Vitamins raise levels of bad cholesterol

ANI[ TUESDAY, MAY 04, 2004 08:26:43 PM ]

WASHINGTON : A new study conducted at the New York University School of Medicine suggests that vitamins, such as E, C, and beta carotene could raise the production of the bad form of cholesterol in the liver, which transports cholesterol into the artery walls.

According to Edward A. Fisher, who leads the study, "It does appear that antioxidant vitamins may be potentially harmful for the heart based on their ability to increase the secretion of VLDL in the liver cells and in the mice that we studied."

After its secretion from the liver, VLDL is converted in the bloodstream to low-density lipoprotein (LDL), the so-called bad form of cholesterol. The liver is the major source of atherosclerosis-causing lipoproteins.

Overall, antioxidants usually have been considered healthful. The vitamins scavenge "free radicals," which are highly reactive and damaging forms of oxygen produced by natural metabolic processes in the body and by external sources like the sun's UV rays, ozone, and toxins in pesticides, among other things.

The new study by Dr. Fisher and his colleagues however indicates that antioxidants hamper a process in the liver that prevents the production of harmful lipoproteins. When cells are under "oxidative stress," free radicals produced by the normal conversion of polyunsaturated fatty acids to lipid peroxides bombard the cells.

The scientists discovered that liver cells respond by activating a pathway that breaks down ApoB100, a critical protein component of VLDL and other harmful lipoproteins. Deprived of ApoB, the liver cannot now produce these bad lipoproteins and their secretion into the bloodstream is reduced substantially.

The scientists also found that the polyunsaturated fatty acids increased the generation of lipid peroxidation products and stimulated the PERPP pathway. In addition to the studies with liver cells in laboratory dishes, they also demonstrated the relationship between lipid peroxidation and reduced production of bad lipoproteins in living mice.

Dr. Fisher plans to conduct further experiments in mice to confirm these findings. "Direct experimentation in people to explore the inner workings of the liver is difficult but there are already observational studies in normal people showing that a diet enriched in polyunsaturated fats increases blood levels of lipid peroxides and decreases levels of VLDL and LDL," said Dr. Fisher

I don't know what to make of this. It runs counter to what we believed before. Antioxidants good. Polyunsaturated Bad.

"Antioxidants for greyhounds? Not a good bet.(research indicates giving megadoses of antioxidants impairs speed of race greyhounds)"

http://www.findarticles.com/cf_dis/...1/article.jhtml

You know what I'm thinking?

Week after week I read about studies on this board. I read about stuff on Google. I hear stuff on the news. I scan Pub Med.


Bottom line? My impression?

Nobody has a clue. About ANYTHING. Studies show anything and everything. Studies are all tweaked to prove what they set out to prove.

I have half a mind to stop reading all this stuff. (No offense gotbeer. I appreciate your diligence.)

I feel better eating low-carb. I feel even BETTER when I don't read all the crap that hits the media every day.

Call it blissful ignorance if you want. I say it doesn't matter. No one has a clue, anyway.

Sorry. I've just had it.

I'd have to agree witih the last. Seems like the more people know, the less they know for certain. Look at politics, globall warming, etc. Where is George Carlin when we need him??

The problem with these articles is there are SO MANY variables which affect outcome. Because they don't control for relevant variables it's hard to identify the true cause of problems.

Here are just a few very important variables which weren't even mentioned in the study:

What sort of lifestyle did these people lead? Was it low in stress, low in toxins (smoking, drinking, pesticides, drugs, etc), low in energy usage (strenuous exercise, over-eating)?
What was the diet like? Were they eating lots of sugars? What composition of fat was consumed (was it too low in saturates and too high in PUFA)? Did they eat a lot of "damaged fats" (fried foods, trans-fat)?
Most important of all, did they make sure to examine people from a wide variety of lifestyles & diets and then observe the effects of anti-oxidants?

Not controlling for these variables makes any conclusions drawn from anything else near worthless, because all of the above activities increase free radical activity. Oxidative stress results in free radicals which contributes to everything that can be considered a result of aging. If the environments and diets were all the same or similar, who's to say it's not the diet or lifestyle which is causing the problems, and the anti-oxidants are just increasing the rate at which the body "mops up the mess" so to speak? Let me explain...

I'm convinced the way the medical establishment views cholesterol is all wrong. Cholesterol is itself not some foreign disease-causing substance that needs to be targeted and eliminated. When your body elevates production of cholesterol it is a sign that really bad things are going on inside of you. Cholesterol is what your body produces in response to some deterioration caused by some other process. High cholesterol is reactionary to damage that is done, it doesn't cause damage. Think of cholesterol as a tourniquette... you use a tourniquet to deal with an immediate threat, but if nothing is done about that threat the tourniquet might cause gangrene. But the tourniquet wouldn't be needed if not for the life-threatening wound, would it? Deal with whatever is causing cholesterol to rise. Refusing to deal with the real problem and then blaming cholesterol for whatever happens is kind of like sitting there, limbs rotting and bleeding to death, and blaming the existence of your tourniquet for your plight.

If you view cholesterol in this light, as a "necessary evil" produced by your body in response to high frequency of cellular & tissue stress/damage, the fact that cholesterol would rise with high anti-oxidant intake coupled with an oxidative-stress inducing diet & lifestyle makes sense.

Cholesterol is a line of defense in cellular damage, its a repair material. If anti-oxidants are believed to protect from free-radical damage, it makes sense that anti-oxidants would cause cholesterol to rise if the body were in an environment where it is exposed to an unnecessarily high level of oxidative damage. The cholesterol rising is your body's attempt to "heal" itself from the damage done. Anti-oxidants promote such activity. The anti-oxidants aren't responsible for the "unfavorable" blood lipids, the cause of the oxidative stress is.

Of course I am just theorizing. We actually don't know if the people in the study all ate very different diets and lived very different lifestyles and still everyone saw a similarly sharp rise in cholesterol. That's because the study was flawed, or the way it was reported by press was flawed. Either way, linking "the evil cholesterol" and its associated diseases with anti-oxidants based on the above evidence is a little premature, IMO.

I don't know that the problem is the studies so much as it is the media reporting on the studies. We don't really have much of a context or enough information to make any sort of decision if the study should be taken seriously or not. One study proves nothing. You can't really take anything seriously until you see many studies done showing similar results.

But I think one thing is certain, its best to get your vitamins and minerals from your diet rather than rely on supplements.

I think the people in this study were of the rodent sort

Good points nevertherless.

Yes... this was done on mice. Naturally mice are avid grain eaters, whereas grain has not been in the human diet long enough to affect human evolution. Although there are some systemic similarities between humans and mice that make mice good case studies, I think there are enough differences to take these mousy studies with a grain of salt (or wedge of cheese, if you will).

I will point out, however, that Dr. Atkins has always championed a variety of different types of fats. In fact, in the Age Defying Diet, I believe, he discusses the pros of saturated fats vs. some of the other types of fats.

Thus from what I've read, an imbalance of dietary fats is not a good thing... too much Omegas of one kind or another is supposed to damage the cardiovascular system. Only consuming polyunsaturated fat and eliminating the saturated and mono-unsaturated fats is NOT heart healthy, at least according to Dr. A and his studies (which have not steered me wrong yet--and which is why I have not left Atkins as my WOL nor do I ever plan to).

In addition, the combination of high fat and high carb does all sorts of mayhem with cholesterol and triglycerides and ultimately leads to heart disease.

All this is predicated on the belief that low density lipoproteins are bad for you and will make you die of heart disease. I don't believe this has in fact been clearly demonstrated. As with all the research related to cholesterol, it is all correlational. Also, the rules for cholesterol levels change as you age anyway..the older you are (over 50), the better off you are with higher levels of cholesterol.

Val

More on the dangers of antioxidants:

ANTIOXIDANTS CAN HARM

Gabe Mirkin, M.D.

Many people take large doses of antioxidant vitamin pills, even though there is little evidence that large doses of antioxidant pills prevent disease, and there is some evidence that they may cause disease. Does it bother you that taking large doses of beta carotene, which is vitamin A, increases risk for heart attacks in men and increase risk for lung cancer in smokers? Does it bother you that large doses of vitamin C do not prevent colon cancer, and do not prolong life in people with cancer? Other studies show that large doses of vitamin E do not prevent lung cancer, heart disease or stroke, or that large doses of selenium do not prevent cancer.

Last year, Barry Haliwell of the National University of Singapore wrote an article in the British medical journal, Lancet, explaining why large doses of antioxidant vitamins sometimes prevent cancer and sometimes cause it. Every chemical reaction in the body releases chemicals called free radicals that damage tissue, which releases certain metals into the cell fluid. Antioxidants convert these free metals, which are harmless, to powerful oxidants that cause further cell damage. So sometimes antioxidants protect cells and other times, they damage them. For example, paraquat is a powerful cancer-causing chemical. If you give vitamin C to animals before giving them paraquat, the vitamin C prevents cells damage and helps protect them from cancer, but if you give these same animals vitamin C after they take paraquat, the vitamin C spreads the cancer. The paraquat causes cells to release large amounts of minerals and the vitamin C then causes these minerals to damage cells and spread the cancer. For this reason and others, the American Cancer Society advises patients not to take large doses of vitamins A, E, C and selenium.

Another reason not to take large doses of antioxidant vitamins is that free radicals kill cancer cells. Rapidly multiplying cancer cells take up antioxidants and use them to protect the cancer cells from being destroyed by oxidants. So antioxidant vitamins can protect preexisting cancer cells from being damaged by oxidants, to spread the cancer. If you think we know all about antioxidants, you do not understand the tremendous controversy going on right now. You should get all the vitamins that you need from the food that you eat. If you want to take recommended dietary allowances of vitamins, go ahead, there is little evidence that you will harm yourself. However when you take large doses of any vitamin, you don't have the foggiest idea whether you are harming yourself and I do not recommend large doses of vitamins to anyone.

http://www.drmirkin.com/nutrition/9384.html

I'd love to see the source for this. Not challenging you--just really curious.

Anderson KM. Cholesterol and Mortality. 30 Years of Follow-up from the Framingham Study. JAMA 1987 Apr 24;257(16):2176-80


Val

Vitamin C can be used as an abortive.

Here's another report on the start article. It does seem to add up to a confusing mess sometimes. I have seen potential benefits of Vitamins (especially E) quetioned before. However, as ItsTheWooo says, the prevailing perception of cholesterol is so warped, anything reported like this is suspect. I think the Eskimos have it right - just eat blubber and combine that with red wine and you'll live to an old age. Red wine antioxidants seem to work so far - thank God.

**************

Vitamin E May Increase 'Bad' Cholesterol
Study says it undoes process that destroys LDL in liver
By Steven Reinberg
HealthDay Reporter


MONDAY, May 3 (HealthDayNews) -- You've probably heard that antioxidants such as vitamin E are good for you, but new research finds antioxidants may actually help produce "bad" cholesterol.

Experiments in cells and mice indicate that oxidation is necessary to reduce the amount of low-density lipoprotein (LDL) cholesterol produced in the liver. That's why polyunsaturated fatty acids, which are oxidants, can reduce cholesterol production.

Oxidation, also called oxidant stress, is a chemical reaction of a substance with oxygen. In the body, oxidant stress releases free radicals that damage cells.

"Not all oxidant stress is bad for you," said lead researcher Dr. Edward A. Fisher, a professor of cardiovascular medicine and cell biology at New York University. "Oxidant stress also has some benefits in terms of the cardiovascular system, by decreasing the liver production of the lipoproteins that cause atherosclerosis."

"Sometimes oxidative stress is good, and sometimes it's bad," said co-researcher Dr. Kevin Jon Williams, a professor of medicine at Jefferson Medical College. For example, humans breathe oxygen because they need oxidation to convert food into energy, and oxidant stress is also how the immune system kills bacteria, he added.

Fisher's team found liver cells under oxidative stress release free radicals made by the normal conversion of polyunsaturated fatty acids to so-called lipid peroxides.

When these free radicals are released, they destroy a critical protein called ApoB100. Without ApoB, the liver cannot make LDL cholesterol, and the amount of cholesterol released into the blood is therefore substantially reduced.

The researchers found that when vitamin E was introduced to these liver cells, it prevented the destruction of ApoB, which lets the liver make more LDL cholesterol, according to their report in the May issue of the Journal of Clinical Investigation.

In large studies, "vitamin E has flunked as a protection against coronary artery disease," Fisher said. So the "blanket recommendation for the use of antioxidants, such as vitamin E, for lowering the risk of heart disease is not warranted."

However, the findings also confirm that diets rich in polyunsaturated fatty acids, such as those found in fish, can substantially reduce the amount of bad cholesterol your body makes, Fisher added.

Williams said the he would "take vitamin E supplements only in circumstances where there has been proven clinical benefit, and that is not the case in cardiovascular disease."

Dr. Ronald Krauss, director of atherosclerosis research at the Children's Hospital Oakland Research Institute, said this study shows how diet can affect blood fat levels.

"This study reminds us that even though there are number of benefits of antioxidants in the diet, we can't assume that all antioxidants will benefit all aspects of health," said Krauss, who wrote an accompanying editorial.

There may be a lack of benefit from antioxidants on blood fat levels, Krauss said. "In order to determine whether antioxidants benefit heart disease, we have to rely on clinical studies," he noted.

"The studies that have been done to date have not shown a benefit from antioxidants. Maybe this study gives us one reason for that negative result," Krauss said.

"If one wants to take advantage of antioxidants, which can have many health benefits, one should rely on eating foods that are rich in antioxidants and not rely on taking supplements to prevent heart disease," Krauss advised.

More information

The American Heart Association can tell you about cholesterol, and the National Institutes of Health has more on vitamin E.


SOURCES: Edward A. Fisher, M.D., Ph.D., professor, cardiovascular medicine and cell biology, New York University, New York City; Kevin Jon Williams, professor, medicine, Jefferson Medical College, Philadelphia; Ronald Krauss, M.D., director, atherosclerosis research, Children's Hospital Oakland Research Institute, Oakland, Calif.; May 2004 Journal of Clinical Investigation