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experiencelifemag.com
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Skimming the Truth
Why low-fat dairy may be overrated and why full-fat dairy could have more going
for it than you’d think - assuming you can tolerate dairy in the first place.
By Courtney Helgoe
|
September 2009 |
Weak Connections
A Second Look at Saturated Fats
In Fat's Favor
A Healthy Balance
Milk: Explore Your Options
Doing Dairy Right
Two containers of yogurt sit side by side, one fat-free
and one
full-fat. Now, without any other information about the contents
therein,
answer quickly: Which of these has been
scientifically proven
to cause
weight
gain and heart
disease, and which has been
proven to support
weight loss and
coronary health? If
you’re like most people who pay
even modest attention to
prevalent nutritional news
bites, you’ll crown
the low-fat
stuff as the
healthier choice. And despite the fact that
your
answer would be solidly backed
by majority opinion, you’d be
wrong. The correct answer to both questions is
actually
“neither,”
since researchers have yet to
provide concrete support for
the
much-ballyhooed reputation of
low-fat dairy products as a
heart-healthy,
weight-loss
panacea. Nor have they confirmed the
reputation of full-fat
dairy as
a diabolical threat to
coronary health and
waistline
reduction. That comes
as a
shock to a
lot of folks, including
health professionals. “Probably most
people who think of themselves as
nutrition-savvy
would be
astonished to learn
that evidence of whole
milk’s being a
ticket to an early grave is conspicuous by
its absence,”
says
food historian Anne Mendelson in Milk: The Surprising Story
of
Milk Through the Ages (Knopf,
2008).
Weak Connections
The prevailing understanding of low-fat dairy products
seems to owe more to powerful food-industry campaigns and wishful
thinking than
to convincing scientific data. In 2003
the
National Dairy Council
began aggressively
promoting the
claim that
consuming three servings of low-fat
dairy products
daily would
contribute to weight loss,
deploying photographs of
slender celebs like
David Beckham and
Kate Moss in milk
moustaches to drive its
message
home. Not surprisingly,
this message was quickly co-opted
by several
large manufacturers of
cheese and yogurt, and soon
the idea that
low-fat dairy
could
aid weight loss
seemed like established fact.
Of course, just
saying
it does doesn’t make it so, and in this case
the Dairy
Council seems to have
been bending the truth. The
weight-loss portion of the council’s three-a-day
campaign was
halted in
2007, after a lawsuit by the
Washington, D.C.–based
Physicians
Concerned with
Responsible Medicine charged that 24
of the 27
research
studies behind the claim had not only
failed to prove a
connection
between dairy and weight loss,
but they
had all been directed by a
single
researcher and
funded by the Dairy Council. The Federal
Trade Commission
ruled that the ads were misleading, and the Dairy
Council was
forced to pull
them. While there have
been a number of
studies showing a correlation
between low-fat dairy
consumption and
weight loss,
skeptics argue that this is
very
different from showing
causation, since in most cases the dairy that
subjects
consumed was
likely replacing other less wholesome
foods, as
with one
study in which
teenage skim-milk drinkers
showed a weight-loss advantage over
their
soda-drinking peers.
The problem is that there’s no way of
knowing if
having the
teens replace soda with whole
milk might have delivered the
same
results, and no reason to
think that replacing the soda with, say,
tomato juice
or water
might not have had an even more
advantageous
effect. Still,
Kate
Moss in a milk moustache
seems to have made a
much more lasting impression than
the
physicians’
lawsuit, and it
remains a widely held belief among health
professionals and average
eaters alike that fat will make you
fat and low- to
no-fat foods,
especially low-fat
dairy
products, will make you look more like
David
Beckham. Beckham’s abs notwithstanding, the popular
reception of the
campaign connecting low-fat dairy to weight
loss was likely compounded
by the
longstanding popularity of
the “lipid hypothesis.” This
is the
theory — a theory
never proven to many experts’
satisfaction — that
saturated fats cause heart
disease and
obesity.
Despite a lack of
scientific support, the hypothesis has
been
promoted unquestioningly by
most nutrition scientists and
government
officials since it was first
proposed in
the
1950s. In 1977, a Senate
committee even
published a
low-fat manifesto entitled “Dietary Goals for the
United
States” that marked the start of a veritable
industrial-food revolution
that allowed manufacturers to
promote margarine and corn syrup as
health foods:
Look Ma, no
saturated fat! As the theory gained
traction,
full-fat dairy
products fell out of favor and even
became reviled by
many well-intended
dietitians. Meanwhile,
low-fat
dairy products did
more than just survive the
trend —
they thrived. Today, Americans
buy about two-and-a-half
times more
skim milk each year — and about
half as much whole
milk — than
they did in 1975.
This would likely
shock
earlier generations
of dairy farmers who prized the
richness
of
whole milk and
cream and often threw the skim to the hogs.
Today,
whole
milk has become a relative rarity.
Last year, Starbucks
switched
its standard milk from whole to
2 percent, all in a bid to adopt a
healthier profile in
accordance with low-fat doctrine. But
here’s
the
disconnect: During the same period that the
consumption of
low-fat
fare rose in
the United States, our
rates of
obesity, type 2 diabetes
and heart disease
multiplied
exponentially — a fact that many health
experts attribute to
our
replacing natural whole foods rich in
nutrients (including
naturally occurring
fats) with nutrient-poor,
processed foods
dense in sugar, refined carbs and
commercial
oils.
Both this trend and a
number of recent studies are
suggesting that fats
from whole foods — even the saturated
kind — are
not the
enemy we’ve been led to believe. Which
means that low-fat
dairy
may not be
nearly the nutritional and
weight-loss ally it once
seemed.
A Second Look at Saturated Fats
A 2001 study by nutrition scientists at
Harvard School of Public Health and published in the Journal of the
American
College of Nutrition reveals that the lipid
hypothesis is
supported by only two
research
experiments —
while a great many more
studies have failed to
find a
positive
correlation between saturated
fat and
heart disease. That’s not a very
strong foundation for what has
essentially become nutritional
gospel.
Critics
like Mary Enig, PhD,
an expert in lipid
biochemistry and
author of
Know Your Fats (Bethesda,
2000),
have long
insisted that evidence tying dietary
fat and
cholesterol to blood cholesterol and arterial damage is
likewise
suspect. They suggest that because the body produces
cholesterol to
heal
internal injuries, elevated
cholesterol
levels could just as well
be a response
to coronary damage as
a cause of it. (For more on the
cholesterol controversy,
see
“Cholesterol
Reconsidered” in the June
2009 archives.) Enig points out,
moreover,
that a low-fat
dietary approach can have a
number of negative
health effects, some of which are
tied to reduced absorption
of certain
nutrients that
can only be assimilated in
the body
when accompanied by
appropriate fats. “Most people are at risk for
lowered intakes of
the important fat-soluble vitamins
and
other fat-soluble
nutrients when
they consume
low-fat diets
for any length of time,” she says.
Likewise, the Harvard
study goes on to state that
the
popularization of a
low-fat
diet may have caused
“unintended health
consequences” by encouraging
increased
general consumption of refined
carbohydrates and
trans fats.
The bad
press about naturally occurring
saturated
fats played a key role, for example,
in driving people to
embrace processed-food products like powdered coffee
creamers,
fake
whipped-cream products and margarines.
Both trans fats and
carbohydrates of any kind were once
praised as healthful
replacements
for
traditional
foods containing saturated fats,
but recent studies
have shown
them
to be more likely
accomplices to skyrocketing obesity,
diabetes and
heart-disease rates. David Ludwig,
MD, PhD, an
endocrinologist at Harvard who
heads the
renowned OWL Program
(Optimal
Weight for Life) for childhood
obesity
at Boston
University Hospital,
has had real
success using a low-glycemic
approach to weight loss
rather
than a low-fat one. In
Ludwig’s view, the
insulin spikes
and
hunger crashes caused by
high-glycemic foods are far more
likely to
spur weight gain
than a reasonable intake
of unrefined saturated fats,
including those in
full-fat dairy products, which help
moderate
appetite
naturally. On this basis, he explains,
no- or low-fat
dairy may actually
function as an obstacle to
weight
loss for some
people. When the fat is removed
from
milk, what remains are a
significant number of unabsorbable
fat-soluble
vitamins and an
overabundance of lactose,
or milk sugar, with
some protein but
no fat
to slow
its entrance into the
bloodstream. This doesn’t even account for
the copious amounts of sugar
often added to low- and no-fat
dairy
products to
improve their
taste in the absence
of naturally pleasing
milk fat. It’s also
likely that one
will drink much more skim milk
than whole (or
eat more low-fat
yogurt, fat-free sour cream, low-fat
ice
cream, etc.)
for three reasons:
- It generally takes larger
servings
of low-fat foods than full-fat foods to
switch on our
bodies’
satiety signals.
- There’s a psychological tendency
to
feel that
because we’re “being good” by eating these
low-calorie, low-fat
products, we are justified in
“making up
for it” by eating more of them
— or
more
of something
else.
- Low-fat foods don’t keep us
satisfied
for as long
and may also destabilize blood sugar, so we’re
likely to
experience cravings to
want to eat again
sooner.
This
last
point deserves some explanation: Low-
and no-fat dairy delivers
more fast-absorbing lactose to the
bloodstream, and
more
potential for
corresponding
insulin spikes and resultant sugar
cravings.
Full-fat
dairy doesn’t have this effect. “The
proportion of lactose
decreases
with every increase in
milk-fat content,”
Mendelson explains. So
relative to
skim
milk, “heavy
cream contains only minute amounts.”
Finally, not only
does an extra dose of lactose potentially lead to
insulin
problems, many experts
argue that most of us
aren’t genetically
inclined to digest it well in the first
place. According
to
Mendelson, about 70 percent
of us are at least somewhat
dairy
intolerant as
adults. In fact, we stop producing lactase
— the enzyme that
breaks down lactose in the intestines — shortly after
we’re
weaned,
when we
technically no longer need it. Eating
dairy may not make us
immediately ill, but
undigested
lactose
in the intestine can cause all
kinds of unpleasant
symptoms,
from painful bloating, flatulence,
diarrhea
and stomach cramps
to skin rashes,
acne and ear
aches. Mendelson notes that
most dairy-eating cultures have
historically consumed milk in
its fermented or soured
state, from the
yogurt of
the Middle
East to the
clabbered milk of the American South.
This may have been
because dairying has been around a lot longer than
refrigeration, and
fermentation functions as a
preservative.
But
fermentation also promotes
digestibility by effectively
“predigesting”
the
lactose before it can cause
trouble in the
intestines.
Even so, says Mendelson, the idea of milk
as a core
nutritional
staple is foreign to most dairying
cultures, where
they
tend to consume
even soured milk products
sparingly, not in tall frothing
glasses
several times
a day.
Including moderate amounts of dairy products can
work well for
those who enjoy it and tolerate it
well, she notes, but
depending
on dairy as a primary source of
nutrition is probably unwise
for most of us. And
for
those who don’t tolerate dairy well,
there’s no
reason to be
concerned about
lack of dairy leading
to nutritional
deficiencies. “Anyone can happily live
without
using
milk in any form,”
says Mendelson, an idea that can be hard for
what she calls our
“milk-in-every-fridge” mindset to
grasp.
In Fat's Favor
So, low-fat dairy may not be all it’s cracked up to be, and
perhaps dairy in general has been oversold as a
health food.
Still, a
life
without any dairy might
seem like just a little
too much
self-denial. If you’re
not lactose intolerant, and
you’d like to enjoy
healthier dairy when you do
consume it,
here’s what
some of the
research suggests about why old-school
full-fat
dairy products might be
worth
embracing: Metabolism Support
Ludwig favors the
consumption of some unrefined
fats for kids trying to lose
weight,
since fats
actively promote a stable metabolism. Fat
is digested slowly,
which helps decrease the rate at which
carbohydrates are
released into
the
system. This in turn makes
the body
more receptive to a pancreatic
hormone
called
glucagon that “unlocks” fat stores for energy. If
there’s too
much
insulin from eating high-glycemic foods (like heavily
sweetened fat-free
yogurt), the body decreases or
stops
glucagon
production, which stalls fat
burning.
Fat is also the
nutrient that
triggers the brain to recognize
satiety,
which
offsets overeating.
Fat-Soluble
Vitamins In contrast with its
fortification
requirements
for 2 percent, 1 percent and skim
milk, the federal
government doesn’t require whole milk be
fortified
with vitamin A.
That’s
because about 1,400 to 1,600
International Units (I.U.) are
already in the milk
fat. Skim
milk does have a slightly higher
percentage
of vitamins D, E and K
than whole milk, but it probably
doesn’t serve much purpose:
All these vitamins
are
fat-soluble, so
without fat, they pass
out of the small
intestine
undigested. Sex
Drive and
Fertility
The very chemicals that make us able
to
reproduce
our species — testosterone, estrogen and progesterone, among
others
— are synthesized from the good old cholesterol produced by our
bodies
and found
in dietary sources such as milk and
other
animal fats. That’s
why fibrates and
statins,
medications used
to lower cholesterol levels,
can also
markedly
decrease sex
drive. Eating full-fat dairy might also
help women get pregnant, at
least according to a 2007 study at
the
Harvard School of
Public Health that
found women
who consumed at least
one
serving a day of full-fat dairy were
27
percent less likely to
experience ovulation-related
fertility problems.
Protective
Fats
Milk fat contains
glycosphingolipids, which some
studies
have shown to have
infection- and disease-fighting properties.
“Butterfat is an
amazing fat — it has properties that
support gut
flora; it has
properties that support your immune
system; it has
properties
that fight
cancer,” says
Sally Fallon, coauthor of Eat Fat,
Lose Fat (Penguin, 2005)
and
founder of the Weston A. Price
Foundation
in
Washington, D.C., which promotes
traditional
foods and farming
methods. “Vegetable oil doesn’t have those
things.”
A Healthy Balance
So is there a place for full-fat dairy in your diet, or
not? That all depends on you — how much you like dairy, how well you
tolerate
it, and what impact it seems to have on your personal
biochemistry and
metabolism. All these things are
highly
individualized. The important thing is
to acknowledge
both
dairy’s
strengths and its potential
drawbacks. Mendelson
stresses the fact
that many
of our problems with milk began
when we started
asking it to
be “nature’s most perfect food,”
expecting it to cure
everything
from
gout to malnutrition to
obesity. This
was asking too much. “No food has to
pretend to be all
things
to all people,” she says. Meanwhile, as the
premium
placed on daily fresh-milk consumption in the United States
clashed with the
lipid hypothesis, many of the things
that
were
originally healthy about dairy
got lost in
the skimming
and processing
anyway — even as we consumed more
of the
stuff
than
ever. Thankfully, there seems to
be a middle way. In the light
of
more moderate
expectations, it does seem that many of us
can enjoy some
benefits
and pleasures from full-fat dairy
products
as part of a diet
based on a variety
of synergistic
whole foods. Ultimately, each of us
needs to decide which
dairy
products, if any, feel best for us. “If we
can shed the
notion
that chugging
down so much milk a day is a duty,”
Mendelson
offers, “perhaps we will be free
to
discover different forms
of it as a joy.” And if we can get
over our notions
that
low-fat dairy
is the only kind
worth eating, our guilt-free enjoyment
of
full-fat
yogurt, cheese, butter and cream may increase that
much more.
Courtney Helgoe is a freelance writer in Minneapolis.
Milk: Explore Your Options
In contrast to the slew of “does a body good”
messages generated by the American
Dairy Council, milk is really only
digestible by a small population of people
who have “lactase
persistence,” a condition that allows them to comfortably
break down
lactose throughout their adult lives. For everyone else it can pose
significant digestive challenges. Most of us are better off with soured
dairy
products like cheese or yogurt, which are produced with a
fermentation process
that “predigests” the lactose. For those who
don’t tolerate any dairy well,
milk substitutes can be a welcome treat.
Sheila Dean, a Palm Harbor, Fla.–based
nutritionist, treats many
dairy-sensitive people in her practice. She’s happy to
recommend milk
substitutes as long as people don’t go overboard with them. “Most
milk
substitutes do have quite a bit of sugar, so as with anything, the key is
moderation,” she says. Rice Milk: Though rice milk is highest in
sugary
carbohydrates, it’s the milk substitute that Dean recommends
most often to her
allergy-prone clients. “Some people who have problems
with milk also have issues
with soy and nuts, and rice milk is really
benign,” she says. Soymilk:
Soymilk is high in fiber and contains
plenty of protein. It has a fuller flavor
than rice milk, and the
better brands can hold their own in tea or coffee. It
does have its
detractors, though. Ron Schmid, ND, author of The Untold Story of
Milk
(New Trends Publishing, 2009), believes that because the soy in soymilk has
not been fermented (like miso, tofu and other traditional Asian soy
foods),
there’s a risk that soy estrogens will depress thyroid
function. Hemp Milk:
Hemp milk seems likely to emerge as a real
winner in the competition between
milk substitutes. It has a growing
legion of fans — both for its flavor and
texture (smooth, rich, plenty
of body) and for its impressive nutritional
profile: One cup contains
46 percent of your daily calcium requirement, along
with a wealth of
other vitamins, minerals, and essential omega-3 and -6 fatty
acids.
Goat’s Milk: Though technically a dairy product, goat’s milk is more
easily digested by many people who are sensitive to cow’s milk. Swiss
naturopath
and allergy specialist Dr. Thomas Rau recommends it for his
patients because the
casein “curd” is softer and more digestible than
the curd in cow’s milk. It’s
also a whole, unprocessed food.
Doing Dairy Right
If you’re aiming to improve the overall quality of your dairy choices, look for
the following labels: “Pasture-Fed” or “Grass-Fed” Milk from pasture-fed cows has significantly
more omega-3 fatty acids, according to a 2008 study by the Nafferton Ecological
Farming Group at Newcastle University. It also contains a dietary compound
called conjugated linoleic acid (CLA), shown to help reduce body fat and
increase lean tissue. The key to the production of CLA appears to be in the
fresh grass cows eat, so grain-fed dairy products won’t have the same benefits.
Pasture feeding is also the most humane method of keeping livestock, and the
low-stress conditions keep stress hormones like cortisol and adrenaline out of
the cow’s milk. “USDA Organic” USDA Organic guarantees that cows
are getting organic-certified feed and aren’t given antibiotics or bovine growth
hormone (rBGH), which means the milk has fewer toxic byproducts. This is
particularly important for full-fat dairy, since toxins concentrate in animal
fat. A note of caution, however: Organic is often assumed to indicate better
living conditions for the animals, but Anne Mendelson, author of Milk: The
Surprising Story of Milk Through the Ages (Knopf, 2008), is skeptical: “There
are huge organic dairies out West where the cows are treated just as badly as on
any factory farm.” She sticks with dairy from small, local producers whether or
not they’re designated organic. Learn the names and brands of your nearest
grass-fed milk producers at www.eatwild.com.
“Non-Homogenized” Homogenizing milk has little to do with milk safety
(pasteurization is what kills bacteria); it’s a cosmetic process that prevents
the cream from rising to the top. Fat globules are extracted and treated with
high pressure to destroy their original membrane and reduce them to a uniformly
smaller size, then injected back into the milk at artificial ratios. Fresh,
unprocessed milk ranges from 4 percent to 5.5 percent milk fat versus only 3.25
percent for homogenized whole milk. This can undermine the nutritional benefits
in the milk fat. “There are lots of anti-cancer substances in the protein
membrane surrounding each fat globule,” says Sally Fallon, coauthor of Eat Fat,
Lose Fat (Penguin 2005). “When the milk is homogenized, those substances are
destroyed.” Many milk connoisseurs insist that the best reason for consuming
non-homogenized milk is flavor, suggesting that the difference is akin to that
between fresh-squeezed and reconstituted orange juice, though for some it’s an
acquired taste.
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Skimming the Truth
Why low-fat dairy may be overrated and why full-fat dairy could have more going
for it than you’d think - assuming you can tolerate dairy in the first place.
By Courtney Helgoe
| Nutrients Department, September 2009 |
Weak Connections
A Second Look at Saturated Fats
In Fat's Favor
A Healthy Balance
Milk: Explore Your Options
Doing Dairy Right
Two containers of yogurt sit side by side, one fat-free
and one
full-fat. Now, without any other information about the contents
therein,
answer quickly: Which of these has been
scientifically proven
to cause
weight
gain and heart
disease, and which has been
proven to support
weight loss and
coronary health? If
you’re like most people who pay
even modest attention to
prevalent nutritional news
bites, you’ll crown
the low-fat
stuff as the
healthier choice. And despite the fact that
your
answer would be solidly backed
by majority opinion, you’d be
wrong. The correct answer to both questions is
actually
“neither,”
since researchers have yet to
provide concrete support for
the
much-ballyhooed reputation of
low-fat dairy products as a
heart-healthy,
weight-loss
panacea. Nor have they confirmed the
reputation of full-fat
dairy as
a diabolical threat to
coronary health and
waistline
reduction. That comes
as a
shock to a
lot of folks, including
health professionals. “Probably most
people who think of themselves as
nutrition-savvy
would be
astonished to learn
that evidence of whole
milk’s being a
ticket to an early grave is conspicuous by
its absence,”
says
food historian Anne Mendelson in Milk: The Surprising Story
of
Milk Through the Ages (Knopf,
2008).
Weak Connections
The prevailing understanding of low-fat dairy products
seems to owe more to powerful food-industry campaigns and wishful
thinking than
to convincing scientific data. In 2003
the
National Dairy Council
began aggressively
promoting the
claim that
consuming three servings of low-fat
dairy products
daily would
contribute to weight loss,
deploying photographs of
slender celebs like
David Beckham and
Kate Moss in milk
moustaches to drive its
message
home. Not surprisingly,
this message was quickly co-opted
by several
large manufacturers of
cheese and yogurt, and soon
the idea that
low-fat dairy
could
aid weight loss
seemed like established fact.
Of course, just
saying
it does doesn’t make it so, and in this case
the Dairy
Council seems to have
been bending the truth. The
weight-loss portion of the council’s three-a-day
campaign was
halted in
2007, after a lawsuit by the
Washington, D.C.–based
Physicians
Concerned with
Responsible Medicine charged that 24
of the 27
research
studies behind the claim had not only
failed to prove a
connection
between dairy and weight loss,
but they
had all been directed by a
single
researcher and
funded by the Dairy Council. The Federal
Trade Commission
ruled that the ads were misleading, and the Dairy
Council was
forced to pull
them. While there have
been a number of
studies showing a correlation
between low-fat dairy
consumption and
weight loss,
skeptics argue that this is
very
different from showing
causation, since in most cases the dairy that
subjects
consumed was
likely replacing other less wholesome
foods, as
with one
study in which
teenage skim-milk drinkers
showed a weight-loss advantage over
their
soda-drinking peers.
The problem is that there’s no way of
knowing if
having the
teens replace soda with whole
milk might have delivered the
same
results, and no reason to
think that replacing the soda with, say,
tomato juice
or water
might not have had an even more
advantageous
effect. Still,
Kate
Moss in a milk moustache
seems to have made a
much more lasting impression than
the
physicians’
lawsuit, and it
remains a widely held belief among health
professionals and average
eaters alike that fat will make you
fat and low- to
no-fat foods,
especially low-fat
dairy
products, will make you look more like
David
Beckham. Beckham’s abs notwithstanding, the popular
reception of the
campaign connecting low-fat dairy to weight
loss was likely compounded
by the
longstanding popularity of
the “lipid hypothesis.” This
is the
theory — a theory
never proven to many experts’
satisfaction — that
saturated fats cause heart
disease and
obesity.
Despite a lack of
scientific support, the hypothesis has
been
promoted unquestioningly by
most nutrition scientists and
government
officials since it was first
proposed in
the
1950s. In 1977, a Senate
committee even
published a
low-fat manifesto entitled “Dietary Goals for the
United
States” that marked the start of a veritable
industrial-food revolution
that allowed manufacturers to
promote margarine and corn syrup as
health foods:
Look Ma, no
saturated fat! As the theory gained
traction,
full-fat dairy
products fell out of favor and even
became reviled by
many well-intended
dietitians. Meanwhile,
low-fat
dairy products did
more than just survive the
trend —
they thrived. Today, Americans
buy about two-and-a-half
times more
skim milk each year — and about
half as much whole
milk — than
they did in 1975.
This would likely
shock
earlier generations
of dairy farmers who prized the
richness
of
whole milk and
cream and often threw the skim to the hogs.
Today,
whole
milk has become a relative rarity.
Last year, Starbucks
switched
its standard milk from whole to
2 percent, all in a bid to adopt a
healthier profile in
accordance with low-fat doctrine. But
here’s
the
disconnect: During the same period that the
consumption of
low-fat
fare rose in
the United States, our
rates of
obesity, type 2 diabetes
and heart disease
multiplied
exponentially — a fact that many health
experts attribute to
our
replacing natural whole foods rich in
nutrients (including
naturally occurring
fats) with nutrient-poor,
processed foods
dense in sugar, refined carbs and
commercial
oils.
Both this trend and a
number of recent studies are
suggesting that fats
from whole foods — even the saturated
kind — are
not the
enemy we’ve been led to believe. Which
means that low-fat
dairy
may not be
nearly the nutritional and
weight-loss ally it once
seemed.
A Second Look at Saturated Fats
A 2001 study by nutrition scientists at
Harvard School of Public Health and published in the Journal of the
American
College of Nutrition reveals that the lipid
hypothesis is
supported by only two
research
experiments —
while a great many more
studies have failed to
find a
positive
correlation between saturated
fat and
heart disease. That’s not a very
strong foundation for what has
essentially become nutritional
gospel.
Critics
like Mary Enig, PhD,
an expert in lipid
biochemistry and
author of
Know Your Fats (Bethesda,
2000),
have long
insisted that evidence tying dietary
fat and
cholesterol to blood cholesterol and arterial damage is
likewise
suspect. They suggest that because the body produces
cholesterol to
heal
internal injuries, elevated
cholesterol
levels could just as well
be a response
to coronary damage as
a cause of it. (For more on the
cholesterol controversy,
see
“Cholesterol
Reconsidered” in the June
2009 archives.) Enig points out,
moreover,
that a low-fat
dietary approach can have a
number of negative
health effects, some of which are
tied to reduced absorption
of certain
nutrients that
can only be assimilated in
the body
when accompanied by
appropriate fats. “Most people are at risk for
lowered intakes of
the important fat-soluble vitamins
and
other fat-soluble
nutrients when
they consume
low-fat diets
for any length of time,” she says.
Likewise, the Harvard
study goes on to state that
the
popularization of a
low-fat
diet may have caused
“unintended health
consequences” by encouraging
increased
general consumption of refined
carbohydrates and
trans fats.
The bad
press about naturally occurring
saturated
fats played a key role, for example,
in driving people to
embrace processed-food products like powdered coffee
creamers,
fake
whipped-cream products and margarines.
Both trans fats and
carbohydrates of any kind were once
praised as healthful
replacements
for
traditional
foods containing saturated fats,
but recent studies
have shown
them
to be more likely
accomplices to skyrocketing obesity,
diabetes and
heart-disease rates. David Ludwig,
MD, PhD, an
endocrinologist at Harvard who
heads the
renowned OWL Program
(Optimal
Weight for Life) for childhood
obesity
at Boston
University Hospital,
has had real
success using a low-glycemic
approach to weight loss
rather
than a low-fat one. In
Ludwig’s view, the
insulin spikes
and
hunger crashes caused by
high-glycemic foods are far more
likely to
spur weight gain
than a reasonable intake
of unrefined saturated fats,
including those in
full-fat dairy products, which help
moderate
appetite
naturally. On this basis, he explains,
no- or low-fat
dairy may actually
function as an obstacle to
weight
loss for some
people. When the fat is removed
from
milk, what remains are a
significant number of unabsorbable
fat-soluble
vitamins and an
overabundance of lactose,
or milk sugar, with
some protein but
no fat
to slow
its entrance into the
bloodstream. This doesn’t even account for
the copious amounts of sugar
often added to low- and no-fat
dairy
products to
improve their
taste in the absence
of naturally pleasing
milk fat. It’s also
likely that one
will drink much more skim milk
than whole (or
eat more low-fat
yogurt, fat-free sour cream, low-fat
ice
cream, etc.)
for three reasons:
- It generally takes larger
servings
of low-fat foods than full-fat foods to
switch on our
bodies’
satiety signals.
- There’s a psychological tendency
to
feel that
because we’re “being good” by eating these
low-calorie, low-fat
products, we are justified in
“making up
for it” by eating more of them
— or
more
of something
else.
- Low-fat foods don’t keep us
satisfied
for as long
and may also destabilize blood sugar, so we’re
likely to
experience cravings to
want to eat again
sooner.
This
last
point deserves some explanation: Low-
and no-fat dairy delivers
more fast-absorbing lactose to the
bloodstream, and
more
potential for
corresponding
insulin spikes and resultant sugar
cravings.
Full-fat
dairy doesn’t have this effect. “The
proportion of lactose
decreases
with every increase in
milk-fat content,”
Mendelson explains. So
relative to
skim
milk, “heavy
cream contains only minute amounts.”
Finally, not only
does an extra dose of lactose potentially lead to
insulin
problems, many experts
argue that most of us
aren’t genetically
inclined to digest it well in the first
place. According
to
Mendelson, about 70 percent
of us are at least somewhat
dairy
intolerant as
adults. In fact, we stop producing lactase
— the enzyme that
breaks down lactose in the intestines — shortly after
we’re
weaned,
when we
technically no longer need it. Eating
dairy may not make us
immediately ill, but
undigested
lactose
in the intestine can cause all
kinds of unpleasant
symptoms,
from painful bloating, flatulence,
diarrhea
and stomach cramps
to skin rashes,
acne and ear
aches. Mendelson notes that
most dairy-eating cultures have
historically consumed milk in
its fermented or soured
state, from the
yogurt of
the Middle
East to the
clabbered milk of the American South.
This may have been
because dairying has been around a lot longer than
refrigeration, and
fermentation functions as a
preservative.
But
fermentation also promotes
digestibility by effectively
“predigesting”
the
lactose before it can cause
trouble in the
intestines.
Even so, says Mendelson, the idea of milk
as a core
nutritional
staple is foreign to most dairying
cultures, where
they
tend to consume
even soured milk products
sparingly, not in tall frothing
glasses
several times
a day.
Including moderate amounts of dairy products can
work well for
those who enjoy it and tolerate it
well, she notes, but
depending
on dairy as a primary source of
nutrition is probably unwise
for most of us. And
for
those who don’t tolerate dairy well,
there’s no
reason to be
concerned about
lack of dairy leading
to nutritional
deficiencies. “Anyone can happily live
without
using
milk in any form,”
says Mendelson, an idea that can be hard for
what she calls our
“milk-in-every-fridge” mindset to
grasp.
In Fat's Favor
So, low-fat dairy may not be all it’s cracked up to be, and
perhaps dairy in general has been oversold as a
health food.
Still, a
life
without any dairy might
seem like just a little
too much
self-denial. If you’re
not lactose intolerant, and
you’d like to enjoy
healthier dairy when you do
consume it,
here’s what
some of the
research suggests about why old-school
full-fat
dairy products might be
worth
embracing: Metabolism Support
Ludwig favors the
consumption of some unrefined
fats for kids trying to lose
weight,
since fats
actively promote a stable metabolism. Fat
is digested slowly,
which helps decrease the rate at which
carbohydrates are
released into
the
system. This in turn makes
the body
more receptive to a pancreatic
hormone
called
glucagon that “unlocks” fat stores for energy. If
there’s too
much
insulin from eating high-glycemic foods (like heavily
sweetened fat-free
yogurt), the body decreases or
stops
glucagon
production, which stalls fat
burning.
Fat is also the
nutrient that
triggers the brain to recognize
satiety,
which
offsets overeating.
Fat-Soluble
Vitamins In contrast with its
fortification
requirements
for 2 percent, 1 percent and skim
milk, the federal
government doesn’t require whole milk be
fortified
with vitamin A.
That’s
because about 1,400 to 1,600
International Units (I.U.) are
already in the milk
fat. Skim
milk does have a slightly higher
percentage
of vitamins D, E and K
than whole milk, but it probably
doesn’t serve much purpose:
All these vitamins
are
fat-soluble, so
without fat, they pass
out of the small
intestine
undigested. Sex
Drive and
Fertility
The very chemicals that make us able
to
reproduce
our species — testosterone, estrogen and progesterone, among
others
— are synthesized from the good old cholesterol produced by our
bodies
and found
in dietary sources such as milk and
other
animal fats. That’s
why fibrates and
statins,
medications used
to lower cholesterol levels,
can also
markedly
decrease sex
drive. Eating full-fat dairy might also
help women get pregnant, at
least according to a 2007 study at
the
Harvard School of
Public Health that
found women
who consumed at least
one
serving a day of full-fat dairy were
27
percent less likely to
experience ovulation-related
fertility problems.
Protective
Fats
Milk fat contains
glycosphingolipids, which some
studies
have shown to have
infection- and disease-fighting properties.
“Butterfat is an
amazing fat — it has properties that
support gut
flora; it has
properties that support your immune
system; it has
properties
that fight
cancer,” says
Sally Fallon, coauthor of Eat Fat,
Lose Fat (Penguin, 2005)
and
founder of the Weston A. Price
Foundation
in
Washington, D.C., which promotes
traditional
foods and farming
methods. “Vegetable oil doesn’t have those
things.”
A Healthy Balance (Back to Top)
So is there a place for full-fat dairy in your diet, or
not? That all depends on you — how much you like dairy, how well you
tolerate
it, and what impact it seems to have on your personal
biochemistry and
metabolism. All these things are
highly
individualized. The important thing is
to acknowledge
both
dairy’s
strengths and its potential
drawbacks. Mendelson
stresses the fact
that many
of our problems with milk began
when we started
asking it to
be “nature’s most perfect food,”
expecting it to cure
everything
from
gout to malnutrition to
obesity. This
was asking too much. “No food has to
pretend to be all
things
to all people,” she says. Meanwhile, as the
premium
placed on daily fresh-milk consumption in the United States
clashed with the
lipid hypothesis, many of the things
that
were
originally healthy about dairy
got lost in
the skimming
and processing
anyway — even as we consumed more
of the
stuff
than
ever. Thankfully, there seems to
be a middle way. In the light
of
more moderate
expectations, it does seem that many of us
can enjoy some
benefits
and pleasures from full-fat dairy
products
as part of a diet
based on a variety
of synergistic
whole foods. Ultimately, each of us
needs to decide which
dairy
products, if any, feel best for us. “If we
can shed the
notion
that chugging
down so much milk a day is a duty,”
Mendelson
offers, “perhaps we will be free
to
discover different forms
of it as a joy.” And if we can get
over our notions
that
low-fat dairy
is the only kind
worth eating, our guilt-free enjoyment
of
full-fat
yogurt, cheese, butter and cream may increase that
much more.
Courtney Helgoe is a freelance writer in Minneapolis.
Milk: Explore Your Options
In contrast to the slew of “does a body good”
messages generated by the American
Dairy Council, milk is really only
digestible by a small population of people
who have “lactase
persistence,” a condition that allows them to comfortably
break down
lactose throughout their adult lives. For everyone else it can pose
significant digestive challenges. Most of us are better off with soured
dairy
products like cheese or yogurt, which are produced with a
fermentation process
that “predigests” the lactose. For those who
don’t tolerate any dairy well,
milk substitutes can be a welcome treat.
Sheila Dean, a Palm Harbor, Fla.–based
nutritionist, treats many
dairy-sensitive people in her practice. She’s happy to
recommend milk
substitutes as long as people don’t go overboard with them. “Most
milk
substitutes do have quite a bit of sugar, so as with anything, the key is
moderation,” she says. Rice Milk: Though rice milk is highest in
sugary
carbohydrates, it’s the milk substitute that Dean recommends
most often to her
allergy-prone clients. “Some people who have problems
with milk also have issues
with soy and nuts, and rice milk is really
benign,” she says. Soymilk:
Soymilk is high in fiber and contains
plenty of protein. It has a fuller flavor
than rice milk, and the
better brands can hold their own in tea or coffee. It
does have its
detractors, though. Ron Schmid, ND, author of The Untold Story of
Milk
(New Trends Publishing, 2009), believes that because the soy in soymilk has
not been fermented (like miso, tofu and other traditional Asian soy
foods),
there’s a risk that soy estrogens will depress thyroid
function. Hemp Milk:
Hemp milk seems likely to emerge as a real
winner in the competition between
milk substitutes. It has a growing
legion of fans — both for its flavor and
texture (smooth, rich, plenty
of body) and for its impressive nutritional
profile: One cup contains
46 percent of your daily calcium requirement, along
with a wealth of
other vitamins, minerals, and essential omega-3 and -6 fatty
acids.
Goat’s Milk: Though technically a dairy product, goat’s milk is more
easily digested by many people who are sensitive to cow’s milk. Swiss
naturopath
and allergy specialist Dr. Thomas Rau recommends it for his
patients because the
casein “curd” is softer and more digestible than
the curd in cow’s milk. It’s
also a whole, unprocessed food.
Doing Dairy Right
If you’re aiming to improve the overall quality of your dairy choices, look for
the following labels: “Pasture-Fed” or “Grass-Fed” Milk from pasture-fed cows has significantly
more omega-3 fatty acids, according to a 2008 study by the Nafferton Ecological
Farming Group at Newcastle University. It also contains a dietary compound
called conjugated linoleic acid (CLA), shown to help reduce body fat and
increase lean tissue. The key to the production of CLA appears to be in the
fresh grass cows eat, so grain-fed dairy products won’t have the same benefits.
Pasture feeding is also the most humane method of keeping livestock, and the
low-stress conditions keep stress hormones like cortisol and adrenaline out of
the cow’s milk. “USDA Organic” USDA Organic guarantees that cows
are getting organic-certified feed and aren’t given antibiotics or bovine growth
hormone (rBGH), which means the milk has fewer toxic byproducts. This is
particularly important for full-fat dairy, since toxins concentrate in animal
fat. A note of caution, however: Organic is often assumed to indicate better
living conditions for the animals, but Anne Mendelson, author of Milk: The
Surprising Story of Milk Through the Ages (Knopf, 2008), is skeptical: “There
are huge organic dairies out West where the cows are treated just as badly as on
any factory farm.” She sticks with dairy from small, local producers whether or
not they’re designated organic. Learn the names and brands of your nearest
grass-fed milk producers at www.eatwild.com.
“Non-Homogenized” Homogenizing milk has little to do with milk safety
(pasteurization is what kills bacteria); it’s a cosmetic process that prevents
the cream from rising to the top. Fat globules are extracted and treated with
high pressure to destroy their original membrane and reduce them to a uniformly
smaller size, then injected back into the milk at artificial ratios. Fresh,
unprocessed milk ranges from 4 percent to 5.5 percent milk fat versus only 3.25
percent for homogenized whole milk. This can undermine the nutritional benefits
in the milk fat. “There are lots of anti-cancer substances in the protein
membrane surrounding each fat globule,” says Sally Fallon, coauthor of Eat Fat,
Lose Fat (Penguin 2005). “When the milk is homogenized, those substances are
destroyed.” Many milk connoisseurs insist that the best reason for consuming
non-homogenized milk is flavor, suggesting that the difference is akin to that
between fresh-squeezed and reconstituted orange juice, though for some it’s an
acquired taste.
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