Beware the "false positive" stress test 4. March 2007 William Davis (11) 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.
Don't neglect your magnesium 3. March 2007 William Davis (3) 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
Third heart scan a charm 1. March 2007 William Davis (0) 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.
Metabolic syndrome--cured 27. February 2007 William Davis (0) 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 LDLInterestingly, 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.
Heart Scan Curiosities #6 27. February 2007 William Davis (0) 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.
Should you become a vegetarian? 24. February 2007 William Davis (0) 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.
Let's make it a lot easier 24. February 2007 William Davis (0) 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 smokingPoor dietPhysical inactivityObesity, especially central adiposityFamily 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 com of the brain.Problem: Most people with central nervous system damage caused by wheat do not have any intestinal symptoms, like diarrhea and abdominal pain, the sort of symptoms usually associated with celiac disease. It means the first sign of wheat-induced brain damage may be bumping into walls and wetting your pants.