The all-cause annual death rate of vegetarian men is slightly more than that of non-vegetarian men (.93% vs .89%); the annual death rate of vegetarian women is significantly more than that of non-vegetarian women (.86% vs .54%) (Am J Clin Nutr 1982 36:873). The International Atherosclerosis Project found that vegetarians had just as much atherosclerosis as meat eaters. (Lab Invest 1968 18:498). 

Hence the debate of vegetarian vs non vegetarian food to reduce arteriosclerosis may not hold true. But its the high fat or carbohydrate diet irrespective of vegetarian or npn-vegetarian which is responsible.

Not an answer to the original question, but I disagree with the comment above. Vegetarian diets have been recognized as cardio-protective. There is sizeable literature to document a lower prevalence of diabetes mellitus, hypertension, hypercholesterolemia, lower prevalence and mortality from ischemic heart disease and stroke in vegetarians, as compared with non-vegetarians.

Fraser G.E. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am. J. Clin. Nutr. 1999;70(Suppl. 3):532S–538S.

Craig W.J. Health effects of vegan diets. Am. J. Clin. Nutr. 2009;89(Suppl. 5):1627S–1633S. doi: 10.3945/ajcn.2009.26736N.

Huang T., Yang B., Zheng J., Li G., Wahlqvist M.L. Cardiovascular disease mortality and cancer incidence in vegetarians: A meta-analysis and systematic review. Ann. Nutr. Metab. 2012;60:233–240.

Crowe F.L., Appleby P.N., Travis R.C., Key T.J. Risk of hospitalization or death from ischemic heart disease among British vegetarians and nonvegetarians: Results from the EPIC-Oxford cohort study. Am. J. Clin. Nutr. 2013 doi: 10.3945/ajcn.112.044073.

Atherosclerosis starts by the formation of fatty streak in the sub-endothelial space. Here oxidized lipids and proteins accumulate inside the macrophages and becomes fatty streak. Later on smooth muscle cells proliferate and various molecules like calcium compounds are accumulate in the affected region forming a bulge.  Since non-vegetarian  foods (read meat) contain a lot lots of oxidized LDL and poly-unsaturated fat chances of atherosclerosis is more.

the question has many answers, all -more or less- plausible. First, there are many different vegetarian diets, which act differently in different races and in different individuals. The reaction is, usually, detached. Second, there is no "vegetarian diet" but the product of an eating habit (and its variability during the life) for a certain time, at a certain stage of life, in interaction with numerous genetic, epigenetic and environmental factors. Third, we must not forget that atherosclerosis is a systemic disease, proliferative and degenerative, slowly progressive, but reversible, which extends along the life, and that ATS is one of the rate-limiting step in the life span of individuals and in growth of populations. Fourth, the experimental methods available currently are not correct and do not provide answers to multidimensional problems with hundreds of variables. Fifth, there is no need to assume that the study of "average trends" (as in controlled clinical research) can help to predict individual responses. Fifth, predictive medicine and medicine of complexity models (i.e. so called System Medicine) have not yet suitable to solve the problems, nor sufficient computing power. (we hope for the future)

So, from the empirical point of view, how would the Doctors of Salerno School of Medicine, many centuries ago, we can say that we have enough evidence to say that certain dietary habits may be healthy. We also know well enough evil: that some diet errors can cause illness. But we should not expect too much from a science that is still in its infancy. From a practical standpoint, we have to go to a few elements essential and I shared when we give instructions to our patients, limiting the essential advice to those trying to customize them also on the basis of elements of clinical and physiopathological  reasoning  NOT encoded by the guidelines or the EBM ( cave canem,  without giving too much weight to a myriad of studies and experiments, each one seemingly plausible but all together completely impossible. For example: if you do the sum of all the proven benefits in GCP published (on dietetic products and nutraceuticals) you will always result in eternal life and perfect health in all men, and yet.........

Vegetarian diet and atherosclerosis protection? I have several doubts on this statement. Rather, diet supplementation has been identified to have beneficial effects on the progression of atherosclerosis.

Dear Dr. Narasimhacharya,

As Dr. Gaddi was mentioning, there are myriades of other influences on health and arteriosclerosis as a systemic disease than just vegetarian diet. Just mind smokers and people who are exposed to hazarous substances and vapors for decades in their jobs. The only fact clearly to observe concerning vegetarian nutrition is that it is not harmful to health, if a proper protein supply is retained. General life-style and habbits are very important as well. One example for extended life span because of a mostly healthy nutrition is the high average age of the Japanese population (link below). Furthermore there is no prove of avoiding or improving health conditions or avoiding development of arteriosclerosis by vegetarian diet generally.

http://www.smithsonianmag.com/science-nature/keeping-track-oldest-people-world-180951976/?no-ist

http://gerontologist.oxfordjournals.org/content/51/4/425.full

I agree with Dr Rueter suggestions. From the pragmatic and clinical point of view, probably, at present, the Doctors should suggest to the patient general life style  and verify that nutrient intake is consistent with  RDA  (as example the right protein intake, the P/M/S FA ratio, the intake of essential nutrients, like  alfa1linolenic acid and other; avoiding unbalanced or deficiency diets, etc etc ). In the future, complex approach to phenome/genome/""environmentome"" may (might, can, should....) solve some problems. In any case, the natural evolution of atherosclerosis,  is typical of each individual. So, as recently stated by  E Topol: "the medicine will be rebooted and reinvented one individual at a time". 

INTERHEART STUDY

Abnormal lipids, smoking, hypertension, diabetes, abdominal obesity, psychosocial factors, consumption of fruits, vegetables, and alcohol, and regular physical activity account for most of the risk of myocardial infarction worldwide in both sexes and at all ages in all regions. This finding suggests that approaches to prevention can be based on similar principles worldwide and have the potential to prevent most premature cases of myocardial infarction.

http://image.thelancet.com/extras/04art8001web.pdf

Dear Dr. Narasimhacharya,

I would like to underline that atherosclerosis and arteriosclerosis are different conditions.

The former, is the buildup of fats, cholesterol and other substances in form of plaques on an artery walls, which can restrict blood flow. This condition is highly preventable, with, for example, low-fat diet, among others.

Differently, arteriosclerosis is a disease affecting the walls of the arteries due to ageing, and increases both arterial wall stiffness and thickness. This condition has stronger genetic factor with respect to atherosclerosis, and it is less preventable.

Sincerely,

Andrea

Most vegetarian diets are low in or devoid of animal products. They are also usually lower than non vegetarian diets in total fat, saturated fat and cholesterol. Most studies have shown that vegetarians seem to have a lower risk of obesity, coronary heart disease, high blood pressure, diabetics mellitus and some form of cancer.

vegetarian diets can be healthful and nutritionally sound if they are carefully planned to include essential nutrients. However, a vegetarian diet can be unhealthy if it contain too many calories and/or saturated fats & not enough important nutrients.

I thank you all for your time and opinions. However, for some reason the second part of my question did not not come up in the query box !

I was wondering if any literature exists on the nature of blood vessels as we age. Do the blood vessels lose their property (if any !) to repel the lipids flowing through them? Does the inner side of the wall undergo any change/s over a period of time so that the plaques are formed decreasing  the diameter of the blood vessels? In other words, do the blood vessels become rugged on their inner surfaces, so the lipids stick to them? Why doesn't atherosclerosis not generally occur at young ( very young included) age ? Does it occur only if  and when diets with high fat content are consumed?

Thank you all once again.

Thanks  Dr

Nice topic to discuss. 

Good Information 

Good luck

Vegetarian diets increase bowel activity and prevent fat absorption. Therefore, less plaque will be made in vessels walls that helps reduce the incidence of arteriosclerosis.

due to presence of antioxidants in veg

The second part of the  comment of Dr Preet Shah is right. In addition there are data that support that in vegans (at least in Europe) the levels of HDLc are lower and those of Lp(a) higher. I invite everyone to not confuse the recommendations on the use of vegetables and fresh fruit (very useful) with a mediterranean diet (certainly useful) with diet tendentially vegetarian or lacto-ovo vegeatariana (probably useful) with the vegan diet, that hides many dangers i