Beware the "false positive" stress test

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

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

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

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.

Heart Scan Curiosities #6
















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?

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

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.

No wonder nobody talks about real prevention

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.

HDL and vitamin D

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.

Even more Michael Pollan

"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.

Triglyceride and chylomicron "stacking"

Continuing the comments started in Grazing is for cattle, here's an interesting study from the Oxford Center for Diabetes, Endocrinology and Metabolism.

Volunteers were fed a test meal breakfast of Rice Krispies, a banana, and a chocolate milkshake (76.4 grams carbohydrates, 51.9 grams fat, 12.2 grams protein). Lunch was served 5 hours later and consisted of a cheese sandwich and a second chocolate milkshake 43.4 grams carbohydrates, 49.6 grams fat, 24.0 grams protein). Frequent blood samples were then assessed over the day. (Don't try this at home: These are obviously very dangerous foods!)

Here's the pattern of triglycerides that was observed (1st dotted vertical line = breakfast, 2nd dotted vertical line = lunch):



Note that triglycerides only begin to decline 3-4 hours after breakfast, only to peak higher after lunch.


Here's the pattern observed for chylomicrons, the "granddaddy" of lipoproteins that derives from intestinal absorption of fatty acids:



Both graphs from Heath RB et al Am J Phyiol Endocrinol Metab 2006.


With chylomicrons, note a similar pattern to triglycerides: Chylomicrons begin to decline at 3-4 hours, only to peak higher after lunch.

This is the first study to examine the effect of sequential meals on such postprandial (after-eating) patterns. But it makes the graphic point that, if insufficient time is permitted between meals, both triglycerides and chylomicrons will "stack" themselves higher and higher. (Chylomicrons are subjected to processing by the enzyme, lipoprotein lipase, to form highly atherogenic, or plaque-causing, chylomicron remnants.)

While not examined in this study, my bet is that "grazing," i.e., eating small meals or snacks frequently, is an extreme instance of triglyceride, chylomicron, and chylomicron remnant stacking. That can only lead to one thing: accelerated heart and vascular plaque.

What is a healthy vitamin D blood level?

When measuring blood levels of vitamin D (as 25-hydroxy vitamin D), what constitutes a desirable level?

There's no study that directly examines this question, no study that enrolled thousands of people and assigned a placebo group and groups receiving escalating doses of vitamin D and/or achieved higher levels of vitamin D, then observed for development of cancer, diabetes, depression, heart disease, multiple sclerosis, osteoporosis, osteoarthritis, etc. Such a study would requires many thousands of participants (particularly to observe cancer and multiple sclerosis incidence), many years of observation, and many tens of millions of dollars. Nope, only a drug company could afford such costs.

So we have to piece together various observations and extrapolate what we believe to be the ideal level of vitamin D. Epidemiologic observations in several cancers (breast, colon, prostate, and bladder) suggest that a 25-hydroxy vitamin D level of 30 ng/ml or higher is desirable (with less cancer incidence above this level). Other data suggest a level of 52 ng/ml or greater is desirable. Unfortunately, much cancer research looked at intake of vitamin D from food and supplement sources, rather than actual blood levels. We also have to factor in the great individual variation in vitamin D metabolism, with a single dose yielding variable blood levels (as much as a 10-fold difference). There's also the variation introduced by vitamin D-receptor variation (genetic polymorphisms).

A new study using vitamin D administration helps chart the desirable levels of vitamin D.

Vitamin D supplementation reduces insulin resistance in South Asian women living in New Zealand who are insulin resistant and vitamin D deficient - a randomised, placebo-controlled trial.

In this New Zealand study, 42 women (23 to 68 years old) were given 4000 units vitamin D, 39 women given placebo. Median 25-hydroxy vitamin D levels increased from 21 nmol/L (8.4 ng/ml) to 75 nmol/L (30 ng/ml). Both HOMA (a measure of insulin sensitivity) and fasting insulin levels improved, with greatest improvement seen at 25-hydroxy vitamin D levels of 80-119 nmol/L (32-47.6 ng/ml) or greater.

We also know that a vacation on a Caribbean beach in a bathing suit will increase vitamin D blood levels to the 80-110 ng/ml range without ill-effect (at least in young people who maintain the capacity to activate vitamin D in the skin, a phenomenon that declines as we age).

So do we really know the truly ideal level of vitamin D to achieve? I believe that, given the above observations, it is reasonable to extrapolate that the ideal vitamin D blood level likely lies somewhere above 50 ng/ml. We also know that vitamin D toxicity (i.e., hypercalcemia) is virtually unheard of until vitamin D blood levels approach 150 ng/ml, and even then is inconsistent. The health benefits of vitamin D supplementation are so tremendous, that I am not willing to wait for the prospective data to explore this question fully. For now, I aim for a blood level of vitamin D of 60-70 ng/ml (150-175 nmol/L).

Grazing is for cattle

Many dietitians and nutritionists advise many people today to "graze," i.e., to eat small snacks every couple of hours. They argue that it blocks the drop in insulin and blood sugar that can trigger greater appetite and claim it can facilitate weight loss.



This is an absurd notion. Humans are not meant to graze. Humans are meant to find a wild boar or other animal, kill it, gorge on the meat, organs, and fat, then revert to berries, roots, leaves, and other foraged foods until the next kill. A human living in the wild does not have a cupboard or refrigerator full of ready-to-eat snacks to graze on.

The several hours after a meal is the most dangerous for creating coronary atherosclerotic plaque, i.e., the post-prandial period. In other words, eat dinner and, for the next 6-12 hours, your intestinal tract degrades the food; food byproducts are absorbed into the blood or lymph system. The blood is literally flooded with the byproducts of your meal.

Postprandial abnormalities are emerging to be a potent, and much underappreciated, means of causing heart disease and atherosclerosis in other vascular territories (especially carotid arteries and thoracic aorta).

Not eating--i.e., the fasting state--for extended periods is good for you. Encouraging people to graze amplifies atherosclerotic risk, since it creates an abnormal prolonged postprandial state.

The disastrous results of a low-fat diet

Rob was never that committed to following the program in the first place.

I met Rob because of a modest heart scan score and consultation for a cholesterol abnormality. Rob had been cycled through all the statin agents by his primary care physician, all of which resulted in terrible muscle aches that he found intolerable.

I started out, as usual, characterizing his cholesterol abnormality with lipoprotein testing (NMR):

LDL particle number 1489 nmol/L
LDL cholesterol (Friedewald calculation) 143 mg/dl
Small LDL 52% of total LDL
HDL 50 mg/dl
Triglycerides 82 mg/dl

(LDL particle number is the emerging gold standard for LDL quantification, superior to calculated or Friedewald LDL cholesterol for prediction of cardiovascular events.)

Rob is a busy guy. After only a couple of brief visits, life and work got in the way and Rob let his attentions drift away from heart health. Since the information I provided made little impact on his thinking, he reverted to the low-fat diet his primary care doctor had originally prescribed and that he read about in magazines and food packages. He also ran out of the basic supplements I had advised, including fish oil and vitamin D, and just never restarted them.

A couple of years passed and Rob decided that just poking around on his own might not cut it. So he came back to the office. We repeated his NMR lipoprotein analysis:

LDL particle number 2699 nmol/L
LDL cholesterol (Friedewald calculation) 229 mg/dl
Small LDL 81% of total LDL
HDL 53 mg/dl
Triglycerides 78 mg/dl


Two years of a low-fat diet had caused Rob's LDL particle number to skyrocket by 81%, nearly all due to an explosion of small LDL. Recall that small LDL is more susceptible to oxidation, more inflammation-provoking, more adhesive--the form of LDL particles most likely to cause heart disease.

Also, note that, despite the enormous increase in small LDL, HDL and triglycerides remained favorable. This counters the popular rule-of-thumb offered by some that small LDL is not present when HDL is "normal."

Low-fat diets as commonly practiced are enormously destructive. In Rob's case, a low-fat diet caused both calculated Friedewald LDL as well as LDL particle number to increase dramatically. In many other people, low-fat diets increase calculated Friedewald LDL modestly or not at all, but cause the more accurate LDL particle number to increase significantly, all due to small LDL.

I'm happy to say that, once Rob witnessed how far wrong he could go on the wrong program, he's back on Track. (Sorry, pun intended.) He has resumed his supplements and eliminated the food triggers of small LDL--wheat, cornstarch, and sugars.

Dr. David Grimes reminds us of vitamin D

In response to the Heart Scan Blog post, Fish oil makes you happy: Psychological distress and omega-3 index, Dr. David Grimes offered the following argument.

Dr. Grimes is a physician in northwest England at the Blackburn Royal Infirmary, Lancashire. He is author of the wonderfully cheeky 2006 Lancet editorial, Are statins analogues of vitamin D?, questioning whether the benefits of statin drugs simply work by way of increased vitamin D blood levels.


There is a fashionable interest in Omega-3 fatty acids, and these become equated with fish oil.

But fish oil is much more. Plankton synthesise the related squalene (shark oil) which, in turn, is converted into 7-dehydrocholesterol (7-DHC). The sun now comes into play and it converts 7-DHC into vitamin D (a physico-chemical process).

Small fish eat plankton, large fish eat small fish, and we eat large fish. So vitamin D passes through the food chain.

This has been a vital source of vitamin D for the the Inuits and also for the Scots and other dwellers of northwest Europe. (Edinburgh is on the same latitude as Hudson Bay and Alaska, further north than anywhere in China). In these locations there is not adequate sunlight energy to guarantee synthesis of adequate amounts of vitamin D, again by the action of sunlight on 7-DHC in the skin.

When the Scots moved from coastal fishing villages to industrial cities such as Glasgow, they became seriously deficient in vitamin D, and so the emergence of rickets. This was followed by a variety of other diseases resulting from vitamin D deficiency: tuberculosis, dental decay, coronary heart disease, and even multiple sclerosis and depression (the Glasgow syndrome).

And so it was with the Inuits. When their diet changed from fish for breakfast, fish for lunch, fish for dinner, they became deficient of vitamin D and they developed diseases characteristic of industrial cities, where there is indoor work for long hours, indoor activities, and atmospheric pollution.

It is the vitamin D component of fish and fish oils that is important.

I recently saw an elderly lady from Bangladesh living in northwest England. I would have expected her to have a very low blood level of vitamin D, as her exposure to the sun was minimal. However the blood level was 47ng/ml, not 4 as expected. She eats oily fish from Bangladesh every day, showing its value as a source of vitamin D with subsequent good health. I expect her blood levels of omega-3 fatty acids would also be high.

But it is unfashionable vitamin D that is important, not fashionable omega-3.

David Grimes
www.vitamindandcholesterol.com


Excellent point. The health effects of omega-3 and vitamin D are intimately intertwined when examining populations that consume fish.

In this study of Inuits, it is indeed impossible to dissect out how much psychological distress was due to reduced vitamin D, how much due to reduced omega-3s. My bet is that it's both. Thankfully, we also have data examining the use of pure omega-3 fatty acids in capsule (not intact fish) form, including studies like GISSI Prevenzione.

Nonetheless, Dr. Grimes reminds us that both vitamin D and omega-3 fatty acids from fish oil play crucial roles in mental health and other aspects of health, and that it's the combination that may account for the extravagant health effects previously ascribed only to omega-3s.

Why does fish oil reduce triglycerides?

Beyond its ability to slash risk for cardiovascular events, omega-3 fatty acids from fish oil also reduce triglycerides.

There's no remaining question that omega-3s do this quite effectively. After all, the FDA approved prescription fish oil, Lovaza, to treat a condition called familial hypertriglyceridemia, an inherited condition in which very high triglycerides in the 100s or 1000s of milligrams typically develop.

The omega-3 fraction of fatty acids are unique for their triglyceride-reducing property. No other fraction of fatty acids, such as omega-6 or saturated, can match the triglyceride-reducing effect of omega-3s.

But why does fish oil reduce triglycerides?

First of all, what are triglycerides? As their name suggests, triglycerides consist of three ("tri-") fatty acids lined up along a glycerol (sugar) "backbone." Triglycerides are the form in which most fatty acids occur in the bloodstream, liver, and other organs. (Fatty acids, like omega-3, omega-6, mono- or polyunsaturated, or saturated, rarely occur as free fatty acids unbound to glycerol.) In various lipoproteins in the blood, like LDL, VLDL, and HDL, fatty acids occur as triglycerides.

Of all lipoproteins, chylomicrons (the large particle formed through intestinal absorption of fatty acids and transported to the liver via the lymph system) and VLDL (very low-density lipoprotein, very low-density because they are mostly fat and little protein) particles are richest in triglycerides. Thus, we would expect that omega-3s exert their triglyceride-reducing effect via reductions in either chylomicrons or VLDL.

Indeed, that seems to be the case. The emerging evidence suggests that omega-3 fatty acids from fish oil reduce triglycerides through:

--Reduced VLDL production by the liver (Harris 1989)
--Accelerating chylomicron and VLDL elimination from the blood
--Activation of peroxisome proliferator-activated receptor gamma (PPAR-gamma)--Omega-3s ramp up the cellular equipment used to convert fatty acids to energy (oxidation) (Gani 2008)

Combine omega-3 fatty acids from fish oil with wheat elimination and you have an extremely potent means of reducing triglycerides. Read a previous Heart Scan Blog post here to read how a patient reduced triglycerides 93.5% from 3100 mg/dl to 210 mg/dl in just a few weeks using fish oil and wheat elimination.

Fish oil makes you happy: Psychological distress and omega-3 index

For another perspective on omega-3 blood levels, here's an interesting study in northern Quebec Inuits.

Traditionally, Inuits consumed large quantities of omega-3-rich seal, fish, caribou, and whale, even eating the fat. However, like the rest of the world, modern Inuits have increased consumption of store-bought foods, largely processed carbohydrates. Along with this trend has emerged more heart disease, diabetes, and depression.

A group from Laval University and University of Guelph, both in Canada, examined the relationship of plasma EPA + DHA levels and measures of psychological distress. This group had previously shown that Inuits older than 50 years had twice the plasma omega-3 levels (11.5%) compared to those younger than 50 years (6.5%), reflecting the shift away from the traditional diet.

Psychological distress was measured with The Psychological Distress Index Santé-Québec Survey (PDISQS-14): the higher the score, the greater the psychological distress. (In the graphs, tertile 1 is least distressed; tertile 5 is most distressed. Sorry about the small chart graphic--click on the graphic to make it bigger.)


From Lucas M et al 2009 (http://www.nutrasource.ca/NDI/Assets/Articles/Plasma%20omega-3%20and%20psychological%20distress%20among%20Nunavik%20Inuit.pdf)

"Our main finding was that women in the second and third tertiles of EPA+DHA concentrations in plasma PLs [phospholipids] had a 3 times lower risk of having a high-level PD [psychological distress] score than women in the lowest tertile."

While the relationship is stronger for women, you can see that, the higher the EPA + DHA plasma level, the lower the likelihood of psychological distress. Interestingly, the tertile with the greatest distress and lowest EPA + DHA levels had a plasma level of 7.0-7.5%--far higher than average Americans.

(Plasma levels of EPA + DHA were used in this study, which tend to reflect more recent omega-3 intake than the more stable and slower-to-change RBC Omega-3 Index that we use. Plasma levels also tend to run about 10-20% lower than RBC levels.)

Of course, there's more to psychological distress than omega-3 blood levels. After all, eating fish or taking fish oil capsules won't make money worries go away or heal an unhappy marriage. But it is one variable that can be easily and safely remedied.

Hospitals are a hell of a place to get sick

I answered a page from a hospital nurse recently one evening while having dinner with the family.

RN: "This is Lonnie. I'm a nurse at _____ Hospital. I've got one of your patients here, Mrs. Carole Simpson. She's here for a knee replacement with Dr. Johnson. She says she's taking 12,000 units of vitamin D every day. That can't be right! So I'm calling to verify."

WD: "That's right. We gauge patients' vitamin D needs by blood levels of vitamin D. Carole has had perfect levels of vitamin D on that dose."

RN: "The pharmacist says he can replace it with a 50,000 unit tablet."

WD: "Well, go ahead while Carole's in the hospital. I'll just put her back on the real stuff when she leaves."

RN: "But the pharmacist says this is better and she won't have to take so many capsules. She takes six 2,000 unit capsules a day."

WD: "The 50,000 units you and the pharmacist are talking about is vitamin D2, or ergocalciferol, a non-human form. Carole is taking vitamin D3, or cholecalciferol, the human form. The last time I checked, Carole was human."

RN: (Long pause.) Can we just give her the 50,000 unit tablet?

WD: "Yes, you can. But you actually don't need to. In fact, it probably won't hurt anything to just hold the vitamin D altogether for the 3 days she's in the hospital, since the half-life of vitamin D is about 8 weeks. Her blood level will barely change by just holding it for 3 days, then resuming when she's discharged."

RN: (Another long pause.) Uh, okay. Can we just give her the 50,000 units?"

WD: "Yes, you can. No harm will be done. It's simply a less effective form. To be honest, once Carole leaves the hospital, I will just put her back on the vitamin D that she was taking."

RN: "Dr. Johnson was worried that it might make her bleed during surgery. Shouldn't we just stop it?"

WD: "No. Vitamin D has no effect on blood coagulation. So there's no concern about perioperative bleeding."

RN: "The pharmacist said the 50,000 unit tablet was better, also, because it's the prescription form, not an over-the-counter form."

WD: "I can only tell you that Carole has had perfect blood levels on the over-the-counter preparation she was taking. It works just fine."

RN: "Okay. I guess we''ll just give her the 50,000 unit tablet."


From the alarm it raises trying to administer nutritional supplements in a hospital, you'd think that Osama Bin Laden had been spotted on the premises.

I laugh about this every time it happens: A patient gets hospitalized for whatever reason and the hospital staff see the supplement list with vitamin D, fish oil at high doses, iodine, etc. and they panic. They tell the patient about bleeding, cancer, and death, issue stern warnings about how unreliable and dangerous nutritional supplements can be.

My view is the exact opposite: Nutritional supplements are a wonderful, incredibly varied, and effective array of substances that, when used properly, can provide all manner of benefits. While there are selected instances in which nutritional supplements do, indeed, have interactions with treatments provided in hospitals (e.g., Valerian root and general anesthesia), the vast majority of supplements have none.

Does fish oil cause blood thinning?

Omega-3 fatty acids from fish oil have the capacity to "thin the blood." In reality, omega-3s exert a mild platelet-blocking effect (platelet activation and "clumping" are part of clot formation), while also inhibiting arachidonic acid formation and thromboxane.

But can fish oil cause excessive bleeding?

This question comes up frequently in the office, particularly when my colleagues see the doses of fish oil we use for cardiovascular protection. "Why so much fish oil? That's too much blood thinning!"

The most recent addition to the conversation comes from a Philadelphia experience reported in the American Journal of Cardiology:

Comparison of bleeding complications with omega-3 fatty acids + aspirin + clopidogrel--versus--aspirin + clopidogrel in patients with cardiovascular disease.(Watson et al; Am J Cardiol 2009 Oct 15;104(8):1052-4).

All 364 subjects in the study took aspirin and Plavix (a platelet-inhibiting drug), mostly for coronary disease. Mean dose aspirin = 161 mg/day; mean dose Plavix = 75 mg/day. 182 of the subjects were also taking fish oil, mean dose 3000 mg with unspecified omega-3 content.

During nearly 3 years of observation, there was no excess of bleeding events in the group taking fish oil. (In fact, the group not taking fish oil had more bleeding events, though the difference fell short of achieving statistical significance.) Thus, 3000 mg per day of fish oil appeared to exert no observable increase in risk for bleeding. This is consistent with several other studies, including that including Coumadin (warfarin), with no increased bleeding risk when fish oil is added.

Rather than causing blood thinning, I prefer to think that omega-3 fatty acids from fish oil restore protection from abnormal clotting. Taking omega-3 fatty acids from fish oil simply restores a normal level of omega-3 fatty acids in the blood sufficient to strike a healthy balance between blood "thinning" and healthy blood clotting.

Heart Scan Blog readers take impressive doses of omega-3s

Here are the results from the latest Heart Scan Blog poll:

What is your dose of omega-3 fatty acids, EPA + DHA, from fish oil? (Add up the total content of EPA + DHA per capsules; multiply times number of capsules.)

The 479 respondents answered:

Less than 1000 mg per day
65 (13%)

1000-1999 mg per day
145 (30%)

2000-2999 mg per day
98 (20%)

3000-3999 mg per day
79 (16%)

4000-4999 mg per day
33 (6%)

5000-5999 mg per day
14 (2%)

6000 mg per day or more
45 (9%)


The poll did not discriminate between who has heart disease, who does not; who is taking omega-3 fatty acids for high triglycerides or for reduction of lipoprotein(a) (which requires high doses), or other indications. So variation is to be expected.

We can say that nearly all respondents are likely receiving sufficient omega-3s to impact cardiovascular risk, since the benefits begin just by consuming fish twice per month. I am especially impressed at the proportion of respondents (53%) who take at least 2000 mg per day of EPA + DHA. It's clear that people are really embracing the notion that omega-3 fatty acids pack a real wallop of health benefits.

Because different people in different situations and lipid/lipoprotein patterns have different omega-3 needs, there is really no "right" or "wrong" dose of omega-3 fatty acids.

However, there are several factors that enter into knowing your ideal omega-3 intake:

--Higher triglycerides require higher doses
--Lipoprotein(a) can respond to higher doses
--Having coronary or carotid plaque means you desire a "therapeutic" dose of omega-3s, not just a "preventive" dose

Time is a factor, also: The longer you take omega-3s, the higher your blood levels go. You can accelerate the replacement of non-omega-3s with higher doses of omega-3s.

But too much is not good either. Some participants in Track Your Plaque, for instance, have experimented with very high doses of EPA + DHA in the 9000-10,000 per day range and witnessed dramatic increases in LDL.

Much of the uncertainty about dosing will also be cleared up as we get more experience with the Omega-3 RBC Index, i.e, the proportion of fatty acids in red blood cells that are omega-3s. We are currently aiming for an Omega-3 Index of 10%, given the heart attack reductions observed at this level.