Table 1 Effects of unsaturated fatty acids on metabolic outcomes through epigenetic mechanisms

 PUFA

n-3 supplementation

3 g n-3 6-weeks

36 overweight and obese subjects

DNA methylation

286 CpG (93%)

22 CpG (7%)

+

-

Improvement of inflammatory and immune responses, lipid metabolism, cardiovascular signaling, and diabetes pathways, reduction of plasma triglyceride and glucose levels, improved total cholesterol/HDL-cholesterol ratio.

[16]

 n-3 intake

93 subjects were in the lowest 3 deciles of PUFA intake and 92 were in the top 3 deciles

185 Yupik/ Alaskan native subjects

DNA methylation

21 CpG

6 CpG

+

-

Improvement of lipid metabolism, insulin sensitivity, glucose tolerance and oxidative stress.

[17]

 n-3 supplementation

MedDiet+ OOEV or MedDiet+ nuts

12 subjects of each study group

DNA methylation

With MedDiet + nuts CPT1B/CHKB-CPT1B

With MedDiet + OOEV

GNASAS GNAS

+

-

Benefits in health associated with changes in genes related to intermediate metabolism, diabetes, and anti-inflammatory state.

[18]

 n-3 supplementation

6 capsules/ per day n-3 8-weeks

7 overweight and obese women

5 control group

DNA methylation

CD14, PDK4 and FADS1

PDK4 (− 229–227)

CD36

FFAR3 CpG (−18, + 33, and + 77)

FFAR3 CpG (− 53 and − 202)

-

+

+

+

Lipid metabolism, improvement of glucose tolerance and diabetes.

[19]

 n-6 intake

40 normal-weight women

DNA methylation

TNF CpG13 and CpG19 (+ 207 + 317pb)

+

Associated with truncal fat, lipid alterations, TNF-α pathway and inflammation process.

[20]

 DHA supplementation

400 mg of DHA/day gestation week 18–22 to parturition.

131 pregnant women

DNA methylation

IGF2 P3

IGF2 DMR

H19 DMR

-

+

+

Favors expression of genes involved in growth and development. Decreases the risk to develop obesity (BMI) in infants.

[21]

 DHA supplementation

800 mg DHA/day

20 weeks gestation to parturition.

517 pregnant women

DNA methylation

21 DMR

Favors appetite regulation and immune response in infants.

[22]

 n-3 supplementation

n-3 1 g/Kg body weight every

day for 12 weeks

30 Rats

DNA methylation

% 5mC

+

Anti-colorectal cancer effect.

[23]

 n-3 supplementation

34.9% weight as fat, 60% kcal was fish oil for 14 weeks

12 Rats

DNA methylation, Histone methylation and acetylation

NE on methylation

Histone H3

++

Ameliorates leptin resistance, decreases accumulation of adipose tissue, regulating food intake and energy expenditure.

[24]

 n-3 supplementation

EPA and DHA 0.5% Gromega, pregnant pigs (150 days) and their offspring (lactation 21 days and nursery 56 days)

5 Pigs

DNA methylation and miRNAs

Chromosome 4 DMR

Intragenic region chromosome 4 and 12

-

+

Improvement of immune response, inflammation, glucose uptake, apoptosis, endoplasmic reticulum stress, insulin resistance, lipid metabolism and oxidative stress.

[25]

 n-6 AA

1 μM

10 μM and 100 μM

Human THP-1 monocytes

DNA methylation

Dose-dependent DNA methylation

A 10.5% increase in 5mC content at 100 mM compared to 1 μM dose

+

Associated with atherosclerosis, diabetes, inflammatory profile, obesity and cancer

[26]

 AA

3 μM

Human umbilical vein endothelial cells (HUVECs) and endothelial progenitors (EPCs)

DNA methylation

Promoter region of genes KDR and Notch4

–

Associated with changes in expression of genes implicated in carcinogenesis and angiogenesis.

[9]

 Oleic acid

1 μM

10 μM and 100 μM

In vitro human THP-1 monocytes

DNA methylation

Global hypomethylation at 100 μM compared to the 1 μM dose

–

Anti-inflammatory effects.

[26]

 Oleic acid

1–200 μM range

20 pregnancy mice and THP-1 cells

DNA methylation

1–50 μM but in 5 μM weaker response peaking

+

Improvement of proinflammatory profile and adipogenesis

[27]