An elevated level of long-chain n-3 fatty acids in tissue membranes has a positive influence on the progression and treatment of many diseases. Therefore, dietary supplementation of n-3 fatty acids is recommended in some diseases.

Even though n-3 fatty acids are absorbed readily from the diet, their incorporation into tissues may be compromised in diseased animals, and in a clinical setting, it is desirable to monitor the success of dietary intervention. Plasma fatty acids as well as erythrocyte membrane (EM) fatty acids can be used to monitor dietary fatty acid intake. This study compares fatty acids from EM and plasma with regard to their reaction time and reliability for monitoring dietary changes of tissue fatty acid profiles in dogs.

Thirty dogs were divided into three groups and fed for 12 weeks. The control group was fed a commercial standard diet low in n-3 fatty acids. One group received the standard diet and 85 mg/kg body weight of a docosahexaenoic acid concentrate. The third group was fed a commercial dog food containing fish oil. EM and plasma fatty acid profiles were analyzed by GC separately. n-3 fatty acids in plasma reached the new level after two weeks (eight weeks in EM). In general, the correlation of n-6 fatty acids between plasma and EM was low. We therefore conclude that analysis of plasma fatty acids is sufficient for monitoring a diet-induced increase in tissue n-3 fatty acids in dogs; however, EM fatty acids should be analyzed if the effect of dietary intervention on tissue n-6 fatty acids is important.

Source : K. Stoeckell et al., 2012. Response of plasma fatty acid profiles to changes in dietary n-3 fatty acids and its correlation with erythrocyte fatty acid profiles in dogs. JAPAN online December 2012. doi: 10.1111/jpn.12023