As reported by our European edition recently, the European Food Safety Authority (EFSA) rejected a weight management claim submitted jointly by BASF and Stepan Lipid Nutrition for the ingredient, citing concerns that it may increase markers of inflammation, together with limited data available on the effects of CLA on vascular function.
Mark Cook, Professor from the University of Wisconsin-Madison and long-term researcher of conjugated linoleic acid (CLA), told us that he has no concerns about the safety of CLA.
“Would I take CLA? I have been since 1994, as have many of my science colleagues and family members,” said Dr Cook. “They take it not because of my recommendations, but because the overwhelming science showing health benefits and they are probably not getting levels from natural sources.”
Falling intakes
CLA is a fatty acid naturally present in ruminant meat and dairy products. Due to changes in the Western diet, average intake of CLA has fallen; if the fat is removed from a dairy product to make a low fat version that will be acceptable to consumers, CLA is removed along with it.
The ingredient has been in supplements for a number of years, and it received GRAS (Generally Recognized as Safe) status in 2008 for use in food and beverages in the US.
‘The safety and efficacy of CLA have already been established globally’
Joseph Moritz, PhD, scientific marketing manager for BASF Nutrition & Health, North America, added that the most recent EFSA opinion contradicts two previous evaluations of safety of the ingredient by the same agency, which concluded CLA is safe to take up to 6 months.
“It's yesterday's news when it comes to the proven safety and efficacy of CLA,” said Dr Moritz. “The safety and efficacy of CLA have already been established by global regulatory authorities including EFSA (in 2010 and 2012), the FDA (2009), Health Canada (2010), and The Ministry of Health of the People's Republic of China (2009).”
“On vascular function: recent studies of CLA show beneficial effects on vascular function, or lack of effect (Pfeuffer et al. 2011, and Herrera et al. 2005). We know that CLA can decrease the release of pro-inflammatory signals in vascular cells as well (Ringseis et al. 2006).”
Regarding the one study EFSA cited (Taylor et al. 2006) which showed negative effects on arm flow mediated dilatation, Dr Moritz questioned the integrity of the measurements, noting that patients lost fat under the arm skin during the study, which could have created “difficulties” taking accurate measures.
‘Frustration’
Dr Cook called EFSA’s decision “frustrating”, claiming the agency, “declined to evaluate the science behind CLA body fat reduction.
“Their opinion that CLA may result in increased inflammation markers contradicts the science supporting the biological activities of CLA.
“Research shows that CLA is a very potent anti-inflammatory agent. EFSA seems to rely on increase in F2 isoprostanes alone in their conclusion that CLA results in increase of lipid peroxidation and inflammation, however it is known that CLA impairs the breakdown of F2 isoprostanes and the finding is not corroborated by other markers of inflammation or lipid peroxidation (Iannone et al. 2008).
“Functional impairment of blood vessels is only shown in one study which may have some measurement complications, and other studies disagree (Pfeuffer et al. 2011, and Herrera et al. 2005).”
Dr Cook also questioned the logic of the EFSA opinion specific to how the data was analyzed. “For example, EFSA has not published objections to linoleic acid as part of the food supply (linoleic acid is the major fat in corn and soy oil),” he said. “Linoleic acid shows pro-inflammatory activity while CLA is the opposite.”
Inflammation
EFSA’s concerns over CLA are ironic, given that “exciting new research” supports a potential anti-inflammatory action of CLA in conditions such as obesity, arthritis, allergy and asthma, as well as in protection against vascular disease. “Comments to the contrary suggest a very limited analysis of the scientific literature,” said Dr Cook.
“The totality of evidence proves that CLA effectively reduces body fat and maintains muscle,” he added. “Now, we have exciting evidence showing that CLA plays an important role in attenuating inflammatory disease, improving immune responses, and protecting against cardiovascular disease.”
Despite the negative news from Europe, BASF’s Dr Moritz predicted a bright future for the company’s Tonalin branded CLA in 2015. “In addition to dietary supplements, Tonalin is widely used for broad applications including milk, yogurt, and juice,” he said. “We're finding that our customers are especially interested in innovative delivery forms such as easy-to-drink shots and meal replacement beverages fortified with CLA.”