Atherosclerosis and Heart Attacks

Atherosclerosis is the thick cholesterol laden plaque that builds up on the inside of our arteries when we eat the typical Australian diet. Arteries do not simply gradually block up like a rusting water pipe. Heart attacks are most often the result of a sudden blockage in an artery that is only partially blocked with plaque. A whole foods plant based diet rapidly reduces the risk of heart attack.

The current paradigm of heart disease* views arteries as if they were water pipes. Factors such as high cholesterol, diabetes and smoking causes a gradual build-up of cholesterol on the inside of the artery like scale in a pipe. Eventually the pipe becomes blocked and blood supply is interrupted.

*There are many diseases that can affect the heart muscle and the heart valves. In this discussion we are using the term “heart disease” to refer to the diseases caused by narrowing or obstruction of the coronary arteries that supply the heart muscle. There are various terms that are used to label this type of heart disease: coronary artery disease (CAD), coronary heart disease (CHD), ischaemic heart disease (IHD), and myocardial ischemia. The processes which occur in the arteries of the heart can and do occur elsewhere in the body.

Atherosclerosis

Atherosclerosis is the end result of the complex process that leads to the accumulation of cholesterol and scar tissue within the artery wall. It is an insidious process that produces few if any symptoms until it is advanced enough to slow or block the flow of blood. In the early stages, fatty streaks develop inside the arteries as cholesterol builds up in the lining of the artery. The primary cause is the unnaturally high levels of LDL cholesterol associated with a diet rich in meat, dairy and processed foods and deficient in whole plant foods. The cholesterol deposited within the artery wall triggers an inflammatory response in which white blood cells invade the diseased artery wall, ingest the cholesterol and release further inflammatory chemicals. Eventually the interior of the artery becomes narrowed by a thick layer of cholesterol-laden scar tissue – this is atherosclerosis.

Arteries are not just water pipes and atherosclerosis has more consequences than just progressively reducing blood flow. The large arteries of the body are more like rubber tubes than hard pipes and they stretch with each heart beat and bounce back between beats, giving the smaller vessels a more steady blood flow. Atherosclerosis makes these arteries stiffer (“hardening of the arteries”) so that they no longer absorb the shock wave that each heartbeat produces. The smaller vessels further down the line then get pounded by the water hammer like shock wave of each heartbeat. These smaller vessels then become diseased more quickly resulting in damage the organs such as the brain and kidneys.

The paradigm of heart disease that views arteries as water pipes has an upgrade that describes how heart attacks occur.

Heart attacks

The gradual reduction in blood supply by atherosclerosis can cause the heart muscle to become weak and baggy so that it cannot pump effectively. The result is heart failure. Other organs in the body can also become progressively impaired. But heart attacks and most strokes happen when blood supply is suddenly cut off, resulting in death by asphyxiation to the cells downstream from the blockage. Atherosclerosis is an uneven process and forms localised lumps on the inside of arteries are called plaques. These plaques can burst open like a pimple on the inside of the artery. The material in the plaque causes the blood to clot immediately completely blocking the artery and obstructing blood flow to everything downstream. This can happen in arteries that are only partially blocked with plaque. Therefore an exercise ECG stress test can remain normal right up until the moment of the heart attack.

Cholesterol plaques that are actively growing are cauldrons of inflammation, and this inflammation causes the “cap” over the plaque to become thinner, increasing the risk of plaque rupture and heart attack – these are “unstable plaques”. It has been observed that rapidly reducing blood cholesterol stabilises plaques in just a few weeks, far quicker than the length of time it takes for a plaque to regress as demonstrated by angiograms. A plant based diet is much better than cholesterol tablets alone for stabilising plaques as it not only reduces fasting cholesterol, but also deals with the inflammatory storm that follows every fatty meat-based meal.

Heart disease in women may follow a slightly different course to men. It is the same disease process but plaque formation tends to be more diffuse. Diffuse plaque leads to relatively more diffuse heart damage (heart failure) than localised events (heart attacks).

Dr Michael Gregor describes the process of plaque formation and plaque rupture as analogous to pimples in his video Arterial Acne:

“Atherosclerotic plaques in coronary arteries may be more aptly described as pimples, initiated by the infiltration of cholesterol into the lining of our arteries. The ending, should blood flow to our heart muscle be cut off by a clot formed by the rupture of one of these inflamed pockets of pus in our arterial lining, is a heart attack”.

In this 8 minute video, Dr Esselstyn discusses how cholesterol accumulates in the coronary arteries, provoking an inflammatory reaction which can lead to plaque rupture. This is the main cause of heart attacks and mostly occurs in arteries that are not badly enough blocked to be treated with stents or bypasses. Fortunately plaques become more stable after only a few weeks on a whole foods plant based diet.

Caldwell Esselstyn, MD — “No More Heart Attacks — Ever”

Our current paradigm of artery disease, even with the ruptured plaque upgrade, is still too much of a water pipe analogy. Only by giving the endothelium centre stage can we understand how dietary factors cause atherosclerosis, high blood pressure and erectile dysfunction. See Endothelium, also Heart Health – Resources

The Canary and other Organs

Atherosclerosis is a whole body disease affecting every artery. Therefore any organ can potentially be compromised by impaired blood supply. A partially blocked artery may cause symptoms such leg muscle pain on exertion. A sudden complete blockage may result in a stroke. Diseased small vessels can cause dementia and kidney failure. Even in the absence of artery narrowing, an unhealthy artery may be unable dilate, resulting in erectile dysfunction.

Penis

Often the first sign of whole body artery disease is erectile dysfunction. The penis has one of the highest concentrations of endothelial cells in the body. Nerve signals cause these endothelial cells to produce more nitric oxide which dilates the arteries to inflate the penis with blood. Anything that narrows arteries or impairs endothelial cell function can disrupt this process which makes the penis a sensitive indicator of artery disease and provides an early warning for heart disease. It has been said that “the penis is the canary in the coal mine”. (Early coal miners carried canaries to warn them of toxic gases underground). Women have similar erectile type tissues and are also affected ( see NutritionFacts.org Cholesterol and Female Sexual Dysfunction  ).
A short video on diet and erectile function: Raise the flag with a vegan diet

Brain

The human brain is an energy hungry organ and is responsible for a significant part of our resting energy use. The high-energy needs of neurons combined with their sensitivity to low oxygen levels makes a good uninterrupted blood supply to the brain critical. Neurons die within minutes of sudden loss of blood supply such as when a stroke occurs, leaving that part of the brain permanently impaired. Strokes also occur on a very small scale. Brain scans of older people on the usual Australian diet are often speckled with scar tissue as a result of these mini-strokes. This damage contributes the decline in brain function which begins as early as one’s forties. Those most severely affected develop vascular dementia. Alzheimer’s disease is different but clearly related to vascular disease, sharing the same risk factors as heart disease. There is an impending epidemic of dementia because of the escalation in diabetes and obesity. You can avoid being part of this statistic. See Neal Barnard’s new book: Power Foods for the Brain

Vision and Hearing

The light receptors and nerve cells at the back of the eye are also very sensitive to lack of oxygen. The blood vessels on the back of the eye can be viewed directly and impaired passage of red blood cells can be observed following a fatty meal. The macular is the area responsible for our central spot of high resolution vision and has an even more precarious blood supply. Macular degeneration is most likely the result of impaired local blood supply and other dietary factors.

The nerve cells of the inner ear have a precarious blood supply and are similarly damaged by arterial disease.

Kidneys

The kidneys are another high blood flow tissue that is frequently affected by artery disease, particularly disease affecting the smaller vessels that feed the individual filtering units. Early kidney damage is revealed by the leakage of small amounts of blood proteins into the urine, microalbuminuria. This is associated with dietary intake, of animal protein, animal fat and cholesterol (see NutritionFacts.org Preventing Kidney Failure Through Diet )

Legs

Obstruction of some of the main arteries running down the legs is extremely common in older persons, particularly if they are diabetics or smokers. Usually this happens gradually and enough blood finds its way down side channels to keep the legs alive. Surgery is frequently performed to bypass blockages of major vessels, but if nothing is done to prevent progressive artery disease, amputation can be the end result.

Lower Back Pain

… is also linked to atherosclerosis (see NutritionFacts.org Cholesterol and Lower Back Pain )

Endothelium

The endothelium is the lining of our arteries and consists of a single layer of tile-like cells. The endothelium is central to artery health and disease. Anything that compromises the health of the endothelium has an immediate effect on the flow of blood to every organ. Atherosclerosis, the obstruction of arteries by cholesterol, is merely the end result of repeated endothelial damage. Every fat and cholesterol laden meal causes an inflammatory storm within the arteries that lasts for many hours and has a measureable effect on endothelial function.

Endothelial cells are continually releasing nitric oxide and many other chemical messengers that control blood flow and blood clotting. Nitric oxide (NO) is the key player. It diffuses into the muscular layer of the artery wall and causes the muscle cells to relax a little. The physics of pipes and fluids dictates that a small increase in the diameter of the vessel results in a big increase in blood flow. This provides for minute to minute adjustment of blood flow so that each area of the body gets enough blood for its needs but no more. There is good reason for this locally acting system. Just having maximum blood flow everywhere at once would result in a fatal drop in blood pressure such as can occur in anaphylactic shock. On the contrary, constricting all of the arteries at once would send blood pressure sky high.

Healthy endothelium has a non-stick “Teflon” quality which assists in blood flow, prevents blood clotting, and resists the uptake of plaque promoting cholesterol. The non-stick endothelium and the associated flexible red blood cells allow blood to flow smoothly through tiny capillaries. Direct observation of blood flowing through these capillaries has shown that eating fats, including polyunsaturated fats, causes blood to sludge and stop flowing.

Our current medical paradigm of endothelial health is focussed almost exclusively on the long term damage that accumulates over years – atherosclerosis – and the physical obstruction to blood flow that this causes. It is well accepted that reducing high cholesterol and other risk factors reduces heart risk within weeks to months by stabilising cholesterol plaques so that they are less likely to burst like pimples. But despite the recognition that endothelial function is central to atherosclerosis and erectile dysfunction, the effect of diet on the hour to hour function of the endothelium is too often ignored. A single fatty meal has bee shown to impair the ability of arteries to dilate for up to five hours (then its time for the next fatty meal).

Meat, other animal “protein” foods and fatty processed foods generate an inflammatory storm within the blood which lasts for many hours. Long term consumption of these foods results in a chronic state of inflammation as part of the so called metabolic syndrome. The inflammatory reaction is in response to toxic levels of fats and other substances within the blood. High levels of insulin and other hormones, high blood sugar levels, and blood milky with fat are part of the body’s attempt to process the rich food. Animal “protein foods” include inflammatory substances other than saturated fat and protein. Carnitine from meats and choline from eggs result in elevated blood levels of the toxic TMAO. Meat also contains endotoxins and both meat and dairy are sources of the foreign inflammatory molecule Neu5Gc. All of this is associated with high levels of oxidative stress within the blood. Under these conditions the “bad cholesterol” particles, LDL, become oxidised and really bad. With all of this going on it is not surprising that the endothelial cells become damaged and unable to maintain their frenetic output of chemical messengers.

Damaged endothelial cells cannot produce enough nitric oxide to dilate arteries fully when more blood flow is required. When blood supply is already compromised, for example by coronary artery disease, a fatty meal may be enough to tip the balance, resulting in angina (heart pain). Endothelial dysfunction also explains the phenomenon of angina in patients with only minimal coronary artery obstruction. Erectile dysfunction in young to middle aged men is an indicator that their endothelium is compromised and unable to release enough nitric oxide to produce an adequate blood flow. More subtle symptoms of endothelial compromise may include decreased exercise capacity, mental clouding and perhaps even conditions such as altitude sickness and migraines. Older persons have many years of accumulated endothelial damage and often quite gross atherosclerosis in which the endothelium is little more than scar tissue. With their nitric oxide production already seriously impaired, any additional short-term assault on the endothelium will have a more marked effect.

Endothelial cells in arteries all over the body are generally maintaining some degree of artery dilation all of time. Dietary factors that impair nitric oxide production will have a whole body effect, increasing the muscle tone of all arteries just a little bit and thus increasing the resistance of the whole vascular system. The body tries to compensate for this by ordering the heart to pump harder to maintain normal flow by raising the blood pressure. Damaged endothelium therefore contributes to hypertension.

As mentioned earlier the endothelial cells do a lot more than just regulate blood flow with nitric oxide, so damaging them has many other consequences. Healthy endothelium down regulates the blood clotting systems so that thrombosis (blood clotting within the vessel) is less likely to occur whereas severely damaged endothelium may even promote thrombosis (as its designed to do when blood vessels are ruptured by trauma). Damaged endothelium loses it’s Teflon quality and both cholesterol particles and white blood cells then stick to it and gain entry into the sub endothelial space between the endothelium and the muscular layer of the artery. This is the first stage of atherosclerosis.

The adverse effects of the typical Australian diet on endothelium is also about what is not being eaten. Whole plant foods are loaded with phytochemicals that are not present in animal products. These phytochemicals include protective substances that neutralise oxidative stress, reduce inflammation and enhance the health of the endothelium, reducing the uptake of cholesterol into the artery wall and the development of atherosclerosis. Nitrate containing green leafy vegetables, such as kale provide the substrate for nitric oxide production. Dr Caldwell Esselstyn now recommends that his patients with severe heart disease consume vegetables such as kale throughout the day to compensate for the impaired capacity of diseased and aged endothelium to produce nitric oxide. The sequence of events from kale to arteries is quite complicated and even involves bacteria in the tongue.

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Resources