MODERN DISEASE PREVENTION
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"If you're afraid of butter, use cream." — Julia Child
"Conjugated linoleic acid (abbreviated to CLA) is a term which refers to a family of 18-carbon fatty acid isomers with two conjugated double bonds. Different CLA isomers have been identified based on the position as well as the arrangement of the double bonds. Along the acyl chain, the two conjugated double bonds could be in positions 7 and 9, 8 and 10, 9 and 11, 10 and 12, or 11 and 13. These are known as positional isomers. Additionally, there could be four possible spatial orientations to the two double bonds as denoted by the nomenclature of cis,cis (c,c); cis,trans (c,t); trans,cis (t,c) and trans,trans (t,t). These are known as geometric isomers..." — Clement Ip, PhD.Opportunities for Basic and Clinical Research on Conjugated Linoleic Acid. Roswell Park Cancer Institute. Accessed 07 July 2011. http://ods.od.nih.gov/pubs/conferences/cla/clasummary.html
POTENT ANTI-CARCINOGEN FOUND IN MILK FAT
Early research with the cis-9, trans-11 CLA isomer suggested that this compound was anti-carcinogenic. Because cis-9, trans-11 CLA is the major CLA isomer found in ruminant fat, our group wanted to determine if the CLA in milk fat was active as an anti-carcinogen. Using natural feed ingredients, we designed a diet that would enhance the cis-9, trans-11 CLA content of milk fat and collected the milk from cows at Cornell's Teaching and Research Farm.
We then collaborated Dr. David Barbano and workers at Cornell's Food Science Department to produce butter. The result was a butter that had a CLA content eightfold greater than control butter. Bauman et al. detail specifics pertaining to the manufacture of this butter.
In collaboration with Dr. Clement Ip and researchers at the Roswell Park Cancer Institute (Buffalo, NY), the butter was used in a study of chemically-induced mammary carcinogenesis in rats. The CLA-enhanced butter was compared to a control butter and to a diet supplemented with chemically synthesized CLA. Both the CLA-enhanced butter and the chemically synthesized CLA were effective at reducing tumor formation.
This study was among the first to show that a naturally occurring anticarcinogen, fed as a component of a naturally produced food was effective at reducing the development of mammary tumors in a biomedical cancer model.
Is Butter Better? During the course of the above experiment, we observed that animals consuming the CLA-enhanced butter had a greater tissue concentration of CLA as compared to those animals receiving the chemical supplement of CLA. Milk fat contains vaccenic acid (trans-11 18:1) and our tissues contain the enzyme delta-9 desaturase that can convert vaccenic acid to cis-9, trans-11 CLA. We hypothesized that this enzyme would convert the vaccenic acid in milk fat to CLA thereby resulting in vaccenic acid also having anticarcinogenic properties.
To examine this, we again used typical feedstuffs and designed a dairy cow diet that would result in a milk fat with enhanced vaccenic acid (VA) and CLA content. Milk was collected and processed to produce a VA/CLA enhanced butter and in this case, vaccenic acid and cis-9, trans-11 CLA represented about 20% of total milk fatty acids.
In the experiment, diets were formulated to have varying amounts of VA and CLA by changing the amount of control and high CLA butter used, as well as adding a small amount of synthetic CLA. Diets A through D contained the same amount of vaccenic acid (trans-11 18:1) with small increases in the CLA content of the diet. While diets E, F, and G were matched with diets B, C, and D respectively for CLA content and had greater amounts of vaccenic acid. Therefore, differences observed between diets B and E, or C and F, or D and G would be due to the increased amount of vaccenic acid provided by the diet.
Comparing diets with identical concentrations of cis-9, trans-11 CLA and increased amounts of trans-11 18:1, we observed that mammary tissue concentrations of cis-9, trans-11 were significantly increased.
Corl et al. were able to show that animals with increased tissue concentrations of CLA also had a decreased incidence of tumors. VA was used as a substrate to produce cis-9, trans-11 CLA and there was a reduction in tumor numbers. It is possible that trans-11 18:1 itself was anti-carcinogenic, however, it is more likely that the reduction in tumor numbers was the result of increased tissue CLA produced from VA. The answer to this was recently determined by Lock et al. who determined that vaccenic acid is anti-carcinogenic due to its conversion to cis-9, trans-11 CLA via delta-9 desaturase.
Data from these and other studies have lead the National Academy of Sciences to state that "...CLA is the only fatty acid shown unequivocally to inhibit carcinogenesis in experimental animals." Recently consumer awareness of functional foods has increased. A functional food is any food or food ingredient that may provide a health benefit beyond the traditional nutrients it contains. Conjugated linoleic acid and vaccenic acid are microcomponents that impart functional food characteristics to dairy products. Therefore a market for CLA-enriched dairy products may exist and should be explored further. Our group remains involved with continuing research on the effects of CLA in cancer models and have branched off to look at the effects of a high CLA butter in an atherosclerosis model. We are also involved in on going research efforts to find feeding/management practices that will elevate and maintain cis-9, trans-11 CLA levels in milk fat.
The Bauman Research Group (Dale E. Bauman PhD, David M Barbano PhD, D A Dwyer, JM Griinari), Conjugated Linoleic Acid Studies, Cornell University, Ithaca, NY.
HIGH CONCENTRATION OF CONJUGATED LINOLEIC ACID IN KERRYGOLD IRISH BUTTER
Dairy cows, cheese and butter have been part of Irish society for thousands of years, according to the Cork Butter Museum in Cork city, Ireland. Cattle have been in Ireland since 3500 BC. Much of the milk from dairy cows was turned into butter. The Cork Butter Exchange, a market created by the merchants of Cork city in 1770, was in its time, the largest butter market in the world; exporting butter as far away as Europe and America.
The modern era of the butter industry began in 1961 with the creation by the Irish government of the Irish Dairy Board – a distribution, marketing and selling cooperative. Today, most of the milk from Ireland’s small dairy farms go to local co-ops, where milk is collected, then sent on to be made into butter and cheeses using age-old processes. The Board exports the dairy products the world over, on behalf of its member farmers and processors.
This form of cooperation ensures the viability of Ireland’s small family farms. The resulting dairy products are all-natural. Cows are not given growth hormones that can find their way into the milk, and butter and cheeses are made without additives or preservatives. Irish Dairy Board products are exported to more than 80 countries.
In the United States, they are sold under the Kerrygold brand to supermarkets and specialty stores around the country. Kerrygold’s higher fat content gives the butter a distinctive richness. It is so naturally golden that it looks as like it has been colored. But the golden color of the butter comes from the natural beta-carotene, a powerful antioxidant, and a higher concentration of Conjugated Linoleic Acid. Kerrygold butter also contains the powerful antioxidant selenium and iodine that helps regulate the thyroid gland.
The flavor is also a consequence of the cows being grass-fed and the type of grass in Ireland. The trace elements in the soil that get into the grass are unique. The moisture-bearing southwesterly winds, the rain, and the warming influence of the Gulf Stream all contribute to year-round lush green pastures of tender grass.
The Irish Dairy Board, headquartered in Dublin, Ireland, is a cooperative of dairy farmers and a major exporter of cheese, butter and other Irish dairy products worldwide. The Board’s American headquarters is located in Evanston, Illinois.
BUTTER IS NATURALLY ENRICHED IN CONJUGATED LINOLEIC ACID AND VACCENIC ACID
BUTTER ALTERS TISSUE FATTY ACIDS AND IMPROVES THE PLASMA LIPOPROTEIN PROFILE IN CHOLESTEROL-FED HAMSTERS
Butter, which is naturally enriched in rumenic acid (cis-9, trans-11 conjugated linoleic acid) and vaccenic acid, has been shown to be an effective anticarcinogen in studies with animal models; however, there has been no examination of the effects of a naturally derived source of vaccenic acid and rumenic acid on atherosclerosis-related biomarkers.
The current study was designed to determine the effect of a diet containing vaccenic acid/ rumenic acid enriched butter on plasma lipoproteins and tissue fatty acid profiles in cholesterol-fed hamsters. Male Golden Syrian hamsters were fed diets containing 0.2% cholesterol and 20% added fat as:
1.) Control, 20% standard butter;
2.) 5% standard butter + 15% vaccenic acid/rumenic acid enriched butter;
3.) 15% standard butter + 5% partially-hydrogenated vegetable oil.
After 4 weeks, plasma lipoproteins were isolated, cholesterol quantified, and tissue fatty acid profiles determined. Tissue concentrations of vaccenic acid and rumenic acid (cis-9, trans-11 conjugated linoleic acid) were increased by consumption of the vaccenic acid/rumenic acid enriched butter diet compared with both the Control (standard butter) diet and the partially-hydrogenated vegetable oil diet, whereas the partially-hydrogenated vegetable oil diet increased their concentration compared with the Control (standard butter) diet only.
Total and LDL (low-density lipoprotein) cholesterol concentrations were significantly reduced in hamsters fed vaccenic acid/rumenic acid enriched butter and hamsters fed partially-hydrogenated vegetable oil compared with hamsters fed Control (standard butter), whereas VLDL (very-low-density lipoprotein) cholesterol concentrations were reduced in hamsters fed vaccenic acid/rumenic acid enriched butter compared with those hamsters fed Control (standard butter) and hamsters fed partially-hydrogenated vegetable oil. HDL (high-density lipoprotein) cholesterol concentrations did not differ among treatments.
The ratio of potentially atherogenic lipoproteins [VLDL + intermediate density lipoproteins (IDL) + LDL] to antiatherogenic HDL was significantly lower in hamsters fed vaccenic acid/rumenic acid enriched butter (0.60) than in those fed either control diet (1.70) or the diet containing partially hydrogenated vegetable oil (1.04). Thus, increasing the vaccenic acid and rumenic acid concentration of butter results in a plasma lipoprotein cholesterol profile that is associated with a reduced risk of atherosclerosis.
Adam Lock, Claire Horne, Dale Bauman, and Andrew Salter. BUTTER IS NATURALLY ENRICHED IN CONJUGATED LINOLEIC ACID AND VACCENIC ACID. J. Nutr. 135, 1934 (2005).
CONJUGATED LINOLEIC ACID AND TRANS VACCENIC ACID IN GRASS-FED BEEF
Red meat, regardless of feeding regimen, is nutrient dense and regarded as an important source of essential amino acids, vitamins A, B6, B12, D, E, and minerals, including iron, zinc and selenium. Along with these important nutrients, meat consumers also ingest a number of fats which are an important source of energy and facilitate the absorption of fat-soluble vitamins including A, D, E and K.
Conjugated linoleic acids (CLA) make up a group of polyunsaturated fatty acids found in meat and milk from ruminant animals (goats, sheep, cows) and exist as a general mixture of conjugated isomers of linoleic acid (LA), an omega-6 fatty acid. Of the many isomers identified, the cis-9, trans-11 CLA isomer (also referred to as rumenic acid or RA) accounts for up to 80-90% of the total CLA in ruminant products. Naturally occurring CLAs originate from two sources: bacterial isomerization and/or biohydrogenation of polyunsaturated fatty acids (PUFA) in the rumen and the desaturation of trans-fatty acids in the adipose tissue and mammary gland.
Microbial biohydrogenation of LA and α-linolenic acid (αLA), an omega-3 fatty acid, by an anaerobic rumen bacterium Butyrivibrio fibrisolvens is highly dependent on rumen pH. Grain consumption decreases rumen pH, reducing Butyrivibrio fibrisolven activity, conversely grass-based diets provide for a more favorable rumen environment for subsequent bacterial synthesis. Rumen pH may help to explain the apparent differences in CLA content between grain and grass-finished meat products.
Grass-fed beef provides a higher concentration of trans-vaccenic acid (C18:1 t11), an important monounsaturated fatty acid (MUFA) for de novo synthesis of conjugated linoleic acid (CLA: C18:2 c-9, t-11), a potent anti-carcinogen that is synthesized within the body tissues. De novo synthesis of CLA from 11t-C18:1 TVA has been documented in rodents, dairy cows and humans. Studies suggest a linear increase in CLA synthesis as the trans-vaccenic acid (TVA) content of the diet increased in human subjects. The rate of conversion of TVA to CLA has been estimated to range from 5 to 12% in rodents to 19 to 30% in humans. True dietary intake of CLA should therefore consider native 9c11t-C18:2 (actual CLA) as well as the 11t-C18:1 (potential CLA) content of foods.
Natural augmentation of CLA c9t11 and TVA within the lipid fraction of beef products can be accomplished through diets rich in grass and lush green forages. While precursors can be found in both grains and lush green forages, grass-fed ruminant species have been shown to produce two to three times more CLA than ruminants fed in confinement on high grain diets, largely due to a more favorable rumen pH.
Over the past two decades numerous studies have shown significant health benefits attributable to the actions of CLA, as demonstrated by experimental animal models, including actions to reduce carcinogenesis, atherosclerosis, and onset of diabetes. Conjugated linoleic acid has also been reported to modulate body composition by reducing the accumulation of adipose tissue in a variety of species including mice, rats, pigs, and now humans. These changes in body composition occur at ultra high doses of CLA, dosages that can only be attained through synthetic supplementation that may also produce ill side-effects, such as gastrointestinal upset, adverse changes to glucose/insulin metabolism and compromised liver function.
Optimal dietary intake remains to be established for conjugated linoleic acid. It has been hypothesized that 95 mg CLA/day is enough to show positive effects in the reduction of breast cancer in women utilizing epidemiological data linking increased milk consumption with reduced breast cancer. Ha et al. (1989) published a much more conservative estimate stating that 3 g/day CLA is required to promote human health benefits. Ritzenthaler et al. (2001) estimated CLA intakes of 620 mg/day for men and 441 mg/day for women are necessary for cancer prevention.
Obviously, all these values represent rough estimates and are mainly based on extrapolated animal data. What is clear is that we as a population do not consume enough CLA in our diets to have a significant impact on cancer prevention or suppression. Reports indicate that Americans consume between 150 to 200 mg/day, Germans consumer slightly more between 300 to 400 mg/day, and the Australians seem to be closer to the optimum concentration at 500 to 1000 mg/day according to Parodi (1994).
Daley, Cynthis A; Abbott, Amber; Doyle, Patrick S; Nader, Glenn A; Larson, Stephanie. A Review of Conjugated Linoleic Acid (CLA) and Trans Vaccenic Acid (TVA) in Grass-Fed Beef. Nutrition Journal 2010, Vol 9:10. accessed July 6 2011 http://www.nutritionj.com/content/9/1/10
Red meat, regardless of feeding regimen, is nutrient dense and regarded as an important source of essential amino acids, vitamins A, B6, B12, D, E, and minerals, including iron, zinc and selenium. Along with these important nutrients, meat consumers also ingest a number of fats which are an important source of energy and facilitate the absorption of fat-soluble vitamins including A, D, E and K.
Conjugated linoleic acids (CLA) make up a group of polyunsaturated fatty acids found in meat and milk from ruminant animals (goats, sheep, cows) and exist as a general mixture of conjugated isomers of linoleic acid (LA), an omega-6 fatty acid. Of the many isomers identified, the cis-9, trans-11 CLA isomer (also referred to as rumenic acid or RA) accounts for up to 80-90% of the total CLA in ruminant products. Naturally occurring CLAs originate from two sources: bacterial isomerization and/or biohydrogenation of polyunsaturated fatty acids (PUFA) in the rumen and the desaturation of trans-fatty acids in the adipose tissue and mammary gland.
Microbial biohydrogenation of LA and α-linolenic acid (αLA), an omega-3 fatty acid, by an anaerobic rumen bacterium Butyrivibrio fibrisolvens is highly dependent on rumen pH. Grain consumption decreases rumen pH, reducing Butyrivibrio fibrisolven activity, conversely grass-based diets provide for a more favorable rumen environment for subsequent bacterial synthesis. Rumen pH may help to explain the apparent differences in CLA content between grain and grass-finished meat products.
Grass-fed beef provides a higher concentration of trans-vaccenic acid (C18:1 t11), an important monounsaturated fatty acid (MUFA) for de novo synthesis of conjugated linoleic acid (CLA: C18:2 c-9, t-11), a potent anti-carcinogen that is synthesized within the body tissues. De novo synthesis of CLA from 11t-C18:1 TVA has been documented in rodents, dairy cows and humans. Studies suggest a linear increase in CLA synthesis as the trans-vaccenic acid (TVA) content of the diet increased in human subjects. The rate of conversion of TVA to CLA has been estimated to range from 5 to 12% in rodents to 19 to 30% in humans. True dietary intake of CLA should therefore consider native 9c11t-C18:2 (actual CLA) as well as the 11t-C18:1 (potential CLA) content of foods.
Natural augmentation of CLA c9t11 and TVA within the lipid fraction of beef products can be accomplished through diets rich in grass and lush green forages. While precursors can be found in both grains and lush green forages, grass-fed ruminant species have been shown to produce two to three times more CLA than ruminants fed in confinement on high grain diets, largely due to a more favorable rumen pH.
Over the past two decades numerous studies have shown significant health benefits attributable to the actions of CLA, as demonstrated by experimental animal models, including actions to reduce carcinogenesis, atherosclerosis, and onset of diabetes. Conjugated linoleic acid has also been reported to modulate body composition by reducing the accumulation of adipose tissue in a variety of species including mice, rats, pigs, and now humans. These changes in body composition occur at ultra high doses of CLA, dosages that can only be attained through synthetic supplementation that may also produce ill side-effects, such as gastrointestinal upset, adverse changes to glucose/insulin metabolism and compromised liver function.
Optimal dietary intake remains to be established for conjugated linoleic acid. It has been hypothesized that 95 mg CLA/day is enough to show positive effects in the reduction of breast cancer in women utilizing epidemiological data linking increased milk consumption with reduced breast cancer. Ha et al. (1989) published a much more conservative estimate stating that 3 g/day CLA is required to promote human health benefits. Ritzenthaler et al. (2001) estimated CLA intakes of 620 mg/day for men and 441 mg/day for women are necessary for cancer prevention.
Obviously, all these values represent rough estimates and are mainly based on extrapolated animal data. What is clear is that we as a population do not consume enough CLA in our diets to have a significant impact on cancer prevention or suppression. Reports indicate that Americans consume between 150 to 200 mg/day, Germans consumer slightly more between 300 to 400 mg/day, and the Australians seem to be closer to the optimum concentration at 500 to 1000 mg/day according to Parodi (1994).
Daley, Cynthis A; Abbott, Amber; Doyle, Patrick S; Nader, Glenn A; Larson, Stephanie. A Review of Conjugated Linoleic Acid (CLA) and Trans Vaccenic Acid (TVA) in Grass-Fed Beef. Nutrition Journal 2010, Vol 9:10. accessed July 6 2011 http://www.nutritionj.com/content/9/1/10
