Polyunsaturated Fatty Acid (PUFA)

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

PUFAs refer to a family of lipids which have a double bond between the 3rd carbon and the 4th carbon from the methyl end of the chain¹. This family of lipids plays an important role in human nutrition.

Omega nomenclature

Since the physiological function of the lipid is dictated by the position of the 1st double bond relative to the methyl end of the chain, PUFA’s have an alternative nomenclature based on the methyl end¹.

• The carbon of the methyl group is the most distant from the carboxyl group, and thus it is called ω (omega; the last letter in the Greek alphabet) carbon¹.
• This ω carbon is given the number 1 (C-1)¹.
• the carboxyl carbon is on the opposite end and thus has the highest number¹.
• This naming scheme allows one to signify the position of the double bond (number) from the methyl group (ω)¹

Example

1. PUFA with a double bond between the C-3 and C-4 carbons are called omega-3 (ω-3) fatty acids¹
2. PUFA with a double bond between C-6 and C-7 are called omega-6 (ω-6) fatty acids¹

Diet

An imbalance of omega-6 and omega-3 PUFAs in the diet is associated with an increased risk of cardiovascular disease¹

According to Lehninger, the optimal dietary ratio of omega-6 to omega-3 fatty acids in the diet ranges from 1:1 and 4:1¹.

References

1.

Nelson DL, Cox MM, Hoskins AA. Lehninger Principles of Biochemistry. 8th ed. Macmillan Learning; 2021.