Cholesterol - What It Actually Is

• Cholesterol is a natural--and necessary--substance found in the body.cholesteral test supplies image by Pix by Marti from Fotolia.com
  
  The Center for Cholesterol Management defines cholesterol as a fatty, waxy substance that is normally found in the bloodstream and in practically every cell in your body. It is vital to many body processes, including healthy cell wall development, the production of important hormones, making vitamin D and aiding in the digestion of fats.
  
  

Good and Bad Cholesterol

• Good and bad cholesterol are labels given to the lipoproteins that carry the cholesterol through the body.human image by Byron Moore from Fotolia.com
  
  The two types of cholesterol that we hear about most frequently are named for the lipoproteins that transport the substance, rather than the cholesterol itself. HDL, or high density lipoprotein cholesterol is called the "good" cholesterol because its function is to carry excess cholesterol back from the cells to the liver, where it can be safely eliminated from the body.
  
  LDL, or low density lipoprotein cholesterol is called the "bad" cholesterol because it carries the cholesterol from the liver to the rest of the body. Again, this isn't a problem unless there is too much cholesterol being transported.
  
  Both of these molecules are carriers. Neither are actually good or bad in themselves. The "good" and "bad" stems from the levels at which they're present. Essentially, high cholesterol and the danger it presents to human health are the results of having far too much of an otherwise good thing.
  
  

Cholesterol as a Danger to Health

• Lipoproteins act like the packages that carry a gift through the mail.packages on white image by Photoeyes from Fotolia.com
  
  Sources agree that a certain level of cholesterol in the body is not only healthy, it's necessary for normal body metabolism and growth. The only time it becomes a danger to health is when it accumulates to levels beyond the body's ability to use or excrete it. Since cholesterol is not soluble in the blood, it must be transported to the rest of the body. The liver, which produces the cholesterol, also produces the lipoproteins that carry it. As long as these are at safe levels, there is no danger.
  
  When cholesterol levels exceed that point, the lipoproteins that transport it begin to build up in the blood vessels, especially those that serve the brain and the heart. It works like this: the liver sends cholesterol out through the body in much the same way as you might send a gift to a relative through the mail. Since the gift can't go by itself, it must be boxed up and wrapped. If the postal service is inundated with more packages than it can deliver, the mail backs up and service slows down.
  
  The cholesterol is the gift and the lipoproteins are the boxes it's packaged in. If your bloodstream is inundated with more cholesterol "packages" than it can use or throw away, they will back up and collect on the walls of the arteries, causing hardened deposits. These deposits thicken until the blood vessels are too restricted to allow normal blood flow. The lack of nourishment and oxygen that blood provides to your brain and heart can cause stroke and heart disease. So we can see that although the slowdown in mail service due to heavy volume is an inconvenience, the consequences of a cholesterol build-up in the bloodstream are far more serious, and can be deadly.
  
  

Cholesterol, Genetics and Health

• High cholesterol has been linked to genetic variation.dna image by Allyson Ricketts from Fotolia.com
  
  As we've seen, a healthy human body produces much of its own cholesterol through the normal function of the liver. However, for some people, there are inherited tendencies that can cause the liver to produce too much. This condition is called hypercholesterolemia, a long word that simply means "too much cholesterol."
  
  According to Professor Patricia Munroe, Dr. Chris Wallace and Professor Mark Caulfield of the William Harvey Research Institute at Barts and the London School of Medicine and Dentistry, "Our study found new genes for serum LDL, the cholesterol which furs arteries, and serum urate, which can cause gout. We believe our findings are of significant clinical importance as they are strongly associated with cardiovascular disease; they also represent excellent targets for new medicines."
  
  People who fall into this category often find that diet and exercise are not enough to control their cholesterol levels, and therefore rely on medications to help them treat this condition.
  
  

Cholesterol and Food

• Since our bodies already produce all the saturated fat we need, we don't need any more from our food.cheeseburger and fries image by sumos from Fotolia.com
  
  There are two factors in food that influence cholesterol levels, according to the Harvard School of Public Health. These are food-borne fats and cholesterol itself, also present in food. Of the fats contained in foods, some are healthy and some aren't, and like our lipoproteins, they've been labeled "good" and "bad."
  
  People have been trying for decades to reduce their cholesterol levels and lose weight by reducing their fat intake to as little as possible. It hasn't worked for a couple of reasons. In the first place, it's impossible to completely eliminate fat from our diets because all foods, even vegetables, contain at least some fat. Vegetables contain the least (except fruits like avocados and a few others), and red meat and dairy products contain the most. According to the Harvard School of Public Health, the second reason lies in their discovery that reducing the total fat consumed is not the solution, because the total fat consumed is not really the problem. Instead, it's the overabundance of trans-fats and saturated fats as opposed to the healthier mono- and polyunsaturated fats that influences the levels of cholesterol found in our bodies.
  
  This happens because our bodies produce all of the saturated fat (this is fat usually found in a solid state, like butter, lard and the fat found in red meat) that we need for normal metabolism--and we do need some. However, since we produce all that we need for ourselves, whatever we eat is excessive. When we take in saturated fats through the food we eat, we flood our bodies with more fat and subsequently more cholesterol, than we can safely metabolize. The additional cholesterol in food contributes to the problem, as it is part of the excess. This is what raises the LDL levels in the bloodstream to the danger point.
  
  Since mono- and polyunsaturated fats are just that--unsaturated--they do not add to the body's already sufficient production of saturated fat and cholesterol. When we substitute these healthy fats for the unhealthy saturated fats found in so many of our processed foods, meat, butter and lard, we introduce less excess fat and cholesterol that would otherwise be added.
  
  

Healthy Cholesterol Levels

• Healthy eating habits help to reduce harmful cholesterol levels.healthy diet image by anna karwowska from Fotolia.com
  
  Sources agree that raising the good cholesterol in the body and lowering the bad will reduce the risk of heart attack and stroke. According to the American Heart Association, a healthy total cholesterol level for someone with no additional risk factors (smoking, obesity) is less than 200mg/dL (milligrams per decaliter), assuming their LDL and HDL totals are also at desirable levels.
  
  When looking at HDL or "good cholesterol" levels, the higher they are, the better. For the average man, optimal levels are at 50 to 60 mg/dL. For the average woman, optimal levels range from 60 to 70 mg/dL.
  
  LDL ("bad cholesterol") levels are just the opposite--the lower they are, the better. Ideally, LDL cholesterol should be kept at under 100mg/dL to keep the risk of heart disease and stroke as low as possible.
  
  Cholesterol is a necessary part of your body's daily requirement, and only becomes a risk when it becomes excessive. Healthy eating habits, exercise, and a nonsmoking lifestyle all contribute to achieving and maintaining healthy cholesterol levels, helping you to protect yourself from the dangers of having too much of a good thing.