For instance, the CLA content could be enhanced up to 2. Naturally CLA-enriched in situ dairy products such as butter, cheese, etc. Overweight or obesity - one of the typical syndromes of lifestyle diseases - is referred to as the excessive fat accumulation that impacts health.
The occurrence of overweight and obesity has been augmented as the most common health issue of modern food style. Obesity is considered as a cause for many health problems such as heart diseases, infertility and insulin resistance [ 35 ]. With a view to lose weight and improve the body composition i. Among them, CLAs draw more attention, since many pre-clinical studies in animal models proved its inverse relationship with obesity.
The significant clinical studies investigating the effect of CLA on body composition and their intervention strategies are shown in Table 2. In clinical studies, several methods or techniques were applied to measure the body composition. The simplest method is that, to measure the thickness of subcutaneous fat in multiple places on the body such as abdominal area, arms, sub-scapular region large triangular muscle near shoulder bone , buttocks and thighs [ 25 , 51 , 52 ].
Other commonly used measures are bioelectrical impedance analysis [ 39 ], hydrodensitometry and dual-energy X-ray absorptiometry DEXA [ 53 — 55 ]. In fact, DEXA measures total body composition and fat content with a high degree of accuracy and is considered as the gold standard for measuring the body composition, since one can get an image of the entire body [ 56 ].
Another commonly used method is the measurement of body mass index, i. In fact, BMI is not necessarily a good measure, especially in terms of body composition; for instance, individuals like athletes with strong bone and greater muscle lean mass have a higher BMI than non-athletes, and hence different BMI classifications of overweight is warranted while assessing obesity in terms of body girth [ 58 ]. Some of the clinical studies suggested a positive association of the intake of 3.
In another study, supplementation of 4. In a different study comprising 60 overweight or obese volunteers including men and women who received 3. Steck et al. They concluded that lean body mass LBM increased by the higher dose after 12 wk of intervention. Supplementation of 9- and CLAs at a dosage of 1. Interestingly, CLA was found to be effective in reducing the weight gain associated with psychiatric medications - one of the major side effects in psychological treatments.
Consumption of CLA at a dosage of 3. A possible explanation for this effect is that green tea extract high in pigallocatechin-gallate can directly inhibit gastric and pancreatic lipases, thereby increasing the thermogenesis and possibly prevent the enzymatic degradation of catechol O-methyltransferase, an enzyme which plays a role in the respiration rate of brown adipose tissue [ 62 ].
Due to overeating and sedentary life, the incidence of weight gain during holiday season i. For instance, supplementation of CLA 3. On the contrary, an inverse relationship between CLA and body composition has been demonstrated. One of the first studies demonstrating negative effects of CLA was performed with 71 subjects including obese men and women of 20 to 50 yr of age. Body was measured by hydrodensitometry, but the results did not show any effect on body composition [ 64 ].
In sedentary young women, intake of 2. Likewise, consumption of 4. Some of the studies observed gender specific effects of CLA intake. Riserus et al. The small sample size and short duration were the major limitations of this study; thus, the effects of CLA in abdominal obesity need to be investigated further in larger studies with longer duration.
Long-term 1 yr supplementation daily dose of CLA was 3. In this double-blind placebo-controlled study, female and male 31 volunteers with BMI of 25—30 were included. In a bicentric study conducted simultaneously at Clermont-Ferrand, France and Maastricht, The Netherlands , eighty-one middle-aged, overweight, healthy men and women were enrolled, and all subjects consumed a drinkable dairy product containing 3 g of high OA sunflower oil daily for 6 wk, the run-in period [ 46 ].
Volunteers were then randomized over five groups receiving daily either 3 g of high OA sunflower oil, 1. Dietary intake was also recorded. It was concluded that, a daily consumption of a drinkable dairy product containing up to 3 g of CLA isomers for 18 wk had no significant effect on body composition in overweight, middle-aged men and women [ 46 ]. A study from Greece reported that CLA administered first at 0. Raff et al. This study gained more importance, as it was reported in children aged between 6 and 10 yr, who were overweight or obese, but otherwise healthy [ 67 ] ].
This report also indicates that CLA per se was less efficient to improve BFM; for instance, a recent non cross-over clinical study conducted on 66 non-trained healthy male students for 2 month showed that CLA supplementation had no effect on LBM, BFM, trunk and visceral fats, and waist circumference [ 69 ]. Some clinical studies suggested that administration of CLA might be the most effective strategy in controlling regionalized reduction of fat mass rather than its constitutional reduction, i.
For instance, administration of 3. Waist-to-hip ratio also decreased significantly in healthy, overweight and obese men, compared with placebo group. Interestingly, these effects were produced independent of diet and specific lifestyle. Exercising individuals often add nutritional supplements to their diet to accelerate the increase in muscle mass and strength from heavy resistance-exercise training. Some short- and long-term studies employing high doses of CLA in healthy and obese, sedentary and exercised adults have shown beneficial effects of CLA in reducing fat mass and increasing LBM.
A daily supplementation of 1. In this study, physical exercise was standardized as 90 min in gym, three times a wk; and concluded that CLA reduces the deposition of fat. These results seem to be encouraging, because much lower dose of CLA produced the expected results - when compared to other studies - wherein comparatively 2 to 4 folds higher concentrations of CLA were used. Effect of CLA Clarinol A supplementation in conjunction with 6 wk of aerobic exercise training on 33 untrained to moderately trained men average age CLA showed no ergogenic benefits on neuromuscular fatigue, and field tests of muscular endurance and power.
This combined strategy showed that supervised resistance exercise training is safe and effective for increasing strength in older adults, because aging is associated with lower muscle mass and an increase in body fat.
Similarly, in another double blind and placebo controlled resistance-training study, no decrease in visceral adipose tissue was observed; however a significant reduction in the cross-sectional area of visceral adipose tissue was noticed in the placebo group [ 22 ]. In this study, 30 overweight and moderately obese, but otherwise healthy middle-aged 35 to 55 yr male subjects received 3.
Pinkoski et al. Thus, some of the studies showed the effectiveness of CLA in fat mass reduction in subjects during resistance-training program. Contrary to this, no CLA-specific effects were observed on body composition, energy expenditure or appetite in non-obese, regularly exercising individuals comprising 25 men and 27 women , who received either 3.
It suggests that CLA supplementation may promote testosterone synthesis through a molecular pathway that should be investigated in detail. Furthermore, this study becomes much relevant, since the correlation between the production of testosterone and body building still remains a controversy. Based upon this background, a few clinical investigations were made on the effect of CLA on fat-mass regain after weight loss - with an assumption that CLA could block body fat gain.
To check this, overweight adults were administered a very low-calorie diet for 3 wk, followed by CLA supplementation at a dosage of either 1. Subjects took CLA in either dose showed increased regain of fat-free mass and resting metabolic rate, thereby lowering the regain of body fat relative to the control subjects.
Interestingly, they concluded in later findings that the measures of appetite hunger, satiety and fullness favorably and dose-independently affected by the same dose of CLA but had no effect on energy intake at breakfast or improved body-weight maintenance after weight loss [ 76 ]. Apart from a few studies that investigated the effects of CLA supplementation in humans, there were some experiments designed to supplement CLA-enriched dairy products.
Consumption of dairy products such as ultra-heat treated milk, butter, and cheese enriched with 1. Another experiment compared the effects of the consumption of a modified butter, naturally enriched with CLA 4. Consumption of a drinkable dairy product containing up to 3 g of CLA isomer for 18 wk did not result in any significant effect on body composition in overweight, middle-aged men and women [ 46 ]. Venkatramanan et al. More precisely, consumption of CLA-enriched milks in either form failed to alter TAG concentrations in the blood; body weight or fat composition [ 51 ].
Thus, in general, dairy products enriched with either of 9- or CLA isomers or its mixture failed to establish a consistent effect on body composition. The question of inconclusive results on efficacy and effectiveness of CLA on body composition and obesity may answer from long-term intervention studies. Effects of any dietary supplement or food ingredient on body composition should be assessed over an extended period of time to conclude the results, because crash diet procedures seem inappropriate.
In most of the studies, the intervention period lasted only for a few wk, and long-term studies were very few. In a study, subjects including men and women were supplemented with 3.
During the first 12 month, significant reduction in BFM and leptin levels was reported. These changes in body composition were not related to diet and exercise. These studies seem to be important as most of weight loss studies in overweight and obese subjects have demonstrated that most subjects will regain the lost weight within the next 1 to 2 yr [ 43 , 80 ].
Gaullier et al. Energy expenditure, substrate utilization and dietary fat oxidation were measured before and after 6 month of CLA supplementation, which showed that fat oxidation and energy expenditure increased during sleep in subjects received CLA, in comparison to placebo [ 81 ].
Supplementation of CLA 6. Such long-term studies have to be conducted in a cross-over design by including men and women of different age groups to generalize the beneficial effects of CLA. However, all of them failed to reproduce the dramatic results reported in animal and in vitro models, especially mice. The extensive controversies in clinical studies limit from proposing a definite statement regarding the beneficial effects of CLA on body composition, so as to address the increasing concerns of health professionals, body builders and athletes.
Hyper-triacylglycerolemia and elevated plasma cholesterol are suggested as the major risk factors for atherosclerosis and cardio-vascular diseases CVD , and that blood lipid profile, blood pressure, BMI and blood sugar are generally considered as the indicators of heart health. The lipid profile is a panel of blood tests performed on the patient to determine the risk of CVD.
These tests are good indicators of whether someone is likely to have a heart attack or stroke caused by blockage of blood vessels or hardening of the arteries atherosclerosis. The lipid profile typically includes the baseline measurements of total cholesterol; high density lipoprotein cholesterol HDL-C , often called good cholesterol; low density lipoprotein cholesterol LDL-C , called bad cholesterol; and TAG in plasma [ 82 ].
Normal cholesterol levels vary by age and sex. LDL-C is the major cholesterol carrier in the blood, and if too much it is in circulation, it can slowly build up in the walls of the arteries of heart and brain leading to arteriosclerotic vascular diseases.
Variations in the concentration of these markers in blood plasma from the normal level indicate dysfunctions of human system. The major circulatory markers associated with heart health and their normal levels in blood are listed in Table 3.
Some animal studies suggest the health benefits anti-CVD effects of CLA such as anti-sclerotic and improvements in blood lipid profile, hypolipidaemic and anti-oxidative effects [ 84 — 86 ].
Two different isomers of CLA i. Epidemiological studies showed that plasma HDL-C concentrations have an inverse relationship with the risk of CVD, and it is anticipated that raising plasma HDL-C levels might protect against atherosclerosis [ 83 ]. Supposed effects of CLA supplementation on blood lipid profile also remains inconclusive.
Similarly, a dose of 0. In this study, 22 volunteers were enrolled and they were divided into study and control groups in a doubly blind design; the study group received 0. Diet was controlled, and no significant differences in energy or macronutrient intake were found between the two groups. A significant reduction of HDL-C was observed when 6. But 2. In this non cross-over double-blind, placebo-controlled and randomized study, 51 normolipidaemic subjects were enrolled.
These results further suggested that CLA supplementation significantly improved the lipid profile in human subjects without any adverse effects on body weight, plasma glucose and insulin concentrations; and thus indicates the supposed cardio-protective effects of CLA.
Contrary to this, the opposing effects 9- and CLAs were observed by Tricon et al. But, later, the same group showed that dairy products enriched with 9-CLA 1. Some studies observed neither a beneficial nor an adverse effect of an isomeric blend of 9- and CLA in a ratio other than A 93 d long study in 17 healthy female volunteers to observe the effect of dietary CLA on blood lipids, lipoproteins, and tissue FA composition showed that daily supplementation of 3.
Furthermore, no adverse effect of CLA supplementation was reported in this study, though plasma concentration of CLA was increased during the intervention period, i. Some studies investigated the effect of dairy products on lipid profile. However, human studies with the supplementation of CLA-enriched dairy products in situ enrichment produced contradictory results. Intake of 1. However, levels of CLA and VA in human milk can be modulated if breastfeeding mothers replace conventional dairy and meat products with organic dairy products enriched by natural feeding [ 95 ].
Recently, Penedo et al. Furthermore, sheep cheese naturally enriched in VA, CLA and ALA improved the lipid profile and reduced anandamide an endogenous cannabinoid neurotransmitter and obesity marker in adults with diagnosed mildly hypercholesterolaemia [ 97 ]. CRP is synthesized by liver in response to inflammation. Inflammations may be due to a variety of reasons such as cancer, diabetes, cardiovascular diseases, etc.
A mixture of 9- and CLA isomers with equal proportions also reported an increased CRP, but not of the other inflammatory markers, i. Another study concluded that a mixture of 9- and CLAs had more adverse effects on CVD markers, while 9-CLA isomer appeared to be more neutral in healthy postmenopausal women. Daily supplementation of 5. The CLA mixture at a dose of 3. High dose of CLA consumption 6. In contrast, CLA in the same composition ratio , but in lower dose i.
Pfeuffer et al. It was observed that CLA did not impair endothelial function. Other parameters associated with metabolic syndrome and oxidative stress were not changed or slightly improved. Forty eight healthy primigravidas with a family history of preeclampsia and with diastolic notch were included in this double-blind and placebo-controlled non cross-over study.
Participants were randomized to daily oral doses of elemental calcium 0. The controversial beneficial and detrimental effects of CLA on heart health observed during clinical studied are summarized in Figure 2. All these studies were too randomized in dosage, composition and duration, which make difficult to conclude the positive effects of CLA on heart health.
Moreover, there is a complete lack of uniformity in assessing the effects CLA on heart health, i. Even though the isomeric mixture of 9- and 10 CLA was found to exert some positive effects, it is necessary to elucidate the mechanism of action to ascertain which of these isomers elicited the effect. Different studies show that the effects of dietary CLA on immune functions in animal as well as human models are highly variable and inconsistent Table 4.
For instance, a 93 d long study in 17 young women upon feeding with 3. Even after immunization with influenza vaccine, the delayed type hypersensitivity response and serum antibody titers were not altered during the intervention period. These data suggest that short-term CLA supplementation in healthy volunteers was safe, but it showed no added benefit to their immune status [ ]. Moreover, short-term consumption of CLA produced no observable physiological change in blood coagulation and platelet function in healthy adult females [ 23 ].
You may also benefit from starting slow and working your way up to a higher dose. Most people see the best results from CLA supplementation when they take it with food. Taking it during or right before a meal can help the body to better utilize the CLA.
It ought to contain at least 3,mg of CLA per serving. Do they test their supplements for purity and efficacy? Do they have a reputation for creating safe, high-quality products? Most people do not experience any negative side effects when they take CLA. In rare cases, they may experience symptoms like nausea, headaches, or fatigue. As you can see, there are plenty of benefits to CLA supplementation, especially for those looking to lose weight and give their metabolism a boost.
Now that you understand the ins and outs of CLA, are you interested in incorporating it into your supplement stack? If so, ProSupps offers lots of supplements that contain this essential fatty acid.
Posted in Perform and Lean. Allow Cookies. Train Gain Lean Perform. Advanced Search. What Is CLA? The following are some of the most promising results experts have seen from their studies thus far: Increased Fat Loss Perhaps the most well-known and greatest benefit CLA has to offer is increased fat loss.
Better Blood Sugar Control Some research shows that higher CLA levels in the body have been linked to a reduced risk of type 2 diabetes. Increased Bone Strength Gym-goers and athletes think a lot about strengthening their muscles. Keep the following guidelines on dosing and timing in mind when you start taking CLA to avoid negative effects and notice improvements sooner: Dosage Most studies show that a minimum of 3 grams or 3,mg of CLA per day is needed to see fat loss and other benefits.
There's simply not enough proof that taking a CLA supplement like Tonalin will benefit your health or your physique. It's possible, however, that researchers are missing something. If you're interested in trying it out yourself, you can safely take CLA. It's generally recommended that you take 3, to 6, milligrams daily, according to Examine. Tonalin CLA is one of the most popular forms, since it's cheaper to extract the fatty acid from safflower than from beef or dairy.
Nutrition Nutrition Basics Vitamins and Supplements. Janet Renee has over a decade of experience as a registered dietitian. Renee attended the University of California, Berkeley and holds an M. Henry is a freelance writer and personal trainer living in New York City.
You can find out more about him by visiting his website: henryhalse. Conjugated linoleic acid, or CLA, promises to help you burn fat, but there is no research to back this up. Another study looked at the impact of long-term two year supplementation of 3. This is important, because the year after initial weight loss is typically the most common time for regaining lost fat. Key takeaway : These studies provide evidence of modest body fat loss from CLA supplements. Taking CLA supplements has a beneficial impact on body fat loss in the first year, and continuing to take the supplements keeps the fat off in the following years.
Taking a CLA supplement can be beneficial for your metabolism , weight loss, and fat loss. However, these changes are very small, and perhaps not meaningful in a real-world context.
Therefore, if taken, CLA supplements must be just that—a supplement to a healthy lifestyle with proper nutrition and exercise. They will not undo the effects of an unhealthy lifestyle. You have high cholesterol. Because CLA is a fat, the impact of the supplement on cholesterol levels must be cautioned.
0コメント