The traditional view that cardiovascular disease is caused by dietary cholesterol and saturated fat is not just outdated, but absurd. Many so called ‘experts’ still believe the fairy stories told about cholesterol, which is unfortunate as this belief causes more people to die of what is essentially a preventable condition. However, prevention of cardiovascular disease is only possible if it is accepted that factors other than cholesterol are involved in its development.
The endothelial lining of arteries plays an important role in maintaining blood flow and blood pressure. The endothelium is a muscular wall that expands and contracts elastically in response to blood flow. Dilation of the endothelium is only possible when nitric oxide is produced in the artery walls. Inhibition of this process causes a dysfunction to develop that results in arteries losing their elasticity, which ultimately causes changes to blood pressure and blood flow.
What Causes Endothelial Dysfunction?
Endothelial dysfunction is caused by a lack of nitric oxide production in the artery walls (nitric oxide is also called endothelium-derived relaxing factor). Normally nitric oxide is synthesised by the enzyme nitric oxide synthase. However, this process is inhibited by free radicals. Long term exposure to free radicals therefore causes cardiovascular disease. Diets that prevent free radicals are therefore protective of cardiovascular disease.
Grapes Prevent Endothelial Dysfunction
Grapes are interesting food. Apart from the obvious benefit that they make great alcoholic drinks, they also have other interesting properties. In particular, they are rich in polyphenol antioxidants. Regular consumption of grapes therefore protects the endothelium of arteries by ensuring that adequate nitric oxide is synthesised. Studies investigating grapes have shown that they lower blood pressure. Grape seed extracts are also beneficial.
Walnuts And Cardiovascular Disease
Walnuts are also a rich source of antioxidants. In particular, walnuts contain ellagic acid. In a similar fashion to grapes, walnuts can therefore protect the endothelium of arteries and prevent endothelial dysfunction. However, walnuts also contain omega-3 fatty acids which may decrease platelet aggregation and blood clot formation. Walnuts therefore are cardioprotective by more than one mechanisms which explains their beneficial health effects.
Low quality diets and smoking contribute to cardiovascular disease because they induce systemic inflammation. Frequent infection and pollution does the same. The more free radicals that an individuals is exposed to, the greater their risk for developing endothelial dysfunction. The solution to this problem is to eat a high quality diet. Healthy snack such as grapes and walnuts can significantly boost antioxidant defences and therefore should be included as part of such a diet.