Saturday, December 11, 2010

Cholesterol Do's and Don'ts for Diabetics (and Non-Diabetics, Too)

All too often doctors use total cholesterol as a measure of statin deficiency. In much of the world, as soon as your total cholesterol reaches 200 to 220 mg/dl, boom, it's a prescription for some statin drug, such as Crestor (rosuvastatin) Lescol (fluvastatin), Lipitor or Torvast (atorvastatin), Lipostat or Pravachol (pravastatin), Litava or Pitava (pitavastatin), or Zocor or Lipex (simvastatin).

Anywhere statin warnings are much more in the news, the test is usually your LDL or so-called "bad" cholesterol. The threshold for treatment recently has been lowered.

  • For high-risk patients (those with a 10-year risk of a cardiac event of 20%): The LDL cholesterol should be lowered to below 100 mg/dL, and consideration should be given to lowering it to below 70 mg/dL.
  • For moderately high-risk patients (those with a 10-year risk of a cardiac event between 10 and 20%): LDL cholesterol should be lowered to below 130 mg/dL, and consideration should be given to lowering it to below 100 mg/dL. 
  • For intermediate-risk patients (those with a 10-year risk of a cardiac event less than 10%): LDL cholesterol should be lowered to below 130 mg/dL.
  • For low-risk patients (those with a 10-year risk of a cardiac event less than 1%): LDL cholesterol should be below 160 mg/dL.
Your official risk factors include smoking, a personal history of a heart attack, a family history of a heart attack, high blood pressure, and type 2 diabetes. If you check "yes" in any of the boxes for these factors in your intake chart, it's highly likely your doctor will feel compelled to offer you a statin drug.

There are two big problems with prescribing statin medication on the basis of your cholesterol levels. One is that if you are a type 2 diabetic, how high your LDL numbers go doesn't really predict whether you will have a heart attack. And also, if you are not a type 2 diabetic, your  LDL numbers and total cholesterol numbers don't really predict heart attack risk, either.

Even worse, if you aren't a type 2 diabetic yet, taking statins to lower your cholesterol may slowly and insidiously raise your blood sugar levels so that you become a type 2 diabetic. And since doctors almost never run the very simple test (it costs less than US $0.20 for a test strip) at the right time to tell you whether this is happening, you'll just get fatter and fatter, your doctor probably blaming you for not staying on your diet, until one day you discover you also have diabetes. This is not even to mention other statin side effects, that frequently include memory loss, and sometimes include muscle tissue damage caused rhabdomyolysis, which in turn puts tremendous stress on the kidneys as they attempt to clear out damaged proteins.

It doesn't have to be this way. But you will need to understand some things about cholesterol, heart attacks, insulin, and blood sugar that most doctors don't to get good care.

Cholesterol does not clog your pipes. For over 50 years, misinformed "experts" have explained the dangers of cholesterol in terms that are more appropriate for plumbing. Your arteries and veins are not pipes. They are living tissue capable of expanding and contracting to regulate blood flow. Most heart attacks occur when blood vessels cannot flex themselves to accommodate changes in flow, not just because they are "clogged."

Cholesterol can form obstructions in arteries, but it's not just any kind of cholesterol that does this. Even "bad" LDL cholesterol is, for the most part, harmless. But the lab test you are likely to get, even in the United States, that tells you your cholesterol numbers doesn't actually measure LDL cholesterol at all. Worse for type 2 diabetics, the better care you take with your blood sugar levels, the more likely this test is to be wrong.

Why doctors get bad LDL numbers for type 2 diabetics and everybody else. The way to measure true LDL cholesterol levels is to count the number of carrier molecules that make their fatty parts soluble in the bloodstream. Fats are not soluble in water, so the only way cholesterol can get around in your bloodstream is if it is attached to a water-soluble protein. Every molecule of LDL cholesterol is attached to a carrier protein called apolipoprotein B (abbreviated APO B).

It is quite expensive to measure APO B in order to get a truly accurate LDL number. The cost of a true LDL test could run more than all the other tests your doctor orders at your checkup, well into the hundreds of dollars. The US $500 for an APO B test is often not covered by American health insurance plans, and if you live in a country with a national health scheme, even if your doctor orders it, the receptionist or the clerk handling your forms may cross it off the list.

Labs typically estimate LDL levels by:

1. Measuring total cholesterol.
2. Measuring the denser, easy to separate, HDL or "good" cholesterol, and
3. Then assuming any cholesterol you happen to have in your blood that isn't HDL or LDL is 1/5 as much as your triglycerides.

Most people don't know that there is yet another major class of cholesterol, VLDL or very low-density lipoprotein. The typical rule of thumb is that you'd have 1/5 as much VLDL as triglycerides (from which it is formed).

So the equation is:

1. Take total cholesterol.
2. Subtract HDL.
3. Subtract triglycerides x 1/5.
4. And the answer is supposedly your LDL.

But suppose you are non-diabetic who has been taking fish oil, eating nuts, using microalgae capsules, or generally consuming the healthy fats that protect the heart. Or you are a diabetic who has been diligently taking care of blood sugar levels.

Your triglycerides go down, so your LDL appears to go up.

Suppose before you started taking better care of yourselfl, you had:

Triglycerides: 400 mg/dl
Total cholesterol: 180 mg/dl
HDL: 45 mg/dl

Then your estimated LDL would be 180 - 45 - (1/5 of 400) or 55.

But then you work really hard at getting your triglycerides down. You take fish oil. You're really careful with your carbohydrates. Or if you are diabetic, you carefully keep your blood sugar levels down. And you get your triglycerides all the way down to 100 mg/dl (5.5 mmol/L). Your total cholesterol stays at 180 and your HDL stays at 45. (We'll use the American measuring system here because the math is easier to follow.)

And let's suppose your LDL didn't really go up--but the estimate will be off:

180 - 45 - (1/5 of 100)= 115.

So you're reward for getting your triglycerides down will be your doctor will want to put you on a statin for high LDL, even if your actual LDL stayed same, and even if your actual LDL went down.

Statins used to be quite expensive. They are now relatively affordable, even if you have to buy them yourself. But in addition to the usual statin side effects, there is a problem most doctors have never heard of. Using statins induces the insulin resistance that first causes weight gain, and then all too often causes type 2 diabetes.

How using statin drugs may make or keep you diabetic. About 10 years ago, Dr. David Jenkins and his colleagues at the University of Toronto in Canada conducted a study of dietary change versus statin medications for lowering cholesterol levels. The Canadian research team found that it was actually more productive to use dietary fiber, plant stanols (products like Cholest-off), and small amounts of soy protein, preferably from edamame and tofu rather than from industrially processed soy protein meat substitutes. 

The Canadian doctors did not question whether lowering cholesterol was a valid objective. But buried deep in the paper was a note that taking statin drugs raised insulin levels. And that explains more recent findings that vast numbers of people given statins for cholesterol develop type 2 diabetes.

The reason high insulin levels lead to weight gain and then type 2 diabetes has to do with the phenomenon of insulin resistance. Insulin, as you probably know, transports sugar out of the bloodstream and into cells.  Too much sugar, however, would cause the energy-making machinery of the cell to "burn too hot" and produce free radicals of oxygen that damage DNA. To keep from absorbing too much sugar, most kinds of cells in the body have the capacity to "shut down" receptor sites for insulin when either blood sugar levels or blood insulin levels are high.

Transporting sugar, however, is not the only thing insulin does. This vital hormone also transports fat. When insulin levels go up high enough to induce insulin resistance, cells fail to absorb sugar, but are primed to receive fat. This is one of the reasons people who take statin drugs often gain weight. 

To be sure, eating too much is also required! However, the process of storing fat becomes much more efficient. Type 2 diabetes probably requires additional genetic and environmental triggers, but in many cases the scenario runs something like this.

The person who is on statin medications gets an infection, has to have surgery, becomes extremely fatigued, or just has to follow a quirky diet for a few days or weeks. As we explain in our book Staying On Your Diabetes Diet, there are at least six genes that can be activated by life events that also contribute to insulin resistance.

The pancreas deals with the problem of too much insulin by making even more insulin. Eventually, there is no amount of insulin that keeps blood sugar levels normal, and type 2 diabetes results.

Doctors usually run the right test for type 2 diabetes at the wrong time. The reason type 2 diabetes "sneaks up" on so many users of cholesterol medication is that doctors using take fasting blood tests. Your pancreas has the ability to work all night to get blood sugars down to normal much longer than it has the ability to lower them in the hour or two after a meal. If doctors just took non-fasting blood sugar levels, then type 2 diabetes could be detected much earlier, while it is relatively easy to reverse. If you have been gaining weight, or if you have a family history of diabetes, you should ask your doctor to take a post-prandial, or after-meal, reading of your blood sugar levels just to make sure you are not on your way to becoming a diabetic. And if you are already a diabetic, you should be taking your post-prandial blood sugar readings to make sure your diet, exercise, and medication are really working for you.

What is the best cholesterol-lowering supplement? Are there foods to eat to lower cholesterol? Is there any one single food that lowers your cholesterol best?  First of all, you need to find out whether lowering your cholesterol levels really should be your highest priority. The people who most urgently need to lower cholesterol levels are those who have markers of inflammation called CR-P, or C-reactive protein. This is a sign that any excess cholesterol in your bloodstream is being transformed into the calcified crystals that actually clog arteries and veins. If you have had a blood test that shows you have high CR-P and high cholesterol, then you almost certainly will benefit from taking a statin. (If you take statins then you need to be aware of the impact of caffeine on statin efficacy. Caffeine from coffee and tea makes it harder for your heart to recover from oxygen deprivation after a heart atttack, if the statins don't actually work for you. And they often don't.)

Then, if you are someone who needs cholesterol control, try plant stanols and more fiber in your diet before you take statin drugs, if you possibly can. Stanols don't cause statin side effects, especially causing your to become diabetic or making your diabetes harder to control! Many, many diabetics find that taking a daily dose of a product like Cholest-Off is all they need to have great LDL numbers.

But if you really want to prevent a heart attack, it's probably more important to keep your blood sugar levels in control. Too much sugar in your bloodstream interferes with the action of nitric oxide, a healthy free radical that enables arteries to relax. That's why so many people have heart attacks after a big holiday meal, and it's also why about half the people who actually have heart attacks have normal or even low cholesterol!

It's also important to have normal blood pressure, to avoid supersizing any meal, and to minimize your consumption of fat at any one meal. The problem that causes heart attacks is not so much "clogs" as "sludge." The risk factors that really make a difference may be temporary, just lasting an hour or two after you eat. But if you keep you blood sugar levels in control, either naturally, because you are non-diabetic, or by good diabetes control, you are far, far less likely to suffer the sludge that cause dangerous cardiovascular events.

Selected references:

White SS et al. Apolipoprotein B but not LDL Cholesterol Is Associated With Coronary Artery Calcification in Type 2 Diabetic  Diabetes August 2009 vol. 58 no. 8 1887-1892 doi: 10.2337/db08-1794

Jenkins D.J., Kendall, C.W., Marchie, A., et. al. 2003. Effects of a dietary portfolio of cholesterol-lowering foods vs Lovastatin on serum lipids and C-reactive protein. JAMA. 290(4): 502-10.

Sattar, N., Preiss, D., Murray, H., et. al. 2010. Statins and risk of incident diabetes: A collaborative meta-analysis of randomised statin trials. Lancet. 375(9716): 735-42..

Read more about a list of foods to avoid for high cholesterol.

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