I can actually give you a one-word answer right now and we can work backward: Inflammation. You see, obesity triggers the body's mechanisms that cause low-grade inflammation within the inner walls of the miles of blood vessels in the body. It is this inflammation which, in large measure, starts one on the road to a heart attack, a stroke, a blocked artery to the leg or even to a kidney. In advanced situations, if left untreated, it may cause all of the above and more. You see, the deleterious effects of obesity are so widespread they can't be neatly confined to just the heart and, as suspected, the one-word answer, inflammation, isn't the only explanation. In addition to the damage caused to the inside of the arteries, obesity is causally related to high blood pressure, sleep apnea, diabetes, and even some forms of cancer.
Since so many people are already on the road to overweight/obesity (currently 62% of the adult American population), we have to understand why we gain weigh incessantly, seemingly without cause. Unless we interrupt this trend, our children are in danger of becoming the first American generation to have a shorter life span than the preceding one.
If we take in more calories than we burn, especially in the form of simple carbohydrates, we will become first overweight, then, if the cycle is uninterrupted, we will become obese (defined as a weight greater than 20% above your ideal body weight). For a variety of reasons, when you get enough fat cells stored up within the abdomen, they collectively turn into a "gland." A gland secretes messengers. One of these messengers is normal and helpful and is called leptin. It tells the brain we're full and we've eaten enough. As we acquire more and more fat cells, and they also become larger in size, leptin is put out in greater supply, but the brain starts to ignore it. Therefore, we never sense that we are full and continue to eat too much food.
These cells also put out more dangerous chemical messengers too. These call into play all the cells responsible for inflaming the inside of arteries. This resultant inflammation, just like a sore on your hand that refuses to heal, creates a heap of tissue inside your artery. It contains cholesterol and is covered by a little cap. If this cap splits open and inflammation makes this more likely, a blood clot is apt to ensue and a heart attack follows if this happens to be inside one of the arteries leading to the heart.
While this does, indeed, occur most commonly to the arteries supplying the heart, the very same mechanisms frequently are occurring throughout all the arteries of the body, even those supplying the brain with blood.
But other obesity-related processes put the heart at risk, too. Obstructive sleep apnea, almost always associated with obesity, causes massive heart "strain" during sleep, which is interrupted every time the fatty tissue of the jowl drops down to obstruct the airways. Frequently, a common heart rhythm disturbance, called atrial fibrillation, accompanies this.
High blood pressure almost always accompanies obesity. So does adult-onset diabetes, usually the insulin resistant form. Paired together, these are the components leading to most strokes and kidney failure.
It turns out that what is good for the heart is always good for the brain--and even the eyes! These are things like olive oil (a monounsaturated fat instead of saturated fat), omega-3 fatty acids (found in fish and other foods), phytonutrients (heavily pigmented plant nutrients) and exercise. Not only that, but some of these, the omega-3s, help arthritis! Why? Because these are the simple things that quell inflammation. They also frequently drop high blood pressure and cholesterol levels.
Well, the converse is also true. Obese people who don't predominantly use olive oil, don't usually take in enough omega-3s, and don't usually exercise, are not only more apt to develop problems with their heart and blood vessels, but are also more apt to develop cognitive impairment than their more health-conscious contemporaries. In other words, people who exercise, follow the Mediterranean diet laden with vegetables, olive oil and omega-3s are less apt to develop not only obesity and heart damage, but Alzheimer's as well.
Additionally, there are also at least four cancer types that seem to be frequently driven by over-nutrition: breast, prostate, colon, and uterine endometrial. If a cancer cell develops when your cells replicate, these same inflammatory messengers just draw in "fast food" for the cancer cell.
Obesity shortens lives. Many of us should heed the advice of two great Americans. For, as Benjamin Franklin put it so many years ago, "One should eat to live, not live to eat." Another great thinker added his admonition many years later. It was John F. Kennedy, who said, "We are under-exercised as a nation. We look instead of play. We ride instead of walk. Our existence deprives us of the minimum of physical activity essential for healthy living."
Dr. Gerry Maddoux is a Board Certified Cardiologist and Fellow of the American College of Cardiology and the American College of Chest Physicians. He has been practicing cardiology for over 30 years. To learn more about Dr. Gerry Maddoux or to purchase a copy of his book, please visit www.lovingyourheart.com