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 they 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.
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.
Risk, danger, side effects
Dr. Lisa C. Vinikoor of the University of North Carolina in Chapel Hill has found that a high intake of trans fats could increase colon cancer risk. Dr. Lisa C. Vinikoor discovered that people who ate the most trans fatty acids were more likely to have pre-cancerous growths or polyps in their colons than those who consumed the least. American Journal of Epidemiology, August 1, 2008.
High intake of trans fats is associated with a higher rate of depression.
High intake of trans fats can increase the risk for endometriosis.
Trans fats, found largely in commercially prepared baked and fried foods, have become notorious in recent years because they not only raise "bad" LDL cholesterol -- as the saturated fats in meat and butter do -- but also lower levels of heart-healthy HDL cholesterol. 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 are formed when liquid fats are hardened to make something more resembling butter or lard. And like the saturated fat in lard, they raise the likelihood of heart disease.
For women with heart disease, eating too many artery-clogging trans fats increases their risk of dying suddenly from cardiac arrest. American Heart Journal, November 2009.
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.
Dietary fatty acid intakes and the risk of ovulatory infertility.
Am J Clin Nutr. 2007. 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. 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.
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, 2006.
Stroke. October 2013. Serum fatty acids and incidence of ischemic stroke among postmenopausal women. Individual serum trans, saturated, and monounsaturated fatty acids are positively associated with particular ischemic stroke subtypes, whereas individual n3 and n6 polyunsaturated fatty acids are inversely associated.
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.
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.
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 didnít.
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).
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 ó 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 ó 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.
Trans fats are formed by processing vegetable oils to increase their shelf-life, and are found in many baked goods, crackers, snacks and other packaged foods. US food producers are now required to list the amount of trans fat contained in their products, and health authorities recommend people avoid eating trans fats entirely.
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.
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.
I 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 Uam aware of at this time.