There's a widely-known (among cardiologists) problem with nuclear stress tests. It's called the "false positive." (Nuclear stress tests are known as stress Cardiolites, stress thalliums, stress Myoviews, persantine stress tests, adenosine stress tests)

Stress tests, nuclear and otherwise, are helpful for identifying areas of poor blood flow. If an area of poor blood flow is detected and the area is substantial, then there may be greater risk of heart attack and other undesirable events in the relatively near future.

What "false positive" means is a stress test that shows an abnormality but it's not true--it is falsely abnormal. There are a number of reasons why this can happen. The problem is that this phenomenon is very common. Up to 20% of nuclear stress tests are false positives.

There are indeed situations where there may an abnormality and it is not clear whether it is true or false. This may lead to a justifiable heart catheterization or CT coronary angiogram. But, given the extraordinary number of false positives, there's a lot of gray in interpreting these tests. Hospital staff, in fact, call nuclear medicine "unclear" medicine. It's common knowledge that you can often see just about anything you want to see on a nuclear image of the heart. Abnormalities in the bottom of the heart, the "inferior" wall, are especially common due to the overlap of the diaphragm with the heart muscle, yielding the appearance of reduced blood flow. Defects in the front of the heart heart are common in females with large breasts for the same reasons.

The problem: The uncertainty inherent in nuclear stress tests opens the door to the unscrupulous or lazy practitioner. Any blip, tick, or imperfection on the nuclear images serve as carte blanche to drag you into the hospital for procedures.

This abusive practice is, in my experience, shockingly common for two reasons: 1) It pays better to do heart catheterizations, and 2) Defensive medicine.

What's the disincentive? Only doing the right thing and maintaining a clear conscience. Slim reasons for many of my colleagues--and a lot less money.

If you are without symptoms and feel fine, and a nuclear stress test is advised by your doctor, followed by a discussion of an abnormality, insist on a discussion of exactly what is abnormal, just how abnormal, and what the alternatives might be. If you receive unsatisfactory or incomplete answers despite your best effort, it's time for another opinion.

Magnesium is kind of boring. So most people don't pay too much attention to it.

Magnesium can be important, however. I saw an interesting phenomenon recently. A type I diabetic patient of mine (that is, an adult who developed diabetes as a child), Mitch, was experiencing wide swings in blood sugar: low low's and very high high's (300-400 mg/dl). Mitch's magnesium was only marginally low at 2.0 mEq/L. (Ranges for normal magnesium blood levels are usually 1.3–2.1 mEq/L or 0.65–1.05 mmol/L.) Note that Mitch's blood levels fall within "normal." I do not agree with these "normal" ranges. I shoot for 2.1 to 2.4 mEq/L, which I think is the truly normal range.

In addition to eating plenty of raw nuts and green vegetables, Mitch began supplementing magnesium with magnesium citrate, 200 mg twice a day (our preferred supplement form). He reported that the wide swings in blood sugar were nearly eliminated.

Mitch's dramatic benefit is just a great illustration of how magnesium can help control blood sugar metabolism. A type I diabetic is more sensitive to the effects, but anyone with type II (adult) diabetes, metabolic syndrome, or just a slightly high blood sugar could benefit from magnesium supplementation.

There's a number of ways to accomplish getting sufficient magnesium in your daily regimen. Track Your Plaque members, Be sure to read:

Your water may be killing you at
http://www.cureality.com/library/fl_03-002magnesium.asp

Magnesium: Water to the rescue! at http://www.cureality.com/library/fl_03-010magnesium2.asp

It struck me recently that, for many people, it's not the second but the third heart scan that more commonly shows a reduction in score.

I think this is because many people's reaction to their first heart scan is "This can't be. There's no way my arteries have that much plaque." They then follow a half-hearted program to correct their patterns.

When the second heart scan shows a significantly higher score, that really catches their attention. This is when they finally buckle down and give it their all.

Only the occasional person will, after the first heart scan, seize full control and take their program very seriously. These tend to be highly motivated people.

Don't feel too bad if your second heart scan score shows an increase. Look at it for what it represents: feedback on the adequacy of your program.

Peter started out at age 59 at 248 lbs, standing 6 ft tall (BMI = 33.6!).

Along with his weight, Peter had the entire panel of phenemena of the so-called "metabolic syndrome", or pre-diabetes:

--Triglycerides 238 mg/dl and associated with extremes of excess VLDL and IDL
--High blood pressure
--Blood sugar 115 mg/dl
--High c-reactive protein
--Small LDL particles 99% of total LDL

Interestingly, Peter's HDL was a surprisingly favorable 58 mg/dl (HDL is usually low in this syndrome). However, when broken down by size, he had nearly zero large, healthy HDL (sometimes called HDL2b). Though total HDL was favorable, most of it was simply ineffective.

Peter eliminated snacks and processed foods, particularly bread; increased his reliance on healthy oils and lean proteins; incorporated soy protein; increased vegetables. He added 30 minutes of a rapid walk on a treadmill every day. He added vitamin D to achieve a blood level of 50 ng/dml. He added a magnesium supplement.

Peter has lost 31 lbs. in the last year. Weight 207 lbs., BMI 28.1 (desirable <25). Blood sugar: 96 mg/dl; triglycerides: 56 mg/dl; HDL 71 mg/dl with 35% in the large fraction; small LDL 45% of total. Not perfect, but a damn site better.

Control of metabolic syndrome is an achievable goal for over 90% of people, just with these simple efforts. We haven't yet had a chance to assess the effect on the progression or regression of Peter's heart scan score, but he has, at the very least, spared himself a future of diabetes and all its complications.

This is a "slice" from a normal heart scan in a 58 year old woman. Heart scan score zero. Look at the lungs, the dark areas left and right of the heart in the center. The lungs are also normal. Black represents normal density, healthy lung tissue. The white streaking is just normal lung blood vessels. This person doesn't smoke.

This woman smokes a pack of cigarettes a day and has done so for 45 years ("45 pack-years"). She had a surprisingly low heart scan score (at age 64) of only 71, despite the smoking. However, look at this woman's lungs. It's a little tough to make out, since the computer graphics loses some of the resolution. But you can see the near absence of lung tissue on both sides. This is an advanced phase of the destructive lung disease, emphysema, from smoking. Even if she quit smoking today, the destroyed lung tissue never grows back. She literally has huge gaps or holes in her lungs where lung tissue used to be.

Smoking is among the most destructive, terrible things you can do to your body, short of swallowing strychnine or jumping off a building. Stay as far the heck away from cigarettes as you possibly can. If you are exposed to "secondary" smoke, insist that the person never smoke in your presence. It's not the smell that destroys your lungs or causes coronary plaque (though it is indeed foul), it's the actual smoke.

Do you need to become a vegetarian in order to reduce your heart scan score?

No. Plain and simple. We’ve had many non-vegetarians drop their scores.

That said, are there still advantages to following a vegetarian diet, or some variation on the vegetarian theme?

Yes, there are. Let’s put aside the moral or religious arguments in favor of not eating animals—the need to eliminate killing animals for food, elimination of suffering common in modern livestock practices, Kosher considerations, etc. (Not that there aren’t real arguments here. Our focus for this conversation is not, however, the moral dilemma, but the health argument.)

Some of the most unhealthy people I’ve ever met, mostly males, are proud carnivores who boast of their prodigious capacities to eat meat. Unfortunately, it’s hard to tease out the ill-effects of excessive meat eating, since these same men also tend to be substantially overweight, smoke, drink excessively, and fail to get exercise unless their job is physically demanding. You know the type.

What advantages does a vegetarian obtain? A number of studies have suggested that the reduced saturated fat, reduced exposure to parasites, as well as reduced exposure to the antibiotics and hormones now used routinely in livestock-raising practices, do indeed provide benefits to the vegetarian. Thus, vegetarians tend to be substantially thinner, experience less bowel cancer, have less diabetes and heart disease, and live longer.

(If you are interested in reading or seeing more about just how inhumane modern livestock practices are, take a look at the video, "Meet Your Meat" at meat.org. Be sure not to view this after dinner.)

Of course, some of the disadvantages of eating animal products diminish when free-range livestock are eaten, i.e., livestock not raised in the inhumane cramped, filthy conditions of livestock factories, but in the open, grazing or rooting freely. These animals tend to have different fat compositions and taste different.

The advantages of vegetarianism, however, have blurred in recent years, since many so-called vegetarians have failed to maintain the distinction between naturally-occurring foods and processed foods. So, Ritz Crackers, Oreo cookies, whole wheat bread, and Raisin Bran fit into a vegetarian program, but they’re awful for your health. I’ll occasionally meet a self-proclaimed vegetarian who looks every bit as unhealthy as a conventionally eating American, that is, overweight, pre-diabetic person with a developing heart scan score.

So it is not necessary to be vegetarian to reduce your score. You might consider vegetarianism for other reasons, such as moral considerations, or to reduce your risk for cancer. But it is not necessary to drop your heart scan score. A non-processed food diet? Now that's is worth giving serious consideration.

The American Heart Association just released a new set of consensus guidelines on heart disease prevention in women: Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women: 2007 Update

For those of you following the Heart Scan Blog and the Track Your Plaque program, there will be little new in the guidelines. In fact, you'll wonder if the date on the front of the report should be 1987, rather than 2007. Did you know that you should exercise and eat healthy?

Take a look at the list of risk factors for coronary vascular disease (CVD) listed in the report:

Major risk factors for CVD, including:
Cigarette smoking
Poor diet
Physical inactivity
Obesity, especially central adiposity
Family history of premature CVD (CVD at <55>

Progress: You'll notice that buried inside the list is "Evidence of subclinical vascular disease (e.g., coronary calcification)". Just a few short years ago that wouldn't have even been included.

The Track Your Plaque contention is that, for the great majority of women, this list could be shortened to one item: coronary calcification. As time goes on, the people who argue and draft these guidelines will come to the realization that coronary calcification is the disease--it's not a risk for the disease, a predictor of the disease. Coronary calcification is the disease itself. The other items on the list recede way into the background when you know whether or not coronary atherosclerosis is present, i.e., you know your heart scan score (of coronary calcium).

The report goes to say such things as taking a little bit of fish oil is a good idea, maintaining a normal blood pressure is desirable. . . yada yada yada. You've heard this all before.

A major part of the treatment guidelines are devoted to LDL cholesterol reduction with statin agents. You shouldn't be surprised. It's amazing what $22 billion dollars in revenues will buy.

A closing paragraph reads:

'Population-wide strategies are necessary to combat the
pandemic of CVD in women, because individually tailored
interventions alone are likely insufficient to maximally prevent
and control CVD. Public policy as an intervention to
reduce gender-based disparities in CVD preventive care and
improve cardiovascular outcomes among women must become
an integral strategy to reduce the global burden of
CVD.'

Say that again? If you understood that bit of gobbledygook, you're a lot smarter than me.

Don't look to the American Heart Association report for any new ideas. It reminds me of the politician who reminds everybody of what a devoted family man he is: It has nothing to do with his policies. It just makes him look good. If compared to prior report, the 2007 report does indeed represent progress--but just oh so little.

Take a look at this eye-opening statement taken from a well-written NY Times article about Dr. Arthur Agatston, the South Beach Diet and now South Beach Heart Program books:

'We have made major improvements in prevention,” Dr. Gregg W. Stone, the director of cardiovascular research at Columbia University, says. “But it’s difficult. It takes frequent visits, a close relationship between a physician and a patient and a very committed patient.'

Which is exactly the atmosphere Dr. Agatston’s practice tries to create. Nurses there give patients specific cholesterol goals to meet and help them deal with the side effects of the drugs they are taking. A nutritionist, Marie Almon, meets with patients frequently enough to discuss real-life issues like how to stick to a high-fiber Mediterranean diet even on a cruise or a business trip.

There is only one problem with this shining example of a medical practice: it is losing money.

From NY Times, January 24, 2007. What’s a Pound of Prevention Really Worth? (Find the full text at http://www.nytimes.com/2007/01/24/business/24leonhardt.html?ex=1172379600&en=4268a738e82857da&ei=5070.)

It gets at one of the fundamental reasons why your cardiologist will probably never talk to you about an intense approach to prevention: it doesn't pay. Because John Q. Cardiologist focuses, instead, on how to increase procedural volume, train how to put in the next best defibrillator, etc., there is little consciousness about preventive issues. Just the simple matter of taking fish oil causes their eyes to glaze over.

That's why the Track Your Plaque program exists: it is a portal for the kind of information you cannot get. Of course, you could read all the scientific studies, attempt years of trial and error, and try to gain a sense of how to do this yourself. Or you could follow this program. We are proud to not worry about generating procedural profits. We ar unbiased by drug or medical device money. We say exactly what we mean.

By the way, we are on a current push to really "beef-up" our online discussions via real-time chat. Long-term, we'd like to be able to offer chat with our staff many hours every day. Be patient. It will happen, but not today.

I know of no published reports on this question, but I've now seen numerous people experience significant jumps in HDL with raising blood vitamin D to 25-OH-vitamin D3.

Last week, for example, I had a man who had struggled with raising HDL from a starting level of 28 mg/dl. On niacin, exercise, weight loss, fish oil, red wine, and cilostazol (a prescription agent that I use occasionally that raises HDL), his HDL rose to 41 mg/dl--better, but hardly to our goal.

I added vitamin D, 4000 units, and raised his 25-OH-vitamin D3 level from 22 ng/ml to 53 ng/ml. Next HDL: 73 mg/dl! Small LDL improves along with a rise in HDL.

Not everybody's response is this dramatic. I see more typical rises of 5 to 10 mg/dl every day. I'm uncertain of why the response is inconsistent, though people who begin with lower vitamin D levels seem to experience a larger HDL increase. I wonder if the partial normalization of insulin and glucose responses is at work, or some anti-inflammatory effect.

Vitamin D provides so many other benefits, as well as HDL-raising. I hope you've gone to the effort to have your blood level checked to determine your replacement need. If not, now's the time. February represents your nadir (lowest point) for 25-OH-vitamin D3 blood levels.

"Eat food. Not too much. Mostly plants.

That, more or less, is the short answer to the supposedly incredibly complicated and confusing question of what we humans should eat in order to be maximally healthy. I hate to give away the game right here at the beginning of a long essay, and I confess that I’m tempted to complicate matters in the interest of keeping things going for a few thousand more words. I’ll try to resist but will go ahead and add a couple more details to flesh out the advice. Like: A little meat won’t kill you, though it’s better approached as a side dish than as a main. And you’re much better off eating whole fresh foods than processed food products. That’s what I mean by the recommendation to eat “food.” Once, food was all you could eat, but today there are lots of other edible foodlike substances in the supermarket. These novel products of food science often come in packages festooned with health claims, which brings me to a related rule of thumb: if you’re concerned about your health, you should probably avoid food products that make health claims. Why? Because a health claim on a food product is a good indication that it’s not really food, and food is what you want to eat."

Michael Pollan, author of my latest favorite book, The Omnivore's Dilemma, wrote a wonderful piece for the New York Times entitled "Unhappy Meals". You can find the full text at http://www.nytimes.com/2007/01/28/magazine/28nutritionism.t.html?ex=1172120400&en=a78c20f4da0cdc7b&ei=5070. (Another favorite read of mine, The Fanatic Cook's Blog at , alerted me to Pollan's article. Incidentally, take a look at the Fanatic Cook's latest posts--very entertaining and informative. She's got incisive insight into foods as well as a great sense of humor.)

Pollan goes on to say that...

"...typical real food has more trouble competing under the rules of nutritionism, if only because something like a banana or an avocado can’t easily change its nutritional stripes (though rest assured the genetic engineers are hard at work on the problem). So far, at least, you can’t put oat bran in a banana. So depending on the reigning nutritional orthodoxy, the avocado might be either a high-fat food to be avoided (Old Think) or a food high in monounsaturated fat to be embraced (New Think). The fate of each whole food rises and falls with every change in the nutritional weather, while the processed foods are simply reformulated. That’s why when the Atkins mania hit the food industry, bread and pasta were given a quick redesign (dialing back the carbs; boosting the protein), while the poor unreconstructed potatoes and carrots were left out in the cold.

Of course it’s also a lot easier to slap a health claim on a box of sugary cereal than on a potato or carrot, with the perverse result that the most healthful foods in the supermarket sit there quietly in the produce section, silent as stroke victims, while a few aisles over, the Cocoa Puffs and Lucky Charms are screaming about their newfound whole-grain goodness."

Not everything Pollan says is new, but he says it so eloquently and cleverly that he's worth reading. If you haven't yet read Omnivore's Dilemma, or just want a condensed version of the book, the New York Times piece is a great piece of the world according to Michael Pollan.

If you'd like to reduce LDL cholesterol with nearly as much power as a statin drug, think thyroid.

When thyroid is corrected to ideal levels, LDL cholesterol drops 20, 30, 40 mg/dl or more, depending on how poor thyroid function and how high LDL are at the start. The poorer the thyroid function (the higher the TSH or the lower the T3 and T4) and the higher the LDL cholesterol, the more LDL drops with thyroid correction.

(For those of you minding LDL particle size, such as Track Your Plaque Members, the "dominant" LDL species will drop: If you are genetic small LDL, small LDL will drop. If you have mostly large LDL because of being wheat-free and sugar-free, then large LDL will drop.)

One of the problems is that many healthcare providers blindly follow what the laboratory says is "normal" or the "reference range," which is usually nothing more than a population average (actually the mean +/- 2 standard deviations, a common method of developing references ranges). In other words, a substantial degree of low thyroid function, or hypothyroidism, can be present when your doctor adheres to the reference range provided by the laboratory.

What does it mean to achieve ideal thyroid status? My list includes:

--Normal oral temperature of 97.3 F first upon arising. (The thyroid is the body's thermoregulatory organ.)
--TSH 1.0 mIU/L or less
--Free T3 upper half "normal" range
--Free T4 upper half "normal" range
--You feel good: mental clarity, energy, upbeat mood. You lose weight when you try.

Iodine replacement should be part of any thyroid health effort. Iodine is not an optional trace mineral, no more than vitamin C is optional (else your teeth fall out). The only dangers to iodine replacement are to those who have been starved of iodine for many years; increase iodine and the thyroid can over-respond. I've seen this happen in 2 of the last 300 people who have supplemented iodine.

In my view, neglecting T3 replacement is absurd. While it is not clear to me why many otherwise healthy people have low T3 at the low range of "normal" or even in the below-normal range, people feel better and have better health--faster weight loss, reduced LDL, reduced triglycerides, they are happier and enjoy more energy--when T3 is increased to the upper half of the reference range. (Crucial question: Why is the 5'-deiodinase enzyme that converts T4 to T3 inhibited, resulting in reduced free T3? What is in our diets or environment that is exerting this effect? I don't have answer, but we sorely need one.)

It pays to be a perfectionist when it comes to thyroid. Not only do you feel better, but LDL cholesterol can drop with a statin-like magnitude, but with none of the adverse effects.

If interested, Track Your Plaque offers fingerstick blood spot testing that you can perform in your own home. Each test kit will test for: TSH, free T3, free T4, along with a thyroid peroxidase antibody (a marker for Hashimoto's thyroiditis, an autoimmune inflammatory condition of the thyroid).

What do you think of these chains of logic?

Cyanide is a potent lethal poison; carbon monoxide is a less lethal poison.
Therefore: plenty of carbon monoxide is good.

Having uterine cancer is a bad thing. Having uterine fibroids is a less bad thing.
Therefore: plenty of uterine fibroids are good.

These are obvious examples of seriously flawed logic. Students of logic and philosophy will recognize the above erroneous sequences as examples of the twisted arguments often used to persuade an argumentative opponent of the logic of a premise. As long ago as 335 B.C., Greek philosopher, Aristotle, recognized the pitfalls of thinking in such arguments. You think we’d know better by now.

Try this one:

White enriched flour is a bad for health; whole grains are less bad for health.
Therefore: plenty of whole grains are good for health.

Ouch!

In the 1960s, we all ate hot dogs on white buns, white flour Wonder Bread® sandwiches, Mom made cookies and cupcakes with white flour. Then, during the 1970s and 1980s, clinical studies were performed demonstrating that whole wheat and whole grains reduced colon cancer, high blood pressure, diabetes, and heart disease compared to white flour. In other words, add back fiber and B vitamins and health benefits develop: No argument here.

Therefore: whole grains must be good for health. Further, lots of whole grains?unlimited quantities of whole grains many times per day, every day?must be even better. Even the USDA says so on their nutrition pyramid, with 8-11 servings of grains per day, 4 of which should be whole grains, at the widest portion of the pyramid.

But what happens when you follow this logic through and fill your diet with whole grains?

Look around you and it’s easy to see: Appetite increases, people become obese, blood sugar increases, diabetes develops, HDL cholesterol plummets, triglycerides skyrocket, inflammatory patterns (e.g., c-reactive protein, or CRP) increase, small LDL (the number one cause for heart disease in the obese U.S.!) shoots through the roof.

I would no more fill my diet with “healthy whole grains” than I would close my garage door with the car running.

Pomegranate juice, 8 oz:

Sugars, total 31.50 g

Sucrose 0.00 g

Glucose (dextrose) 15.64 g

Fructose 15.86 g

In your quest to increase the flavonoids in your diet, do you overexpose yourself to fructose?

Remember: Fructose increases LDL cholesterol, apoprotein B, small LDL, triglycerides, and substantially increases deposition of visceral fat (fructose belly?). How about a slice of whole grain bread with that glass of pomegranate juice? The Heart Association says it's all low-fat!

(Coming on the Track Your Plaque website: A full in-depth Special Report on fructose in all its glorious forms and whether this is truly an issue for your health. Fructose tables and the scientific data to establish a safe "threshold" value will be included.)

Image courtesy Wikipedia

Honeydew melon:

Sugars, total 51.97 g

Sucrose 15.87 g

Glucose 17.15 g

Fructose 18.94 g

Because sucrose is half fructose (the other half is glucose), there are approximately 26 grams of fructose per one-half honeydew melon.

Image courtesy Wikipedia

Apple, 1 medium: Fructose 10.74 g

Honey: Fructose 17.19 grams per 2 tablespoons

Barbecue Sauce: HFCS number 1 ingredient

Ingredients: High Fructose Corn Syrup, Vinegar, Concentrated Tomato Juice (Water, Tomato Paste), Water, Modified Food Starch, Salt, Honey, Contains Less Than 2% of Molasses, Natural Flavor, Paprika, Spice, Mustard Flour, Guar Gum, Red 40.

A1 Steak Sauce: HFCS number 2 ingredient

Ingredients: Tomato puree (water, tomato paste), high fructose corn syrup, vinegar, salt, water dried onions, contains less than 2% of black pepper, modified food starch, citric acid, dried parsley, dried garlic, xanthan gum, caramel color, potassium sorbate and calcium disodium EDTA as preservatives, molasses, corn syrup, sugar, spices, tamarind, natural flavor

Another in a series of data extrapolations that attempt to predict long-term cancer risk from medical radiation exposure was published in the July 13, 2009 Archives of Internal Medicine, viewable here.

Over the years, I've fussed about the radiation dose used by some centers for CT heart scans. (Note: I'm talking about CT heart scans, not CT coronary angiograms, an entirely different test with different radiation exposure.) In the "old" days, when electron-beam devices (EBT) were the best on the block, the old single-slice CT scanners (the predecessor of the current 64-slice MDCT scanners) exposed patients to ungodly quantities of radiation, while the EBT devices required very small quantities (0.5 mSv or about the equivalent of 4 standard chest x-rays or one mammogram).

But CT technology has advanced considerably. While EBT has been phased out (although it was an exceptional technology, GE acquired the small California manufacturer, then promptly scrapped the operation; you can guess why), multi-detector CT (MDCT) technology has improved in speed, image quality, and radiation exposure.

While it has improved, radiation exposure still remains an issue. The authors of the study applied the scanning protocols used at three hospitals and those in several CT heart scan studies, then calculated radiation exposure. They found a more than ten-fold range of exposure, from 0.8 mSv to 10.5 mSv. (All scanners were MDCT, none EBT.)

That's precisely what I've been worrying about: In the rapid rush to develop new devices, radiation exposure has often been a neglected issue. While some scan centers do an excellent job and take steps to minimize exposure, others barely lift a finger and consequently expose their patients to unnecessary radiation.

However, it's not as bad as it sounds. For one, the study included 16-slice MDCT scanners, a scanner type that I warned people to not use because of radiation. On the current most popular 64-slice devices, much lower radiation exposure is possible, on the order of 0.8-1.2 mSv routinely--if the center takes the effort.

This study, while eye-opening, will achieve some good: CT heart scans are here to stay. But the day-to-day practice of heart scanning should be:

1) standardized
2) conducted with radiation exposure as low as possible, preferably <0.8 mSv

To read more about this issue, below I've reprinted a 2007 full Track Your Plaque Special Report, CT Heart Scans and Radiation: The Real Story.

CT heart scans and radiation: The real story

“My personal opinion is that many patients today who are receiving multiple CT scans may well be getting at least comparable doses to subjects that have now developed malignancies from x-ray radiation received in the 1930s and '40s. And, similar to those days when the doses were unknown, the dose that patients receive today over a course of years of multiple CT scans is also completely unknown . . .

“I recommend that all healthcare providers become familiar with the concept that 1 in 1000 CT studies of the chest, abdomen, or pelvis may result in cancer.”

Richard C. Semelka, MD

Professor and Vice Chairman, Department of Radiology

University of North Carolina–Chapel Hill

Is this just hype to generate headlines? Or is the truth buried in the enormous marketing clout of the medical device industry, among which the imaging device manufacturers reign supreme?

It’s been over 110 years since radiation was first used for medical imaging. Over those years, it has had its share of misadventures.

In the 1930s and 1940s, before the dangers of radiation were recognized, shoe shoppers had shoes fitted using an x-ray device of the foot to assess fit. High doses of radiation were used to shrink enlarged tonsils and extinguish overactive thyroid glands. Attitudes towards radiation were so lax that doctors commonly permitted themselves to be exposed without protection day after day, year after year, until an unexpected rise in blood cancers like leukemia was observed. As recently as the 1970s and 1980s, cancers like Hodgkins’ disease were treated with high doses of radiation, also leading to radiation-induced diseases decades later.

Not all radiation is bad. Radiation can also be used as a therapeutic tool and even today remains a useful and reasonably effective method to reduce the size, sometimes eliminate, certain types of cancer. Forty percent of people with cancer now receive some form of radiation as part of their treatment (Ron E 2003).

Just how much does medical radiation add to our exposure?

Estimates vary, but most experts estimate that medical imaging provides approximately 15% of total lifetime exposure. In other words, radiation exposure from medical imaging is simply a small portion of total exposure that develops over the years of life. Exposure can be much higher, however, in a specific individual who undergoes repeated radiation imaging or treatment of one sort or another.

For all of us, exposure to medical radiation is part of lifetime exposure from multiple sources, added to the radiation we receive from the world around us. Just by living on earth, we are exposed to radiation from space and naturally-occurring radioactive compounds, and receive somewhere around 3.0 mSv per year (U.S. Nuclear Regulatory Commission). (Doses for radiation exposure are commonly expressed in milliSieverts, mSv, a measure that reflects whole-body radiation exposure.) People living in high-altitude locales like Colorado get exposed to an additional 30–50% ambient radiation (1.0–1.5 mSv more per year).

Much of the information on radiation exposure comes from studies like the Life Span Study that, since 1961, has tracked 120,000 Japanese exposed to radiation from the atomic bombs dropped in 1945 (Preston DL et al 2003). Although regarded as a high-dose exposure study for obvious reasons, there are actually thousands of people in this study who were exposed to lesser quantities of radiation (because of distance from the bomb sites) who still display a “dose-response” increased risk for cancer many years later in life. Radiation exposures of as little as 5–20 mSv showed a slight increase in lifetime risk.

Occupational and excessive medical exposure to radiation also provides a “laboratory” to examine radiation risk. Miners exposed to radon gas; patients exposed to the imaging agent, Thorotrast, containing radioactive isotope thorium dioxide and used as an x-ray contrast agent in the 1930s and 1940s and possesses the curious property of lingering in the body for over 30 years after administration; radium injections administered between 1945 and 1955 to treat diseases like ankylosing spondylitis and tuberculosis, all provide researchers an opportunity to study the long-term effects of various types of radiation exposure over many years (Harrison JD et al 2003).

The excess exposure of workers and several hundred thousand nearby residents to the Mayak nuclear plant in Russia has also revealed a “dose-response” relationship, with increasing exposure leading to more cancers, including leukemia and solid cancers of the bone, liver, and lung (Shilnikova NS et al 2003). Nuclear waste released into the Techa river between 1948 and 1956 contaminated drinking water used by over 100,000 Russians. A plant explosion in 1957 also released an excess of radiation into the atmosphere, yielding exposure via inhalation. Some sources estimate that at least 272,000 people have been affected by radiation from the Mayak plant. This unfortunate situation has, however, yielded plenty of data on radiation exposure and its long-term effects.

It’s also been known for several decades that people who receive therapeutic radiation for treatment of cancer, even with the reduced doses now employed, are subject to increased risk of a second cancer consequent to the radiation treatment.

From experiences like this, radiation experts estimate that an exposure of 10 mSv increases a population’s risk for cancer by 1 in 1000 (Semelka RC et al 2007).

This question was recently thrust into the spotlight with publication of a study from Columbia University in New York suggesting that a 20-year old woman would be exposed to a lifetime risk of cancer as high as 1 in 143 consequent to the radiation received during a CT coronary angiogram. (Important note: This was estimated risk from a CT coronary angiogram, not a simple heart scan that we advocate for the Track Your Plaque program.) The risk at the low end of the spectrum would be in an 80-year old man (because of the shorter period of time to develop cancer), with a risk of 1 in 5017. If “gating” to the EKG is added (which many scan centers do indeed perform nowadays), risk for a 60-year old woman is estimated at 1 in 715; risk for a 60-year old male, 1 in 1911 (Einstein AJ et al 2007). This study generated some criticism, since it did not directly involve human subjects, but used “phantoms” or x-ray dummies to simulate x-ray exposure. Nonetheless, the point was made: CT coronary angiograms in current practice do indeed expose the patient to substantial quantities of radiation, sufficient to pose a lifetime risk of cancer.

The media frenzy

The NY Times ran an article called With Rise in Radiation Exposure, Experts Urge Caution on Tests in which they stated:

"According to a new study, the per-capita dose of ionizing radiation from clinical imaging exams in the United States increased almost 600 percent from 1980 to 2006. In the past, natural background radiation was the leading source of human exposure; that has been displaced by diagnostic imaging procedures, the authors said."

“This is an absolutely sentinel event, a wake-up call,” said Dr. Fred A. Mettler Jr., principal investigator for the study, by the National Council on Radiation Protection. “Medical exposure now dwarfs that of all other sources.”

Radiation is a widely used imaging tool in medicine. Although CT scans of the brain, bones, chest, abdomen, and pelvis account for only 5% of all medical radiation procedures, they are responsible for nearly 50% of medical radiation used. It’s been known for years that increasing radiation exposure increases cancer risk over many years, but the boom of newer, faster devices that provide more detailed images has opened the floodgates to expanded use of CT scanners.

But before we join in the hysteria, let's first take a look at exposure measured for different sorts of tests:

Typical effective radiation dose values for common tests

Computed Tomography

Head CT 1 – 2 mSv
Pelvis CT 3 – 4 mSv
Chest CT 5 – 7 mSv
Abdomen CT 5 – 7 mSv
Abdomen/pelvis CT 8 – 11 mSv
Coronary CT angiography 5 – 12 mSv

Non-CT

Hand radiograph Less than 0.1 mSv
Chest radiograph Less than 0.1 mSv
Mammogram 0.3 – 0.6 mSv
Barium enema exam 3 – 6 mSv
Coronary angiogram 5 – 10 mSv
Sestamibi myocardial perfusion (per injection) 6 – 9 mSv
Thallium myocardial perfusion (per injection) 26 – 35 mSv

Source: Cynthia H. McCullough, Ph.D., Mayo Clinic, Rochester, MN

A plain, everyday chest x-ray, providing less than 0.1 mSv exposure, provides about the same quantity of radiation exposure as flying in an airplane for four hours, or the same amount of radiation from exposure to our surroundings for 11–12 days. Similar exposure arises from dental x-rays.

If you have a heart scan on an EBT device, then your exposure is 0.5-0.6 mSv, roughly the same as a mammogram or several standard chest x-rays.

With a heart scan on a 16- or 64-slice multidetector device, exposure is ideally around 1.0-2.0 mSv, about the same as 2-3 mammograms, though dose can vary with this technology depending on how it is performed (gated to the EKG, device settings, etc.)

CT coronary angiography presents a different story. This is where radiation really escalates and puts the radiation exposure issue in the spotlight. As Dr. Cynthia McCullough's chart shows above, the radiation exposure with CT coronary angiograms is 5-12 mSv, the equivalent of 100 or more chest x-rays or 20 mammograms. Now, that's a problem.

The exposure is about the same for a pelvic or abdominal CT. The problem is that some centers are using CT coronary angiograms as screening procedures and even advocating their use annually. This is where the alarm needs to be sounded. These tests, as wonderful as the information and image quality can be, are not screening tests. Just like a pelvic CT, they are diagnostic tests done for legitimate medical questions. They are not screening tests to be applied broadly and used year after year.

It’s also worth giving second thought to any full body scan you might be considering. These screening studies include scans of the chest, abdomen, and pelvis. These scans, performed for screening, expose the recipient to approximately 10 mSv of radiation (Radiological Society of North American, 2007). Debate continues on whether the radiation exposure is justified, given the generally asymptomatic people who generally undergo these tests.

Always be mindful of your radiation exposure, as the NY Times article rightly advises. However, don't be so frightened that you are kept from obtaining truly useful information from, for instance, a CT heart scan (not angiography) at a modest radiation cost.

Heart scans, CT coronary angiograms and the future

Unfortunately, practicing physicians and those involved in providing CT scans are generally unconcerned with radiation exposure. The majority, in fact, are entirely unaware of the dose of radiation required for most CT scan studies and unaware of the cancer risk involved. It is therefore up to the individual to insist on a discussion of the type of scanner being used, the radiation dose delivered (at least in general terms), the necessity of the test, alternative methods to obtain the same diagnostic information, all in the context of lifetime radiation exposure.

Our concerns about radiation exposure all boil down to concern over lifetime risk for cancer, a disease that strikes approximately 20% of all Americans. Many factors contribute to cancer risk, including obesity, excessive saturated fat intake, low fiber intake, lack of vitamin D, repeated sunburns, excessive alcohol use, smoking, exposure to pesticides and other organochemicals, asbestos and other industrial exposures, electromagnetic wave exposure, and genetics. Radiation is just one source of risk, though to some degree a controllable one.

Some people, on hearing this somewhat disturbing discussion, refuse to ever have another medical test requiring radiation. That’s the wrong attitude. It makes no more sense than wearing lead shielding on your body 24 hours a day to reduce exposure from the atmosphere. Taken in the larger context of life, radiation exposure is just one item on a list of potentially harmful factors.

It is, however, worth some effort to minimize radiation exposure over your lifetime, particularly before age 60, and by submitting to high-dose testing only when truly necessary, or when the potential benefits outweigh the risks. Thus, with heart scans and CT coronary angiography, some thought to the potential benefits of knowing your score or the information gained from the CT angiogram need to be considered before undergoing the test. Often the practical difficulty, of course, is that your risk for heart disease simply cannot be known until after the test.

In our view, in the vast majority of instances a simple CT heart scan can serve the simple but crucial role of quantifying risk for heart attack and atherosclerotic plaque. CT heart scans yield this information with less than a tenth of the radiation exposure of a CT coronary angiogram. In people without symptoms and a normal stress test, there is rarely a need for CT coronary angiography with present day levels of radiation exposure. Perhaps as technology advances and the radiation required to generate images is reduced, then we should reconsider.

Early experiences are suggesting that the newest 256-slice scanners, now being developed but not yet available, will cut the dose exposure of 64-slice CT angiograms in half (from 27.8 mSv to 14.1 mSv in a recent Japanese study). The 256-slice scanners will allow scanning that is faster over a larger area in a given period of time.

Thankfully, the scanner manufacturers are increasingly sensitive to the radiation issue and have been working on methods to reduce radiation exposure. However, it still remains substantial.

References:
Einstein AJ, Henzlova MJ, Rajagopalan S. Estimating risk of cancer associated with radiation exposure from 64-slice computed tomography coronary angiography. JAMA 2007 Jul 18;298(3):317–323.

Harrison JD, Muirhead CR. Quantitative comparisons of cancer induction in humans by internally deposited radionuclides and external radiation. Int J Radiat Biol 2003 Jan;79(1):1–13.

Hausleiter J, Meyer T, Hadamitzyky M et al. Radiation Dose Estimates From Cardiac Multislice Computed Tomography in Daily Practice: Impact of Different Scanning Protocols on Effective Dose Estimates. Circulation 2006;113:1305–1310.

Kalra MK, Maher MM, Toth TL, Hamberg LM, Blake MA, Shepard J, Saini S. Strategies for CT radiation dose optimization. Radiology 2004;230:619–628.

Mayo JR, Aldrich J, Müller NL. Radiation exposure at chest CT: A statement of the Fleischner Society. Radiology 2003; 228:15–21.

Mori S, Nishizawa K, Kondo C, Ohno M, Akahane K, Endo M. Effective doses in subjects undergoing computed tomography cardiac imaging with the 256-multislice CT scanner. Eur J Radiol 2007 Jul 10; [Epub ahead of print].

Preston DL, Pierce DA, Shimizu Y, Ron E, Mabuchi K. Dose response and temporal patterns of radiation-associated solid cancer risks. Health Phys 2003 Jul;85(1):43–46.

Ron E. Cancer risks from medical radiation. Health Phys 2003 Jul;85(1):47–59.

Shilnikova NS, Preston DL, Ron E et al. Cancer mortality risk among workers at the Mayak nuclear complex. Radiation Res 2003 Jun;159(6):787–798.

Semelka RC, Armao DM, Elias J Jr, Huda W. Imaging strategies to reduce the risk of radiation in CT studies, including selective substitution with MRI. J Magn Reson Imaging 2007 May;25(5):900–9090.

Copyright 2007, Track Your Plaque.

A carefully-conducted study by a collaborative research group at University of California-Berkeley has finally closed the lid on the fuss over fructose vs. glucose and its purported adverse effects.

The study is published in its entirety here.

Compared to glucose, fructose induced:

1) Four-fold greater intra-abdominal fat accumulation--3% increased intra-abdominal fat with glucose; 14.4% with fructose. (Intraabdominal fat is the variety that blocks insulin responses and causes diabetes and inflammation.)

2) 13.9% increase in LDL cholesterol but double the increase for Apoprotein B (an index of the number of LDL particles, similar to NMR LDL particle number).

3) 44.9% increase in small LDL, compared to 13.3% with glucose.

4) While glucose (curiously) reduced the net postprandial (after-eating) triglyceride response (area under the curve, AUC), fructose increased postprandial triglycerides 99.2%.

The authors propose that fructose specifically increases liver VLDL production, the lipoprotein particle that yields abnormal after-eating particles, increased LDL, and provides building blocks to manufacture small LDL particles. The authors also persuasively propose that fructose metabolism, unlike glucose, is not inhibited (via feedback loop) by energy intake, i.e., it's as if you are always starving.

Add to this the data that show that fructose increases uric acid (that causes gout and may act as a coronary risk factor), induces leptin resistance, causes metabolic syndrome (pre-diabetes), and increases appetite, and it is clear that fructose is yet another common food additive that, along with wheat, is likely a big part of the reason Americans are fat and diabetic.

Fructose is concentrated, of course, in high-fructose corn syrup, comprising anywhere from 42-90% of total weight. Fructose also composes 50% of sucrose (table sugar). Fructose also figures prominently in many fruits; among the worst culprits are raisins (30% fructose) and honey (41% fructose).

Also, beware of low-fat or non-fat salad dressings (rich with high-fructose corn syrup), ketchup, beer, fruit drinks, fruit juices, all of which are rich sources of this exceptionally fattening, metabolism-bypassing, LDL cholesterol/small LDL/ApoB increasing compound. Ironically, this means that many low-fat foods meant to reduce cholesterol actually increase it when they contain fructose in any form.

When you hear or say "fructose," run the other way, regardless of what the Corn Refiners Association says.

Matt came to me because his doctor couldn't reduce his LDL cholesterol.

His doctor had prescribed Zocor (simvastatin), Lipitor, Crestor, even pravastatin, all of which resulted in incapacitating muscle aches and weakness within a week of starting. No surprise, Matt had a jaundiced view of statin drugs.

We started out by characterizing his lipoprotein patterns:

--LDL 155 mg/dl

--72% of LDL was small LDL, a moderately severe pattern. (This means that small LDL comprised 112 mg/dl of the total 155 mg/dl LDL; large LDL comprised 43 mg/dl--small LDL was the problem.)

--HDL 42 mg/dl --Triglycerides 133 mg/dl

--No lipoprotein(a)

Beyond lipoproteins, Matt proved severely deficient in vitamin D with a starting level of 18 ng/ml.

Matt's doctor had advised that he avoid salt, as his blood pressure had been borderline high. His thyroid assessment disclosed a TSH of 3.89 mIU/ml with thyroid hormones free T3 and free T4 in the lower half of the normal range.

I therefore asked Matt to:

--Eliminate wheat, cornstarch, and sugars to reduce small LDL
--Add iodine
--Supplement 6000 units of an oil-based vitamin D preparation
--Take fish oil to provide at least 1800 mg EPA + DHA per day
--Take Armour Thyroid 1 grain per day

Several months later on this program, Matt had a repeat basic lipid panel:

--LDL 82 mg/dl--a 47% reduction

--HDL 52 mg/dl a 24% increase

--Triglycerides 60 mg/dl--a 55% decrease

In addition, vitamin D was 66 ng/ml, TSH was <1.0 mIU/ml with free T3 and free T4 in the upper half of the "reference range." Matt also felt great.

While the numbers could be slightly better, Matt had made tremendous progress towards achieving perfect values.

There you have it: Marked correction of cholesterol values, no statin drugs involved.

Even if you’re not interested in building big muscles like a bodybuilder, there are health benefits to increasing muscle mass: increased bone density, better balance, and fewer injuries. Greater muscle mass means higher metabolic rate, improved insulin responsiveness, lower blood sugar. The inevitable loss of muscle mass of aging can lead to frailty, an increasingly common situation for the elderly. Muscle loss be reversed, health improved as a result.

Since its introduction in 1994, creatine has exploded in popularity, particularly among bodybuilders and athletes interested in gaining muscle mass and strength. But creatine is not just for young weight lifters. If you are just interested in increasing muscle mass for its health benefits, then creatine is something to consider.

A study of creatine supplementation in men, average age 70 years, demonstrated that, when creatine was combined with strength training, it increased muscle mass 250% better than placebo (7.26 lb muscle vs 2.86 lb muscle), along with improved leg strength and endurance. The same group also demonstrated 3.2% increased bone density (measured using dual energy X-ray absorptiometry) after 12 weeks in participants taking creatine with strength training, while the control (no strength training, no creatine) group decreased by 1.0%.

Benefits are not confined to men. Similar results were observed in another study that included women (age 65 and older), with outcomes in females comparable to males. This is especially important for females, given the common development of osteopenia and osteoporosis in postmenopausal females.

Other studies have shown that benefits are maintained after stopping creatine supplementation.

The most popular form of creatine is the monohydrate, generally taken as a “loading” phase of 15-20 grams per day (generally split into 3-4 doses of 5 grams) for 5-7 days, followed by weeks to months of 2-5 grams per day.

An alternative form, polyethylene glycosylated creatine (PEG-creatine) provides similar effects at one-fourth to one-half the dose of creatine, i.e., 1.25-2.5 grams per day.

Despite previous concerns about kidney toxicity with prolonged use, another study showed that athletes taking creatine for up to 21 months have shown no adverse effects on kidney function, lipid (cholesterol) values, or other basic health measures.

Having healthy muscle mass doesn't make you bulge like a bodybuilder. With modest efforts at strength training, augmented with creatine supplementation, you have a wonderful tool to feel better, reduce injury, increase bone density, and combat abnormal insulin resistance, not to mention accelerate weight loss, since lean muscle mass consumes energy.

There has been a lot of debate over whether or not “bio-identical” hormones, i.e., hormones identical to the human form, are superior to non-human forms dispensed by the drug industry.

The FDA is currently taking steps to clamp down on availability of bioidentical hormones and their claims of superiority, despite a groundswell of grassroot support for them. The argument has pitted anti-aging practitioners and the public, as well as the likes of Oprah and Suzanne Somers, against Big Pharma and the FDA, the two forces trying to squash the bioidentical hormone movement.

Regardless of what heavy-handed approach the FDA takes, we already have access to hormones identical to the original human form. It requires no prescription and yields downstream hormones that the human body recognizes as human.

That "bioidentical" hormone is pregnenolone.

Pregnenolone is the first biochemical step in the conversion of dietary cholesterol (yes-cholesterol!) to numerous other hormones. Pregnenolone is the source of the hormones that lie at the center of the bioidentical hormone controversy: estrogens, progesterone, and testosterone. We therefore already have our own over-the-counter, non-prescription form of bioidentical hormones.

Supplemental pregnenolone increases estrogens (mildly), progesterone, and testosterone. Prenenonlone supplementation simply provide more of the basic substrate for hormone production. The increase in hormones is usually modest, not as vigorous as direct hormone replacement like, say, testosterone or progesterone topical creams. But pregnenolone can be useful when small to moderate increases are desired, such as for reduction of Lp(a). A theoretical downside is that pregnenonlone can also convert to cortisol, the adrenal gland hormone that regulates fluid and blood pressure. However, I've not seen any measurable increase in cortisol with low doses of pregnenonlone and limited data suggest that it does not. Pregnenolone also converts to the other adrenal gland hormone, DHEA; I call DHEA "the hormone of assertiveness," since some people who take too much pregnenolone (or direct DHEA) acquire excessive assertiveness.

The key to pregnenolone supplementation is to proceed gradually and begin with a small dose, e.g., 5 mg every morning. Hormonal assessment is best conducted periodically to assess the effects and to determine whether a dose adjustment is in order.

Beware the "false positive" stress test

Don't neglect your magnesium

Third heart scan a charm

Metabolic syndrome--cured

Heart Scan Curiosities #6

Should you become a vegetarian?

Let's make it a lot easier

No wonder nobody talks about real prevention

HDL and vitamin D

Even more Michael Pollan

Thyroid: Be a perfectionist

Nutrition Syllogism

Is pomegranate juice healthy?

Honeydew melon

Where do you find fructose?

Do heart scans cause cancer?

Goodbye, fructose

The statin-free life

Creatine: Not just for muscle heads

The ultimate “bioidentical” hormone