Recent estimates indicate that consumers in Western countries may receive
from 0.5 to 2.5% of total energy intake as trans
fatty acids. Trans fat is
found in many common foods including some margarine, fast foods, biscuits,
cakes and pastry. Trans fats are used to increase the shelf life of foods.
Invented in the early 1900s, partially hydrogenated
vegetable oil was initially believed to be a healthy substitute for
natural fats like butter or lard. It was also cheaper, performed better
under high heat and had a longer shelf life. Today, the oil is used as a
shortening in baked goods like cookies, crackers and doughnuts, as well as
in deep frying. When eaten, trans fats significantly raise the level of
so-called "bad" cholesterol in the blood, clogging arteries and causing
heart disease. Researchers at Harvard's School of Public Health estimated
that trans fats contribute to 30,000 U.S. deaths a year.
Trans fats are found in fried foods, packaged snacks, commercial
baked goods and other sources, and increase the risk of heart disease and
diabetes. For more information on
fat. If you would like
suggestions on a
healthy diet.
Add healthy fats to your diet
If you can't make the necessary dietary changes to add enough healthy fats
to your diet, consider supplementing with
Fish-Oil-Wild capsules or
Krill-Oil capsules. Another option is
Flaxseed-Oil.
How are Trans Fats made?
Trans fatty acids or trans fats are formed by partial hydrogenation of vegetable and marine oils or by bacterial activity in the rumen of ruminants. Main dietary sources are margarine, meat, milk fat and bakery products. Unsaturated fatty acids in the trans form have a more straight structure than their cis counterparts. They therefore have properties more like saturated fatty acids. Trans fats may compete with essential fatty acids for elongating and desaturating enzymes and thereby interfere in the formation of eicosanoids. Trans fatty acids in the diet will increase LDL-cholesterol but to a lesser degree than the saturated fatty acids C12-C16. They also decrease HDL-cholesterol. By these unfavorable effects on blood lipids it may be expected that they will increase the risk of coronary heart disease. Provided the diet contains sufficient amounts of essential fatty acids there are no strong indications that trans fatty acids in small amounts have other unfavorable effects on health. However, higher intake of trans fats can have a deleterious effect on cardiovascular disease and may be a contributing factor for many medical conditions worsened by inflammation.
Trans Fats
in Food
Common sources of trans fats in the American diet include French fries,
stick margarine or shortening, microwave oven popcorn, certain chocolate bars,
donuts, cookies, cakes and pastries, and fast food.
Trans fats and heart disease
People with high levels of trans fat in their blood have a higher risk of heart
disease compared to those with low levels.
Trans fats and infertility
Dietary fatty acid intakes and the risk of ovulatory infertility.
Am J Clin Nutr. 2007 Jan;85(1):231-7. Chavarro JE, Rich-Edwards JW, Rosner
BA, Willett WC. Department of Nutrition, Brigham and Women's Hospital, Harvard
Medical School, Boston, MA 02115, USA.
Pharmacologic activation of the peroxisome proliferator-activated receptor gamma
(PPAR-gamma) improves ovulatory function in women with polycystic ovary
syndrome, and specific dietary fatty acids can affect PPAR-gamma activity. The
objective of the study was to assess whether the intakes of total fat,
cholesterol, and major types of fatty acids affect the risk of ovulatory
infertility. We conducted a prospective cohort study of 18 555 married,
premenopausal women without a history of infertility who attempted a pregnancy
or became pregnant between 1991 and 1999. During follow-up, 438 incidents of
ovulatory infertility were reported. In logistic regression analyses, intakes of
total fat, cholesterol, and most types of fatty acids were not related to
ovulatory infertility. Each 2% increase in the intake of energy from trans
unsaturated fats, as opposed to that from carbohydrates, was associated with a
73% greater risk of ovulatory infertility after adjustment for known and
suspected risk factors for this condition. Obtaining 2% of energy intake from
trans fats rather than from n-6 polyunsaturated fats was associated with a
similar increase in the risk of ovulatory infertility). In addition, obtaining
2% of energy from trans fats rather than from monounsaturated fats was
associated with a more than doubled risk of ovulatory infertility. CONCLUSION:
trans Unsaturated fats may increase the risk of ovulatory infertility when
consumed instead of carbohydrates or unsaturated fats commonly found in
nonhydrogenated vegetable oils. For more info on
fertility.
Less Fats,
more Carbohydrates?
Public health recommendations for the US population in 1977 were to
reduce fat intake to as low as 30% of calories to lower the incidence of
coronary artery disease. These recommendations resulted in a shift in food
materials throughout the agricultural industry, and the fractional content of
fats was replaced principally with carbohydrates. Subsequently,
high-carbohydrate diets were recognized as contributing to hihg cholesterol and
triglycerides. People do not realize that when people reduce fat intake, they
often substitute sugar which is even worse.
Trans Fats and
Fast Food
McDonald's French fries contain
one-third more trans fats than previously thought after the company used a new
method to test for the harmful ingredient still widely used in many foods. The disclosure comes as food
companies are implementing new US government rules in force since January 2006
requiring all packaged food labels to specify the level of trans fats in food
products.
Wendy's International Inc. is cutting trans fats from
its menu, beating market leader McDonald's Corp., which still has not made good
on its promise to remove the artery-clogging fats from french fries in the
United States. Wendy's is the No. 3 U.S. burger chain. It's restaurants in the
United States and Canada switched to a new blend of corn and soy oil for french
fries and breaded chicken items in August, 2006.
Trans Fats
and Heart Disease
Higher intake of trans fatty acids could adversely affect endothelial
function, which might partially explain why the positive relation between trans
fats and cardiovascular risk is greater than one would predict based solely on
the adverse effects of trans fats on lipids.
Trans fats also raise levels of low-density lipoprotein (LDL), the harmful
cholesterol, in the blood and lower the amount of high-density lipoprotein, the
beneficial cholesterol.
Trans fats and infertility
The more trans fats a woman eats, the more likely she is to be infertile. Dr.
Jorge E. Chavarro of the Harvard School of Public Health in Boston reports that
trans fats can interfere with the activity of a cell receptor involved in
inflammation, glucose metabolism and insulin sensitivity, Drugs that activate
the receptor have been shown to improve fertility in women with a condition
known as polycystic ovary syndrome. For every 2 percent increase in the amount
of calories a woman got from trans fats instead of carbohydrates, her risk of
infertility increased by 73 percent. The risk rose by 79 percent for every 2
percent of energy in trans fats if they replaced omega-6 polyunsaturated fats.
And for every 2 percent of calories derived from trans fats instead of
monounsaturated fats, the risk of infertility more than doubled.
For a woman eating 1,800 calories a day, 2 percent of energy intake in trans
fats equals 4 grams. People should avoid all foods that list hydrogenated or
partially hydrogenated oils in their ingredients. American Journal of Clinical
Nutrition, January 2006.
==========================================================
According to the headlines, a low-fat diet fails
to decrease cancer and heart risks in older women. With such an important
announcement, it behooves us to take a closer look at this 415 million
dollar study funded with your tax dollars. Perhaps we can find flaws that may get it nominated for the "Worthless Research of the
Year," award. This is an award that I created this week, motivated by this
study. I know it's still early in the year 2006 and another study could
still trump this one.
Here are the basic facts about the study published in
the February 8, 2006 issue of the Journal of the American Medical
Association. It involved 48,000 postmenopausal women with an average age
of 62. These women were advised to cut overall fat consumption and
increase vegetables, fruits and grains. The women in the study had 18
sessions in small groups with a trained nutritionist in the first year and
four sessions a year after that. Women in the intervention group were
instructed to reduce their intake of total fat to 20 percent of their
energy intake and to increase their consumption of vegetables and fruits
to at least five servings daily, and to increase their grain consumption. All fats were supposed to be reduced without distinction between
various types of fat. The results were compared to women (the control
group) who continued their usual eating habits. Supposedly, and according
to the headlines, the eight-year study showed no difference in the rate of
breast cancer, colon cancer and heart disease among those who ate
lower-fat diets and those who didn’t.
SuperSized Study Flaws
1. It is naive and simplistic to categorize all fats as having the
same health benefit or risk. There are good fats, neutral fats, and bad
fats, and the ratios can make a huge difference. The scientific thinking
on the role fats play in disease prevention has evolved since this study
was designed back in the early 1990s. We now know that not all fats are
bad. Some fats, like the kind in fish, olive oil and nuts, are healthier
than the saturated fats and trans fats found in processed and fried foods,
cookies, cakes, and junk foods. Study participants probably reduced intake
of all kinds of fats, assuming that all fats carried the
same risk.
2. The women started this diet too late, an average age of 62. Most
cancers take years or decades to form and be detected. For breast cancer
in particular, earlier eating habits may have the most influence on risk.
Hardening of the arteries takes years and decades to form.
3. The researchers mentioned that in the study women did not reduce the fat
content of their diet to the extent that the study required. They admit
the low fat diet was difficult to follow. The diet they were told to
follow meant, for example, no butter on bread, no cream cheese on bagels,
no oil in salad dressings. The researchers did not differentiate between
trans fats (for instance in baked goods), saturated fats, monounsaturated
fats (found in olive oil), and polyunsaturated fats. They told the women
to reduce all fats.
4. Both groups started out with about 37 percent of
daily calories from fat. The goal was to cut that to 20 percent for the
low-fat group; the women managed about 24 percent on average in the first
year, but it climbed to about 29 percent later on. We all know how
difficult it is to follow a particular diet for prolonged periods without
cheating. And, by the way, not overtly mentioned by the media, the subgroup of women who reduced their fat
intake the most, did have a lower rate of breast cancer and heart disease.
5. Most of the women in the study remained overweight. Excess pounds
increase the risk for heart disease and cancer, whether the pounds come
from fats or carbohydrates. Both groups had on average a similar weight at
the end of the study and they consumed about the same number of calories.
6. When a person is asked to lower their fat intake, guess what they often
substitute: carbohydrates. Carbohydrates, particularly simple
carbohydrates from sugar, fructose, and pasta, get converted into
saturated fats, one of the worst kinds of fats. If you are
not getting enough fat in the diet, your body may crave simple carbs, and
simple carbs are probably worse than saturated fats.
7. Some of the women in the control group who ate their
regular diet may possibly have changed their eating habits with time by just following
recommendations mentioned in the media and women's magazines over the past few years on how to
eat healthier. Therefore, their diet may not have been significantly different than
those in the study group as the researchers would have hoped. It appears
that both groups had relatively low rates of heart disease, about 2.5
percent compared with just over 4 percent among postmenopausal women
nationally.
Who and What to Believe
Certain comments by so called researchers and pundits regarding the
results of this study were clearly.... how shall I say... eh... stupid.
Yes, that's the word I'm looking for, Stupid.
Dr. Timothy Johnson, the medical commentator on ABC
nightly news, said, "This is a wake up call. This study shows we can't
rely on lifestyle changes, like weight loss, exercise, diet changes, to
reliably reduce the risk of disease. I say to people to take advantage of
testing, colonoscopy, blood tests, and mammograms. We can get these diseases
even living a good lifestyle."
Yes, Dr. Johnson, it is very true that we can get these
diseases even by living a good lifestyle, but I am shocked that you would
minimize the role of food choices on health and disease based on this
flawed study.
Barbara V. Howard, an epidemiologist at MedStar
Research Institute, a nonprofit hospital group, and a principle
investigator in the study, is quoted in a newspaper article saying
"People should realize that diet alone is not enough to stay healthy. We
are not going to reverse any of the chronic diseases in this country by
changing the composition of the diet."
I wonder if she said this while wolfing down a double
cheeseburger sandwiched with two large empty calorie white buns along with a
64 ounce sugared soda refill cup and a side order of deep fried onion
rings.
No one denies that genetics, smoking and exercise play
a crucial role in health and disease, but to minimize and dismiss the role of diet is just plain.... what's the word... (you fill in the blank).
Summary
We did learn a few things from this 415 million dollar study: a) Most
people find it
difficult to stick to a low fat diet for prolongrd periods, b)
Scientists, even with the best intentions, may design a study with a poor
understanding of nutritional knowledge, ie, not recognizing that different
fats have different health effects, and c) After several decades of
nutritional research the consumer, and researchers, are as confused as
ever about the role of diet in health and disease.
My suggestion is that you try your best at eating a
variety of foods, increase your intake of fresh vegetables, fruits, whole
grains and beans, spices, and fish, and reduce your intake of simple sugars and
trans fats, along with reducing intake of pastry and junk food. It's not
that complicated.
A friend of mine commented recently that she learned
more about the influence of diet on health from seeing the movie Supersize
Me than learning the results of this study.
For suggestions on a
reasonable diet you can follow for long term health maintenance, see
http://www.raysahelian.com/diet.html
KFC sued over Trans Fats
July 2006 - The US consumer advocacy group the Center for Science
in the Public Interest (CSPI) has sued fast-food chicken chain KFC over
its use of trans fats. Its suit demands KFC better inform consumers that
many KFC foods are high in trans fats or ceases using the oils that have
been linked to high cholesterol and heart disease altogether. "Grilled,
baked or roasted chicken is a healthy food — and even fried chicken can be
trans fat-free," said CSPI executive director Michael Jacobson. "But
coated in breading and fried in partially hydrogenated oil, this otherwise
healthy food becomes something that can quite literally take years off
your life. KFC knows this, yet it recklessly puts its customers at risk of
a Kentucky Fried Coronary." KFC said the action was 'frivolous' and that
it would 'vigorously defend our position.' We provide a variety of menu
choices and provide nutrition information, including trans fat values, on
our website and in our restaurants so consumers can make informed choices
before they purchase our products," spokeswoman Laurie Schalow said. "We
have been reviewing alternative oil options, but there are a number of
factors to consider, including maintaining KFC's unique taste and flavour
of Colonel Sanders' original recipe, supply availability and
transportation, among others." The action comes as another US-based fast
food chain, Wendy's, committed to significantly reducing or removing trans
fats in many of its items. McDonalds gave a similar commitment in 2003 but
failed to deliver on its targets and ended up paying $7 million to the
American Heart Association last year as a settlement.
October 2006 - KFC Corp. will start using zero trans fat soybean oil for its Original Recipe and Extra Crispy fried chicken, Potato Wedges and other menu items. KFC's system wide rollout is to be completed by April 2007, but the company said many of its approximately 5,500 restaurants already have switched to low linolenic soybean oil, replacing partially hydrogenated soybean oil. Crispy Strips, Wings, Boneless Wings, Buffalo and Crispy Snacker Sandwiches, Popcorn Chicken and Twisters also are part of the menu change. Some products including biscuits will still be made with trans fat while KFC keeps looking for alternatives. KFC isn't the only business preparing for a trans-fat-free future. Dow AgroScience, a maker of three types of zero-trans-fat canola and sunflower seed oils, said it has ramped up production capacity to 1.5 billion pounds a year — enough to replace about a third of the 5 billion pounds of partially hydrogenated vegetable oil sold annually in the U.S. Wendy's, the national burger chain, has already switched to a zero-trans fat oil. McDonald's had announced that it intended to do so as well in 2003, but has yet to follow through. Ironically, many big fast food companies only became dependent on hydrogenated oil a decade and a half ago when they were pressured by health groups to do something about saturated fat. McDonald's emptied its french fryers of beef tallow in 1990 and filled them with what was then thought to be "heart healthy" partially hydrogenated vegetable oil.
California bans trans fats
Gov. Arnold Schwarzenegger signed legislation in July 2008 making
California the first U.S. state to prohibit restaurants from preparing
food with trans fats. The bill will be phased in starting in 2010 across
California. New York City and Philadelphia are among other U.S.
jurisdictions with laws banning trans fats.
New York and Trans Fat in restaurants
New York City's Health Department in September 2006 proposed a near ban on the use of artificial trans fat at restaurants, likening its health danger to that of lead paint. The proposal would limit the use of the artery-clogging fat, which is often used in fast foods, to 0.5 grams per serving. The proposal comes after a year-long city campaign to educate restaurants on the effects of such fats and encourage them to stop their use. The city said the voluntary campaign failed and while some of New York's more than 20,000 restaurants reduced or stopped using artificial trans fat, overall use did not decline at all. "Trans fat causes heart disease. Like lead in paint, artificial trans fat in food is invisible and dangerous, and it can be replaced," New York City Health Commissioner Thomas Frieden said in a statement.
Trans Fat emails
Q. I am a medical doctor in Los Angeles. Thank you for your excellent
review of the absurd Low Fat Study. To add insult to injury, "Experts" end
up making ridiculous comments about a study they obviously did not review
carefully. Keep up the good work.
Q. Have you heard anything about trans fats
contributing to problems such as ADHD or other disorders not related to
the heart at all? I heard a doctor speak about trans fats and ADHS as a
seemingly little-known, but widespread
problem and would like to know your take on it.
A. We have not seen research in this area, but trans fats can
potentially cause so many problems that high intake could make some
medical conditions worse. Whether trans fats influence ADHD is not
something we are aware of at this time.