Nutrition & Health Info Sheets for Consumers - Trans Fats

French fries

Nutrition & Health Info Sheets contain up-to-date information about nutrition, health, and food. They are provided in two different formats for consumer and professional users. These resources are produced by Dr. Rachel Scherr and her research staff. Produced by Anna Jones, BS, Sheri Zidenberg-Cherr, PhD, UC Cooperative Extension, Center for Health and Nutrition Research, Department of Nutrition, University of California, Davis, 2008.

What are cardiovascular disease and coronary heart disease?

  • Cardiovascular disease includes all diseases affecting the heart and circulation (1).
  • It includes coronary heart disease (CHD), heart failure, stroke, pulmonary heart disease, atherosclerosis, and high blood pressure (1).
  • Coronary heart disease is the partial or complete blockage of the arteries supplying the heart by atherosclerotic plaques.
  • Heart attacks, or myocardial infarctions, are considered CHD events and are caused by a complete blockage, cutting off blood flow to a portion of the heart muscle (1).

What are the major risk factors for coronary heart disease?

There are several modifiable risk factors for CHD (1,2):

  • Cigarette smoking.
  • Elevated low-density lipoprotein (LDL) levels (“bad cholesterol)
  • High blood pressure
  • Diabetes mellitus
  • Low level of physical activity
  • Overweight and obesity
  • Low high-density lipoprotein (HDL) levels (“good cholesterol”)
  • Poor diet

What are trans fatty acids (TFA)?

  • Trans fatty acids (TFA) are a type of unsaturated fatty acid that behave more like saturated fat in foods.
  • Most TFA acids found in foods are produced commercially (4-7).
  • The chemical process used to produce TFA results in a semi-solid or solid product with a higher melting point, increased stability, resistance to oxidation, and shelf life (3-7).

What foods contain TFA?

The major source of TFA in the diet are commercially-produced hydrogenated oils found in many processed foods, because it provides these foods with a desirable texture and longer shelf-life (4,7). The most common foods are:

  • Margarine
  • Bakery products
  • Cookies and crackers
  • Fried potatoes
  • Chips and snacks
  • Household shortening

What are the current estimated intakes of TFA?

The average consumption of TFA is estimated to be 2 to 3 percent of total calories consumed, which corresponds to an average of 5.3 to 5.8 g of trans fatty acids per day, most of which comes from commercially-produced TFA. (4-6, 9).

What are the current estimated intakes of saturated and unsaturated fat?

The average daily intake of fat is 79 grams (32.7 percent of calories), with 27 grams coming from saturated fat (11.2 percent of calories), 30 grams of monounsaturated fat and 16 grams of polyunsaturated fat (10,11).

What are the health concerns related to TFA?

The main concern is the effect of TFA on heart health. Trans fatty acids have been shown to negatively impact several factors that increase risk for cardiovascular disease.
Consumption of TFA:

  • Lowers high-density lipoprotein (HDL, “good cholesterol”) concentrations, while raising low-density lipoprotein (LDL “bad cholesterol”) and very low-density lipoprotein (VLDL) concentrations, resulting in higher total cholesterol to HDL ratios (4,6,8,12-14).
  • Increases blood levels of triglycerides (4,13,14).

How do the effects on health of TFA compare to that of unsaturated and saturated fats?

  • Consumption of saturated fatty acids and TFA raises LDL cholesterol, however, TFA also lower HDL, while saturated fat does not (5,13,14).
  • Both saturated and TFA are associated with increased CVD risk, but there is greater increase in risk with consumption of TFA.
  • Consumption of poly- and mono-unsaturated fatty acids (found in the cis formation) tends to lower overall cholesterol by lowering LDL, while HDL rises or remains relatively unchanged (12,13). For this reason, consumption of unsaturated fatty acids is associated with a decreased risk of CVD (6,13,14).

What are the concerns associated with reducing TFA in food and TFA consumption?

  • To reduce TFA in foods, manufacturers will have to replace it with another kind of fat that will give the same texture and taste to foods. Replacing TFA with healthier fats will not reduce the amount of calories in the food.
  • There is concern that foods will become higher in saturated fat, cost more, and/or lose some of their palatability (4,6).
    • Denmark banned the use of oils containing more than 2 percent TFA in 2004, and has not experienced these problems (4).
    • Overall, saturated fat consumption in Denmark has not increased, and cost, quality, and availability has not noticeably changed (4).
  • Another concern is that by focusing on eliminating TFA, individuals may ignore other lifestyle changes that could have a greater impact on reducing risk for CVD, such as exercising regularly or smoking cessation. (17). Effective prevention should include emphasis on healthy diet and lifestyle choices, and not focus solely on one risk factor (17).

 

References:

  1. Rosamond W, et al. Heart Disease and Stroke Statistics – 2007 Update: A Report From the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation; 2007; 115: 69-171.
  2. Pasternak RC, et al. Spectrum of Risk Factors for Coronary Heart Disease. J Am Coll Cardiol; 1996; 27: 964-1047.
  3. Rodriguez T, et al. Trends in mortality from coronary heart and cerebrovascular diseases in the Americas: 1970-2000. Heart; 2006; 92: 453-60.
  4. Mozaffarian D, et al. Trans Fatty Acids and Cardiovascular Disease. N Engl J Med; 2006; 354: 1601-13.
  5. ASCN/AIN Task Force on Trans Fatty Acids. Position paper on trans fatty acids. Am J Clin Nutr; 1996; 63: 663-70.
  6. Tarrago-Trani MT, et al. New and Existing Oils and Fats Used in Products with Reduced Trans-Fatty Acid Content. J Am Diet Assoc; 2006; 106: 867-80.
  7. Kuhnt K, et al. Dietary supplementation with 11trans- and 12trans-18:1 and oxidative stress in humans. Am J Clin Nutr; 2006; 84: 981-8.
  8. Lichtenstein AH, et al. Effect of different forms of dietary hydrogenated fats on serum lipoprotein cholesterol levels. N Engl J Med; 1999; 340: 1933-40.
  9. Allison DB, et al. Estimated intakes of trans fatty and other fatty acids in the US population. J Am Diet Assoc; 1999; 99: 166-174.
  10. Wright JD, et al. Dietary intake of ten key nutrients for public health, United States: 1999-2000. Advance Data From Vital and Health Statistics; No. 334. Hyattsville, Maryland: National Center for Health Statistics. 2003.
  11. Ervin RB, et al. Dietary intake of fats and fatty acids for the United States population: 1999-2000. Advance Data From Vital and Health Statistics; No. 348. Hyattsville, Maryland: National Center for Health Statistics. 2003.
  12. Lopez-Garcia E, et al. Consumption of Trans Fatty Acids is Related to Plasma Biomarkers of Inflammation and Endothelial Dysfunction. J Nutr; 2005; 135: 562-6.
  13. Hu FB, and Willett WC. Optimal Diets for Prevention of Coronary Heart Disease. JAMA; 2002: 288: 2569-78.
  14. Hu FB, et al. Types of Dietary Fat and Risk of Coronary Heart Disease: A Critical Review. J Am C Nutr; 2001; 20: 5-19.
  15. Mensink RP, et al. Effect of dietary cis and trans fatty acids on serum lipoprotein[a] levels in humans. J Lipid Res; 1992; 33: 1493-1501.
  16. Endemann DH, and Schiffrin EL. Endothelial dysfunction. J Am Soc Nephrol; 2004; 15:1983-92.
  17. Lomangino K. A Contrarian Take on Trans Fats. Nutrition and the MD; 2007; 33(3): 3-5.

 

Production of this material was supported by a grant from the Vitamin Cases Consumer Settlement Fund, created as a result of an antitrust class action. One of the purposes of the fund is to improve the health and nutrition of California consumers.


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