Book Review
Fats or Fiction?
A biochemist argues that the key to preventing obesity lies in lessons from biochemistry class.
Book review by Gregory A. Plotnikoff, M.D., M.T.S.
The U.S. Army estimates that 27 percent of Americans between the ages of 17 and 24—more than 9 million people—are too fat to enlist. Members of the Pentagon group Mission: Readiness report that the obesity epidemic is a national security concern. “When over a quarter of young adults are too fat to fight, we need to take notice,” James Barnett Jr., a retired Navy rear admiral said in a recent New York Times article.1
Physicians need to take notice as well. Obesity is the key public health issue of our day. And its impact is felt daily in our clinics and hospitals. But what do most physicians have to offer sick and overweight patients? What is currently in our medical bag? Medications and surgery. It is no wonder patients are asking, What else can I do?
Without waiting for an answer, the public is moving ahead, often staking their health on the promises of supplement and food manufacturers. As an example, sales in the multibillion-dollar-a-year fish oil industry have increased 30 percent to 40 percent in recent years, according to industry experts.2
Yet how many physicians have the capacity to counsel their patients about this nutritional issue? How many can name the five forms of essential fatty acids that humans consume, explain why each is essential, and describe which ones have been studied extensively in regard to pregnancy, heart disease, cancer, mental health, and inflammatory pain? How many can tell their patients in which foods these fatty acids are found and whether they are at risk for deficiency? How many can describe the risk factors and symptoms that suggest deficiency?
One new book that provides the background physicians need to answer such questions is The Fats of Life: Essential Fatty Acids in Health and Disease. Written by Glen D. Lawrence, Ph.D., a professor in the department of chemistry and biochemistry at Long Island University who has served as a science advisor to the U.S. Food and Drug Administration, the book describes the chemical and biochemical characteristics of the fatty acids, explains how they are metabolized in the body, and reviews the research on how fats in the diet contribute to health and/or disease.
Lawrence explains the differences between omega-3s, omega-6s, trans-fats, polyunsaturated fatty acids, and linoleic acid. He also emphasizes that our understanding of the biochemical and physiological effects of dietary fats has advanced tremendously as a result of careful research, and he argues that this knowledge has not translated easily into sound dietary recommendations in this country.
For every physician who groaned about the apparent irrelevance of second-year biochemistry class, the book is a great opportunity to relearn the science of fats and fatty acids and apply it to health and disease. Lawrence has transformed his years of lectures into very readable chapters that are well-illustrated. They cover pertinent topics such as the metabolism of arachadonic acid to bioactive eiconasoids, and oxidative stress and the destruction of cell membranes and lipoproteins.
But the book goes far beyond being a mere recounting of medical school biochemistry. The author explores the limitations of the cholesterol hypothesis and asserts that “the dietary advice of avoiding saturated fats and cholesterol seems to be focusing too much on readily measurable markers and ignoring the profound effects that polyunsaturated vegetable oils can have on health and longevity.” He argues convincingly that a low-fat diet can be worse than a high-fat one.
Lawrence believes that while Americans have decreased their overall fat consumption, they’ve shifted to over-consumption of polyunsaturated fatty acids, especially vegetable oils, which have in the past three decades become a “copious presence in cell membranes.” He explains they are highly susceptible to lipid peroxidation, which leads not only to destruction of cell membranes but also to formation of carcinogens, deposition of low-density lipoprotein cholesterol in blood vessels, and the negative effects of pro-inflammatory eicosanoids related to asthma, diabetes, and neurological problems including Alzheimer’s disease.
One of the many clinically relevant topics covered in the book is the metabolic difference between glucose and fructose. He points out that fructose has the highest free-radical generation of any sugar tested, while glucose has the lowest, and he explains how those ubiquitous high-fructose corn syrup soft drinks can wreak havoc with our cell membranes. Fructose also has high potential for protein glycation; glucose has low potential. The primary metabolic product of fructose is fat, not glycogen. Fructose increases very-low-density lipoprotein cholesterol and triglycerides and over the long term causes hyperglycemia and hyperinsulinemia. Additionally, fructose leads to measurable production of formaldehyde in drinks.
Whether or not one accepts his thesis that the dietary direction of this country is off-target, the science behind Lawrence’s ideas is credible and the book will augment any physician’s ability to address patients’ questions about what they should eat or avoid. From the well-described basic science to the review of randomized controlled trials, the book is a well-documented resource that can help physicians understand, critique, and contribute to the ongoing discussion about nutrition and health that patients are now having without them. MM
Gregory Plotnikoff is senior consultant for integrative medicine at the Allina Center for Health Care Innovation.
References
1. National Security and the Waistline. New York Times, April 23, 2010. Available at: www.nytimes.com/2010/04/25/weekinreview/25grist.html?scp=1&sq=too%20fat%20to%20fight&st=cse. Accessed May 7, 2010.
2. DeGuzman D. The use of omega-3 fatty acids in food fortification and supplements continues to expand. ICIS Chemical Business. November 2, 2009. Available at: www.icis.com/Articles/2009/11/09/9260250/omega-3-fatty-acid-use-is-growing-rapidly.html. Accessed May 7, 2010.