Can This Fat Metabolism Gene Influence Nutrition and Cholesterol? (FADS1)

FADS1 is a gene that plays an integral role in the metabolism of certain types of fats. This is because FADS1 is responsible for encoding a protein called delta-5 desaturase (D5D) [R].

The D5D protein is an enzyme that is responsible for the conversion of polyunsaturated fatty acids (PUFAs) [R].

PUFAs play several key roles in the body, such as being a structural component of cells, acting as an energy source, and regulating cell signaling pathways [R].

Research suggests that certain variants in FADS1 may impair the body’s ability to metabolize fatty acids, potentially leading to negative effects on nutrition [R].

Learn more about fatty acids here.

A number of studies suggest that specific variants in FADS1 may cause fat metabolism issues.

This is likely because these variants can reduce the activity of the D5D enzyme, which plays a key role in the production of PUFAs, including omega-3 and omega-6 fatty acids [R, R].

A reduction in D5D activity can lead to lower levels of important PUFAs, such as EPA and DHA [R].

This may also lead to an imbalance in cholesterol and triglyceride levels as fatty acids can influence the concentration of these two compounds [R].

In the following sections, we’ll go over the specific FADS1 variants that may alter fat metabolism and who might be affected.

Imbalances In Fatty Acid Levels

According to research, several variants in FADS1 may lead to lower levels of PUFAs, including omega-3 and omega-6 fatty acids [R].

Using data from 426 individuals from Spain, one genome-wide study found that the ‘T’ allele of rs174546 is associated with lower levels of omega-3 fatty acids, such as AA, EPA, and DHA [R].

Another study of 224 people from an isolated island population in the U.S. found that the ‘T’ allele is also associated with reduced levels of omega-6 fatty acids [R].

Similar results have been found for other SNPs, such as rs174547, rs174548, and rs174550. In all these cases, the minor allele was associated with lower D5D activity and lower levels of omega-3 and omega-6 fatty acids [R, R, R, R].

Research suggests that the minor allele in several FADS1 variants may be associated with lower levels of omega-3 and omega-6 fatty acids.

Changes In Cholesterol and Triglycerides

Studies show that FADS1 variants may influence triglyceride and cholesterol levels in the body [R, R].

For example, the ‘T’ allele of rs174546 has been associated with higher triglyceride levels, but lower LDL (“bad” cholesterol) and total cholesterol, based on research in European, Canadian, and Mexican populations [R, R, R, R].

However, this association may vary depending on ethnicity, dietary intake of fats, and age [R, R, R].

A different study looked at the SNP rs174547 in over 21,000 Japanese and over 1,200 Mongolian individuals [R]. 

Researchers found that the ‘C’ allele was associated with higher triglycerides and lower HDL (“good” cholesterol) in Japanese individuals [R].

On the other hand, the ‘C’ allele in the Mongolian population was only associated with lower LDL. There was no link to triglycerides or HDL in this group [R].

Another study of rs174547 suggests that the ‘C’ allele is only associated with lower LDL in people who have a low intake of omega-3 fatty acids [R].

In addition, the ‘C’ allele of rs174550 may also be associated with low HDL and higher triglyceride levels, according to research in Chinese populations [R].

According to research, the minor allele in certain FADS1 variants may be associated with lower cholesterol, but higher triglyceride levels.

You can see your genotypes for FADS1 in the table below. However, keep in mind that these associations are based on studies from certain ethnic populations — so you should interpret your results with caution if you are not descended from one of these specific groups!

Primary SNPs: 

FADS1 rs174546

• ‘C’ = Associated with normal levels of fatty acids
• ‘T’ = Associated with lower levels of certain omega-3 and omega-6 fatty acids, lower cholesterol, and higher triglycerides
• These associations have been found in Spanish, American, European, Canadian, and Mexican populations

FADS1 rs174547

• ‘T’’ = Associated with normal levels of fatty acids
• ‘C’ = Associated with lower levels of certain omega-3 and omega-6 fatty acids, lower cholesterol, and higher triglycerides
• These associations have been found in Spanish, Chinese, Japanese, Mongolian, and Swedish populations

FADS1 rs174548

• ‘C’ = Associated with normal levels of fatty acids
• ‘G’ = Associated with lower levels of certain omega-6 fatty acids
• This association has been found in European, Hispanic American, and Chinese American populations

FADS1 rs174550

• ‘T’ = Associated with normal levels of fatty acids
• ‘C’ = Associated with lower levels of certain omega-3 and omega-6 fatty acids, lower HDL, and higher triglycerides
• These associations have been found in Spanish and Chinese populations

Population Frequency

The frequency of alleles for FADS1 SNPs can vary wildly depending on ethnicity.

In rs174546, the ‘T’ allele (the risk allele) is considered the minor allele. About 44% of people worldwide carry at least one ‘T’ allele.

However, in certain ethnic groups, such as American and East Asian populations, the ‘T’ allele is actually more common than the ‘C’ allele.

For instance, about 77% of East Asians and 80% of Americans carry at least one ‘T’ allele.

This trend also occurs in the other mentioned SNPs (rs174547, rs174548, and rs174550) — the less common minor allele is actually the more frequent allele in American and East Asian groups.