Diet fatty acid profile, membrane composition and lifespan: An experimental study using the blowfly (Calliphora stygia)

Abstract

The membrane pacemaker theory of ageing proposes that the polyunsaturated fatty acid (PUFA) composition of membrane lipids of a species is an important determinant of its maximum lifespan. We report three experiments using the blowfly Calliphora stygia, where this theory was tested by manipulation of dietary fat profile. Although the fat profile of the larval diet resulted in small alterations of individual membrane fatty acids, it had no effect on the peroxidation index (PI) of membrane lipids and furthermore had no effect on maximum lifespan. Similarly, manipulation of the fat profile of the adult diet resulted in small changes in individual fatty acids, but had no effect on the PI of membrane lipids. There was a small increase in maximum lifespan when adult diet was supplemented with PUFA in form of vegetable oils but no effect when diet was supplemented with pure PUFA. This difference is possibly due to antioxidant content of vegetable oils. The relative refractoriness of membrane PI to dramatic changes in response to diet is similar to the situation in the rat. These results also indicate the blowfly is unable to convert 18-carbon PUFA to more highly polyunsaturated 20- and 22-carbon PUFA.

Omega-3 deficiency impairs honey bee learning

“…Whereas diet quality is affected by amino acid content and composition, proteins alone cannot explain some of the effects of diet on bee health and colony functioning and deficits in additional nutritional factors: specifically, lipids are suspected (9). ALA and LA are generally considered essential fatty acids (eFAs) for most insects (20,21), including bees (22).…”

Perspectives on the membrane fatty acid unsaturation/pacemaker hypotheses of metabolism and aging

“…The membrane pacemaker hypotheses of metabolism and aging have been promoted by some authors (Hulbert, 2010;Kelly et al, 2014;Naudí et al, 2013) and dismissed by others (Konarzewski and Książek, 2013;Valencak and Ruf, 2007), but there are still basic gaps in the understanding of the mechanisms behind these hypotheses, as well as consistent problems with the way that they are studied. A more concrete understanding of how the amount of PUFA in a membrane affects protein activity would significantly strengthen the membrane pacemaker hypothesis of metabolism.…”

Polyunsaturated fats, membrane lipids and animal longevity

“…Of the eight desaturase genes that have been identified in the Drosophila melanogaster genome seven are Δ9-desaturases capable of producing MUFA from SFA but there are no Δ6-or Δ5-desaturases which are necessary to produce 20:4n-6 (Fang et al 2009). Similarly, the blowfly Calliphora stygia appears unable to convert dietary 18-carbon PUFA to 20-carbon PUFA (Kelly et al 2013). A detailed study of the lipidome of adult Drosophila melanogaster found no 20-carbon PUFA in either phospholipids or triglycerides (Hammad et al 2011) supporting the inability of Drosophila to produce such PUFA.…”

“…Insects unable to synthesise such PUFA may still incorporate them into their membrane lipids if they obtain them preformed in their food. This is the case with Calliphora which being carrionfeeders have a larval diet consisting of meat or fish (see Kelly et al 2013). However, because they are found in membrane lipids of an insect does not necessarily mean they are essential for normal function.…”

“…It is obviously not essential for neuronal function in all animals as, for example, insects such as honeybees have highly functional neuronal systems yet it is not present in phospholipids of the head in honeybees (Haddad et al 2007). It is not present in phospholipids of blowflies fed fish as larvae or provided fish oil or krill oil as adults (Kelly et al 2013).…”