STRAIGHT TALK
STEVEN E. NISSEN, MD
Diet, Conventional Wisdom
and the Herd Mentality
I
n a classical novel Nineteen Eighty Four written by George Orwell, nearly everything is
the opposite of what it seems. The “Ministry
of Peace” manages endless war, the “Ministry of
Love” supervises torture and brainwashing, and
the “Ministry of Truth” generates propaganda.
During the last few years, many physician-scientists may feel like we are experiencing our own
version of this Orwellian society. Many unassailable scientific truths have been proven catastrophically wrong, often with the emerging evidence
demonstrating the opposite of what we were led
to believe. In analyzing these scientific mistakes,
we learn something pivotal about ourselves and
our approach to advancing scientific knowledge.
Consider this example.
In 1947, Dr. Ancel Keys began the now
famous “Seven Countries Study” that ultimately
became the foundation for contemporary wisdom
about diet and heart disease. This observational
research initiated a scientific dictum that spanned
at least 5 decades, promulgating the concept that
excessive fat intake, particularly saturated fat, represented the key dietary driver of a rising epidemic
of coronary heart disease (CHD). Patients and
our entire society were educated to avoid milk fat
including butter, whole milk and cream, eschew
well-marbled beef and fatty meats like bacon, and
substitute lower-fat alternatives for these “harmful” foods. Congress (through legislation), the
food industry, and public advocacy groups like the
American Heart Association (AHA) joined the chorus. Margarine soon substituted for butter as the
preferred spread for the “heart-healthy” consumer.
Grocery shelves were lined with low-fat alternatives and the term “fat-free” became synonymous
with “heart-healthy.”
The AHA proudly trumpeted this public health
message by developing and popularizing a low
saturated fat diet based upon these principles.
Even now, the AHA website proclaims the virtues
of this diet with statements such as these1:
• Choose lean meats and poultry without skin and prepare them without
added saturated and trans fat.
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• Select fat-free, 1% fat and low-fat
dairy products.
• To lower cholesterol, reduce saturated fat to no more than 5% to 6%
of total calories. For someone eating
2,000 calories a day, that’s about 13
grams of saturated fat.
Americans in substantial numbers heeded this
advice and the result was catastrophic. We experienced an epidemic of obesity and diabetes that has
not yet peaked and simultaneously, we failed to
defeat the very disease we sought to eliminate.
Now, in retrospect, the quality of the research
that supported the low-fat diet has come under
increasingly negative scrutiny. First, Dr. Robert
Atkins, a zealot with a completely opposite perspective, wrote a book in 1972 entitled Dr. Atkins’
Diet Revolution that promoted an ultra-low carbohydrate (and high fat) diet as a means to achieve
weight loss, rapidly gaining a following of true
believers. More recently, thoughtful researchers
began exploring the science underlying Ancel Keys
original observations with astonishing findings.
Chowdhury and colleagues analyzed 32 observational studies involving more than 500,000 participants, demonstrating no increase in heart di 6V6P