Cholesterol Dilemma : Bad or Good ?

Some decades back, the US government released warnings about the damage the devil Cholesterol can do to our body. 40 years passed going by that notion and Cholesterol was put in the bad light. You possibly have found, every other layman guiding and lecturing about the ills Cholesterol would to do your body. Regardless of the cause, high  cholesterol poses dangers. It plays a major role in the development of atherosclerosis, or hardening and narrowing of the arteries, which in turn raises the risk of heart attack and stroke. Cholesterol has been a fixture in dietary warnings in the United States at least since 1961, when it appeared in guidelines developed by the American Heart Association. Later adopted by the federal government, such warnings helped shift eating habits per capita egg consumption dropped about 30 percent and harmed egg farmers.

As far back as the 19th century, scientists recognized that the plaque that clogged arteries consisted, in part, of cholesterol. What the  early scientists may not have foreseen is how complicated the science of cholesterol and heart disease could turn out that the body creates cholesterol in amounts much larger than their diet provides, that the body regulates how much is in the blood and that there is both “good” and “bad” cholesterol.

Crashing all the believes, that were injected in the society by nutritionists some years before, a new finding follows an evolution of thinking among many nutritionists who now believe that, for healthy adults, eating foods high in cholesterol may not significantly affect the level of cholesterol in the blood or increase the risk of heart disease. The greater danger in this regard, these experts believe, lies not in products such as eggs, shrimp or lobster, which are high in cholesterol, but in too many servings of foods heavy with saturated fats, such as fatty meats, whole milk, and butter.

A top nutrition advisory panel has decided to drop its caution about eating cholesterol-laden food, a move that could undo almost 40 years of government warnings about its consumption. The group’s finding that cholesterol in the diet need no longer be considered a “nutrient of concern” stands in contrast to the committee’s findings five years ago, the last time it convened. During those proceedings, as in previous years, the panel deemed the issue of excess cholesterol in the American diet a public health concern.

The change on dietary cholesterol also shows how the complexity of nutrition science and the lack of definitive research can contribute to confusion for Americans who, while seeking guidance on what to eat, often find themselves afloat in conflicting advice. Yet even today, after more than a century of scientific inquiry, scientists are divided. Some nutritionists said lifting the cholesterol warning is long overdue, noting that the United States is out-of-step with other countries, where diet guidelines do not single out cholesterol. Others support maintaining a warning.

The forthcoming version of the Dietary Guidelines the document is revised every five years is expected to navigate myriad similar controversies. Among them: salt, red meat, sugar, saturated fats and the latest darling of food-makers, Omega-3s.

Now comes the shift on cholesterol.

Yet many have viewed the evidence against cholesterol as weak. As late as 2013, a task force arranged by the American College of Cardiology and the American Heart Association looked at the dietary cholesterol studies. The group found that there was “insufficient evidence” to make a recommendation. Many of the studies that had been done, the task force said, were too broad to single out cholesterol.

The current U.S. guidelines call for restricting cholesterol intake to 300 milligrams daily. American adult men on average ingest about 340 milligrams of cholesterol a day, according to federal figures. That recommended figure of 300 milligrams, is just one of those things that gets carried forward and carried forward even though the evidence is minimal.

Other major studies have indicated that eating an egg a day does not raise a healthy person’s risk of heart disease, though diabetic patients may be at more risk.

The persistence of the cholesterol fear may arise, in part, from the plausibility of its danger. It would have seemed logical, then, that a diet that is high in cholesterol would wind up clogging arteries. In 1913, Niokolai Anitschkov and his colleagues at the Czar’s Military Medicine Institute in St. Petersburg, decided to try it out in rabbits. The group fed cholesterol to rabbits for about four to eight weeks and saw that the cholesterol diet harmed them. They figured they were on to something big. In passing, the paper noted that while the cholesterol diet harmed rabbits, it had no effect on white rats. In fact, if Anitschkov had focused on any other animal besides the rabbit, the effects wouldn't have been so clear -- rabbits are unusually vulnerable to the high-cholesterol diet. That was 40 or so years ago. We still don’t know what explains the difference.

But it wasn’t until the 1940s, when heart disease was rising in the United States, that the dangers of a cholesterol diet for humans would come more sharply into focus. Experiments in biology, as well as other studies that followed the diets of large populations, seemed to link high cholesterol diets to heart disease.

Public warnings soon followed. In 1961, the American Heart Association recommended that people reduce cholesterol consumption and eventually set a limit of 300 milligrams a day. (For comparison, the yolk of a single egg has about 200 milligrams.)

Eventually, the idea that cholesterol is harmful so permeated the country's consciousness that marketers advertised their foods on the basis of "no cholesterol." Adding to the complexity, the way people process cholesterol differs. Scientists say some people -- about 25 percent -- appear to be more vulnerable to cholesterol-rich diets. “It’s turned out to be more complicated than anyone could have known,” said Lawrence Rudel, a professor at the Wake Forest University School of Medicine. “Eggs are a nearly perfect food, but cholesterol is a potential bad guy,” he said. “Eating too much a day won’t harm everyone, but it will harm some people.”

Scientists have estimated that, even without counting the toll from obesity, disease related to poor eating habits kills more than half a million people every year. That toll is often used as an argument for more research in nutrition.

The turn around on cholesterol, some critics say, is just more evidence that nutrition science needs more investment.

Others, however, say the reversal might be seen as a sign of progress.

In science, change is normal and expected. When our view of the cosmos shifted from Ptolemy to Copernicus to Newton and Einstein, Allison said, “the reaction was not to say, ‘Oh my gosh, something is wrong with physics!’ We say, ‘Oh my gosh, isn’t this cool?’