Fish oil: The natural triglyceride form is better

If you have a choice, the triglyceride form of fish oil is preferable. The triglyceride form, i.e., 3 omega-3 fatty acids on a glycerol "backbone," is the form found in the body of fish that protects them from cold temperatures (i.e., they remain liquid at low ambient temperatures).

Most fish oils on the market are the ethyl ester form. This means that the omega-3 fatty acids have been removed from the glycerol backbone; the fatty acids are then reacted with ethanol to form the ethyl ester.

If the form is not specified on your fish oil bottle, it is likely ethyl ester, since the triglyceride form is more costly to process and most manufacturers therefore boast about it. Also, prescription Lovaza--nearly 20 times more costly than the most expensive fish oil triglyceride liquid on a milligram for milligram basis--is the ethyl ester form. That's not even factoring in reduced absorption of ethyl esters compared to triglyceride forms. Remember: FDA approval is not necessarily a stamp of superiority. It just means somebody had the money and ambition to pursue FDA approval. Period.

Taking any kind of fish oil, provided it is not overly oxidized (and thereby yields a smelly fish odor), is better than taking none at all. All fish oil will reduce triglycerides, accelerate clearance of postprandial (after-eating) lipoprotein byproducts of a meal (via activation of lipoprotein lipase), enhance endothelial responsiveness, reduce small LDL particles, and provide a physical stabilizing effect on atherosclerotic plaque.

But if you desire enhanced absorption and potentially lower dose to achieve equivalent RBC omega-3 levels, then triglyceride forms are better.

Here are cut-and-pasted abstracts of two of the studies comparing forms of fish oil.

Bioavailability of marine n-3 fatty acid formulations.

Dyerberg J, Madsen P, Moller JM et al. 
Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark.


The use of marine n-3 polyunsaturated fatty acids (n-3 PUFA) as supplements has prompted the development of concentrated formulations to overcome compliance problems. The present study compares three concentrated preparations - ethyl esters, free fatty acids and re-esterified triglycerides - with placebo oil in a double-blinded design, and with fish body oil and cod liver oil in single-blinded arms. Seventy-two volunteers were given approximately 3.3g of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) daily for 2 weeks. Increases in absolute amounts of EPA and DHA in fasting serum triglycerides, cholesterol esters and phospholipids were examined. Bioavailability of EPA+DHA from re-esterified triglycerides was superior (124%) compared with natural fish oil, whereas the bioavailability from ethyl esters was inferior (73%). Free fatty acid bioavailability (91%) did not differ significantly from natural triglycerides. The stereochemistry of fatty acid in acylglycerols did not influence the bioavailability of EPA and DHA.
(Full text of the Dyerberg et al study made available at the Nordic Naturals website here.)

Eur J Clin Nutr 2010 Nov 10. 

Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters.

Neubronner J, Schuchardt JP, Kressel G et al. 
Institute of Food Science and Human Nutrition, Leibniz Universität Hannover, Am Kleinen Felde 30, Hannover, Germany.


There is a debate currently about whether different chemical forms of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are absorbed in an identical way. The objective of this study was to investigate the response of the omega-3 index, the percentage of EPA+DHA in red blood cell membranes, to supplementation with two different omega-3 fatty acid (n-3 FA) formulations in humans. The study was conducted as a double-blinded placebo-controlled trial. A total of 150 volunteers was randomly assigned to one of the three groups: (1) fish oil concentrate with EPA+DHA (1.01?g+0.67?g) given as reesterified triacylglycerides (rTAG group); (2) corn oil (placebo group) or (3) fish oil concentrate with EPA+DHA (1.01?g+0.67?g) given as ethyl ester (EE group). Volunteers consumed four gelatine-coated soft capsules daily over a period of six months. The omega-3 index was determined at baseline (t(0)) after three months (t(3)) and at the end of the intervention period (t(6)). The omega-3 index increased significantly in both groups treated with n-3 FAs from baseline to t(3) and t(6) (P < 0.001). The omega-3 index increased to a greater extent in the rTAG group than in the EE group (t(3): 186 versus 161% (P < 0.001); t(6): 197 versus 171% (P < 0.01)). Conclusion: A six-month supplementation of identical doses of EPA+DHA led to a faster and higher increase in the omega-3 index when consumed as triacylglycerides than when consumed as ethyl esters.

Diarrhea, asthma, arthritis--What is your wheat re-exposure syndrome?

Have you experienced a wheat re-exposure syndrome?

As I recently discussed, gastrointestinal distress--cramps, gas, diarrhea--is the most common "syndrome" that results from re-exposure to wheat after a period of elimination.

Others experience asthma, sinus congestion and infections, mental "fogginess" and difficulty concentrating, or joint pains and/or overt swelling.

Still others say there is no such thing.

Let's take a poll and find out what readers say.

Marathoners, triathletes, and heart disease

Curious thing: People with lipoprotein(a) gravitate towards elite levels of exercise.

I tell my lipoprotein(a) patients that, if they want to see a lot of other people with lipoprotein(a), go to a marathon or triathlon.

This effect applies more to males than to females, just as the fascination with numbers seems to be confined to men, too. That's why I've posted in past about the "prototypical" lipoprotein(a) male.

I believe this is a big part, perhaps the only, reason why there seems to be a modest increased risk for cardiovascular events despite high exercise levels in marathoners. It has nothing to do with the exercise itself; it has to do with the kind of people who choose to exercise at this level.

The best fish oil

The best fish oils available are the liquid forms. Contrary to many people's expectations, the best liquid fish oils have no fishy odor or taste.

I use a lot of liquid fish oils because of the higher doses we use in the Track Your Plaque program, as well as our strategy of high-dose fish oil to reduce lipoprotein(a). Women, in particular, don't like taking the oodles of capsules required to achieve the higher doses we need. So the ladies really like the liquid forms.

The best liquid fish oils are non-fishy, highly-concentrated, and come in the better absorbed triglyceride form. Many capsules, including prescription Lovaza, are the less well-absorbed ethyl ester form. Several studies, such as this one, have now demonstrated that the naturally-occurring triglyceride form yields higher blood (RBC) levels of omega-3 fatty acids, likely due to more efficient digestion via pancreatic lipase.

While there are many good forms of fish oil and only a few bad, these are the best of the best:

The Pharmax Finest Pure Fish Oil with Essential Oil of Orange contains 1800 mg EPA + DHA per teaspoon. This is the preparation I've been taking.

Nordic Naturals
The Nordic Naturals lemon-flavored ProOmega Liquid contains 2752 mg EPA + DHA per teaspoon, the most concentrated of any fish oil I've seen.

(This list is not exclusive. These are just two brands I've used extensively with good results.)

These highly-concentrated, triglyceride forms are more expensive, due to their concentrated nature. 1 teaspoon Pharmax fish oil, for example, provides an equivalent quantity of omega-3 fatty acids as 6 standard fish oil capsules on a milligram for milligram basis, but more like 8 to 9 capsules when absorption efficiency is factored in. The triglyceride form is also more laborious to manufacture. On our Track Your Plaque Marketplace, our Pharmax 500 ml runs $58.95 list. (500 ml provides 100 teaspoons or 600-capsule equivalent.)

Note that, minus the protection of the capsule, liquid fish oils will oxidize if not refrigerated. So be sure to keep your liquid fish oil in the fridge.

What do Salmonella, E coli, and bread have in common?

Say you happen to eat some chicken fingers contaminated with bacteria because the 19-year old kid behind the counter failed to wash his hands after using the toilet, or because the kitchen is poorly managed with unwashed counters and cutting boards, or because the food is undercooked. You get a bout of diarrhea and cramps, along with a desire to banish chicken from your life.

Here's yet another odd wheat phenomenon: About 30% of people who eliminate wheat from their lives experience an acute food poisoning-like effect on re-exposure. You've been wheat-free for, say, 6 months. You've lost 25 lbs from your wheat belly, you've regained energy, joints feel better. You go to an office party where they're serving some really yummy looking bruschetta. Surely a couple won't hurt! Within a hour, you're getting that awful rumbling and unease that precede the explosion.

The majority of people who experience a wheat re-exposure syndrome will have diarrhea and cramps that can last from hours to days, similar to food poisoning. (Why? Why would a common food trigger a food poisoning-like effect? It happens too fast to attribute to inflammation.) Others experience asthma attacks, joint pains that last 48 hours to a week, mental fogginess, emotional distress, even rage (in males).

Wheat re-exposure in the susceptible provides a tidy demonstration of the effects of this peculiar product of genetic research. So if you are wheat-free but entertain an occasional indulgence, don't be surprised if you have to make a beeline to the toilet.

The world of intermediate carbohydrates

There are clear-cut bad carbohydrates: wheat, oats, cornstarch, and sucrose. (Fructose, too, but in a class of bad all its own.)

Wheat: The worst. Not only does wheat flour increase blood sugar higher than nearly all other carbohydrates, it invites celiac disease, neurologic impairment, mental and emotional effects, addictive (i.e., exorphin) effects, asthma, irritable bowel syndrome, acid reflux, sleepiness, sleep disruption, arthritis . . . just to name a few.

Oats: Yeah, yeah, I know: "Lowers cholesterol." But nobody told you that oats, including slow-cooked oatmeal, causes blood sugar to skyrocket.

Cornstarch: Like wheat, cornstarch flagrantly increases blood sugar.It also stimulates appetite. That's why food manufacturers put it in everything from soups to frozen dinners.

Sucrose: Not only does sucrose create a desire for more food, it is also 50% fructose, the peculiar sugar that makes us fat, increases small LDL particles, increases triglycerides, slows the metabolism of other foods, encourages diabetes, and causes more glycation than any other sugar.

But there are a large world of "other" natural carbohydrates that don't fall into the really bad category. This includes starchy beans like black, kidney, and pinto; rices such as white, brown, and wild; potatoes, including white, red, sweet, and yams; and fruits. It includes "alternative" grains like quinoa, spelt, triticale, amaranth, and barley.

For lack of a better term, I call these "intermediate" carbohydrates. They are not as bad as wheat, etc., but nor are they good. They will still increase blood glucose, small LDL, triglycerides, etc., just not as much as the worst carbohydrates.

The difference is relative. Say we compare the one-hour blood glucose effects of 1 cup of wheat flour product vs. one cup of quinoa. Typical blood sugar after wheat product: 180 mg/dl. Typical blood sugar after quinoa: 160 mg/dl--better but still pretty bad.

Some people are so carb-sensitive that they should avoid even these so-called intermediate carbohydrates. Others can have small indulgences, e.g., 1/2 cup, and not generate high blood sugars.

Heroin, Oxycontin, and a whole wheat bagel

For a substantial proportion of people who remove wheat from their diet, there is a distinct and unpleasant withdrawal syndrome. Here are the comments of Heart Scan Blog reader, Scott, from Texas:

Hello Dr. Davis,

I've been experimenting with diet, converging upon a Paleo type diet, but I keep running into problems. I have isolated the problem to cutting out wheat.

Sugar, rice, fruit, corn, potatoes, etc. are relatively ok to add or remove from the diet, but cutting out wheat in particular brings on a moderate headache with heavy fatigue all day long. This resembles the wheat withdrawal symptoms I found on your blog. As I write this, I'm on day 8 of wheat-free. I consume a fair variety of meat and veggies each day with a moderate amount of white rice for carbs. Perhaps a bowl of corn flakes with milk and half a bar of dark chocolate a day. I've learned from experience over the past 5 months or so that none of these foods affect the withdrawal. It's purely wheat.

My question is, what is the range of times for withdrawal symptoms that you've heard from different people? Has there been anyone who never recovered from the wheat withdrawal symptoms even after many months?

It's very tough to get work done like this, and even though my body and head feel much healthier in general, my sinuses have cleared, don't have to take a big nap after I eat, etc., I don't want to go down a path where this is the way things are going to be forever. 

People who have never experienced wheat withdrawal pooh-pooh the effect. But, for about 30% of people, wheat withdrawal is a real, palpable, and sometimes incapacitating experience.

Beyond removing an exceptionally digestible carbohydrate that yields blood sugar rises higher than nearly any other known food (due to the unique amylopectin structure of wheat-derived carbohydrate), wheat withdrawal is a form of opiate withdrawal, somewhat like stopping heroin, Oxycontin, and other opiates. Stop eating whole wheat toast for breakfast, whole grain sandwiches for lunch, or whole grain pasta for dinner, and the flow of exorphins, i.e., exogenous morphine-like compounds, stops. You experience dysphoria (sadness, unhappiness), mental "fog," inability to concentrate, fatigue, and decreased capacity to exercise. It is milder than withdrawal from prescription opiates. Unlike withdrawal from more powerful opiates like heroine, there are, thankfully, no seizures or hallucinations. There are also no deaths.

In my experience, most people get through with wheat withdrawal in about 5 days. An occasional person will struggle for as long as 4 weeks. Thankfully for Scott, I've never seen it last longer than 4 weeks. (Interestingly, people who survive the withdrawal syndrome are often prone to a peculiar re-exposure phenomenon that I will discuss in future, i.e., they get sick upon re-exposure.)

The modern dwarf mutant variant of Triticum aestivum (that our USDA urges us to eat more of) contains greater proportions of gluten proteins compared to wheat pre-1970; glutens are the source of wheat-derived exorphins.

Incidentally, a drug company should be releasing a drug in the next year that will contain naltrexone, an oral opiate blocking drug, for a weight loss indication. They claim it is a blocker of the "mesolimbic reward system." I say it's a blocker of wheat exorphins.

The five most powerful heart disease prevention strategies

You've seen such lists before: 5 steps to prevent heart disease or some such thing. These lists usually say things like "cut your saturated fat," eat a "balanced diet" (whatever the heck that means), exercise, and don't smoke.

I would offer a different list. You already know that smoking is a supremely idiotic habit, so I won't repeat that. Here are the 5 most important strategies I know of that help you prevent heart disease and heart attack:

1) Eliminate wheat from the diet--Provided you don't do something stupid, like allow M&M's, Coca Cola, and corn chips to dominate your diet, elimination of wheat is an enormously effective means to reduce small LDL particles, reduce triglycerides, increase HDL, reduce inflammatory measures like c-reactive protein, lose weight (inflammation-driving visceral fat), reduce blood sugar, and reduce blood pressure. I know of no other single dietary strategy that packs as much punch. This has become even more true over the past 20 years, ever since the dwarf variant of modern wheat has come to dominate.

2) Achieve a desirable 25-hydroxy vitamin D level--Contrary to the inane comments of the Institute of Medicine, vitamin D supplementation increases HDL, reduces small LDL, normalizes insulin and reduces blood sugar, reduces blood pressure, and exerts potent anti-inflammatory effects on c-reactive protein, matrix metalloproteinase, and other inflammmatory mediators. While we also have drugs that mimic some of these effects, vitamin D does so without side-effects.

3) Supplement omega-3 fatty acids from fish oil--Omega-3 fatty acids reduce triglycerides, accelerate postprandial (after-meal) clearance of lipoprotein byproducts like chylomicron remnants, and have a physical stabilizing effect on atherosclerotic plaque.

4) Normalize thyroid function--Start with obtaining sufficient iodine. Iodine is not optional; it is an essential trace mineral to maintain normal thyroid function, protect the thyroid from the hundreds of thyroid disrupters in our environment (e.g., perchlorates from fertilizer residues in produce), as well as other functions such as anti-bacterial effects. Thyroid dysfunction is epidemic; correction of subtle degrees of hypothyroidism reduces LDL, reduces triglycerides, reduces small LDL, facilitates weight loss, reduces blood pressure, normalizes endothelial responses, and reduces oxidized LDL particles.

5) Make exercise fun--Not just exercise for the sake of exercise, but physical activity or exercise for the sake of having a good time. It's the difference between resigning yourself to 30 minutes of torture and boredom on the treadmill versus engaging in an activity you enjoy and look forward to: go dancing, walk with a friend, organize a paintball tournament outdoors, Zumba class, plant a new garden, etc. It's a distinction that spells the difference between finding every excuse not to do it, compared to making time for it because you enjoy it.

Note what is not on the list: cut your fat, eat more "healthy whole grains," take a cholesterol drug, take aspirin. That's the list you'd follow if you feel your hospital needs your $100,000 contribution, otherwise known as coronary bypass surgery.

Topping up your vitamin D tank

Now that my vitamin D replacement experience dates back nearly 5 years, I've been witnessing an unusual phenomenon:

The longer you take vitamin D, the less you need.

Let me explain. You take 10,000 units D3 in gelcap form. 25-hydroxy vitamin D levels, checked every 6 months, have remained consistently between 60 and 70 ng/ml. Three years into your vitamin D experience and 25-hydroxy vitamin D level rises to 98 ng/ml--an apparent need for less vitamin D.

So we cut your intake from 10,000 units per day to 8000 units per day. Another 25-hydroxy vitamin D level 6 months later: 94 ng/ml. We cut dose again to 6000 units, followed by another 25-hydroxy vitamin D level of 66 ng/ml.

This has now happened in approximately 20% of the people who have been taking vitamin D for 3 or more years. I know of no formal analysis of this effect, what I call the "topping up" phenomenon. Reasoned simply, it seems to me that, once your vitamin D "tank" is topped up (i.e., tissue stores have been replenished), it requires less to keep it full.

No one has experienced any adverse consequence of this topping up effect though it has potential for some people to develop toxic levels if 25-hydroxy vitamin D levels are not monitored long-term. In my office, I measure 25-hydroxy vitamin D levels every 6 months.

It means that long-term monitoring of 25-hydroxy vitamin D is crucial to maintain favorable and safe levels.

Thirteen catheterizations later

When I first met her, Janet couldn't stop sobbing. She'd just been through her 10th heart catheterization in two years.

It started with chest pains at age 56, prompting her first heart catheterization that uncovered severe atherosclerotic blockages in all three coronary arteries. Her cardiologist advised a bypass operation.

Six months after the bypass operation, Janet was back with more chest pains, just as bad as before. Another heart catherization showed that two of the three bypass grafts had failed. The third bypass graft contained a severe blockage that required a stent, along with multiple stents in the two now unbypassed arteries.

In the ensuing 18 months, Janet returned for 8 additional catheterizations, each time leaving the hospital with one or more stents.

Janet's doctor was puzzled as to why her disease was progressing so aggressively despite Lipitor and the low-fat diet provided by the hospital dietitian. So he had Janet undergo lipoprotein testing (NMR):

LDL particle number: 3363 nmol/L
Small LDL particle number: 2865 nmol/L
HDL cholesterol: 32 mg/dl
Triglycerides: 344 mg/dl
Fasting blood glucose 118 mg/dl
HbA1c 5.8%

Unfortunately, Janet's doctor didn't understand what these values meant. He pretty much threw his arms up in frustration. That's when I met Janet.

From her lipoprotein panel and other values, it was clear to me that Janet was miserably carbohydrate-sensitive and carbohydrate-indulgent, as demonstrated by the extravagant quantity (2865 nmol/L) and proportion (2865/3363, or 85%) of small LDL, the form of LDL particles created by carbohydrate exposure. Janet struggled with depression over the years and had been using carbohydrate foods as "comfort" foods, often resorting to cookies, pies, cakes, breads, and other wheat-containing foods for emotional solace.

It took a bit of persuasion to convince Janet that it was low-fat, "healthy whole grains," as well as comfort foods, that had led her down this path. I also helped Janet correct her severe vitamin D deficiency, mild thyroid dysfunction, and lack of omega-3 fatty acids.

Since meeting Janet and instituting her new prevention program, she has undergone three additional catheterizations (performed by another cardiologist), all performed for chest pain symptoms that struck during periods of emotional stress. All showed . . . no significant blockage. (Apparently, the repeated "need" for stents triggered a Pavlovian response: chest pain = "need" for yet more stents.)

In short, correction of the causes of coronary atherosclerotic plaque--small LDL, vitamin D deficiency, omega-3 fatty acid deficiency, and thyroid dysfunction--and Janet's disease essentially ground to a halt.

Imagine, instead, that Janet had undergone 1) a heart scan to identify hidden coronary plaque 5-10 years before her first heart procedure, then 2) corrected the causes before they triggered symptoms and posed danger. She might have been spared an extraordinary amount of life crises, hospital procedures, expense (nearly $1 million), and emotional suffering.