Dietary protein level interacts with omega-3 polyunsaturated fatty acid deficiency to induce hypertension.
BACKGROUND
Dietary omega-3 fatty acid deficiency can lead to hypertension in later life; however, hypertension is affected by numerous other dietary factors. We examined the effect of altering the dietary protein level on blood pressure in animals deficient or sufficient in omega-3 fatty acids.


METHODS
Female rats were placed on one of four experimental diets 1 week prior to mating. Diets were either deficient (10% safflower oil; DEF) or sufficient (7% safflower oil, 3% flaxseed oil; SUF) in omega-3 fatty acids and contained 20 or 30% casein (DEF20, SUF20, DEF30, SUF30). Offspring were maintained on the maternal diet for the duration of the experiment. At 12, 18, 24, and 30 weeks, blood pressure was assessed by tail cuff plethysmography.


RESULTS
At both 12 and 18 weeks of age, no differences in blood pressure were observed based on diet, however, by 24 weeks hypertension was evident in DEF30 animals; there were no blood pressure differences between the other groups. This hypertension in DEF30 group was increased at 30 weeks, with systolic, diastolic, and mean arterial pressure all elevated.


CONCLUSIONS
These results indicate that the hypertension previously attributed to omega-3 fatty acid deficiency is dependent on additional dietary factors, including protein content. Furthermore, this study is the first to plot the establishment of omega-3 fatty acid deficiency hypertension over time.
Begg
Denovan P
DP
School of Medicine, Deakin University, Geelong, Australia.
Sinclair
Andrew J
AJ
Stahl
Lauren A
LA
Garg
Manohar L
ML
Jois
Mark
M
Weisinger
Richard S
RS
D000375:Aging / Q000502:physiology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002364:Caseins / Q000494:pharmacology; D004032:Diet; D004044:Dietary Proteins / Q000009:adverse effects*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D010991:Plethysmography; D051381:Rats; D017207:Rats, Sprague-Dawley
D002364:Caseins; D004044:Dietary Proteins; D015525:Fatty Acids, Omega-3