Table 4 Comparison of different types of FA influences on epigenetic mechanisms
From: Fatty acids, epigenetic mechanisms and chronic diseases: a systematic review
FA | Dose | Study model | Epigenetic mechanism | Epigenetic signature | Metabolic effect | Reference |
|---|---|---|---|---|---|---|
HUMANS | ||||||
Excessive SFA palmitic acid intake (+ 750 kcal/d) Excessive PUFA n-6 intake (+ 750 kcal/d) | High-caloric muffins that contained refined palm oil or refined sunflower oil for 7 wk | 17 subjects (adipose tissue) 14 subjects (adipose tissue) | DNA methylation | PUFA n-6 + SFA modify 4933 CpG sites (4795 hypermethylated and 138 hypomethylated) Expression changes in 1117 transcripts (776 up, 241 down regulated) 26 pathways up-regulated 3 pathways down-regulated | SFA and PUFA n-6 diets modify methylation patterns of genes related to adipose tissue accumulation, obesity, pathways related to cancer, cell cycle, FA uptake, transport, and lipid metabolism. | [45] |
Lower PUFA/SFA ratio and lower PUFA+MUFA/ SFA ratio | A higher unsaturated: saturated ratio considered ‘healthier’, and a lower unsaturated: saturated ratio considered ‘unhealthier‘ | 35 obese and 34 normal-weight preadolescents | DNA methylation | The methylation levels of 2 islands, 11 island shores, and 16 sites were correlated with PUFA/SFA; 9 islands, 26 island shores, and 158 sites for MUFA/SFA; 10 islands, 40 island shores, and 130 sites for (MUFA+PUFA)/SFA | A lower PUFA/SFA ratio was associated with adipogenesis and mechanisms regulated by PPARα, regulation of energy intake, inflammatory processes and obesity; a lower MUFA+PUFA vs SFA ratio was related to pathways linked to NF-kB (inflammation process) | [46] |
Fish oil (FO) and Sunflower oil (SO) | 3.8 g/day of fish oil (FO) or sunflower oil (SO) for 9 months | 12 (9-months-old) infants | DNA methylation | Change in the methylation profile (> 10%) of 43 CpG | FO supplementation was associated with higher amounts of n-3, EPA, and DHA and lower levels of n-6 and AA in RBC, improved arterial pressure and a tendency to lower levels of IL-6. | [47] |
PUFA (EPA) MUFA (palmitoleic acid) SFA (palmitic acid) | A single Western diet (post-prandial) or no meal (fasting samples). | 49 lactating infants and 12 adult males | DNA methylation Histone deacetylation | Global DNA methylation was higher in PUFA than in MUFA and SFAs. | SFA were associated with obesity (BMI), lipid metabolism, and glucose disbalance, whereas PUFA (EPA) were related to normal weight, and MUFA with insulin sensitivity. | [48] |
ANIMAL AND IN VITRO MODELS | ||||||
PUFA Linoleic acid (olive oil) MUFA Oleic acid (sunflower oil) SFA palmitic acid (coconut oil) | 10% fat of different oils | 24 rats/3 T3-L1 cells | DNA methylation | Hypomethylation in Tnf promoter in SFA vs PUFA and MUFA | SFA was associated with inflammation (TNF-α elevation), adiposity and obesity, whereas PUFA and MUFA did not induce changes in TNF-α | [49] |
PUFA Linoleic n-6 (sunflower oil) MUFA oleic FA (olive oil) SFA palmitic FA (coconut oil) | 10% fat of the different oils | Rats / 3 T3-L1 cells. | DNA methylation | Lower methylation levels of Vegfb promoter in rats that were fed with coconut oil vs olive and sunflower oil | SFA was related to higher levels of Vegfb, involved in insulin resistance, lipid distribution and lipid metabolism in type 2 diabetes vs MUFA and PUFA | [50] |
High fat butter (SFA) Fish oil (FO) (n-3 PUFA) | Rats received 3.5, 7% or 21% butter or fish oil (FO) from 14 days preconception until weaning | 6 rats per group offspring | DNA methylation | Methylation of CpG (− 623,− 394, −84 and − 76) of Fads2 was higher in the offspring of dams fed 21% than 3.5% or 7% fat; FO higher than butter. | SFA was associated with fat accumulation in liver, dysregulation of vascular tone vs n-3 PUFA. Epigenetic regulation of Fads2 may contribute to the regulation of PUFA synthesis. | [51] |
Olive oil (OO) Fish oil (FO) Linseed oil (LO) Palm oil (PO) | 80–90 mg/day from conception to day 12 of gestation | Pregnant rats and their offspring | miRNAs | Pregnant rats fed SO and FO diets showed a significant lower expression of miR-449c-5p, miR-134–5p, miR-188, miR-32, miR130a, miR-144–3p, miR-431, miR-142–5p, miR-33, miR-340–5p, miR-301a, miR-30a, miR-106b, and miR-136–5p, as compared with OO, LO, and PO diets in liver and adipose tissue. | Adipose tissue mass was lower in the FO group compared with other groups, except with LO group. Decreased expression of miRNAs related to insulin and glucose metabolism compared with PO and OO No differences in miRNA expression between FO and LO | [52] |