High Fish Oil Diet Increases Oxidative Stress Potential in Mammary Gland of Spontaneously Hypertensive Rats

Abstract

1. The purpose of this study was to determine whether high omega-3 (19% menhaden oil, 1% corn oil) or high omega-6 (20% corn oil) fatty acid diets would decrease expression of hypertension in the female spontaneously hypertensive rat (SHR), promote tumourigenesis in the rat 7,12-dimethylbenz[a]anthracene (DMBA) model of mammary cancer or increase the susceptibility of the mammary gland to lipid peroxidation. A group of rats on a 5% corn oil diet served as the low fat control group. 2. We found that the high omega-3 and high omega-6 fatty acid diets did not significantly decrease mean arterial pressure. Marked differences occurred between the effects of omega-3 and omega-6 high fatty acid diets on baseline oxidation, auto-oxidation and iron-ascorbate catalyzed oxidation. The omega-3 diet showed 675% increase in basal oxidation, a 2624% increase in auto-oxidation and a 4244% increase in iron-ascorbate catalyzed oxidation compared to the omega-6 diet in mammary tissue homogenates. Although all rats were given 5 mg DMBA (i.g.), no mammary tumours were observed in any of the dietary groups. 3. We conclude that: (i) high polyunsaturated fatty acid diets do not decrease blood pressure in the female SHR; (ii) high fish oil diet markedly increases oxidative potential in the mammary gland; and (iii) the female SHR is resistant to DMBA-induced tumourigenesis.

Possible effects of pollock and herring on the growth and reproductive success of Steller sea lions (Eumetopias jubatus): insights from feeding experiments using an alternative animal model,Rattus norvegicus

“…The fatty acid profiles of the diets used in our study (Table 3) are similar to profiles in the literature for both herring and maize oil (Stansby, 1969(Stansby, , 1986Mehta et al 1994). A profile for pollock oil was not found.…”

“…Efficiency of energy utilization was calculated as the weight gain over 9 weeks, divided by the energy intake (Harris, 1991;Mehta et al 1994;Iossa et al 1997); protein efficiency ratio was calculated as the weight gain over 9 weeks divided by the amount of protein consumed (Muller & Tobin, 1980).…”

Medium-chain TAG attenuate hepatic oxidative damage in intra-uterine growth-retarded weanling piglets by improving the metabolic efficiency of the glutathione redox cycle

“…The degree of lipid peroxidation is proportional to the number of double bonds in unsaturated fatty acids ( 1 ) . The observation that MCT diet-fed piglets had lower hepatic MDA concentrations than SO diet-fed piglets supports the findings of Diniz et al ( 43 ) , who reported that the ratio of PUFA:SFA in diets played an important role in lipid peroxidation.…”

“…They can form organic free radicals, causing a cascade of damages to endogenous lipids and oxidative stress ( 2 , 3 ) . In fact, a positive correlation has been observed between the amounts of dietary PUFA and the extent of lipid peroxidation ( 1 ) .…”

The Adverse Effect of a High Energy Dense Diet on Cardiac Tissue

“…The Western diet generally includes at least 30-40% of energy as fat, and a typical American diet is 20% fat, resulting in a 40% energy intake from fat [1]. Current recommendations are to lower dietary fat and calories, but a dietary change often results in high carbohydrate and high protein diets.…”