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 lip

I had a heart attack--and I don't know why!

Kevin came to my office for another opinion.

A husband and father of two teenagers, Kevin had his first heart attack at age 39. Kevin received two stents to his right coronary artery. The entire process took place in a flurry with little explanation over 48 hours, start to finish.

He smoked a pack of cigarettes a day, but the only history of heart disease in his family was his father, who, also a smoker, had his heart disease uncovered in his late 70s.

His internist subsequently prescribed Zocor even though Kevin's LDL cholesterol was a relatively unimpressive 128 mg/dl.

Kevin subsequently asked his cardiologist, "Where did I get the heart disease from?"

"Cigarettes. And genetics. You can quit the first. There's nothing you can do about the second." End of explanation.

This left Kevin frightened and demoralized. If much of the cause of his heart disease couldn't be identified, why bother quitting smoking? Why not enjoy what time he had left?

Kevin was understandably shocked when I told him that genetic causes were 1)identifiable, 2)quantifiable, and 3) correctable.

Kevin's full lipoprotein analysis subsequently showed the most dire combination that commonly accounts for coronary disease in young people: Lp(a) with small LDL particles. This, along with smoking, fully accounted for this young father of two's heart disease.

Along with starting Kevin on a new program for correction of his patterns, I also persuaded him to get a heart scan. What usefulness is a heart scan after the fact? Plenty. Even though Kevin's right coronary was no longer "scorable" because the steel in the stent obscured our measurements, the two remaining unstented arteries would still yield a score. This provides a baseline for future comparison. Even after a stent, Kevin could "track his plaque".

Butter basics

There’s lot of confusion about butter, margarines, and their substitutes. Butter/margarine substitutes that avoid the negative aspects and provide modest health benefits are available, but I find that people confuse what's what. So here’s a brief primer.


Butter--Avoid it. Plain and simple. Butter is a rich source of saturated fat. Of 11.5 grams total fat per tablespoon, 7.3 grams are saturated. It is not better than margarine, contrary to simple-minded reports from some media sources. Butter raises LDL cholesterol, raises blood pressure, and has been related to various cancers.

Margarine--Not better than butter, arguably worse. Some argue that the trans-fatty acids, or hydrogenated oils, used to solidify vegetable oils to make margarine solid are worse than butter. In addition to the ill-effects of butter, margarine reduces HDL and raises cancer risk, perhaps even more than saturated fats. Hydrogenation yields a very unnatural structure that modifies cellular behavior of the sort that may promote the appearance of cancer cells. More recently, however, some of the major manufacturers, like Blue Bonnet, have produced soft spread products without hydrogenation. These are reasonable substitutes when used sparingly.

Smart Balance--This is a product made with canola oil, a source of monounsaturates (the best oil source after omega-3s), but manufactured without hydrogenation and therefore has no trans-fats. It does have, in my view, a bit too much saturated fat (1.5 gm per tbsp. in the 37% Light Spread; 2.5 gm per tbsp in the 67% regular spread). This is a reasonable product to use in small quantities.

There is also a Smart Balance Omega PLUS product that contains added flaxseed oil and sterol esters. I do not recommend this product because of the sterol content (see below). I also object to the manufacturers who label their products “rich in omega-3s” when they mean linolenic acid (in flaxseed), which is converted to a trivial quantity of omega-3s. Linolenic acid may pose unique benefits of its own, but it should not be listed as an omega-3 source.

Benecol--This is a butter substitute that contains stanol esters, a substance that reduces total and LDL cholesterol. Two tablespoons a day reduces LDL around 20 mg/dl, more or less depending on your starting cholesterol.
There’s a light and regular spread. The light contains 20 calories less per tablespoon but somewhat less monounsaturates, but the same LDL-reducing stanol esters. The manufacturer does hydrogenate the oils, yielding 0.5 mg trans-fats per tablespoon--a small drawback.

Take Control--Similar to Benecol, but made with sterol esters. Take Control also reduces LDL cholesterol. However, data from several high-quality studies from Finland suggest that sterol esters may, in some people, be absorbed into the blood. This is potentially concerning. There is a rare disease called sitosterolemia that results in coronary disease in teenagers and young adults in their 20s from increased absorption of sterol esters. While you can’t acquire this genetic disease, some people have the capacity to absorb sterol esters from their intestines very efficiently. I find it very disturbing and I suggest that you stay away this product and other sterol-containing products like HeartWise orange juice and Smart Balance Omega PLUS until the issue is clarified and safety assured.

Brummel and Brown--A blend of vegetable oils (soybean and partially hydrogenated soybean) with calories and fats reduced by blending in yogurt. This is an okay product. The hydrogenation yields trans-fats below the FDA required declaration limit of 1.0 mg.
There’s also 1.0 mg each of saturated and monounsaturated fats. The calories are relatively low as a consequence of the added yogurt, only 45 calories per tablespoon. This makes the Brummel and Brown a reasonable choice.


Other products are making their way out to supermarkets. Look for the type of oil used. Canola, olive, and flaxseed are the best. Also look for trans-fats and saturated fat content; both should be low, preferably <1.0 mg per tablespoon, ideally none.

The best choice among the above products in my view is Benecol, though it’s also the most expensive. It will yield substantial drops in LDL cholesterol. All the products in our informal tastings taste a lot like butter, or at least as well as we can remember what butter tasted like! The key with all of these products is use in moderation, since they all provide between 45?80 calories per tablespoon.

Let Dr. Friedewald rest in peace

In the 1960s, doctors struggled with the concept of cholesterol and its relationship to heart disease. It was becoming clear that higher levels of cholesterol were predictive of heart disease. It was also becoming clear that the low-density fraction of cholesterol, or LDL, was somewhat better than total cholesterol in predicting heart attack.

Cholesterol was easily measurable in the 1960s. LDL was not. So, Dr. Friedewald, a noted lipid researcher at the National Institutes of Health, proposed an easy method to calculate LDL cholesterol from total choleseterol, HDL, and triglycerides:

LDL cholesterol = Total cholesterol – HDL cholesterol – triglycerides/5

This simple manipulation would put LDL cholesterols into the hands of the practicing physician and the American public. Dr. Friedewald recognized that this calculation only represented an approximation of LDL cholesterol and that it was thrown off, sometimes substantially, by any abnormal rise in triglycerides or reduction in HDL. But it served its purpose at an age when most doctors hadn’t even heard of cholesterol and the public was still sold on whole milk and “farm-fresh” butter, and Chesterfields were the cigarette choice of most doctors.



The world has since changed. Most doctors have heard about cholesterol and, along with the public, have been drowned in drug company marketing for cholesterol-reducing drugs. Most people with some level of common sense and health awareness no longer use butter or whole milk, and no longer believe that the brand of cigarette you choose can be healthy. But we’re still using Dr. Friedewald’s original calculation for LDL cholesterol. When you get an LDL cholesterol from your clinic, doctor, or hospital, >99% of the time it is obtained using Dr. Friedewald’s calculation.

Is it because there’s nothing better available? No, it’s not. There’s two reasons why your neighborhood primary care physician or cardiologist is still using this dinosaur of testing called LDL:

1) The lag in science to practice is 20 years. Accept that most primary care doctors are 20 years behind the times on many issues, LDL cholesterol included.

2) Insurance companies vigorously discourage testing beyond conventional lipids. The array of objections we get from insurance companies is mind-boggling. It would be funny if human life and finances weren’t at stake. These “new” tests are “experimental”, “unproven”, not endorsed by standard guidelines, not approved by some internal committee, or simply “We don’t know what this test is” ?we’ve heard them all.

What are the tests that are superior to Dr. Friendewald’s calculated LDL? There are several, listed here in order of best to worst:

1) LDL particle number--the value generated by NMR lipoprotein testing. This is the gold standard, most reliable test available, and the one I recommend.

2) Apoprotein B--More widely available even from conventional laboratories in hospitals. Not as accurate as NMR LDL particle number, but a pretty good choice. Apo B is the principal protein in LDL, VLDL, and IDL particles, and so it’s a better reflector of risk from all of these lipoprotein fractions, not just LDL.

3) “Direct” LDL--This is LDL that is actually measured. Unfortunately, it ignores the issues of LDL size and has some other pitfalls, but it’s still better than calculated LDL

4) Non-HDL cholesterol--So-called because it incorporates all undesirable cholesterol-containing lipids except good HDL, thus “non-HDL”. This is another calculation, though better than LDL (because it sums up the risk from other apoprotein B-containing lipoproteins). Non-HDL is calculated from Total cholesterol – HDL. It’s therefore available from any standard lipid panel. It’s little used in everyday practice, however, because most people and their physicians find it confusing.

5) Friedewald calculated LDL--You can see that calculated LDL is last on a list of choices. Yet this is the measure that doctors use day in, day out. It’s the measure that drug companies base billions of dollars of revenue and profits on.

It’s an everyday occurrence in my office that calculated LDL is 89 mg/dl, but the real value is somewhere between 160 and 200 mg/dl. That’s a big difference. Imagine your realtor tells you your house’s estimated value is $200,000 and that’s what you sell it for to an eager buyer. After closing, you find out your house was really worth $300,000. You’d be upset. But that’s what you’re often getting with LDL cholesterol?a bum deal.

It’s part of the reason people will say, “My doctor said my cholesterol was fine and that no cause for my heart disease can be found. He said it was genetic.” In reality, they could have sky-high LDL cholesterol revealed by LDL particle number or apoprotein B.

Use LDL cholesterol in a pinch when you’ve got nothing else. It’s also helpful to gauge any treatment effect of diet, functional foods, drugs, etc. But it is a seriously flawed tool to diagnose your initial level of risk.

The key to losing weight

I saw three people this past week, all of whom set off on an effort to lose substantial quantities of weight. And all seriously needed to.

All three started with at least 70 lbs. excess weight; all showed substantial weight-sensitive lipoprotein patterns like low HDL, small LDL, high triglycerides, VLDL, and pre-diabetic levels of blood sugar. They also all shared high blood pressure.

All three also had high heart scan scores. Kate’s score was just over 1200. Tom, a 58-year old real estate developer, had a score of nearly 600. Susan, the youngest of the three at 52, had a heart scan score of 377¾99th percentile at this age. Losing weight was an absolute requirement for their plaque control program. Because their lipoprotein abnormalities and pre-diabetic patterns were triggered by weight, weight loss would provide powerful correction. Each and every one of them would need to lose much of their excess weight¾at least 50 lbs¾if they hoped to halt the relentless progression of their heart scan scores.

All three of them returned after 6-8 weeks, and all had lost between 17-24 lbs: spectacular results.

There’s no secret to weight loss. Each of them achieved their weight loss in slightly different ways. But they also shared several critical ingredients in their weight-loss efforts:

1) All three dramatically slashed their intake of wheat flour-containing foods and other processed carbohydrates and did so consistently. All also avoided the usual high-fat, high caloric-density foods like butter, margarine, fried foods, greasy foods, nuts roasted in oil, etc. They concentrated on vegetables, salads, raw nuts, lean proteins (inc. turkey, chicken, fish, lean red meats, low-fat cottage cheese and yogurt).

2) They stopped using food as a reward or as a consolation tool.

3) Exercise for one hour a day at least 5 days a week. The exercise in 2 of 3 of these people was just walking. It wasn’t strenuous, it wasn’t expensive. The women both liked walking with friends or their spouse. Tom followed a more common male path of more strenuous work on his treadmill, elliptical, and biking at the fitness club. But they all did it religiously and missed rare sessions.

4) They refrained from any and all alcoholic beverages. Yes, there are some advantages to 1-2 glasses of wine per day, but it stalls weight loss efforts.

5) They didn’t allow themselves any major indiscretions. There were no binges, major pig-outs at weddings, barbecues, or all-you-can-eat buffets. They did allow themselves an occasional “treat” but did so in small portions.

That’s it. But for most people, that’s simply too much. Adhering to an effort to lose dramatic weight requires day-after-day consistency. Nobody can lose the equivalent of 70,000 calories (20 lbs.) just by skipping a meal, a 20-minute walk, skipping the mashed potatoes at dinner.

It can be done. You’ve just got to be consistent about it.

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.