Trans forming the American Diet

1. Transforming the American Diet Presented by Jean Zancanella MS RD Division of Nutrition, University of Utah June 12, 2007

2. The Newest Food Fear!

3. What are trans fats? • Trans fats are formed during the process of partial hydrogenation • They are used to harden and stabilize liquid vegetable oil

4. Review of fats • Saturated (no double bonds between carbons) • Unsaturated (one or more double bonds between carbons) • Mono-unsaturated • Polyunsaturated • Omega 3 fatty acids

5. Fatty acid configurations

7. Fatty acid composition of oils

8. What are trans fats • Trans fat is the common name for a type of unsaturated fat with trans isomer fatty acid(s). They may be monounsaturated or polyunsaturated. • A particular class of trans fats occurs, in very small quantities, in meat and dairy products from ruminants • Most trans fats consumed today, however, are industrially created as a side effect of hydrogenation of plant oils

9. Hydrogenation Hydrogenation results in the conversion of liquid vegetable oils to solid or semi-solid fats, such as those present in margarine. Hydrogenation converts unsaturated fatty acids to saturated ones. In practice the process is not usually carried to completion. The result is usually described as partially hydrogenated vegetable oil.

10. Cis Fatty acid

11. Trans fatty acids (kinky fat)

12. Major trans fat found in vegetable oil (elaidic acid)

13. Oleic acid (a cis unsaturated fatty acid that makes up 55-80% of olive oil

14. Why do food processors use them? • They improve shelf life • Changes the melting point • Produces a more desirable texture in baking • Produces a desirable mouth feel • For years we thought they were better than the alternative saturated fats (prior to 1988)

15. The health concerns • Trans fat consumption has been strongly linked to risk for coronary heart disease • Trans fats have adverse effects on serum lipids and lipoprotein patterns • Trans fats increase LDL cholesterol and decrease HDL cholesterol • Saturated fats increase LDL cholesterol but have no effect on HDL levels

16. Lipoprotein review • HDL: high density lipoprotein, aka good cholesterol • LDL: low density lipoprotein; aka bad cholesterol • Cholesterol: a sterol found only in animal products. In humans it is strongly correlated with cardiovascular disease

17. The Nurses Health Study • A Harvard study in which 120,000 nurses have been followed since 1976. • Analyzed 14 years of data and 900 coronary events. • For each 2% increase in energy from trans fats, a nurses CHD risk doubled

18. Trans fats and disease risk • There may be other risks for disease as well • Cancer • Diabetes • Obesity • Liver Disfunction • Infertility • At this time results are inconclusive

19. The regulatory environment

20. FDA regulations • On July 11, 2003, the FDA issued a regulation requiring manufacturers to list trans fat on the Nutrition Facts panel of foods and some dietary supplements. • The regulation allows trans fat levels of less than 0.5 grams per serving to be labeled as 0 grams per serving. The FDA did not approve nutrient content claims such as "trans fat free" or "low trans fat,"

21. Declaration of Trans Fat in the Nutrition Facts Panel Trans fat is included in the U.S. Nutrition Facts table on a separate line immediately under the line for saturated fat. • No DV is listed for trans fat. • Declared as "0" if < 0.5 g per serving; if "0" may omit declaration and state "not a significant source of trans fat"

22. Nutrition Facts Panel

23. The Food Industry • Trans fat free Crisco!

24. Main approaches used by industry to decrease trans fat in food • Customization of crop varieties (genetic engineering of crops) • Modification of fatty acid composition by processing • Use of fully saturated fats (animal fats, tropical oils, etc) • Food reformulation (change the “recipe”)

25. University Dining Services at Princeton

26. Applebees Denny’s Starbucks McDonalds Kentucky Fried Chicken Friday’s The Walt Disney Co. Red Lobster Olive Garden Wendy’s Can the restaurant industry step up?

27. How much are we eating and how much should we be eating?

28. Average trans fat intake vs recommended intake • About 5.8 grams (2.6% of calories) • American Heart Association recommends <1% of daily calories as trans fat • FDA guidelines: 2 grams or less

29. How much trans fat are we eating?

30. Typical Trans Fatty Acid Content of Foods Produced or Prepared with Partially Hydrogenated Vegetable Oils in the United States Mozaffarian D et al. N Engl J Med 2006;354:1601-1613

31. Reducing intake of trans fats • “Optimal Levels: Adverse effects are seen even at low levels ofintake: 1 to 3 percent of total energy intake, or approximately20 to 60 calories (2 to 7 g) for a person consuming 2000 caloriesper day.” • “Thus, complete or near-complete avoidance of industriallyproduced trans fats — consumption of less than 0.5 percentof the total energy intake — may be necessary to avoidadverse effects and would be prudent to minimize health risks. “ NEJM, April 2006

32. What not to eat • Avoid foods with "partially hydrogenated" or "shortening" in the ingredients list. • Even if the label says zero trans fats, don't believe it. If the words "partially hydrogenated" or "shortening" are in the ingredients list, it DOES contain trans fat. • Assume that all unlabeled baked and fried goods contain partially hydrogenated oil, unless you know otherwise. • Keep saturated fat intake low too. • Remember that polyunsaturated fat and monounsaturated fats are good fats.

33. Questions????

34. Bibliography • hydrogenation." Wikipedia. Wikipedia, 2007. June. 2007. • Canadian Task Force on Trans Fats:TRANSforming the Food Supply, co-chaired by Health Canada and the Heart and Stroke Foundation of Canada, June 2006 • FDA: Revealing Trans Fats, FDA Consumer September 2003 • Trans Fats: Wikipedia 2007, June 2007 • The American Heart Association • Bantransfats.com: the campaign to ban partially hydrogenated oils • Mayo Clinic.com: Trans Fats; a Cholesterol Double Whammy, December 2006 • New England Journal of Medicine, April 2006

35. What are trans fats? • Chemically, trans fats are made of the same building blocks as non-trans fats, but have a different arrangement. In trans fatty acid molecules, the hydrogen atoms bonded to pair(s) of doubly bonded carbon atoms (characteristic of all unsaturated fats) are in the trans rather than the cis arrangement. This results in a straight, rather than kinked, shape for the carbon chain. The shapes of these trans molecules are similar to saturated fats, which are always straight chains.