There is science research that has found olive oil to be able to dilate blood vessels possibly due to the polyphenols that have an astringent effect. So people who have problems with their blood vessels might be wise to avoid olive oil and take other kinds of fat.
Dr Vogel's research properly explains how olive oil can significantly injure the endothelium and that the effects of other oils used in the research such as canola oil had insignificant effects on the endothelium.
"The olive oil meal caused vessels to constrict by 34%, whereas the canola oil and salmon meals caused insignificant changes in blood vessels, Vogel reports. Because such constrictions injure the blood vessels' endothelium, they contribute to heart disease."
The postprandial effect of components of the Mediterranean diet on endothelial function.
"CONCLUSIONS: In terms of their postprandial effect on endothelial function, the beneficial components of the Mediterranean and Lyon Diet Heart Study diets appear to be antioxidant-rich foods, including vegetables, fruits, and their derivatives such as vinegar, and omega-3-rich fish and canola oils."
Since Dr Vogel's research has found that oils such as canola "caused insignificant changes in blood vessels", other oils such as flaxseed and hemp oils should be alright to consume. Oils rich in omega 3 has been found to improve endothelium function.
Effect of omega-3 fatty acids supplementation on endothelial function: a meta-analysis of randomized controlled trials.
"Supplementation of omega-3 fatty acids significantly improves the endothelial function without affecting endothelium-independent dilation."
Beneficial fats that contain high amounts of omega 3 can be found in foods like tofu, soya beans, soybean oil, soymilk, flaxseed oil, walnuts etc. A good balance of omega 3 and 6 is already found in soybeans but if one can choose to consume flaxseed oil to gain more omega 3 fats.
The recommended daily requirement for fat intake is 65grams. So each meal could contain about 20grams of fat.
A 14g tablespoon of flaxseed oil contains 14grams of fat and about 7000mg of omega 3. A 14g tablespoon of soybean oil contains about 1000mg of omega 3. 7 full pieces of walnuts of 28g contains 18grams of fat and 10000mg of omega 3.