Conjugated linoleic acids as functional food: an insight into their health benefits

Abstract

This review evaluates the health benefits of the functional food, conjugated linoleic acids (CLA) -a heterogeneous group of positional and geometric isomers of linoleic acid predominantly found in milk, milk products, meat and meat products of ruminants. During the past couple of decades, hundreds of reports -principally based on in vitro, microbial, animal, and of late clinical trials on humans -have been accumulating with varying biological activities of CLA isomers. These studies highlight that CLA, apart form the classical nuclear transcription factors-mediated mechanism of action, appear to exhibit a number of inter-dependent molecular signalling pathways accounting for their reported health benefits. Such benefits relate to anti-obesitic, anti-carcinogenic, antiatherogenic, anti-diabetagenic, immunomodulatory, apoptotic and osteosynthetic effects. On the other hand, negative effects of CLA have been reported such as fatty liver and spleen, induction of colon carcinogenesis and hyperproinsulinaemia. As far as human consumption is concerned, a definite conclusion for CLA safety has not been reached yet. Parameters such as administration of the type of CLA isomer and/or their combination with other polyunsaturated fatty acids, mode of administration (eg., as free fatty acid or its triglyceride form, liquid or solid), daily dose and duration of consumption, gender, age, or ethnic and geographical backgrounds remain to be determined. Yet, it appears from trials so far conducted that CLA are functional food having prevailing beneficial health effects for humans.

Dairy Propionibacteria: Less Conventional Probiotics to Improve the Human and Animal Health

“…Many health benefits have been attributed to consumption of CLA-containing foods such as anticarcinogenic, antiatherogenic, antidiabetogenic and antioxidative properties, immune system modulation and reduction of body fat gain [94]. CLA-isomers are formed by biohydrogenation of LA in the rumen and through conversion of vaccenic acid by Δ9-destaurase in the mammary gland so that ruminant meats and milk-derived products are main dietary sources of CLA.…”

Influence of α-tocopherol supplementation on trans-18:1 and conjugated linoleic acid profiles in beef from steers fed a barley-based diet

“…In humans, intake of dairy products enriched with t11-18:1 and cis(c)9, t11-18:2 (rumenic acid) also had limited effects on blood lipid profiles (Tricon et al, 2006;Sofi et al, 2010), however, some unhealthy changes were noted when relatively high levels were consumed (Chardigny et al, 2008). Vaccenic acid, however, may have other positive health influences either independently, or by desaturation to rumenic acid (Field et al, 2009;Wang et al, 2012), which has many potential health benefits mostly relating to its anticarcinogenic, immune modulatory and anti-inflammatory properties (Benjamin and Spener, 2009). Currently, nutritional strategies that substantially prevent the t10-18:1 shift (i.e.…”

In vitro study of dietary factors affecting the biohydrogenation shift from trans-11 to trans-10 fatty acids in the rumen of dairy cows

“…Conjugated linoleic acids (CLA) have a number of biological effects on animal models including anti-obesitic, anti-carcinogenic, antiatherogenic, anti-diabetagenic, immunomodulatory, apoptotic and osteosynthetic effects, and deserve interest as some of these properties have been evidenced in human subjects (Bhattacharya et al, 2006;Benjamin and Spener, 2009). Part of the effects of CLA are isomer-specific and some studies showed adverse effects of t10,c12-CLA (Bhattacharya et al, 2006;Ip et al, 2007).…”