Trans Fatty Acids
TRANS FATTY ACIDS
Trans fatty acids among the most damaging fats in the diet. Eating trans fatty acids may:
- Adversely affect functioning of cell membranes (dumb down cells).
- Increase insulin resistance.
- Increase LDL cholesterol.
- Decrease HDL cholesterol.
- Increase triglycerides.
- Increase Lp(a) (another risk factor for heart disease).
Based on results of the Nurses Health Study, researchers estimated that for every 1% increase in trans fatty acids, risk of heart disease would increase by 33-35%. They also found trans fatty acids were strongly associated with an increased risk of type 2 diabetes, while polyunsaturated fats were associated with a reduced risk. The researchers estimated that by replacing 2 percent of calories from trans fatty acids with polyunsaturated fat, risk for type 2 diabetes would fall by 40 percent.
The WHO/FAO Diet and Diseases 2002 report suggests intakes of trans fatty acids should be less than 1 percent of calories. For someone eating 2,000 calories a day, that amounts to no more than 2.2 grams of trans fatty acids.
Trans fatty acids are formed when oil is turned into solid fat by adding hydrogen under pressure (hydrogenation). Technically, trans fatty acids are still “unsaturated fats”, but unlike the more common form of unsaturated fats (“cis” form), which are flexible and curved in shape, trans fatty acids are straighter, more rigid molecules. These molecules behave much like saturated fat – only worse.
Trans fatty acids are present mainly in processed packaged foods (crackers, cookies, baked goods, margarine, etc.) and deep fried foods. To minimize dietary intake of trans fatty acids, avoid:
- Foods containing partially-hydrogenated oils.
- Shortening or products containing shortening.
- Deep fried foods (many are cooked in partially hydrogenated oils)
Trans Fatty Acid Content of Selected Foods*
|
Food |
Total Fat (grams) |
Trans Fatty Acids (grams) |
| Microwave Popcorn, 3.5 oz. |
25 |
7.5 |
| French Fries, large |
23.7 |
5 |
| Cookies, chocolate chip, 4 |
12 |
5 |
| Donut, honey-glazed, 1 |
15 |
3.8 |
| Shortening, 1 Tbsp. |
14 |
3.7 |
| Cake, yellow commercial with frosting, 1 piece |
12.8 |
3.2 |
| Margarine, hard, 1 Tbsp. |
12 |
3.1 |
| Crackers, snack, 8 |
7 |
2.6 |
| Margarine, soft, 1 Tbsp. |
12 |
1.4 |
| Potato chips, 2 oz. |
19.6 |
1.1 |
* From the USDA Nutrient Database.
