Dairy nutrients and their effect on inflammatory profile in molecular studies

Dairy products contain milk fat, proteins, minerals, vitamin D, and other bioactive nutrients that have the potential to contribute to the association observed between increased dairy intake and a decreased risk of inflammation. The objective of this paper is to review the role of dairy bioactive molecules including dairy fat, proteins, micronutrients, and vitamins on inflammation markers in adipose, macrophage, and vascular tissues, which play a key role in the regulation of inflammation. A review was conducted to identify current scientific literature on dairy nutrients and inflammation in cell studies published until November 2014. The majority of saturated fatty acids (FAs) activate proinflammatory markers. Therefore, other dairy FAs or components may offset these harmful effects. Protein and amino acid composition of dairy products may have anti‐inflammatory action. Magnesium may have beneficial effects on inflammatory profile; on the contrary, studies on vitamin D demonstrate conflicting results. In conclusion, numerous studies assessed the effects of individual or mixtures of FAs on inflammatory markers; yet, there is far less research on the effects of other dairy bioactive nutrients. The exact bioactive molecule or combination of these molecules in dairy products, which underlies the inverse association between dairy intake and inflammation remains to be elucidated.     

Gene expression after dietary intervention with trans fatty acids (trans‐11/trans‐12 18:1) in humans

Gene‐by‐diet interactions play an important role in the prevention of several diseases. Conjugated linoleic acids (CLA) are ligands of gene regulators [e.g. peroxisome proliferator‐activated receptors (PPAR)] and have anti‐inflammatory properties. The aim of the study was to investigate the changes in gene expression in monocytes during the intervention with two trans fatty acids (trans‐11 18:1 and trans‐12 18:1) and endogenous CLA from trans‐11 18:1 as precursor in humans. Monocytes were isolated at baseline and after a 6‐week intervention period. The female and male test groups received Σ6.0 g trans‐11 and trans‐12 18:1/day (1 : 1). The control group received control oil. The expression of candidate genes was determined by quantitative RT‐PCR. Gender‐ and treatment‐related gene expression was found. Due to trans fatty acid intake in both gender subgroups, the relative PPARγ expression was up‐regulated. In the female test group, the expression of FAT, SCD, COX2 and BCL2 were induced, while in the male test group E‐FABP, CYP, GLUT4 and PBE were induced. In the male test group compared to controls, a clear increase in gene expression of PPARγ and GLUT4 was shown. The results reveal a gender‐ and treatment‐related gene expression. There is no clear indication as to what extent the supplemented trans fatty acids and the synthesized cis‐9,trans‐11 CLA were involved.