Conjugated linoleic acid: A potent fatty acid linked to animal and human health

Abstract

Conjugated linoleic acid (CLA) is a mixture of isomers of linoleic acid (C18:2 n-6), which is mostly found in the ruminant meat and dairy products. The CLA is known to have many potential health benefits, and considered a potent powerful fatty acid, which is linked to animal and human health. The present work aims to discuss the source and production, mechanism of action, and effects of CLA on humans, poultry, and ruminants by reviewing the recent studies carried out on CLA. Despite most of the recent studies indicating beneficial effects of CLA on improving body weight control parameters, its effects on reducing risk factors of cardiovascular diseases (CVD), inflammation, blood glucose, and insulin are still controversial, and need to be further studied in different hosts.

Serum Conjugated Linoleic Acid and Risk of Incident Heart Failure in Older Men: The British Regional Heart Study

“…We have observed a positive association between CLA% and blood pressure, in contrast to studies suggesting that CLA supplementation may decrease blood pressure . However, CLA% was associated with lower levels of CRP, consistent with clinical and dietary intervention studies suggesting an anti‐inflammatory effect of CLA . Other studies, however, have reported no association or positive associations between CLA and inflammation .…”

“…CLA is produced naturally in ruminant animals, such as cows, sheep, and goats. Dairy products are a primary source of cis ‐9, trans ‐11‐CLA (c9,t11‐CLA), the most prevalent CLA isomer, in the diet of humans . Epidemiological studies have shown a strong positive association between the intake of TFAs and coronary heart disease (CHD) .…”

“…Epidemiological studies have shown a strong positive association between the intake of TFAs and coronary heart disease (CHD) . However, evidence largely based on animal models has paradoxically shown CLA to have antiatherosclerotic, antidiabetic, anti‐inflammatory, and immune‐modulating properties . In vitro and in vivo studies in rats have also shown CLA to suppress cardiac hypertrophy, a major risk factor for heart failure (HF) .…”

“…In vitro and in vivo studies in rats have also shown CLA to suppress cardiac hypertrophy, a major risk factor for heart failure (HF) . CLA has gained an increasing amount of attention in the past decade because of its potential health benefit and in the potential for naturally increasing the isomer c9,t11‐CLA content of milk and dairy products . However, in human studies, evidence on the antiatherosclerotic effects of CLA remains contradictory .…”

‘Browning’ the cardiac and peri-vascular adipose tissues to modulate cardiovascular risk

“…Animal and, to a lesser extent, human studies have shown promising results for CLA supplementation in the prevention of atherosclerotic plaque development and improvements in lipid profile [147], [148]. There have also been several studies suggesting that CLA supplementation in humans can favourably alter body composition, by reducing body fat percentage [149], [150], [151], however, other studies have not observed this [152], [153].…”