Wednesday, May 4, 2011

Book Review: The China Study

The China Study by Dr. T. Collin Campbell is next up for review.  Dr. Campbell is an accomplished researcher who is a Professor in Nutritional Biochemistry at Cornell University.  Dr. Campbell has published a ton of research papers and has served as a member on a number of government nutrition and health committees.  He is probably most well known for his work on the China Study, which is an ecological study of nutrition and disease among 6,500 people across China.  The focus of this book is what Dr. Campbell learned from the China Study.

Dr. Campbell strongly believes that we should eat a very low fat, low protein diet devoid of all animal products.  If you read this blog regularly or have read my book, you know I am not a low fat or vegetarian guy.  In fact, I feel that low fat diets can have a negative impact on our health due to their resulting high glycemic load.  However, in the young field of nutritional epidemiology, I believe it is important to read work that goes against your own personal views to further understand the controversies that make this field so interesting and thought provoking.  The book presents a lot of Dr. Campbell’s research on nutrition and disease.  He then tells you what foods to eat, and goes into a detailed explanation of the problems with nutrition research and policy at both the academic and government level.  Overall the book was well written and an interesting read.

5 Things I Liked About The China Study
1) Points out the dangers of red meat and saturated fat.  One thing we have all learned from low fat diet advocates is that saturated fat and lots of red meat can be harmful.  This book is no exception.

2) Emphasis on fruits and vegetables.  Fruits and vegetables are the best things we can eat to improve our health.  This is stressed throughout the book.

3) Emphasis on whole grain foods.  While I’m not a high carb guy by any stretch, I realize the importance of whole grains in our diet.  The literature is teeming with evidence that whole grains improve our health and reduce risk of heart disease, stroke, diabetes and certain cancers.

4) De-empahsizes dairy products.  Those of you who know my writing know that I’m not a huge fan of dairy. 

5) Nutrition policy section  As a member of a number of government committees on nutrition policy, Dr. Campbell can relate his first hand experience on the competing interests of academia, the food industry, research science and the government’s influence on our food policy recommendations.  I found this section a very interesting read.

What I didn’t agree with in The China Study
1) This books groups all fats as unhealthy.  While certain fats are unhealthy (saturated fat and Trans fat) other fats like mono-unsaturated fat, poly-unsaturated fat and omega 3 fatty acids are extremely health promoting.  I don’t know why he didn’t differentiate the different classes of fats.

2) This book groups all animal proteins as unhealthy.  There is a very big difference in how chicken, salmon, turkey and egg whites treat our bodies when compared to steak, bacon and hot dogs.  Some animal proteins are bad for you and some are not.

3) Very high carbohydrate diets have recently been shown to have a negative impact on HDL cholesterol and triglycerides when compared to more Mediterranean style diets.  This isn’t mentioned anywhere in the book.

4) Very high carbohydrate diets result in a high dietary glycemic load.  The glycemic load has been associated with a variety of diseases in the past 10 years.  There was no mention of this anywhere in the book or even of the glycemic load as a concept.

5) His criticism of the Nurse’s Health Study was baffling.  He feels that NONE of the research out of Harvard tells us anything because of flaws in the design of the study.  I had a hard time understanding this argument.  His study is ecological in nature, follows 6,500 Chinese citizens and measures diet one time via a 3 day food record and he has total confidence in the results.  The Nurses’ Health Study is a prospective cohort study, follows 120,000 American nurses for over 30 years and measures diet by means of a validated food frequency questionnaire that is updated every 4 years to reflect changes in diet.  Every aspect of the Nurses’ Health Study is superior to the China study yet it is given no respect in this book. 

Is The China Study Worth Reading?
Absolutely.  I enjoyed the book and learned a lot.  At the end of the day, low fat diet advocates taught us a lot about a healthy diet: the dangers of saturated fat, red meat and dietary cholesterol as well as the benefits of fruits, vegetables and whole grains.  However, well designed research has added a lot to our understanding about the benefits of healthy fats, lean animal proteins, fish and other sources of omega 3’s and most importantly, a low glycemic load diet. 

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