CONJUGATED LINOLEIC ACID
(CLA) weight loss and side effects, benefits; research finds
zhion@zhion.com May 7, 2006
(CLA) weight loss and side effects, benefits; research finds
zhion@zhion.com May 7, 2006
Conjugated linoleic acid (CLA) is a group of positional and
geometric isomers of linoleic acid (LA, C18:2 cis-9, cis-12). From
a few recent research studies, conjugated linoleic acid (CLA) may
have a substantial impact in reducing body fat and increasing
muscle mass. Conjugated linoleic acid (CLA) may offer protection
against atherosclerosis and cancers. Probably, beause of these
multiple possible health benefits, conjugated linoleic acid (CLA)
has became one of the most popular sport supplements in the
market.
SOURCES OF CONJUGATED LINOLEIC ACID (CLA)
Conjugated linoleic acid (CLA) is found mainly in dairy products, beef,
poultry, eggs, and corn oil. Bacteria that live in the intestine of
humans can convert linoleic acid to conjugated linoleic acid (CLA). The
source of conjugated linoleic acid (CLA) for some supplements are
derived from safflower oil. Most brands of conjugated linoleic acid
(CLA) on the market today contain 70% conjugated linoleic acid (CLA);
with no trans-fats present.
SIDE EFFECTS of CONJUGATED LINOLEIC ACID (CLA)
Conjugated linoleic acid (CLA) is probably safe to healthy human
subjects. However, it may impose serious side effects to overweight
subjects.
OVERWEIGHT SUBJECTS Conjugated linoleic acid (CLA) may
increase the risk for heart disease. In a study, overweight volunteers
who took 4.5 grams of conjugated linoleic acid (CLA) daily for one
year had an increase in their blood levels of lipoprotein(a), a risk
factor for heart disease. [1] Conjugated linoleic acid (CLA) may also
reduce the insulin sensitivity for overweight men. A reduction in
insulin sensitivity was also observed in a study of overweight men
without diabetes after treatment with 3 grams of conjugated linoleic
acid CLA daily for three months. [2] Conjugated linoleic acid (CLA)
feeding was found to promote insulin resistance in obese/diabetic
mice by at least inverse regulation of leptin and adiponectin, and
TNFalpha, adipocytokines known to either ameliorate or deteriorate
insulin sensitivity, respectively. [3] In another study of people with
type 2 diabetes, supplementing with 3 grams of conjugated linoleic
acid (CLA) daily for eight weeks significantly increased blood glucose
levels by 6.3% and decreased insulin sensitivity. [4] However,
researchers also found that 4 grams of conjugated linoleic acid (CLA)
daily for eight weeks improved insulin sensitivity of young men. [5]
t10,c12-CLA-induced hyperinsulinemia may trigger liver steatosis
(fatty liver), by inducing both fatty acid uptake and lipogenesis. [6]
Conjugated linoleic acid CLA supplementation induces a profound
reduction of leptin, adiponectin and then excessive secretion of insulin
and hepativc lipid content in a study of mouse. These observations
cast doubt on the safety of dietary supplements containing CLA. [7]
CONJUGATED LINOLEIC ACID (CLA) BENEFITS
Various studies have demonstrated that conjugated linoliec acid
(CLA) is an antioxidant, and it has multiple health benefits on
various chronic diseases such as atherosclerosis and cancer.
BENEFITS ON CHOLESTEROL AND ATHEROSCLEROSIS
Conjugated linoleic acid CLA has antiatherosclerotic and antioxidant
activity by increasing oxidative stability in plasma and hepatic
membrane in the vitamin E-deficient rats [8] Individual conjugated
linoleic acid CLA isomers was shown to reduce atherosclerotic lesion
development in hamsters. [9]In a cell culture, conjugated linoleic acid
(CLA) reduces apoB100 production and secretion compared to
saturated and polyunsaturated fatty acids, possibly by limiting the
availability of free cholesterol (required for apoB100 production). A
reduction in apoB100 production in the body would decrease the
levels of VLDL and atherogenic LDL and thus reduce the risk of
developing cardiovascular disease. Some other studies in animals
also showed that conjugated linoleic acid (CLA) may reduce the risk of
atherosclerosis . [15-17]
BENEFITS ON CANCERS
Dietary conjugated linoleic acid CLA was shown to inhibit colon tumor
cell proliferation in vitro and in vivo via the CDK inhibitor
p21(CIP1/WAF1). [15] And, various basic research studies have
demonstrated that conjugated linoleic acid (CLA) might reduce the
risk of several types of cancers including breast, prostate, colorectal,
lung, skin, and stomach. [10-13] Scientists have also investigated on
howconjugated linoleic acid (CLA) inhibited cancer cell growth
extensively. Conjugated linoleic acid CLA may trigger apoptosis in the
estrogen unresponsive MDA-MB-231 human breast cancer cell line via
mechanisms involving above all the mitochondrial pathway. [14]
BENEFITS ON IMMUNE FUNCTIONS
Conjugated linoleic acid CLA improved performance, lymphocyte
proliferation, and increased the CD8+ lymphocyte population, while
reduced the production of PGE2 and interleukin-lbeta (IL- 1beta).
Supplementation of conjugated linoleic acid; CLA enhanced
lymphocyte proliferation function, possibly by regulating the PGE2
production, and improved growth performance of pigs. [15]
BENEFITS ON GLUCOSE TOLERANCE?
Animal research suggests an effect of conjugated linoleic acid (CLA)
supplementation on improving glucose tolerance. [16]
BENEFIT ON WEIGHT MANAGEMENT
There are a few studies showing that conjugated linoleic acid (CLA) is
effective on reduction of body fat. In a study, conjugated linoleic acid
(CLA) significantly reduced percent body fat, but did not significantly
reduce body weight [17] In another study, supplementation with 4.2
grams of conjugated linoleic acid (CLA); per day for four weeks
produced a reduction in waist size but not weight loss. [18]
CONJUGATED LINOLEIC ACID IN MILK
Supplementation of vegetable oils tended to improve milk production of lactating
cows, and the conjugated linoleic acid (CLA) content in milk fat was significantly
increased. Soybean oil seemed to be the optimal source to increase conjugated
linoleic acid (CLA) production. [17]
HOME
THIS CONJUGATED LINOLEIC ACID (CLA) ARTICLE IS FOR YOUR REFERNCE ONLY. IF YOU
HAVE ANY QUESTION ABOUT CONJUGATED LINOLEIC ACID (CLA) OR YOUR HEALTH ,
PLEASE, CONSULT WITH YOUR DOCTOR IMMEDIATELY. ALL RIGHTS RESERVED 2006
REFERENCE
[1] Gaullier JM et al. Conjugated linoleic acid supplementation for 1 y reduces body fat
mass in healthy overweight humans. Am J Clin Nutr 2004;79:1118?25.][2] Riserus U et al
Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity,
lipid peroxidation, and proinflammatory markers in obese men. Am J Clin Nutr
2004;80:279?83] [3] Ohashi A et al, Health Sciences University of Hokkaido, Conjugated
linoleic acid deteriorates insulin resistance in obese/diabetic mice in association with
decreased production of adiponectin and leptin. J Nutr Sci Vitaminol (Tokyo). 2004
Dec;50(6):416-21 [4]Moloney F, et al. Conjugated linoleic acid supplementation, insulin
sensitivity, and lipoprotein metabolism in patients with type 2 diabetes mellitus. Am J Clin
Nutr 2004;80:887-95][5] Eyjolfson V, et al. Conjugated linoleic acid improves insulin
sensitivity in young, sedentary humans. Med Sci Sports Exerc 2004;36:814?20 [6] Clement
L et al, Ecole Nationale Superieure de Biologie Appliquee a la Nutrition et a l'Alimentation,
France, J Lipid Res. 2002 Sep;43(9):1400-9.][7] Poirier H et al, University of Burgundy,
France, Hyperinsulinaemia triggered by dietary conjugated linoleic acid is associated with
a decrease in leptin and adiponectin plasma levels and pancreatic beta cell hyperplasia in
the mouse. Diabetologia. 2005 May 3; 2005.[8] Kim HK et al, Korea Food Research
Institute, Dietary conjugated linoleic acid reduces lipid peroxidation by increasing
oxidative stability in rats. J Nutr Sci Vitaminol (Tokyo). 2005 Feb;51(1):8-15. [9] Mitchell PL
et al, Dalhousie University, Canada, Effect of conjugated linoleic acid CLA isomers on
lipoproteins and atherosclerosis in the Syrian Golden hamster. Biochim Biophys Acta.
2005 May 23 2005. [10] Cesano A et al. Opposite effects of linoleic acid and conjugated
linoleic acid on human prostatic cancer in SCID mice. Anticancer Res 1998;18:1429-34.
[11] Thompson H et al. Morphological and biochemical status of the mammary gland as
influenced by conjugated linoleic acid: implication for a reduction in mammary cancer
risk. Cancer Res 1997;57:5067-72.[12] Ip C. Review of the effects of trans fatty acids, oleic
acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary
carcinogenesis in animals. Am J Clin Nutr 1997;66(suppl):1523S-29S [review]. [13] Parodi
PW. Cows? milk fat components as potential anticarcinogenic agents. J Nutr
1997;127:1055-60 [review].[14] Miglietta A University of Torino, Italy, Conjugated linoleic
acid induces apoptosis in MDA-MB-231 breast cancer cells through ERK/MAPK signalling
and mitochondrial pathway. Cancer Lett. 2005 May 7; 2005][15] Lim DY et al, Hallym
University. Korea, Inhibition of colon cancer cell proliferation by the dietary compound
conjugated linoleic acid is mediated by the CDK inhibitor p21(CIP1/WAF1). J Cell Physiol.
2005 May 5; 2005 [15] Pal S et al, Curtin University of Technology, Australia, Conjugated
linoleic acid suppresses the secretion of atherogenic lipoproteins from human HepG2
liver cells. Clin Chem Lab Med. 2005;43(3):269-74. [16] Nicolosi RJ, et al. Dietary
conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in
hypercholesterolemic hamsters. Artery 1997;22:266-77. [17] Lee KN, et al. Conjugated
linoleic acid and atherosclerosis in rabbits. Atherosclerosis 1994;108:19-25. [15] Lai C et
al, China Agricultural University, Effects of dietary conjugated linoleic acid
supplementation on performance and immune function of weaned pigs. Arch Anim Nutr.
2005 Feb;59(1):41-51. [16] Houseknecht KL et al. Dietary conjugated linoleic acid
normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochem
Biophys Res Commun 1998;244:678-82] [17]Zheng HC et al, Zhejiang University, China,
Effects of dietary sources of vegetable oils on performance of high-yielding lactating cows
and conjugated linoleic acids in milk. J Dairy Sci. 2005 Jun;88(6):2037-42.[17] Thom E,
Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat in healthy
exercising humans. J Int Med Res 2001;29:392-6] [18] Riserus U, Berglund L, Vessby B.
Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged
men with signs of the metabolic syndrome: a randomised controlled trial. Int J Obes
2001;25:1129-35]
geometric isomers of linoleic acid (LA, C18:2 cis-9, cis-12). From
a few recent research studies, conjugated linoleic acid (CLA) may
have a substantial impact in reducing body fat and increasing
muscle mass. Conjugated linoleic acid (CLA) may offer protection
against atherosclerosis and cancers. Probably, beause of these
multiple possible health benefits, conjugated linoleic acid (CLA)
has became one of the most popular sport supplements in the
market.
SOURCES OF CONJUGATED LINOLEIC ACID (CLA)
Conjugated linoleic acid (CLA) is found mainly in dairy products, beef,
poultry, eggs, and corn oil. Bacteria that live in the intestine of
humans can convert linoleic acid to conjugated linoleic acid (CLA). The
source of conjugated linoleic acid (CLA) for some supplements are
derived from safflower oil. Most brands of conjugated linoleic acid
(CLA) on the market today contain 70% conjugated linoleic acid (CLA);
with no trans-fats present.
SIDE EFFECTS of CONJUGATED LINOLEIC ACID (CLA)
Conjugated linoleic acid (CLA) is probably safe to healthy human
subjects. However, it may impose serious side effects to overweight
subjects.
OVERWEIGHT SUBJECTS Conjugated linoleic acid (CLA) may
increase the risk for heart disease. In a study, overweight volunteers
who took 4.5 grams of conjugated linoleic acid (CLA) daily for one
year had an increase in their blood levels of lipoprotein(a), a risk
factor for heart disease. [1] Conjugated linoleic acid (CLA) may also
reduce the insulin sensitivity for overweight men. A reduction in
insulin sensitivity was also observed in a study of overweight men
without diabetes after treatment with 3 grams of conjugated linoleic
acid CLA daily for three months. [2] Conjugated linoleic acid (CLA)
feeding was found to promote insulin resistance in obese/diabetic
mice by at least inverse regulation of leptin and adiponectin, and
TNFalpha, adipocytokines known to either ameliorate or deteriorate
insulin sensitivity, respectively. [3] In another study of people with
type 2 diabetes, supplementing with 3 grams of conjugated linoleic
acid (CLA) daily for eight weeks significantly increased blood glucose
levels by 6.3% and decreased insulin sensitivity. [4] However,
researchers also found that 4 grams of conjugated linoleic acid (CLA)
daily for eight weeks improved insulin sensitivity of young men. [5]
t10,c12-CLA-induced hyperinsulinemia may trigger liver steatosis
(fatty liver), by inducing both fatty acid uptake and lipogenesis. [6]
Conjugated linoleic acid CLA supplementation induces a profound
reduction of leptin, adiponectin and then excessive secretion of insulin
and hepativc lipid content in a study of mouse. These observations
cast doubt on the safety of dietary supplements containing CLA. [7]
CONJUGATED LINOLEIC ACID (CLA) BENEFITS
Various studies have demonstrated that conjugated linoliec acid
(CLA) is an antioxidant, and it has multiple health benefits on
various chronic diseases such as atherosclerosis and cancer.
BENEFITS ON CHOLESTEROL AND ATHEROSCLEROSIS
Conjugated linoleic acid CLA has antiatherosclerotic and antioxidant
activity by increasing oxidative stability in plasma and hepatic
membrane in the vitamin E-deficient rats [8] Individual conjugated
linoleic acid CLA isomers was shown to reduce atherosclerotic lesion
development in hamsters. [9]In a cell culture, conjugated linoleic acid
(CLA) reduces apoB100 production and secretion compared to
saturated and polyunsaturated fatty acids, possibly by limiting the
availability of free cholesterol (required for apoB100 production). A
reduction in apoB100 production in the body would decrease the
levels of VLDL and atherogenic LDL and thus reduce the risk of
developing cardiovascular disease. Some other studies in animals
also showed that conjugated linoleic acid (CLA) may reduce the risk of
atherosclerosis . [15-17]
BENEFITS ON CANCERS
Dietary conjugated linoleic acid CLA was shown to inhibit colon tumor
cell proliferation in vitro and in vivo via the CDK inhibitor
p21(CIP1/WAF1). [15] And, various basic research studies have
demonstrated that conjugated linoleic acid (CLA) might reduce the
risk of several types of cancers including breast, prostate, colorectal,
lung, skin, and stomach. [10-13] Scientists have also investigated on
howconjugated linoleic acid (CLA) inhibited cancer cell growth
extensively. Conjugated linoleic acid CLA may trigger apoptosis in the
estrogen unresponsive MDA-MB-231 human breast cancer cell line via
mechanisms involving above all the mitochondrial pathway. [14]
BENEFITS ON IMMUNE FUNCTIONS
Conjugated linoleic acid CLA improved performance, lymphocyte
proliferation, and increased the CD8+ lymphocyte population, while
reduced the production of PGE2 and interleukin-lbeta (IL- 1beta).
Supplementation of conjugated linoleic acid; CLA enhanced
lymphocyte proliferation function, possibly by regulating the PGE2
production, and improved growth performance of pigs. [15]
BENEFITS ON GLUCOSE TOLERANCE?
Animal research suggests an effect of conjugated linoleic acid (CLA)
supplementation on improving glucose tolerance. [16]
BENEFIT ON WEIGHT MANAGEMENT
There are a few studies showing that conjugated linoleic acid (CLA) is
effective on reduction of body fat. In a study, conjugated linoleic acid
(CLA) significantly reduced percent body fat, but did not significantly
reduce body weight [17] In another study, supplementation with 4.2
grams of conjugated linoleic acid (CLA); per day for four weeks
produced a reduction in waist size but not weight loss. [18]
CONJUGATED LINOLEIC ACID IN MILK
Supplementation of vegetable oils tended to improve milk production of lactating
cows, and the conjugated linoleic acid (CLA) content in milk fat was significantly
increased. Soybean oil seemed to be the optimal source to increase conjugated
linoleic acid (CLA) production. [17]
HOME
THIS CONJUGATED LINOLEIC ACID (CLA) ARTICLE IS FOR YOUR REFERNCE ONLY. IF YOU
HAVE ANY QUESTION ABOUT CONJUGATED LINOLEIC ACID (CLA) OR YOUR HEALTH ,
PLEASE, CONSULT WITH YOUR DOCTOR IMMEDIATELY. ALL RIGHTS RESERVED 2006
REFERENCE
[1] Gaullier JM et al. Conjugated linoleic acid supplementation for 1 y reduces body fat
mass in healthy overweight humans. Am J Clin Nutr 2004;79:1118?25.][2] Riserus U et al
Effects of cis-9,trans-11 conjugated linoleic acid supplementation on insulin sensitivity,
lipid peroxidation, and proinflammatory markers in obese men. Am J Clin Nutr
2004;80:279?83] [3] Ohashi A et al, Health Sciences University of Hokkaido, Conjugated
linoleic acid deteriorates insulin resistance in obese/diabetic mice in association with
decreased production of adiponectin and leptin. J Nutr Sci Vitaminol (Tokyo). 2004
Dec;50(6):416-21 [4]Moloney F, et al. Conjugated linoleic acid supplementation, insulin
sensitivity, and lipoprotein metabolism in patients with type 2 diabetes mellitus. Am J Clin
Nutr 2004;80:887-95][5] Eyjolfson V, et al. Conjugated linoleic acid improves insulin
sensitivity in young, sedentary humans. Med Sci Sports Exerc 2004;36:814?20 [6] Clement
L et al, Ecole Nationale Superieure de Biologie Appliquee a la Nutrition et a l'Alimentation,
France, J Lipid Res. 2002 Sep;43(9):1400-9.][7] Poirier H et al, University of Burgundy,
France, Hyperinsulinaemia triggered by dietary conjugated linoleic acid is associated with
a decrease in leptin and adiponectin plasma levels and pancreatic beta cell hyperplasia in
the mouse. Diabetologia. 2005 May 3; 2005.[8] Kim HK et al, Korea Food Research
Institute, Dietary conjugated linoleic acid reduces lipid peroxidation by increasing
oxidative stability in rats. J Nutr Sci Vitaminol (Tokyo). 2005 Feb;51(1):8-15. [9] Mitchell PL
et al, Dalhousie University, Canada, Effect of conjugated linoleic acid CLA isomers on
lipoproteins and atherosclerosis in the Syrian Golden hamster. Biochim Biophys Acta.
2005 May 23 2005. [10] Cesano A et al. Opposite effects of linoleic acid and conjugated
linoleic acid on human prostatic cancer in SCID mice. Anticancer Res 1998;18:1429-34.
[11] Thompson H et al. Morphological and biochemical status of the mammary gland as
influenced by conjugated linoleic acid: implication for a reduction in mammary cancer
risk. Cancer Res 1997;57:5067-72.[12] Ip C. Review of the effects of trans fatty acids, oleic
acid, n-3 polyunsaturated fatty acids, and conjugated linoleic acid on mammary
carcinogenesis in animals. Am J Clin Nutr 1997;66(suppl):1523S-29S [review]. [13] Parodi
PW. Cows? milk fat components as potential anticarcinogenic agents. J Nutr
1997;127:1055-60 [review].[14] Miglietta A University of Torino, Italy, Conjugated linoleic
acid induces apoptosis in MDA-MB-231 breast cancer cells through ERK/MAPK signalling
and mitochondrial pathway. Cancer Lett. 2005 May 7; 2005][15] Lim DY et al, Hallym
University. Korea, Inhibition of colon cancer cell proliferation by the dietary compound
conjugated linoleic acid is mediated by the CDK inhibitor p21(CIP1/WAF1). J Cell Physiol.
2005 May 5; 2005 [15] Pal S et al, Curtin University of Technology, Australia, Conjugated
linoleic acid suppresses the secretion of atherogenic lipoproteins from human HepG2
liver cells. Clin Chem Lab Med. 2005;43(3):269-74. [16] Nicolosi RJ, et al. Dietary
conjugated linoleic acid reduces plasma lipoproteins and early aortic atherosclerosis in
hypercholesterolemic hamsters. Artery 1997;22:266-77. [17] Lee KN, et al. Conjugated
linoleic acid and atherosclerosis in rabbits. Atherosclerosis 1994;108:19-25. [15] Lai C et
al, China Agricultural University, Effects of dietary conjugated linoleic acid
supplementation on performance and immune function of weaned pigs. Arch Anim Nutr.
2005 Feb;59(1):41-51. [16] Houseknecht KL et al. Dietary conjugated linoleic acid
normalizes impaired glucose tolerance in the Zucker diabetic fatty fa/fa rat. Biochem
Biophys Res Commun 1998;244:678-82] [17]Zheng HC et al, Zhejiang University, China,
Effects of dietary sources of vegetable oils on performance of high-yielding lactating cows
and conjugated linoleic acids in milk. J Dairy Sci. 2005 Jun;88(6):2037-42.[17] Thom E,
Wadstein J, Gudmundsen O. Conjugated linoleic acid reduces body fat in healthy
exercising humans. J Int Med Res 2001;29:392-6] [18] Riserus U, Berglund L, Vessby B.
Conjugated linoleic acid (CLA) reduced abdominal adipose tissue in obese middle-aged
men with signs of the metabolic syndrome: a randomised controlled trial. Int J Obes
2001;25:1129-35]
| Conjugated linoleic acid (CLA) has rapidly become one of the most talked about weight loss products since its introduction to the public in the late 90s. |
