All posts by william-davis

I'm presently attending the Society for Cardiovascular Computed Tomography meetings in Washington, DC, along with 500 of my colleagues. It's exciting to see how interest in CT scanning for heart disease has balloonned in the past couple of years.

Several trends are noticeable today, based on the content and tone of the discussions:

--CT scanning of the heart, and imaging in general, is just getting started. In other words, the capabilities for CT scanners and other devices to detect heart disease (coronary and otherwise) are where the gasoline engine was in the 19th century. Scanning is getting faster, easier, safer, and more precise. Just as few people in 1905 could have predicted that automobiles would be computer-enhanced, high-speed, ubiquitous devices with several per household, the potential for CT imaging for heart disease is truly in its infancy.

--CT coronary angiography (so-called "64-slice CT scans") are not screening tests for hidden coronary disease in people without symptoms. I was grateful that this point has been made and reiterated by several speakers, as this is consistent with our views. Simple CT heart scans for coronary calcium scoring, in contrast, are screening tests. When the radiation exposure of CT angiograms are reduced to tolerable levels, then they may be used as screening tests. We are probably 3-4 years away from this point.

--Both stress testing and heart catheterizations will be partially replaced by CT scanning. In particular, over the next decade, you will see a dramatic drop in unnecessary catheterizations, i.e,, far less people saying "I had a heart cath but they told me that it was normal."

There has been heavy focus on applications of CT scanning for acute settings, particularly the emergency room and hospitals.

What has surprised me is that there is virtually no conversation whatsoever about the preventive uses of CT heart scanning. So far, only Dr. Daniel Berman of UCLA has shown that he has "seen the light": CT scans are a crucial tool for identification of early coron All posts by william-davis

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

30. October 2009 William Davis (24)

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

29. October 2009 William Davis (19)

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?

27. October 2009 William Davis (20)

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

24. October 2009 William Davis (28)

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.

How old are you?

17. October 2009 William Davis (21)

George walks into my office. I ask him his age.

"I'm 21 years old," he declares.

Yet I look at George. He's got gray thinning hair, his posture is slumped forward rather than erect, the flesh on his upper arms hangs loosely, he's got wrinkles on his hands and face, brown spots on the back of his hands and arms. He looks more like 70 years old to me. "I don't think you're 21 years old. I think you're 70."

"Prove it," he says.

Okay. What now? Minus any formal identification like a driver's license, how do I prove that George is really 70-something and not 20-something? Not an easy thing, when you think about it. If George were a tree, I'd cut him down and count his rings. Is there such a phenomenon in humans?

This is actually a fascinating area of research, looking for reliable biomarkers of aging.

Among the most quantitative markers of aging is telomere length. Telomeres were once dismissed as nonsense sequences in DNA. However, more recent thought among geneticists is that telomeres shorten with aging and provide the body's cells a timeline of aging. This way, George's cells act like they are 70, not 13, and don't start producing gobs of growth hormone and testosterone in preparation for puberty.

What can slow or stall the shortening of telomere length? There are two I'm aware of:

1) Caloric deprivation--i.e., taking in fewer calories. This was among the theories explored by Dr. Roy Walford during his Biosphere2 experience, based on his work in mice that showed that caloric deprivation nearly doubled lifespan.

2) Vitamin D--Richards et al (2007) found that, the higher the vitamin D, the longer the telomere length. The highest vitamin D levels conferred a 5-year effective difference in telomere length.

So, if I could look inside George's cells and count his telomeres, I could judge with confidence whether he was 21 or 70. Or, he could take vitamin D sufficient to increase blood levels to a healthy range and be more like 65.

No high blood pressure

14. October 2009 William Davis (20)

Primitive cultures that were, until recently, unexposed to the modern world, reveal some important insights into blood pressure.

The Yanomamo of South American, the Xingu Indians of Brazil, rural Kenyans, and the natives of Papua, New Guinea have average blood pressures of 103/63 mmHg. Even more incredibly, while 90% of modern Americans will develop high blood pressure as they age, the members of these primitive cultures do not develop age-related hypertension.

What's the secret? Perhaps the full "secret" of their remarkably low blood pressure has not been fully unraveled, but several observations have emerged:

--They are not exposed to modern processed foods like pretzels, crackers, and breakfast cereals.
--Low-carbohydrate foods. Carbohydrates are largely the product of the food industry, convenience foods bought in stores. No such thing in the jungle.
--Living outdoors, having to forage and hunt, walk to your destination, not drive or wait in line for food.
--Outdoor lives, wearing little more than a few strands of clothing, exposes you to plentiful vitamin D activation from sunlight exposure.
--Consuming wild game, rich in omega-3 fatty acids, enhances endothelial health and reduces blood pressure.
--Wild plants, roots, and berries, as well as wild game, along the coast, are richer in iodine.

The studies examining the habits of the Yanomamo and other primitive cultures focused principally on sodium intake. Indeed, the very low sodium intake of primitive cultures was associated with lower blood pressure--up to 6 mmHg reduction. But there's clearly more to learn than "cut your salt."

Name that food

13. October 2009 William Davis (30)

What common food can:

• Cause destructive intestinal damage that, if unrecognized, can lead to disability and death?
• Increase blood sugar higher and faster than table sugar?
• Trigger an autoimmune inflammatory condition in the thyroid (Hashimoto’s thyroiditis)?
• Create intestinal bloating, cramps, and alternating diarrhea and constipation, often labeled irritable bowel syndrome?
• Trigger schizophrenia in susceptible individuals?
• Cause behavioral outbursts in children with autism?
• Cause various inflammatory diseases such as rheumatoid arthritis, ulcerative colitis, dermatitis herpetiformis, systemic lupus, pancreatic destruction, and increase measures of inflammation like c-reactive protein?
• Cause unexplained anemia, mood swings, fatigue, fibromyalgia, eczema, and osteoporosis?

The food is wheat. Yes, the ubiquitous grain we are urged to eat more and more of by the USDA (8-11 servings per day, according to the USDA food pyramid), American Heart Association, American Dietetic Association, and the American Diabetes Association. Wheat is among the most destructive ingredients in the modern diet, worse than sugar, worse than high-fructose corn syrup, worse than any fat.

What other common food can result in such an extensive list of diseases, even death?

Celiac disease alone, a severe intestinal inflammatory condition from wheat gluten, affects an estimated 3 million Americans (Celiac Disease Foundation). The medical literature is filled with case reports of deaths from this disease, often after many years of struggle with incapacitating intestinal dysfunction and the sufferer's last days plagued by encephalopathy (brain inflammation).

What happens when you remove wheat from the diet?

The majority of people quickly shed 20-30 lbs in the first few weeks, selectively lost from the abdomen (what I call “wheat belly”); blood sugar plummets; triglycerides drop up to several hundred milligrams, HDL increases, LDL drops (yes, wheat elimination is a means of achieving marked reduction in LDL cholesterol, especially the small, heart disease-causing variety); c-reactive protein plummets. In addition to this, intestinal complaints improve or disappear, rashes improve, inflammatory conditions like rheumatoid arthritis improve, diabetes can improve or be cured, and behavioral disorders and mood improve.

Along with the ill-fated low-fat dietary advice of the last 40 years, the advice to eat plenty of "healthy whole grains" is responsible for untold disease and suffering. Yes, if you start with a fast food and junk diet and replace some of the calories with whole grains, you will be better off. (That was the logic--the Nutritional Syllogism--of the studies that established the benefits of whole grains over processed, "white" grains.)

But eliminate wheat grains and health takes a huge leap forward. And, no, there is no such thing as wheat deficiency--B vitamins, insoluble fiber, some protein--can easily be replaced by other foods.

Heart Defects Simplified

12. October 2009 William Davis (0)

For as long as I've known him, echocardiography technologist, Ken Heiden, has had a deep fascination with congenital heart disease. Ken has just written a wonderful book on congenital heart disease called Heart Defects Simplified.

While this is a bit off-topic for the Heart Scan Blog, I know that there is a serious lack of helpful information for people with congenital heart disease and parents of children with congenital heart defects. So I asked Ken to tell us something about his book.

WD: I've reviewed your book and have been thoroughly impressed with the clarity and detail with which you handle a complicated topic. You somehow manage to make it easy to grasp, far more than any other resource I've used in past. Do you feel that your book serves a previously unmet need?

KH: This book serves an unmet need in that it presents the complex subject of congenital heart defects in a simplified manner. Most books on this subject are anywhere from 300-1700 pages in length and tend to be written for doctors. Further, most of these books have very few diagrams, and they rely upon their explanations to describe these defects.

Heart Defects Simplified is 104 pages in length, describes the most common defects, including surgical repairs, in a two-page format with full-color diagrams on the left and complete descriptions on the right of each chapter. The book is particularly written for sonographers, nurses and parents, but it is valuable for anyone interested in this subject. It is particularly useful in clinical situations because it is convenient to lay out at your side with a coil-bound format and durable pages. Further, there are appendixes which include "Surgical Procedures in Alphabetical Order," "Prevalence of Congenital Heart Disease," "Scanning Protocols for Echocardiographers," "Imaging Tips," a glossary and a worksheet for echocardiographers.

WD: I know that many people with loved ones who have congenital heart defects, particularly parents of children with such conditions, are often kept in the dark about the details of the condition. Is your book suitable for the non-technical reader, such as parents?

KH: This book is an excellent resource for parents. It is written in language that is understandable by parents as well as technologists and nurses. The full-color diagrams provide invaluable insight into this very complex world. Most importantly, this book attempts to make the subject of congenital heart defects accessible to anyone who wishes to comprehend this subject.

WD: I understand that people with congenital heart defects and parents are active participants in online discussion groups. Will your book serve as a resource for people who participate in these groups?

KH: This book is not only a resource for sonographers and parents, but the book is accompanied by a blog (HeartDefectsforEveryone.blogspot.com) that attempts to address many of the concerns commonly encountered with congenital heart defects. This blog is a work in progress, but I hope to provide a forum for parents, healthcare personnel, and others to share their questions and concerns about congenital heart disease.

My experience with the omega-3 index

8. October 2009 William Davis (23)

I just got back my own results from the Gene Smart laboratory reporting my omega-3 index and omega-6:omega-3 ratio.

My results:

Omega-3 index: 8.2%

Omega-6:omega-3 index: 3.2 to 1

Not too bad, but not as good as I'd expected. Hmmm.

Although the omega-3 index of 8.2% puts me in the lower risk category for sudden cardiac death, I was hoping for a level of 10% or slightly greater, the level that I believe is more likely to be related to plaque inactivation or reversal. I obtained this level of omega-3 averaging an intake of EPA and DHA of about 2500 mg per day.

I was somewhat disappointed by the omega-6:omega-3 index. Although it's clearly better than the American average range of 20:1, it is short of the ideal of 2:1 or even 1:1. Since I purposely avoid omega-6-rich sources like corn oil, vegetable oils, sunflower or safflower oils, I wonder if I've overdone the nuts. The two ways to improve the omega-6:omega-3 ratio are to 1) decrease omega-6, or 2) increase omega-3. I'm going to do both.

So I thought I was doing pretty well. But there's clearly room for improvement.

Remember: If just reduction of cardiovascular risk is your interest, then a lackadaisical attitude towards these issues might work. But if your interest is elimination of risk and reversal of atherosclerotic plaque, then it pays to go the extra mile. In this case, knowing your omega-3 index and omega-6:omega-3 ratio might tighten up your program.

The Omega-3 Index: The higher, the better?

6. October 2009 William Davis (26)

So you take a few fish oil capsules every day and eat fish once or twice a week. What is the blood and tissue level of omega-3 fatty acids generated by your habits?

A number of variables enter into the equation. For instance, if you take fish oil capsules, what is the concentration of omega-3 fatty acids? How well are they absorbed? After absorption, how effectively are omega-3 fatty acids incorporated into cell membranes?

Even if you take fish oil supplements, it is hard to know just how much you’ve increased blood levels. It is now possible to measure the amount of omega-3 fatty acids in your bloodstream, a value called the omega-3 index. Too little and you might still be at high risk for cardiovascular events.

The Omega-3 index and sudden cardiac death

Two large studies have demonstrated that higher omega-3 blood (the level in red blood cells, or RBCs) levels were associated with reduced likelihood of sudden cardiac death. The risk for sudden cardiac death was 10-fold higher for the lowest omega-3 RBC levels compared to the highest.

Harris WS 2008; adapted from Siscovick DS et al 1995 and Albert CM et al 2002
(The omega-3 Index was derived from whole blood omega-3 levels, which correlate with RBC omega-3 levels, and are thus “estimated.”)

What’s the average omega-3 RBC level for Americans? Most Americans have omega-3 RBC levels in the 2.5-4.0% range, consistent with the tallest bars at the left and associated with greatest risk for sudden cardiac death. People with heart disease can have levels less than 1%. Some authorities propose that this new measure be called the omega-3 index.

Subsequent studies have shown that the omega-3 index has greater power to discriminate who will have a heart attack or die from sudden cardiac death better than any other common laboratory measure of coronary risk, including LDL cholesterol, HDL cholesterol, triglycerides, total cholesterol to HDL ratio, homocysteine, and c-reactive protein.

Just as hemoglobin A1c offers a 3-month look into blood glucose levels, the omega-3 index reflects your long-term omega-3 intake. The quantity of RBC omega-3s also closely parallels the quantity of omega-3s in heart tissues.

What is an ideal omega-3 index?

The above studies relating RBC omega-3 levels and sudden cardiac death suggest that a level of 6.3-7.3% is associated with far fewer fatal events?but events are not eliminated at this level. Is there even greater benefit with levels higher than 6.3-7.3%?

A recent analysis of females from the Harvard School of Public Health suggested that RBC omega-3 levels as high as 8.99% were still associated with non-fatal heart attack (myocardial infarction), compared to 9.36% in those without heart attacks. This suggests that even higher levels are necessary to prevent non-fatal events.

Should we target 10%? 12%? Maybe higher? Any higher and we are toeing the level achieved by the Inuits, the “Eskimoes” of Greenland, northern Canada and Alaska who have been observed to have a low rate of heart disease.

What’s your omega-3 index?

The appreciation of the importance of omega-3 fatty acids marks one of the greatest health revelations of the last 50 years. We can now measure it.

The ability to measure the proportion of omega-3 fatty acids in red blood cells may provide yet another means for all of us to further reduce risk for cardiovascular events.

If you are interested in knowing your omega-3 index, we are now making the fingerstick test kits available by going here.

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