In 1948, a random
sample of 5209 citizens in the small rural village of Farmingham
Massachusetts (about 2/3 of the population) volunteered to become
active participants in a collaborative health study with the National
Heart Institute (NHI) known as the 'Farmington Heart Study (FHS)'.
The goal of this on-going study was to determine the effects of diet
on cardiovascular disease. The
bottom line, Dr. Kannel and his team of researchers found no direct
correlation between the dietary intake of fats and elevated serum
cholesterol levels. Uh...what?
That's right, the scientists and researchers of
the FHS complied
all the results of the study in the
early 1970's
and
published their findings in
section 24 of 'The Farmingham Study An Epidemiological Investigation
Of Cardiovascular Disease, The Farmingham Diet Study: Diet And The
Regulation Of Serum Cholesterol'. In
this report they concluded “There
is no indication of a relationship between dietary cholesterol and
serum cholesterol levels.
If the intake of
animal fat is held constant there is still no relation of cholesterol
intake to serum cholesterol levels.
If a multiple regression is calculated [using animal fat and dietary
cholesterol] there is also little suggestion of an association
between this pair of variables and serum cholesterol levels.”
That's
a pretty shocking statement as many organizations including the
American Heart Association (AHA) have based their dietary fat
recommendations on the results of the FHS. Cardiologist Dr.
Christopher Wegener in his article 'On Trial: Saturated Fat: Proven
Villain or Medical Myth? States “When compared to the low-fat diet
and alternative popular diets, it is the low-carbohydrate dietary
strategy that has led to greater weight loss, significant increases
in HDL-C with concomitant decreases in total
glucose (TG),
and noteworthy reductions in hemoglobin A1c. Such findings should not
be surprising as such results were evident in the data on the much
earlier NIH-funded Framingham cohorts which demonstrated that the
subjects who ate the most fat and least amount of refined grains and
sugars experienced the greatest increase in HDL-C.” If
these findings are true, then why have we been taught to believe that
all fats are bad for us?
In this article, I
am going to try and address the differences between saturated,
polyunsaturated, and monounsaturated fats. I will also try explain
why they are not only necessary for proper bodily function, but how
they can be beneficial for promoting weight loss. In addition, we
will examine how partially hydrogenated oils (PHO's) also known as
trans fats are the one bad fat that everyone can agrees that we
should avoid.
Saturated Fats
Saturated fats are
mostly found in animal fats (beef, pork, poultry), dairy products
(butter, heavy cream, and cheese) as well as in tropical oils
(coconut and palm). However, our bodies naturally make a certain
amount of saturated fatty acids from the carbohydrates that we
consume. Saturated fats are not the 'evil monster' that many believe
them to be, and current medical research has proven that there is no
direct link between the cardiovascular disease and the consumption of
natural saturated fats found in most animal and or dairy products.
Harvard Medical School concluded that in a meta analysis of 21
independent studies “that there was not enough evidence to conclude
that saturated fat increases the risk of heart disease”.
In fact, when consumed in their natural state they may even be
beneficial to your cholesterol levels as they contain many beneficial
saturated fatty acids that your body needs. “Recent research has
also shown that Mediterranean diets -- admittedly skimpy on red meat
but hardly light on saturated fats -- have outpaced both statins and
low-fat diets as a means of preventing repeat heart attacks. Other
research suggests that the saturated fat in dairy foods may protect
against hypertension, inflammation and a host of other dysfunctions
increasingly linked to heart attacks.” (Healey, 2013). New York
Times best selling author Dr. Joesph Mercola in his article regarding
saturated fats states “when you reduce saturated fat and increase
refined carbohydrates, you end up promoting obesity, heart disease
and diabetes”. He goes on to further state “Saturated fats from
animal and vegetable sources provide a number of important health
benefits. In fact, your body
cannot function without
saturated fats! Saturated fats are needed for the proper function of
your: cell membranes, heart, bones, liver, lungs, hormones, immune
system, satiety (reduces hunger) and genetic regulation.”
Polyunsaturated Fats
(PUFA'S)
Polyunsaturated fats
can be found in fish, nuts, seeds, leafy greens, and vegetable oils.
Sometimes called 'essential fats', polyunsaturated fats are used by
your body to build cell membranes, are needed for proper muscle
movement, help with blood clotting, fight inflammation, and are an
essential component used to build myelin sheaths which are necessary
for proper neuromuscular function. Unlike saturated fats, our bodies
do not naturally produce the necessary polyunsaturated fats our
bodies need to function properly so we must get them from the foods
we eat.
According to the
Harvard Medical School, “Eating polyunsaturated fats in place of
saturated fats or highly refined carbohydrates reduces harmful LDL
cholesterol and improves the cholesterol profile. It also lowers
triglycerides”. I think the key phrase here is “in place of
highly refined carbohydrates”, as many cardiologists now believe
that there is no direct link between saturated fat intake and
cardiovascular disease, however there is a direct correlation between
heart disease and high carbohydrate intake. In their article 'The
Truth About Saturated Fat' Enig and Fallon state that “Elevated
triglycerides in the blood have been positively linked to proneness
of
heart disease, but these triglycerides do not come directly from
dietary fats; they are made in the liver from any excess sugars that
have not been used for energy. The source of these excess sugars is
any food containing carbohydrates, particularly refined sugar and
white flour”. This
is why it is extremely important that Americans
need to change
our eating habits by reducing or eliminating the amount of highly
processed and refined carbohydrates and sugars in our diet, not fats.
This is especially true
for people
who have
been diagnosed with diabetes or
have cardiovascular issues.
Monounsaturated Fats
(MUFA'S)
The most common
monounsaturated fat found in the typical American diet is oleic acid.
Oleic acid occurs naturally in vegetable and animal oils. Olive oil
is one of the most common and best sources of oleic acid, but it can
also be found in almond
oil, peanut oil, canola oil,
corn oil, avocados,
sunflower oil, safflower oil,
red meat, fish,
whole milk, and
most nuts. MUFA's
are beneficial to your
health by lowering “unhealthy” low density lipoprotein (LDL)
cholesterol levels and increasing “healthy” high density
lipoprotein (HDL) levels. According
to the American Heart Association “Monounsaturated fats can help
reduce bad cholesterol levels in your blood which can lower your risk
of heart disease and stroke. They also provide nutrients to help
develop and maintain your body’s cells. Oils rich in
monounsaturated fats also contribute vitamin E to the diet, an
antioxidant that most
Americans need more of”.
As
mentioned in our discussion on saturated fats, The
Mediterranean Diet also
includes a large amount of monounsaturated
fats. Studies
suggest that overall,
the
populace of Mediterranean
countries consume more total fat than the
populace of Northern
European countries (up
to 40% of
total dietary intake in
some regions),
however
most of the
fat is in the form of monounsaturated fats from olive oil, fish,
vegetables, and meats such
as lamb.
While the
total fat consumption is high, the rate of cardiovascular disease and
diabetes among Mediterranean
populations
is well below the average of
Northern
European
and American
populations.
Partially
Hydrogenated Oils (PHO's) aka Trans Fats
The one type of
dietary fat that everyone can agree on that is bad are 'trans fats'.
Trans fats are created through a process called hydrogenation which
turns liquid oils into solids such as margarine and shortening. This
process of hydrogenation turns healthy vegetable oils into
not-so-healthy saturated fats. During the Great Depressions (1930's)
and World War II (1939 – 45), butter was in short supply and
oleomargarine (originally made with beef fat) became an inexpensive
and popular substitution. By 1950, manufacturers began to replace the
beef fat with cheaper partially hydrogenated vegetable oils.
Soon food
manufacturers began using partially hydrogenated vegetable oils
(PHO's) in everything from commercial cookies and pastries to
fast-food French fries. Originally believed safe, research over the
last 30 years has proven that eating foods rich in trans fats not
only increases the amount of harmful LDL cholesterol in the
bloodstream, but reduces the amount of beneficial HDL cholesterol. In
addition, trans fats create inflammation of the blood vessels, which
is linked to heart disease, stroke, diabetes, and other chronic
conditions. Trans fats have also been proven to contribute to insulin
resistance, which increases the risk of developing type 2 diabetes.
According to Enig and Fallon, “Consumption
of hydrogenated fats is associated with a host of other serious
diseases, not only cancer but also atherosclerosis, diabetes,
obesity, immune system dysfunction, low- birth-weight babies, birth
defects, decreased visual acuity, sterility, difficulty in lactation
and problems with bones and tendons”.
According
to TIME magazine, “In 2013, the FDA determined that PHO's do not
meet their distinction of “generally recognized as safe” for
human consumption”. Because
of the health risks related to partially hydrogenation oils
associated
with trans fats, the
United States Food and Drug Administration (FDA)
announced in June 2016 that it is moving towards baning artificial
trans fats
here in the
United States. “Over the next three years, food manufacturers must
remove the primary source of artificial trans fat—partially
hydrogenated oils (PHO's)—from their products” (TIME,
2016). Keep
in mind that trans fat will not totally disappear from the American
diet as they naturally occur in some products like meat and dairy
products and may be present
at very low
levels in some oils. However,
the ban on PHO's by the FDA should
significantly reduce the amount of trans fats consumed by Americans
which
should lead
to a healthier population. However,
the future
is yet to be determined.
So What Does It All
Mean?
Saturated fats tend
to have a neutral to beneficial effect on weight and cholesterol
levels, whereas polyunsaturated fats which our bodies do not make are
necessary for proper bodily function and must be acquired via diet.
Monounsaturated fats actually lower “unhealthy” low density
lipoprotein (LDL) cholesterol levels and increasing “healthy”
high density lipoprotein (HDL) levels. This is why people who live in
the Mediterranean, and
consume a traditional Mediterranean
Diet which
is high in saturated and and monounsaturated fats (up to 40%) have
some of the lowest cholesterol levels as well as low levels of
cardiovascular disease. Countries such as the United States and Great
Britain whose populations consume less saturated, polyunsaturated,
and monounsaturated fats, but consume
large amounts of foods
that contain partially
hydrogenation oils (trans
fats)
as well as carbohydrates have the highest
rates of
obesity, diabetes, and cardiovascular disease.
The following comes
from an article in the News, Farmingham-Natick, Friday October 30,
1970 in which a reporter interviewed Dr. Kannel, then director of the
FHS about the studies findings regarding the relationship between
diet and serum cholesterol.
'Although
there is no discernible relationship between reported diet intake and
serum cholesterol levels in the Farmington Diet Study group, “it is
incorrect to interpret this finding to mean that diet has no
connection with blood cholesterol” Dr. William B. Kannel, director
of the Farmingham Heart Study has stated. “It has been repeatedly
demonstrated that blood cholesterol levels can be altered by changes
in diet; and dietary alteration is still the most acceptable form of
medical management for persons with elevated blood lipids” Dr.
Kannel said. “The available evidence indicates that coronary heart
disease appears to result from a combination of
contributing factors and that no single factor capable
of producing disease by itself has been convincingly demonstrated,”
he stated.
Even
the director of the FHS study Dr. William Kannel states that changing
dietary habits is the best way to decrease serum cholesterol levels.
Substituting saturated, polyunsaturated, and monounsaturated fats for
unhealthy trans fats, and decreasing the amounts of refined sugars,
and carbohydrates consumed can definitely decrease the risks of
diabetes, and cardiovascular disease.
Conclusion
Going back and
looking at this article I may have went into overload mode and listed
more information here than was necessary. However, I hope that this
article was informative and helpful. There is no doubt that some of
the newer research goes against current conventional thinking when it
comes to dietary fat intake. Change is inevitable, but it is a slow
process, and many of my colleagues in the medical field are just not
ready to make the change despite the current scientific and medical
research.
On a side note, I
have been on a low carbohydrate high fat diet for eight weeks. As of
the writing of this article I have lost a total of 23.25 pounds,
decreased my BMI from to 36.6 to 33.2. I have been able to stop
taking my insulin as my blood glucose is averaging 105.7 fasting,
104.7 at midday, 107.2 before bedtime. The real proof of the
effectiveness of this dietary regimen for me will be in mid December
2016 when I see my endocrinologist and my labs are drawn after being
on this diet for 3 ½ months.
Whatever the
results, I will post my serum cholesterol and my hemoglobin A1c as an
addendum to this article so that you can see whether the choices I
have made regarding my dietary fat intake have been benefited or
harmed my health. As always, if you have found this article
informative, we ask that you share it with your friends and family.
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References:
American Heart
Association, Monosaturated Fats, accessed October 23, 2016.
Enig, Mary, PhD,
Fallon, Sally, The Truth About Saturated Fat, Dr. Axe Food Is
Medicine, accessed September 28, 2016
Beyond the Olive: 9
Healthy Oils For Cooking, Dressing Dishes, Today Food February 26,
2013
Crosby, Guy, PhD,
CFS, Ask The Expert: Concerns About Canola Oil, Harvard School Of
Public Health, accessed October 24, 2016
Eades, Michael, MD,
Framingham Follies, The Blog Of Michael R. Eades, MD, accessed
October 24, 2016
Enfeldt, Andreas, MD
Saturated Fat Completely Safe According To New Big Review Of Science,
March 18, 2014.
Healy, Melissa, Time
To End The War Against Saturated Fat? The LA Times, October 22, 2013
Mercola, Joseph DO,
Saturated Fat: The Forbidden Food You Should Never Stop Eating.
September 01. 2011.
Sifferlin,
Alexandra, This Is Why The FDA Is Banning Trans Fats, Time, June 16,
2015
The Farmingham Study
An Epidemiological Investigation Of Cardiovascular Disease, Section
24, The Farmingham Diet Study: Diet And The Regulation Of Serum
Cholesterol.
The Healthiest Oils
For Cooking And Frying, Atkins, accessed September 12, 2016
The 5 Best Cooking
Oils For Health! Bodybuilding November 4, 2015
The Truth bout Fats:
The Good, The Bad, And The In-between, Harvard Medical School,
accessed October 24, 2016
Villacorta, Manuel,
RD, Did You Know That Healthy Oils Don't Stop With Olive?, The
Huffington Post, February 16, 2014
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MD, On Trial: Saturated Fat: Proven Villain or Medical Myth? Fall
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