-no-mind-grain-brain; accessed July 30, 2014. Markets and Markets. Gluten-free products market by type (bakery & confectionery, snacks, breakfast cereals, baking mixes & flour and meat & poultry products), sales channel (natural & conventional) & geography—global trends & forecasts to 2019. July 2014. Available at http:// www.marketsandmarkets.com/Market-Reports/gluten-free-productsmarket-738.html; accessed July 29, 2014. Nash DT, Gensini G, Simon H, Arno T, Nash SD. The Erysichthon syndrome. progression of coronary atherosclerosis and dietary hyperlipidemia. Circulation 1977;56(3):363–365.
Baylor University Medical Center Proceedings
Volume 27, Number 4
