What does the FADS1 gene do?

In our Western diet we tend to have too much omega 6 which increases inflammation and too little omega 3. Although things are not as quite as simple as that, some omega 6’s are good, the FADS1 gene is associated with a higher (less healthy) ratio.

Basically, FADS1 variations affects the ratio of omega 6 to omega 3 circulating in the blood stream.

CC variants tend to have a higher ratio than CT or TT variants. Omega 6 is important but a high omega 6:3 ration with lead to increased levels of inflammation by increasing a chemical called “arachidonic acid”.

The FADS1 gene codes for a very important enzyme called delta 5 desaturase. CC are associated with enhanced conversion of the omega 6 GLA with the inflammatory messenger “arachidonic acid”. This is associated with systemic inflammation and inflammatory disorders.

High levels of omega 3, in particular EPA will inhibit this enzyme reducing the production of arachidonic acid and reducing inflammation in the body.

In the modern western diet the increased consumption of cooking oils and processed food has led to the three-fold increase of dietary levels of omega 6 long chain polyunsaturated fatty acid (PUFA), broken down into linoleic acid (LA).  In our current diet, linoleic acid contributes to more than 90% our PUFA intake.  Linoleic acid is then metabolised in three other steps (LA > GLA. DHGLA>AA) into a long chain PUFA, known as arachidonic acid (AA).

AA plays a major role in inflammation and immunity. These have mainly pro-inflammatory effects. Fats derived from omega 3 oils such as fish oils, are less inflammatory.

The AA impacts the immune responses through a variety of mechanisms.

The FADS gene family variants determine the levels of circulating fats in cells and tissues. FADS 1 gene variants are likely to be a contributor in different levels of fat found in fat cells in the blood and the red blood cell membranes.

The TT genotype, tend to have lower level of pro-inflammatory chemicals, in comparison to a GG result. The T allele is associated with lower risk of heart disease.

If you have the CC genotype, it has been linked with higher levels of LDL (bad) cholesterol levels compared to TT genotype so this should be checked regularly. The GG genotype is mainly observed in African American at 87%, in Europeans 41% and Asians at 31%.

Due to this variant dietary guidelines regarding the type of dietary fat eaten is important on. Remember your genes are only a tendency. Check your lipid levels and omega 6:3 ration to see how you are doing.

You can check your genes by taking a DNA test at humanpeople.

References:

Interactions between dietary n-3 fatty acids and genetic variants and risk of disease

Desaturase and elongase-limiting endogenous long-chain polyunsaturated fatty acid biosynthesis