ruminant trans fat

Are ruminant trans fats healthy?

Pawel Malczewski
facebook twitter google pinterest PLAUSIBLE
 

Short summary

Naturally occurring fats, also known as ruminant fats, are often compared to trans fats obtained from partially hydrogenated fats, which have been proven to be harmful to health. Find out what ruminant trans fatty acids (rTFAs) are and what the latest scientific studies say about their health effects. For a quick answer click here.

Explanation

Where do ruminant trans fatty acids (rTFAs) come from?

Food sources of rTFAs

The most common food sources of naturally occurring trans fats are meat and dairy products from cows, sheep and goats, but also any other ruminant animals. These trans fatty acids have been a part of our diets since the agricultural revolution, around 10,000 years ago.

The process of creating rTFAs: bio-hydrogenation

rTFAs are produced in the gut of grazing animals (ruminants). It is a natural process that occurs at a normal body temperature and pressure, using bacterial enzymes. (1)O’Brian R. Fats and Oils: Formulating and Processing for Applications. 3rd Edition. Available here.

The process of rTFAs production is called microbial bio-hydrogenation, where unsaturated fatty acids are saturated with hydrogen by the microbes living in the gut of the ruminants. During this process, some of these unsaturated fatty acids are converted into saturated fats and some to trans fats. Cows fed with grass produce up to 5 times more of these trans fats than cows fed with grains. (2)Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here. (3)Dhiman TR, Anand GR, Satter LD, Pariza MW. Conjugated linoleic acid content of milk from cows fed different diets. J Dairy Sci. 1999 Oct;82(10):2146-56. Available here.

Where are rTFAs more abundant?

Dairy products contain up to 5% of rTFAs of total fat and beef and lamb up to 9% (in comparison to about 60% of industrial trans fatty acids – iTFAs – in partially hydrogenated oils) (see table below). (4)Salas-Salvadó J, Márquez-Sandoval F, Bulló M. Conjugated linoleic acid intake in humans: a systematic review focusing on its effect on body composition, glucose, and lipid metabolism. Crit Rev Food Sci Nutr. 2006;46(6):479-88. Available here. (5)Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here. rTFAs cannot be removed from dairy products and meat.

In countries that have imposed bans on iTFAs, most TFAs come in the form of milk and other dairy products and meat. Only a negligible amount comes from iTFAs.

For instance, in Denmark, which banned iTFAs in 2004,  the average consumption of TFAs is 1.7g per day (ranging from 0.9-2.7g per day), and most comes from ruminant sources. Of the ruminant trans fats, 85% comes from milk and 15% from meat. (6)Jakobsen MU, Bysted A, Andersen NL, Heitmann BL, Hartkopp HB, Leth T, et al. Intake of ruminant trans fatty acids in the Danish population aged 1-80 years. Eur J Clin Nutr. 2006 Mar; 60(3):312-8. Available here.

Amounts of naturally occurring trans fats in commonly consumed ruminant products (7)Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here.

FoodTFA (g/serving)
Dairy products
Cheese, cheddar (28 g, 1 oz)0.24
Milk, whole (244 g, 1 cup)0.21
Yogurt, plain, low-fat (255 g, 1 cup)0.06
Meat
Meat, beef, ground, 20.8% fat, raw (115 g, 4 oz)0.91
Meat, beef, ground, 22.1% fat, raw (115 g, 4 oz)1.07

Because of the low contents of rTFAs in dairy and meat products, it is difficult to consume them in high amounts. In countries where ruminant dairy and meat is consumed, it is estimated that the maximum intake of ruminant fats is 4-5 g daily. (8)Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.

What are the components of rTFAs?

rTFAs mainly consist of two fatty acids:

  1. Conjugated linolenic fatty acids or CLA (rumenic).
  2. Vaccenic acid (VA) which makes up about 45% of rTFA and is partially converted to CLA by the bodies of both ruminants and humans.

These components are investigated the most. (9)O’Brian R. Fats and Oils: Formulating and Processing for Applications. 3rd Edition. Available here. (10)Turpeinen AM, Mutanen M, Aro A, Salminen I, Basu S, Palmquist DL, et al. Bioconversion of vaccenic acid to conjugated linoleic acid in humans. Am J Clin Nutr September 2002. vol. 76 no. 3 504-510. Available here..

Potential effects of naturally occurring trans fats

While there are many studies on iTFAs and the evidence of their negative health effects strong, the number of studies on rTFAs are limited by comparison. (11)Bendsen NT1, Christensen R, Bartels EM, Astrup A. Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: a systematic review and meta-analysis of cohort studies. Eur J Clin Nutr. 2011 Jul;65(7):773-83. Available here.

The current knowledge of rTFAs is mostly based on observational, epidemiological or animal studies, either in its natural form (e.g. consuming rTFAs in the form of milk) or using its pure components, such as CLA or VA.

The bottom line is that there are no results showing that rTFAs coming from milk and meat in its natural form, increase the risk of cardiovascular disease or cancers or have any other detrimental effect on health.

What has been found so far is that they may even have some positive health benefits (more studies are needed). The following are the conclusions so far: (12)Gayet-Boyer C, Tenenhaus-Aziza F, Prunet C, Marmonier C, Malpuech-Brugere M, Lamarche B, et al. Is there a linear relationship between the dose of ruminant trans-fatty acids and cardiovascular risk markers in healthy subjects: results from a systematic review and meta-regression of randomised clinical trials. British Journal of Nutrition (2014), 112, 1914–1922. Available here. (13)Parodi PW. Cows’ milk fat components as potential anticarcinogenic agents. J Nutr. 1997 Jun;127(6):1055-60. Available here.

  • Naturally occurring trans fatty acids (rTFAs) – studies show that a daily consumption of up to 4g of rTFAs is not associated with coronary heart diseases. (14)Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.
    rTFAs have been connected with a reduced risk of developing type 2 Diabetes.
  • Conjugated Linolenic Acid (CLA) – predominantly, found in milk, CLA is one of the major components of rTFAs and has been shown to have various health benefits: (15)Arab A, Akbarian SA, Ghiyasvand R, Miraghajani M. The effects of conjugated linoleic acids on breast cancer: A systematic review. Adv Biomed Res. 2016; 5: 115.Published online 2016 Jul 6. Available here. (16)Smit LA, Baylin A, Campos H. Conjugated linoleic acid in adipose tissue and risk of myocardial infarction. Am J Clin Nutr. 2010 Jul; 92(1): 34–40. Available here. (17)Kim JH, Kim Y, Kim YJ, Park Y. Conjugated Linoleic Acid: Potential Health Benefits as a Functional Food Ingredient. Annual Review of Food Science and Technology. Vol.7:1-482 2016. Available here.
    Anti-carcinogenic properties (e.g. breast cancer) (18)Ip C, Singh M, Thompson HJ, Scimeca JA. Conjugated Linoleic Acid Suppresses Mammary Carcinogenesis and Proliferative Activity of the Mammary Gland in the Rat. American Association for Cancer Research. Volume 54, Issue 5, pp. 1212-1215. Available here.
    Anti-diabetic properties
    Reduced numbers of myocardial infarctions
    Prevents the development of atherosclerosis
    Promotes fat reduction while improving lean body mass (19)Whigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr. 2007 May;85(5):1203-11. Available here.
    Modulates immune responses
    Modulates inflammatory responses

Please note that most of these studies are measuring the effects of extracted CLA, rather than in amounts naturally occurring in rTFAs. (20)Ji-Na Lim, Jin-Ju Oh, Tao Wang, Jae-Sung Lee, Sang-Hun Kim, Yoon-Jin Kim, Hong-Gu Lee. trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells. Nutrients 2014, 6(2), 627-636. Available here.

Supplementation with CLAs may have also negative health effects in some people, such as effects on the liver function, glucose metabolism, oxidative stress and insulin resistance, especially in obese men. (21)Treatment with dietary trans10cis12 conjugated linoleic acid causes isomer-specific insulin resistance in obese men with the metabolic syndrome. Available here. (22)Supplementation with conjugated linoleic acid causes isomer-dependent oxidative stress and elevated C-reactive protein: a potential link to fatty acid-induced insulin resistance. Available here. (23)Dilzer A, Park Y. Implication of conjugated linoleic acid (CLA) in human health. Crit Rev Food Sci Nutr. 2012;52(6):488-513. Available here.

  • Special note on grass fed vs. grain fed ruminants.
    Meat from grass-fed animals contain more Omega-3 fatty acids and CLAs than meats from grain-fed animals. In fact, the contents of Omega-3 in grass fed cows is high enough to be considered by the Food Standards Australia and New Zealand as a good Omega-3 food source. (24)Ponnampalam EN1, Mann NJ, Sinclair AJ. Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on human health. Asia Pac J Clin Nutr. 2006;15(1):21-9. Available here.

  • Vaccenic acid (VA) – is another major component in rTFAs (45%). Vaccenic acid is partially converted to CLAs inside the human body.
    When considering the effects of vaccenic acid that occurs in its natural form in dairy and meats, no negative effects have been reported. (25)Brouwer A, Wanders AJ, Katan MB. Trans fatty acids and cardiovascular health: research completed? European Journal of Clinical Nutrition (2013) 67, 541–547. Available here. (26)Gebauer SK, Chardigny JM, Jakobsen MU, Lamarche B, Lock AL, Proctor SD, Baer DJ. Effects of Ruminant trans Fatty Acids on Cardiovascular Disease and Cancer: A Comprehensive Review of Epidemiological, Clinical, and Mechanistic Studies. Adv Nutr July 2011 Adv Nutr vol. 2: 332-354, 2011. Available here.

    When the vaccenic acid was tested in larger dosages (10 times more) than normally consumed from natural foods, it showed detrimental effects similar to those in the high iTFAs diet. These amounts of vaccenic acid, however, were artificially synthesized in the lab and don’t occur in such quantities in foods. (27)Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here.

The following are the main conclusions of the major studies on these subjects.

Some studies show that vaccenic acid may have anti-carcinogenic effects on breast cancer cases (28)Ji-Na Lim, Jin-Ju Oh, Tao Wang, Jae-Sung Lee, Sang-Hun Kim, Yoon-Jin Kim, Hong-Gu Lee. trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells. Nutrients 2014, 6(2), 627-636. Available here. and may have protective effects in diabetes. (29)Wang X, Gupta J, Kerslake M, Rayat G, Proctor S, Chan CB. Trans-11 vaccenic acid improves insulin secretion in models of type 2 diabetes in vivo and in vitro. Volume 60, Issue 4. April 2016, Pages 846–857. Available here.

A 2015 double-blind, randomized controlled trial showed that when VA was compared gram for gram with iTFAs, the results on total cholesterol and LDL cholesterol were similar. Although the study suggested that vaccenic acid may have similar effects on the risk of developing cardiovascular diseases (CDA), due to the blood cholesterol increase, it is important to note that although it raised LDL cholesterol, it also raised HDL cholesterol. The overall effect on CDA from this study is not clear, since LDL cholesterol consists of both “bad” and “good” cholesterol. (30)Stender S. In equal amounts, the major ruminant trans fatty acid is as bad for LDL cholesterol as industrially produced trans fatty acids, but the latter are easier to remove from foods. Am J Clin Nutr December 2015. vol. 102 no. 6 1301-1302. Available here. (31)Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here. (32)Field CJ, Blewett HH, Proctor S, Vine D. Human health benefits of vaccenic acid. Applied Physiology, Nutrition, and Metabolism, 2009, Vol. 34, No. 5 : pp. 979-991. Available here.

Another study found that the circulating blood triglycerides have a higher concentration of vaccenic acid in hyperinsulinemic and hyperglycemic people and higher concentrations were associated with insulin resistance. (33)Zulyniak MA, Ralston JC, Tucker AJ, MacKay KA, Hillyer LM, McNicholas PD, et al. Vaccenic acid in serum triglycerides is associated with markers of insulin resistance in men. Applied Physiology, Nutrition, and Metabolism, 2012, 37(5): 1003-1007, 10.1139/h2012-081. Available here.

IMPORTANT NOTE: The positive effects of rTFAs are sometimes promoted by studies sponsored by the dairy industry. When searching for proof, consider who the sponsors are or any conflicts within the scientific studies.

Problems with the current studies

For ethical reasons, randomized intervention studies, which could show the extent of these fats on human health, may never be conducted. Most studies are done on animals or are observational or epidemiological.

Studies of iTFAs are easier to conduct and more abundant because they can be produced in high quantities using the partial hydrogenation process. (read more..) Studies on rTFAs, on the other hand, are harder since they are available in very small amounts in their natural form. (34)Bendsen NT1, Christensen R, Bartels EM, Astrup A. Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: a systematic review and meta-analysis of cohort studies. Eur J Clin Nutr. 2011 Jul;65(7):773-83. Available here.

The current knowledge of rTFAs is mostly based on observational studies of these fats, either in  their natural form (e.g. consuming rTFAs in the form of milk) or using its pure components, such as CLA or VA.

The rTFAs’ molecular structure is slightly different from the iTFAs’. Therefore, they have different effects in our body. More studies are needed to clearly show these differences.

Comparing the health effects of these two fats may be difficult, since there are other variables that may alter the results. For example fats containing iTFAs are mainly unsaturated while rTFAs are mostly saturated. In addition, some fats may have higher omega-3 fatty acids concentration which counteracts many of the TFAs actions, such as inflammation.

CLAs are the most studied component of rTFAs, while VAs have not been investigated as much. (35)Stender S. In equal amounts, the major ruminant trans fatty acid is as bad for LDL cholesterol as industrially produced trans fatty acids, but the latter are easier to remove from foods. Am J Clin Nutr December 2015. vol. 102 no. 6 1301-1302. Available here.

The association with the risk of developing cancer has not yet been well studied. (36)Gebauer SK, Chardigny JM, Jakobsen MU, Lamarche B, Lock AL, Proctor SD, Baer DJ. Effects of Ruminant trans Fatty Acids on Cardiovascular Disease and Cancer: A Comprehensive Review of Epidemiological, Clinical, and Mechanistic Studies. Adv Nutr July 2011 Adv Nutr vol. 2: 332-354, 2011. Available here.

Some studies show that rTFAs alone (or their individual components, such as CLAs or VAs) may be responsible for some health benefits. Other studies, however, suggest that the health benefits are due to other components that are present in foods containing rTFAs, such as dairy. (37)Parodi PW. Cows’ milk fat components as potential anticarcinogenic agents. J Nutr. 1997 Jun;127(6):1055-60. Available here.

Conclusion

Back to top

Current science shows that there is no harm resulting from trans fats in a natural form, such as the ones from dairy products and meats of ruminants (grazing animals), even if they are  in higher amounts – from grass fed ruminants (grass fed ruminants produce much more rTFAs than grain fed ruminants).

Some studies show that the consumption of rTFAs may have positive health effects, especially on major diseases such as cardiovascular disease and cancers. It is not clear, however, if these can be attributed to other components of the foods containing rTFAs or to individual components of rTFAs, such as CLAs and VAs. It is also not clear what amounts exert the optimum health benefits.

Whether high amounts of rTFAs, compared gram for gram to iTFAs, pose any health risks is not known and current studies are conflicting.

References   [ + ]

1. O’Brian R. Fats and Oils: Formulating and Processing for Applications. 3rd Edition. Available here.
2. Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.
3. Dhiman TR, Anand GR, Satter LD, Pariza MW. Conjugated linoleic acid content of milk from cows fed different diets. J Dairy Sci. 1999 Oct;82(10):2146-56. Available here.
4. Salas-Salvadó J, Márquez-Sandoval F, Bulló M. Conjugated linoleic acid intake in humans: a systematic review focusing on its effect on body composition, glucose, and lipid metabolism. Crit Rev Food Sci Nutr. 2006;46(6):479-88. Available here.
5. Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.
6. Jakobsen MU, Bysted A, Andersen NL, Heitmann BL, Hartkopp HB, Leth T, et al. Intake of ruminant trans fatty acids in the Danish population aged 1-80 years. Eur J Clin Nutr. 2006 Mar; 60(3):312-8. Available here.
7. Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here.
8. Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.
9. O’Brian R. Fats and Oils: Formulating and Processing for Applications. 3rd Edition. Available here.
10. Turpeinen AM, Mutanen M, Aro A, Salminen I, Basu S, Palmquist DL, et al. Bioconversion of vaccenic acid to conjugated linoleic acid in humans. Am J Clin Nutr September 2002. vol. 76 no. 3 504-510. Available here.
11. Bendsen NT1, Christensen R, Bartels EM, Astrup A. Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: a systematic review and meta-analysis of cohort studies. Eur J Clin Nutr. 2011 Jul;65(7):773-83. Available here.
12. Gayet-Boyer C, Tenenhaus-Aziza F, Prunet C, Marmonier C, Malpuech-Brugere M, Lamarche B, et al. Is there a linear relationship between the dose of ruminant trans-fatty acids and cardiovascular risk markers in healthy subjects: results from a systematic review and meta-regression of randomised clinical trials. British Journal of Nutrition (2014), 112, 1914–1922. Available here.
13. Parodi PW. Cows’ milk fat components as potential anticarcinogenic agents. J Nutr. 1997 Jun;127(6):1055-60. Available here.
14. Stender S, Astrup A, Dyerberg J. Ruminant and industrially produced trans fatty acids: health aspects. Food Nutr Res. 2008; 52: 10.3402/fnr.v52i0.1651. Available here.
15. Arab A, Akbarian SA, Ghiyasvand R, Miraghajani M. The effects of conjugated linoleic acids on breast cancer: A systematic review. Adv Biomed Res. 2016; 5: 115.Published online 2016 Jul 6. Available here.
16. Smit LA, Baylin A, Campos H. Conjugated linoleic acid in adipose tissue and risk of myocardial infarction. Am J Clin Nutr. 2010 Jul; 92(1): 34–40. Available here.
17. Kim JH, Kim Y, Kim YJ, Park Y. Conjugated Linoleic Acid: Potential Health Benefits as a Functional Food Ingredient. Annual Review of Food Science and Technology. Vol.7:1-482 2016. Available here.
18. Ip C, Singh M, Thompson HJ, Scimeca JA. Conjugated Linoleic Acid Suppresses Mammary Carcinogenesis and Proliferative Activity of the Mammary Gland in the Rat. American Association for Cancer Research. Volume 54, Issue 5, pp. 1212-1215. Available here.
19. Whigham LD, Watras AC, Schoeller DA. Efficacy of conjugated linoleic acid for reducing fat mass: a meta-analysis in humans. Am J Clin Nutr. 2007 May;85(5):1203-11. Available here.
20. Ji-Na Lim, Jin-Ju Oh, Tao Wang, Jae-Sung Lee, Sang-Hun Kim, Yoon-Jin Kim, Hong-Gu Lee. trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells. Nutrients 2014, 6(2), 627-636. Available here.
21. Treatment with dietary trans10cis12 conjugated linoleic acid causes isomer-specific insulin resistance in obese men with the metabolic syndrome. Available here.
22. Supplementation with conjugated linoleic acid causes isomer-dependent oxidative stress and elevated C-reactive protein: a potential link to fatty acid-induced insulin resistance. Available here.
23. Dilzer A, Park Y. Implication of conjugated linoleic acid (CLA) in human health. Crit Rev Food Sci Nutr. 2012;52(6):488-513. Available here.
24. Ponnampalam EN1, Mann NJ, Sinclair AJ. Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on human health. Asia Pac J Clin Nutr. 2006;15(1):21-9. Available here.
25. Brouwer A, Wanders AJ, Katan MB. Trans fatty acids and cardiovascular health: research completed? European Journal of Clinical Nutrition (2013) 67, 541–547. Available here.
26. Gebauer SK, Chardigny JM, Jakobsen MU, Lamarche B, Lock AL, Proctor SD, Baer DJ. Effects of Ruminant trans Fatty Acids on Cardiovascular Disease and Cancer: A Comprehensive Review of Epidemiological, Clinical, and Mechanistic Studies. Adv Nutr July 2011 Adv Nutr vol. 2: 332-354, 2011. Available here.
27. Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here.
28. Ji-Na Lim, Jin-Ju Oh, Tao Wang, Jae-Sung Lee, Sang-Hun Kim, Yoon-Jin Kim, Hong-Gu Lee. trans-11 18:1 Vaccenic Acid (TVA) Has a Direct Anti-Carcinogenic Effect on MCF-7 Human Mammary Adenocarcinoma Cells. Nutrients 2014, 6(2), 627-636. Available here.
29. Wang X, Gupta J, Kerslake M, Rayat G, Proctor S, Chan CB. Trans-11 vaccenic acid improves insulin secretion in models of type 2 diabetes in vivo and in vitro. Volume 60, Issue 4. April 2016, Pages 846–857. Available here.
30. Stender S. In equal amounts, the major ruminant trans fatty acid is as bad for LDL cholesterol as industrially produced trans fatty acids, but the latter are easier to remove from foods. Am J Clin Nutr December 2015. vol. 102 no. 6 1301-1302. Available here.
31. Gebauer SK, Destaillats F, Dionisi F, Krauss RM, Baer D. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial. Am J Clin Nutr December 2015. vol. 102 no. 6 1339-1346. Available here.
32. Field CJ, Blewett HH, Proctor S, Vine D. Human health benefits of vaccenic acid. Applied Physiology, Nutrition, and Metabolism, 2009, Vol. 34, No. 5 : pp. 979-991. Available here.
33. Zulyniak MA, Ralston JC, Tucker AJ, MacKay KA, Hillyer LM, McNicholas PD, et al. Vaccenic acid in serum triglycerides is associated with markers of insulin resistance in men. Applied Physiology, Nutrition, and Metabolism, 2012, 37(5): 1003-1007, 10.1139/h2012-081. Available here.
34. Bendsen NT1, Christensen R, Bartels EM, Astrup A. Consumption of industrial and ruminant trans fatty acids and risk of coronary heart disease: a systematic review and meta-analysis of cohort studies. Eur J Clin Nutr. 2011 Jul;65(7):773-83. Available here.
35. Stender S. In equal amounts, the major ruminant trans fatty acid is as bad for LDL cholesterol as industrially produced trans fatty acids, but the latter are easier to remove from foods. Am J Clin Nutr December 2015. vol. 102 no. 6 1301-1302. Available here.
36. Gebauer SK, Chardigny JM, Jakobsen MU, Lamarche B, Lock AL, Proctor SD, Baer DJ. Effects of Ruminant trans Fatty Acids on Cardiovascular Disease and Cancer: A Comprehensive Review of Epidemiological, Clinical, and Mechanistic Studies. Adv Nutr July 2011 Adv Nutr vol. 2: 332-354, 2011. Available here.
37. Parodi PW. Cows’ milk fat components as potential anticarcinogenic agents. J Nutr. 1997 Jun;127(6):1055-60. Available here.

Leave a Reply

Your email address will not be published. Required fields are marked *