Omega-3 & Omega-6 & Aging & Longevity Baste on 07 Feb 2007 03:36 pm
Omega-3:Omega-6 Ratio Affects Lifespan
Source: Aging Cell (2007), 6: 15-25
Article Type: Original Contribution
Authors: TG Valencak, T Ruf
Image taken from:
http://www.macvillage.de/blog/wp-content/uploads/2006/07/dali_zeit.jpg
Omega-3 fatty acids (n-3) are generally considered as health-beneficial (see also post discussed yesterday). When talking about the lifespan of mammals, however, n-3 fatty acids seem to hamper longevity. The reason for this correlation has been linked to:
• the high susceptibility of polyunsaturated fatty acids (PUFA; n-3, n-6) to oxidation
• the boost in basal metabolic rate (BMC) in the presence of PUFA, e.g. by up-regulating the activity of membrane-associated proteins
These effects have been summarized in the ‘membrane pacemaker theory of aging’: PUFA (up) –> BMR (up) –> longevity (down).
After correcting for body weight and phylogenetic effects, Valencak & Ruf found a clear correlation between the ratio of n3:n6 in muscle and maximum lifespan (MLS), based on the analysis of 42 mammalian species. Noteworthy, MLS was unrelated to docosahexaenoic (DHA, n-3) content, total membrane unsaturation as well as BMR, thus questioning the ‘membrane pacemaker theory of aging’.
Does this mean now that we should avoid consuming PUFAs, particularly n-3?
I would say no, because the current recommendation (see also Simopoulos, 2006) to increase dietary n-3 intake is largely based on the discrepancy in the composition of ingested dietary fat between western societies (n-3:n-6 = 1:15) and our hunting & gathering ancestors (n-3:n-6 = 1:1). Hence, the risk of reducing your (maximum) lifespan by consuming n-3-rich plant and animal foods (which consequently will enhance your n-3:n-6 ratio) is rather small.