Comment on: Efficacy of omega-3 fatty acid supplementation on serum levels of tumour necrosis factor-alpha, C-reactive protein and interleukin-2 in type 2 diabetes mellitus patients

I read with interest Malekshahi Moghadam et al’s article,⁽¹⁾ “Efficacy of omega-3 fatty acid supplementation on serum levels  of tumour necrosis factor-alpha, C-reactive protein and interleukin-2 in type 2 diabetes mellitus patients”, which showed that  omega-3 fatty acid supplementation can decrease the serum levels of tumour necrosis factor-alpha (TNF-α) and interleukin-2 in  type 2 diabetes mellitus patients. The authors recommended that diabetic patients take omega-3 fatty acid supplements on a daily basis.⁽¹⁾ It is important to mention in this context that single nucleotide polymorphisms (SNPs) modulate the ability of fish oil to decrease TNF-α production.

 

Approximately ten years ago, a study was conducted in which 111 healthy men were tested for polymorphisms in the TNF-α (TNF*1 and TNF*2) and lymphotoxin (LT)-α (TNFB*1 and TNFB*2) genes, and the lipopolysaccharide-induced TNF-α production by peripheral blood mononuclear cells was measured after a 12-week period of fish oil supplementation (6 g/day). This study revealed that in the group with the highest TNF-α levels, homozygosity for TNFB*2 was 2.5 times higher. In the group with the lowest  TNF-α levels, fish oil supplementation significantly increased the mean TNF-α production from 1,458 ± 600 ng/L to 3,809 ± 2,571 ng/L. In the group with the highest TNF-α levels and the most homozygotes for TNFB*2, the mean TNF-α production  decreased significantly from 9,277 ± 4,338 ng/L to 5,323 ± 3,941 ng/L.⁽²⁾ The anti-inflammatory effect of fish oil is also affected by body mass index and possession of the LT-α+252 A allele.⁽³⁾ Thus, the variability of genetic expression through the SNPs of the genes involved is an important determinant of the course and outcome of an inflammatory process.⁽³⁾ For this reason, when considering individual reactions to nutrients that modulate or might modulate inflammatory reactions, it is always advisable to take into account the genetic disposition of the individual.⁽²⁾