Hydrogenated vegetable oils have been an increasingly significant part of the human diet for about 100 years and some deleterious effects of trans fat consumption are scientifically proved. The exact biochemical methods by which trans fats produce specific health problems are a topic of continuing research. One theory is that the human lipase enzyme works only on the cis-configuration and cannot metabolize a trans-configured fat. It leads to changes in the phospholipid fatty acid composition in the aorta, the main artery of the heart, thereby increasing risk of coronary heart disease.
High intake of trans fatty acids can lead to many health problems throughout one’s life. Trans fat is abundant in fast food restaurants. It is consumed in greater quantities by people who do not have access to a diet consisting of fewer hydrogenated fats, or who often consume fast food.
A diet high in trans fats can contribute to obesity, high blood pressure, and a greater risk for heart disease and type 2 Diabetes. For example, a low-income neighborhood in New York City, East Harlem, mostly has fast food restaurants, which might be a part of why 31% of adults in East Harlem are obese compared to 22% citywide and only 9% in the high-income Upper East Side (NYC Department of Health and Mental Hygiene, Eating Well in Harlem: How Available is Healthy Food? 2007)
Trans fat increases your risk of heart disease because:
- Trans fat raises your LDL (bad) cholesterol AND
- Trans fat lowers your HDL (good) cholesterol
To minimize the risk of trans fats
- Follow the suggestions in Canada’s Food Guide to Healthy Eating. The guide advises you and your children to choose lower fat dairy products, leaner meats and foods prepared with little or no fat.
- Read the labels on pre-packaged food products. Since December 2005 it has been mandatory in Canada for most foods to list on the Nutrition Facts table the amount of trans fat in the product.
- Also look for the phrase “partially hydrogenated oil” – if you see this phrase in the list of ingredients on the label it means the product contains trans fat.
- Choose soft margarines that are labelled as being free of trans fats or with ingredient lists including fully hydrogenated or non-hydrogenated oil.
- Avoid products made with partially hydrogenated oil.
- Fry foods less often and use healthier oils with a higher proportion of unsaturated fats.
- Do not re-use oil for frying more than two or three times.
- When you eat out, ask about the trans fat content of the foods on the menu.
What foods have trans-fat?
Historically, most trans fats have been found in such things as crackers, cookies, margarine (especially hard margarine), donuts, cakes, pastries, muffins, croissants, snack food and fried and breaded foods.
Foods that often have trans-fat:
- Deep fried foods (spring rolls, chicken nuggets, frozen hash browns, French fries)
- Ready to eat frozen foods (quiche, burritos, pizza, pizza pockets, French fries, egg rolls, veggie and beef patties)
- Hard (stick) margarine and shortening
- Commercially baked goods (donuts, Danishes, cakes, pies)
- Convenience foods (icing, puff pastry, taco shells, pie crusts, cake mixes)
- Toaster pastries (waffles, pancakes, breakfast sandwiches)
- Oriental noodles
- Snack puddings
- Liquid coffee whiteners
- Packaged salty snacks (microwave popcorn, chips, crackers)
- Packaged sweet snacks (cookies, granola bars)
Why trans fats are still widely in use?
Trans fats are easy to use, inexpensive to produce and last a long time. Trans fats give foods a desirable taste and texture. Many restaurants and fast-food outlets use trans fats to deep-fry foods because oils with trans fats can be used many times in commercial fryers.