"Heart attack" is a much feared "two words" as millions of people across the world fall prey to this disease with high fatality potential. In spite of tons of literature which claim that the reasons of heart attack, also called Myocardial Infraction (MI), are well known, from time to time serious questions are raised regarding the present state of knowledge about this scourge. Over weight, Obesity, Cholesterol, Saturated fat, Trans fats are all being indicted as the villains for causing MI but the ground reality is that no single factor has yet been proved conclusively that will cause the disease. This does not mean that one can violate the existing dietary guidelines evolved based on lot of scientific data and the theory of probability.
The relation between cholesterol and heart attack is well established as the former creates arterial plaques through stubborn deposits on the walls of the arteries thus narrowing down the effective diameter of the blood vessels near the heart. Logically heart needs to pump the blood with more strain in people having such plaques, determined usually by non-invasive techniques like Angiogram or scanning and such strain on the the heart is supposed to cause seizure of the cardiac muscles causing irreversible damage. World has more or less reconciled to surgical intervention like Angioplasty, heart by pass operation etc to deal with medical problems associated with atherosclerosis. Though preventive measures that include prudent dieting to exclude saturated fat, trans fats, high cholesterol containing food components in the diet and restricting red meat are well known, human weakness for rich foods and low will power to control the food intake invariably lead to atherosclerosis. There is also the genetic factor which can cause health conditions vulnerable to heart disease but still appropriate diets and physical exercise can alleviate the danger to a significant extent.
The eternal debate between carnivores and herbivores regarding the advantages of plant foods centers around the fact that red meat is a rich source of cholesterol and regular consumption of saturated fat rich meat can increase the blood cholesterol levels leading to arterial plaque build up. Though this may be factually correct, there is still some question as to why cholesterol is not metabolized in the body as it is a biological compound necessary for fat metabolism and is produced in the body. The concept of bad cholesterol and good cholesterol is still an accepted one and the ratio of HDL (high density lipoproteins) to LDL (low density lipoproteins) is widely used to monitor the heart health by many doctors. Even this established concept is under a cloud as a result of newer studies which question this theory. In the midst of these uncertainties, one thing is sure-that by-pass surgery or Angioplasty which opens up the arteries in CVD patients do bring relief from symptoms of Angina Pectoris and extend the life span very significantly.
Latest revelation that high levels of saturated fat or cholesterol in the red meat cannot be entirely blamed for heart disease is going to put some of the present thoughts on CVD under a cloud. According to these studies saturated fat and cholesterol play a very small role in causing heart disease and the blame has to go some where else. It is averred that meat consumption causes the bacteria in the intestine of regular meat eaters to generate a lethal chemical from one of the unique amino acids present in meat called Carnitine which leads to conditions ripe for heart disease. Carnitine is a fuel for some species of microorganisms present exclusively in the intestines of carnivores and in the process they produce a lethal chemical called Trimethylamine N-oxide (TMAO) which causes the heart attack. The studies clearly brought out the connection between red meat, carnitine, bacteria, TMAO and heart attack in no uncertain terms. While vegetarians did not show any TMAO in their blood, carnivores had consistently high levels of this chemical. It is the TMAO which facilitates formation of plaques from cholesterol and in the absence of TMAO cholesterol is likely to be metabolized in the body.
One of the outcomes of the above studies is the safety of the widely prevalent consumption of some of the products containing Carnitine which athletes and sports persons consume for enhancing their performance. While those not used to meat consumption may be relatively safe from the possibility of TMAO formation due to likely absence of TMAO forming bacteria in their guts, there is a greater chance for meat eaters to generate TMAO in their body which my have deadly consequences. Food safety authorities must frown upon the practice of the industry in marketing products containing carnitine to save precious lives!
These observations are ground breaking in that it opens up a new avenue to tackle CVD through methods that can eliminate the bacteria which converts Carnitine to TMAO. Unfortunately so far there is no clue as to the identity of these bacteria and any antibiotic therapy can be developed only if scientists get a clue regarding their characteristics and metabolic profile. One of the species of microbes called Acinetobacter spp is reported to have the ability to form TMAO from Carnitine and Lecithin but considerable further studies only can throw more light on this area. Of course there will be many questions that will be raised about the universality of the above observations but this is going to be an area which will receive increasing attention from scientists across the world. Probably the day is not too far when meat eaters can safely eat this food with no guilt or fear of the consequences in the form of arterial diseases.
Having praised the above studies for the new trail blazing revelations, an unbiased observer cannot help asking a simple question as to why some of the vegetarians shunning meat as well as egg are also prone to CVD though their intestine does not contain TMAO forming bacteria and they do not consume Carnitine rich foods? Beef is the richest source of Carnitine. about 100 mg per 100 gm, though pork meat also contains about one fourth to one fifth of that present in beef. As for vegetarians Milk is a minor source of this amino acid (about 2 mg per 100 ml) though it is consumed in large quantities regularly by most vegetarians. The million dollar question is whether there is another TMAO like substance in plant foods that facilitates plaque build up in them? Very inconvenient question which no body can answer for the time being!