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JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
VOL. 66, NO. 14, 2015
ª 2015 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION
ISSN 0735-1097/$36.00
PUBLISHED BY ELSEVIER INC.
http://dx.doi.org/10.1016/j.jacc.2015.06.1347
EDITORIAL COMMENT
Pharma Versus Farmer
Food as Heart Medicine*
Robert A. Vogel, MD
E
valuating drugs is easy; assessing the health-
Although
factually
correct,
last
year’s
meta-
fulness of food is not. For drugs, we have
analysis showing a neutral effect of dietary satu-
a proscribed process: determine the dose;
rated fatty acids (SFA) on coronary heart disease
screen for toxicity; and then randomly give the drug
(CHD) lacked insight into food substitution (4). Add-
or its placebo to enough subjects for a sufficient
ing to the public’s confusion, a responding Time
length of time to acquire statistically meaningful end-
magazine cover story was headlined “Eat Butter.
points. Deciphering good nutrition is far more com-
Scientists labeled fat the enemy. Why they were
plex. As omnivores, our food choices are endless.
wrong” (5). In this issue of the Journal, Li et al.
We select food by habit, taste, cost, and availability.
(6) clarify substitutions for SFA to reduce CHD.
Food healthfulness trails these selection factors and
SEE PAGE 1538
is generally poorly understood, even by the medical
community. On average, medical students receive
Combining data from the large, observational Nurses’
only 23.9 h of instruction on nutrition (1). Drugs
Health and Health Professionals Follow-up Studies,
come ready to take; food needs preparation. Unfortu-
these investigators report that replacing 5% of energy
nately, this task is increasingly done for us by the
intake (about 100 kcal) from SFA with equivalent
food industry. Unlike Pharma, the food industry is
energy from polyunsaturated fatty acids (PUFA),
not required to assess healthfulness. Cooking tech-
monounsaturated fatty acids, or carbohydrates from
niques matter. Baked and broiled fish reduce the inci-
whole grains significantly reduced CHD by between
dence of heart failure; fried fish does the opposite (2).
9% and 25%. In contrast, replacing SFA with car-
As with drugs, food combinations affect their biolog-
bohydrates from refined starches or sugars (5% of
ical impact. Endothelial function is decreased by olive
energy intake) increased CHD risk by 10%, and sub-
oil alone, but not when consumed on a salad (3). Eval-
stitution with trans fats (2% of energy intake)
uating food requires long-term studies because dis-
increased CHD risk by 20%. This clarification has
eases such as atherosclerosis take years to decades
important public health implications. We have been
to become manifest. Unlike drug trials, food trials
rightly demonizing saturated and trans fats, but
cannot be blinded, and adherence to an experimental
ignoring the adverse impact of refined starches and
diet is often problematic. Importantly, removal of a
added sugars on CHD. Following this incomplete
food or macronutrient from a diet to assess its poten-
advice, Americans since 1960 have continually eaten
tial harm requires adding back some other food
more refined starch and sugar and less fiber (7). The
to maintain energy intake. Without certainty of the
current study also reports that neither low total fat
healthfulness of the substituted food, such an assess-
nor low total carbohydrate diets were associated with
ment is meaningless.
reduced CHD risk. It is time to set aside the low-fat
versus low-carbohydrate diet debate. Healthfulness
clearly lies in the quality or type of both fat and
*Editorials published in the Journal of the American College of Cardiology
reflect the views of the authors and do not necessarily represent the
views of JACC or the American College of Cardiology.
From the Cardiology Section, Department of Veterans Affairs Medical
carbohydrate.
The benefit of substituting PUFA for SFA is well
supported, although the most convincing randomized
Center, Denver, Colorado. Dr. Vogel has served as a consultant to the
controlled trial literature is fairly old. A good example
Pritikin Longevity Institute, Doral, Florida.
is the Finnish Mental Hospital Study, which, using a
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Vogel
JACC VOL. 66, NO. 14, 2015
OCTOBER 6, 2015:1549–51
Food as Heart Medicine
crossover design, compared a usual diet served in
A meta-analysis of 39 dietary trials recently showed
1 facility with a diet in which PUFA replaced SFA in
that a high intake of added sugar is associated with
another facility (8). Leaving aside issues of subject
increased low-density lipoprotein cholesterol, trigly-
consent, diet adherence was ensured. The PUFA-
cerides, and blood pressure, the latter by 7/6 mm Hg (11).
substituted
low-SFA
diet
significantly
reduced
One important limitation of the current study is
serum cholesterol by 42 mg/dl and reduced nonfatal
that all SFA do not have the same association with
myocardial infarction plus CHD death by approx-
CHD (4). The most common SFA, palmitic and stearic
imately one-half in both crossover periods. In
acids (found in meat and dairy products), are almost
contrast, a meta-analysis of 11 cohort studies in
certainly associated with CHD. Less common SFA,
which SFA were replaced by carbohydrates showed
such as margaric acid, are probably harmless. Even
no reduction in CHD (9).
for SFA, it is misleading to make blanket categoriza-
Is a dietary carbohydrate as bad as a saturated fat?
tions. The other limitations of this study are inher-
As with fats, the answer totally depends on the type
ently those of food versus drug research. The study is
of carbohydrate. Again, the current study provides
observational, probably confounded to some degree
useful clarification of carbohydrate type beyond the
by unmeasured factors, and does not prove causation.
usual simple versus complex (saccharide chain
The investigators excluded fruits, vegetables, and
length) or glycemic index (blood glucose rise) classi-
legumes because of their association with reduced
fications. In this study, carbohydrates were divided
CHD, without definitive evidence from randomized
into 3 categories: those from whole grains; those from
trials. Whereas randomized trials have recommended
refined starches and sugars; and those from fruits,
increased fruit and vegetable intake as part of overall
vegetables, and legumes. Fruits, vegetables, and
dietary changes, none have dealt solely with this food
legumes were not included in the analysis because
category. The fructose in fruit differs from that in
their health benefit is thought to be independent of
regular soft drinks only by quantity, although the latter
their carbohydrate content, a point I will discuss
is an important factor in hepatic conversion to glucose
later. The nutrition facts box required on packaged
versus triglycerides. Clearly, fruit is more than fruc-
food lists SFA and trans fat content (monoun-
tose, and its fiber and micronutrients make a differ-
saturated fatty acids and PUFA may also be listed),
ence. Our current understanding of nutrition is not
but it is more difficult to recognize true whole-grain
sufficient to assign benefit to the specific micro-
foods, especially when faced with pervasive product
nutrients that make fruits and vegetables so healthful.
mislabeling. True whole-grain foods should list
Alcohol, a simple sugar, was also excluded because
whole-grain wheat or other whole grains as the first
of its widely recognized association with reduced CHD,
ingredient. Inclusion of bran is also a good sign, but
especially as consumed in the Mediterranean diet.
terms such as refined grain, bleached grain, or even
Lastly, even the most detailed, self-reported diet
multigrain do not connote healthfulness. Impor-
questionnaire is never as accurate as a good pill count.
tantly, true whole-grain breads, cereals, and pasta
should minimally contain 3 g of fiber per serving.
What we are left with is a slightly clearer message
about food as heart medicine. We in health care need
Nutrition science is slowly realizing the adverse
to be better informed about nutrition and nutritional
cardiovascular effects of refined starches and added
research and have a clearer public health message.
sugars. In a National Health and Nutrition Examination
The challenge will be to convince an increasingly
Survey study of 11,733 healthy subjects, daily con-
wary public that we know what we are talking about.
sumption of >25% of energy intake from added sugar
was associated with an almost 3-fold increase in car-
REPRINT REQUESTS AND CORRESPONDENCE: Dr.
diovascular disease mortality compared with that
Robert A. Vogel, Cardiology Section (111B), Depart-
of subjects with <10% added sugar intake (10). Three
ment of Veterans Affairs Medical Center, 1055 Cler-
12-oz cans of most regular soft drinks provide
mont
>25% of daily energy intake from added sugar.
[email protected].
Street,
Denver,
Colorado
80220.
E-mail:
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Status of nutrition education in medical schools.
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5. Walsh B. Eat butter. Time, June 23, 2014:29–35.
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Vogel
JACC VOL. 66, NO. 14, 2015
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Food as Heart Medicine
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KEY WORDS carbohydrates, coronary heart
disease, diet, fats
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