trans fatty acid

[stabilo]

Beware of Trans fatty acids (trans fat)

What is it?
We are used to hearing about saturated and unsaturated fatty acids, what is trans fatty acid?
Saturated fatty acids: from animal fat (meat, dairy product) and tropical oils (coconut and palm oils)
Unsaturated fatty acids: vegetable oils from canola, olive, corn, sunflower, etc (not subjected to hydrogenation). Contain monounsaturated or polyunsaturated fatty acids that can reduce total cholesterol and increase HDL cholesterol

Unsaturated fats are healthy, however when exposed to air, they are unstable, absorb oxygen and turn rancid. Manufacturers can prevent this by adding hydrogen to the oil in a process called hydrogenation at a high temperature; turning liquid oils into semisolid fats. When healthy unsaturated fats are hydrogenated, the chemical structures of the oil are rearranged thus a new type of fatty acid is formed; trans fatty acid   

Unsaturated Fat(i.e., unsaturated fatty acid)

H       H
|       |
-C   =   C-


Trans Fat(i.e., trans fatty acids)

H       
|       
-C   =   C-
        |
        H

Low level of trans fat can also be found in dairy products; lamb and beef fat as small amounts are produced in the GI tract of ruminants

Where can trans fat be found?
-   Vegetable shortening
-   Some margarines
-   Bakery products (Doughnuts, Cookies, Cake, Muffin)
-   Crackers
-   Candies
-   Peanut butter
-   Deep-fried fast food (French fries)
-   Packaged snack foods

Dangers of trans fat: 
-   Increase serum LDL cholesterol
-   Increase serum triglyceride
-   Promote inflammation (associated with increased level of IL-6 & C-reactive protein)
-   Causing endothelial dysfunction
-   Lowers HDL cholesterol
-   Positive association with the risk of coronary heart disease (CHD)
-   Positive association with sudden death from cardiac causes 

Consumption of trans fatty acids results in considerable potential harm with no apparent benefit. Adverse effects can be seen even it is taken at low levels of intake.

Health tips:
It is good to limit intake of both saturated fat and trans fat
-   Use unhydrogenated oil such as canola or olive oil when cooking or making salad dressing
-   Look for processed foods made with unhydrogenated oil rather athan partially hydrogenated or saturated fat (read labels)
-   Use margarine rather than butter. However, choose soft margarines over harder forms that contain more trans fatty acids (look for those labeled trans fat free)
-   Reduce intake of fried foods and baked goods such as French fries, cookies and crackers
-   Choose trans fat free bread
-   Eat lean meats, fish, fruits, vegetables and whole grain products

Reference:
Department of Health and Human Services, Department of Agriculture. Dietary guidelines for Americans 2005. (Accessed March 17, 2006, at http://www.health.gov/dietaryguidelines/dga2005/document/.)
Mozaffarian, D., Katan, M. B., Ascherio, A., Stampfer, M. J., Willett, W. C. (2006). Trans fatty acids and cardiovascular disease.. NEJM 354: 1601-1613
Food and Drug Administration. FDA acts to provide better information to consumers on trans fats. 2005. (Accessed March 17, 2006, at http://www.fda.gov/oc/initiatives/transfat/.)
Mensink RP, Katan MB. Effect of dietary trans fatty acids on high-density and low-density lipoprotein cholesterol levels in healthy subjects. N Engl J Med 1990;323:439-445.
Murray S, Flegel K, Chewing the fat on trans fats, CMAJ • November 8, 2005; 173 (10). doi:10.1503/cmaj.051271.

  there is one question, which is worse; saturated fat or trans fat?
hope you guys can help answer this
thanks in advance

[Admin]

I did a search in pubmed and found a study below:
Kromhout D, Menotti A, Bloemberg B, Arauanis C, Blackburn H, Buzina R, Dontas AS, Fidanza F, Giampaoli S, Jansen A, et al. Dietary saturated and trans fatty acids and cholesterol and 25-year mortality from coronary heart disease: the seven countries study. Prev Med. 1995;24:308-315.

BACKGROUND. In the Seven Countries Study associations between intake of individual fatty acids and dietary cholesterol were studied in relation to serum cholesterol and 25-year mortality from coronary heart disease. All analyses concern only intercohort comparisons. METHODS. In the baseline surveys carried out between 1958 and 1964, risk factors for coronary heart disease were measured among 12,763 middle-aged men constituting 16 cohorts in seven countries. In 1987 and 1988 equivalent food composites representing the average food intake of each cohort at baseline were collected locally and analyzed in a central laboratory. The vital status of all participants was verified at regular intervals during 25 years of follow-up. RESULTS. Of the individual saturated fatty acids, the average population intake of lauric and myristic acid was most strongly related to the average serum cholesterol level (r > 0.8, P < 0.001). Strong positive associations were observed between 25-year death rates from coronary heart disease and average intake of the four major saturated fatty acids, lauric, myristic, palmitic, and stearic acid (r > 0.8, P < 0.001); the trans fatty acid elaidic acid (r = 0.78, P < 0.001); and dietary cholesterol (r = 0.55, P < 0.05). CONCLUSIONS. Interpreted in the light of experimental and clinical studies, the results of these cross-cultural analyses suggest that dietary saturated and trans fatty acids and dietary cholesterol are important determinants of differences in population rates of coronary heart disease death.

Quoted from American Heart Association website http://www.americanheart.org/presenter.jhtml?identifier=1728

"

Effect of Trans Fatty Acids or Hydrogenated Fat Relative to Cis Fatty Acids, Native Oil, or Saturated Fat on Plasma Lipid Levels Clinical Data

The data on trans fatty acid intake and plasma lipid levels are relatively consistent; trans fatty acids or hydrogenated fat result in higher plasma cholesterol levels than native oil and lower plasma cholesterol levels than more saturated fat.Effects on triglyceride levels are highly variable. These results have persisted despite the marked difference among study designs, levels of trans fatty acids consumed by study subjects, and the actual source of transfatty acids. Not withstanding these data, a pivotal study published in 1990 refocused attention on trans fatty acids from total cholesterol levels to effects on specific lipoprotein particles. When a relatively high level of a trans fatty acid, 11% of energy as elaidic acid (18:1 trans 9), was substituted for a cisfatty acid, oleic acid (18:1 cis 9), or a saturated fatty acid, stearic acid (18:0), total and low-density lipoprotein (LDL) cholesterol levels increased, whereas high-density lipoprotein (HDL) levels were comparable when the subjects consumed the oleic- or stearic acid-enriched diets. HDL levels were lower when they consumed the elaidic acid-enriched diet. These changes resulted in a less favorable total cholesterol/HDL cholesterol ratio. Using a similar study design but a lower level of transfatty acid, 7.7% of energy, this basic observation was made again. Subsequent confirmation of the independent effect of trans fatty acids on HDL cholesterol levels has been somewhat inconsistent. Variations in the level of trans fatty acids fed and whether a one-to-one substitution of a trans for a cis double bond containing fatty acid was made or hydrogenated fat was substituted for oil or butter has introduced critical variables into the experimental design, which may impact study outcome. The most recent plasma lipoprotein issue related to the effects of trans fatty acids is lipoprotein (a) (Lp[a]) levels. The majority of studies have reported that transfatty acid intake increases Lp(a) levels. A positive relationship has been reported between Lp(a) levels and risk of cardiovascular disease (CVD). Issues related to the magnitude of potential change in Lp(a) levels induced by transfatty acid intake and risk for disease need clarification. "

Therefore in general terms, trans fatty acid seems "better" than saurated fat in in terms of more favourable lipid profile. However, other factors such as lp(a) level needs to be considered. Perhaps more evidence is needed to show which is "better" trans fat or saturatred fat.
Having said that, I personally think that it is of no clinical value to dertermine which one, the saturated fat or transfat is "better" since both of them are associated with increased CAD risk and need to be reduced in the diet. To know trans fatty acid or saturated fat - which is "better" or "worse" is like asking smoking and alcohol - which is "better" or "less dangerous".
Anyway, whatever the answer is, we know that both are associated with increased cardiovascular risks and consumption of both trans and saturated fats needs to be reduced.

Great post, stabilo.

[stabilo]

trans fat free bread
healthy 

[amanda]

People who are not diet conscious and does not know about the consequences on bad eating habits may develop health problems like obesity secondary to hypertension, diabetes,  heart disease and more.  Most of the people seek the latest intervention like tumescent liposuction and other forms of surgical interventions, but they didn't accompany it healthy habits of diet and exercise.