Tag Archives: fish oil supplements

Omega-3S From Fish Oil Supplements No Better Than Placebo For Dry Eye 

Yesterday, a patient I’m seeing for atrial fibrillation told me that he was taking fish oil supplements that his eye doctor had recommended and sold to him for dry eyes. This patient reads my blog and knows that I strongly recommend not taking fish oil supplements (unless your triglycerides are >500). At the time I told him I didn’t know the literature on fish oil and dry eyes but that I was skeptical of any proven benefit.

It turns out that in April of this year an NIH-sponsored study concluded that Omega-3s from fish oil supplements are no better than placebo for dry eye.

The NIH story on this study notes that

Despite insufficient evidence establishing the effectiveness of omega-3s, clinicians and their patients have been inclined to try the supplements for a variety of conditions with inflammatory components, including dry eye. “This well-controlled investigation conducted by the independently-led Dry Eye Assessment and Management (DREAM) Research Group shows that omega-3 supplements are no better than placebo for typical patients who suffer from dry eye.”

I suspect that one by one the various alleged benefits of fish oil supplements will be proven to be nonexistent.  I’m not sure the general public will stop buying snake or fish oil  then but I feel like one by one I’m getting my patients off them. Doing my part to save the ocean bottom-feeders.

Krillingly Yours,

-ACP

N.B. I’m writing this while flying to Miami to begin the great Galapagos adventure and the Voyage of the Samba.

Three More Nails In The Omega-3 Supplement Coffin: Stop Taking Fish Oil Pills (The Complete Post)

If by now you are still taking fish oil supplements despite my last post on the topic I present three more reasons to stop wasting your money and destroying the ocean’s ecosystem.

The first nail: No Reason To Take Fish Oil Pills

A Cochrane review showing shows there is little or no effect of omega 3 supplements on our risk of experiencing heart disease, stroke or death.

This is the most extensive systematic assessment of effects of omega-3 fats on cardiovascular health to date. Moderate- and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Previous suggestions of benefits from EPA and DHA supplements appear to spring from trials with higher risk of bias. Low-quality evidence suggests ALA may slightly reduce CVD event risk, CHD mortality and arrhythmia.

Second Nail. Peruvian Anchoveta: Put Them On A Pizza Not in A Pill

Paul Greenberg’s recently published book, The Omega Principle, emphasizes the damage the fish oil supplement business is doing to the ocean environment,

During a recent interview on Fresh Air on NPR he summarized the concerns:

GREENBERG: So omega-3 supplements come from this critical layer of the ocean biosphere that are small – what are called pelagic fish. They’re the silvery, little fish like anchovies and herring and other fish called menhaden that most people haven’t heard of, but it’s actually the most caught fish in the lower 48 of the United States. These fish are really essential for ecosystem dynamics in the ocean.

So the way that oceans work is that all the energies coming from the sun – it goes – all that energy is processed by plankton, by phytoplankton. And it’s really these fish that are – these little fish that are used for omega-3 supplements that transfer the energy from plankton to larger fish. So in other words, you know, you have the solar energy going into the plankton. The little fish then eat the plankton. And then they are in turn eaten by larger fish. So if you harvest this middle layer – if you overharvest this middle layer of anchovies, of herring, of menhaden – if you take them out of the picture, there’s no way for the energy to be transferred from phytoplankton up to larger predators. So I guess that’s my main concern here.

So in particular, where are the omega-3 supplements coming from? Most of the omega-3 supplement oil is coming from a fish called a Peruvian anchoveta. And it is the most caught fish in the world. In some years, Peruvian anchoveta harvests have equaled as much as 10 million metric tons. Just to give you some perspective, that’s like one-eighth of all the fish caught in the world. And the crazy thing about it is that those fish are completely, totally edible. I’ve eaten them. They’re delicious. You can have them on a pizza. You could do anything with them. But 99 percent of those Peruvian anchoveta are ground up into animal feed, boiled down into oil and turned into supplements. So to me, to my mind, that is not necessarily the wisest use to be made of this really, really important source both for the ecology of the ocean but also for humans

Nail Three. Save the Krill!

The supplement industry is incredibly creative in their marketing. As the uselessness of fish oil supplementation has become clear, supplement manufacturers have begun touting krill oil as superior to fish oil.

Claims like the following are all over the internet:

Krill have an edge over your ordinary fish – when you take a krill oil supplement, you also get astaxanthin along with your DHA and EPA. It’s an antioxidant. In terms of antioxidant power of potency, it’s been found to be 500x to 6,000x stronger than regular vitamins like vitamin E and vitamin C.

This is just hogwash. There is no good clinical evidence to support any health claim for krill oil in general or astaxanthin in particular. Please read my post on the failure of anti-oxidant supplements and vitamins and recognize that claims of antioxidant power do not indicate any health benefit.

A technical paper from Greenpeace review the importance of krill to to the marine ecosystem in the Antarctic and this paper, entitled “License to Krill” details the problem.

Do you want to be responsible for starving penguins, whales and seals??!

Let me reiterate my original 2013 fish oil post pithy summary:

the bottom line on fish oil supplements is that  the most recent scientific evidence does not support any role for them  in preventing heart attack, stroke, or death. There are potential down sides to taking them, including contaminants and the impact on the marine ecosystem. I don’t take them and I advise my patients to avoid them (unless they have triglyceride levels over 500.)

Prokrilly Yours

-ACP

 

 

 

 

Flaxseed: Plant-Based Omega 3 Super Food or Faux Fish Oil?

Ground flaxseed plus Trader’s Point Creamery full fat plain yoghurt. It’s not pretty but tastes pretty good.

The skeptical cardiologist has a confession to make: he’s been adding ground flaxseed to his typical late morning full fat yoghurt plus berries and almonds.

Adding flaxseed seems dangerously close to dietary behaviour I have been advising against: supplementing instead of eating real food.

Also, I am philosophically opposed to going out of my way to eat any edible that is consistently promoted as a “super food” or a “functional food.” To me, these are meaningless terms and marketing blather

When I began writing this post in 2017 I was getting my flaxseed from Stober Farms (Est. 1901) who had been producing “for over 100 years  the finest flax in the world.”  Stober Farms provided me with “organic Golden Flax Seed which has been Cold-Milled Processed.”

Stober Farms (who have since mysteriously gone into bankruptcy) also informed me:

Flax is digested most effectively when ground. Some grinding methods generate heat when milled, spurring early omega-3 oxidation. Stober Farms uses a unique cold-milled process, which gently grinds the seed without significantly raising the temperature. This proprietary method preserves the nutrients, flavor and extends the shelf life to 22 months.

Honestly, I don’t recall exactly why I began “flaxing” but I suspect I felt it was a good way to boost the fat content in my full fat yoghurt (yes, I am now spelling yoghurt with an h) and berries and perhaps sufficiently satiate me that it would be the only food I would need to consume until dinner or late afternoon.

Two tablespoon (14 grams) is what I typically  imprecisely add. These tablespoons provide 75 kcal of energy which comes from 3 grams of protein, 6 grams of fat, and 4 grams of carbs.  Three of the four carb grams are soluble fibre.

About half of the fat in flaxseed is in the form of alpha-linolenic acid (ALA)(18:3) an omega-3 polyunsaturated (PUFA) fat.  Flaxseed oil contains five times more ALA than walnut oil or canola oil, which are the next highest sources of ALA.

Is Flaxseed A Super Functional Food?

Many seemingly authoritative sites on the internet proclaim that flaxseed is incredibly healthy. For example, Healthline.com’s “Authority Nutrition” (they must be authoritative as authority is in their name)  presents their 10 health benefits of eating flaxseed “backed by science”  and concludes:

They can be used to improve digestive health, lower blood pressure and bad cholesterol, reduce the risk of cancer and may benefit people with diabetes.

But typical of  Authority Nutrition’s overblown claims  these are not truly proven by science. The studies cited are weak; typically short-term tests of biomarkers or animal studies or human studies with very small numbers. Most importantly. these studies , which are often funded by flaxseed promoters are highly likely to be biased in favor of positive results.

Most websites tout the cardiovascular benefits of the omega-3 PUFA in flaxseed, the high percentage of soluble fibre and  the benefits of a chemical which cannot be named (due to a name which is too difficult to pronounce), SDG.

Omega-3 PUFAs and fibre I’ve touched on previously (and positively) but what about the mysterious and unpronounceable SDF. Per a 2010 review article

Flaxseed is the richest source of the lignan secoisolariciresinol diglucoside (SDG). After ingestion, SDG is converted to secoisolariciresinol, which is further metabolised to the mammalian lignans enterodiol and enterolactone. A growing body of evidence suggests that SDG metabolites may provide health benefits due to their weak oestrogenic or anti-oestrogenic effects, antioxidant activity, ability to induce phase 2 proteins and/or inhibit the activity of certain enzymes, or by mechanisms yet unidentified.

Like so many putative wonder phytochemicals, SDG has a “growing body of evidence” for lots of things but actual proof that it does anything worthwhile in humans is lacking and awaits  well done randomized clinical trials

Poorly researched articles on flaxseed are highly likely to tout its anti-inflammatory properties. These properties are seen in rats but unfortunately haven’t been proven in my favorite species, Homo Sapiens ,  Flaxseed doesn’t seem to decrease the inflammatory marker CRP in humans as reported in this systematic review and meta-analysis.

ALA and Cardiovascular Disease

As I’ve indicated in previous posts, evidence supports fatty fish consumption as beneficial in reducing cardiovascular disease presumably by increasing levels of marine omega-3 PUFAs in the body.

The value of fish oil supplementation, however, is not proven (see here).

How does ALA compare to the seafood omega 3s  in preventing cardiovascular disease (CVD)?

In 2012, researchers at the Harvard School of Public Health published a systematic review and meta-analysis of the existing data on ALA and the risk of CVD..

Their introductory paragraph nicely lays out why ALA could be very important to public health:

A large body of evidence supports a potential protective effect of seafood omega-3 (n−3) fatty acids, particularly EPA (20:5n−3) and DHA (22:6n−3), on coronary heart disease (CHD. However, fewer studies have evaluated how the plant-derived omega-3 fatty acid α-linolenic acid (ALA; 18:3n−3) relates to risk of CHD and other cardiovascular disease (CVD) outcomes, and the results have been inconsistent As an essential fatty acid that cannot be synthesized by humans, ALA is mainly consumed from plant sources, including soybeans, walnuts, and canola oil. Compared with seafood omega-3 fatty acids, ALA from plant sources is more affordable and widely available globally. Thus, whether ALA can reduce the risk of CVD is of considerable public health importance.

If plant-derived ALA can provide our omage-3 PUFA needs then perhaps we can stop stripping the ocean of all the menhaden.

In the Harvard analysis when all 27 studies were combined the authors found a significant risk reduction of 14% in CVD events with flaxseed.

There were lots of issues with the data which I won’t bore you with leading the authors to conclude that “ALA consumption may be beneficial “.  They emphasized the need for additional well-designed observational studies and randomized clinical trials in the area.

Since observational studies cannot prove causality, I await a good randomized clinical trial of ALA supplementation before I can recommend ALA supplementing to prevent heart disease.

After Performing This Review Is The Skeptical Cardiologist Still “Flaxing”?

I am. Because I’ve found that when I consume flaxseed I feel 20 years younger, full of vitality. and with a youthful golden sheen to my hair, nails and skin.

Actually, that last sentence is untrue.

I’m still adding ground flaxseed to my yoghurt but not with any expectation that it is reducing my risk of heart attack and definitely not because I perceive it as a super or functional food.

I like the taste, the convenience, and the extra (presumably healthy) calories it provides but I’m still an advocate of just eating real food rather than trying to identify specific nutrients, nutraceuticals or supplements and add them to your diet.

Flaxseedingly Yours,

-ACP

N.B. I did not touch on omega-6/omega-3 ratios in the diet. I’ve been examining that inflammatory (enjoy the pun) topic for years and once I come across a good study that adds to understanding in the area I will likely publish a post on it.

 

Still More Evidence That Fish Oil Supplements Do Not Prevent Cardiovascular Disease

Avid readers of the skeptical cardiologist know that he is not an advocate of fish oil supplements.

One of my first posts (1/2013) was devoted to taking down the mammoth OTC fish oil industry because recent scientific evidence was clearly showing no benefit for fish oil pills.

I concluded:

", the bottom line on fish oil supplements is that  the most 
recent scientific evidence does not support any role for them  inpreventing heart attack, stroke, or death. There are potential 
down sides to taking them, including contaminants and the impact on the marine ecosystem. I don’t take them and I advise my
patients to avoid them (unless they have triglyceride levels 
over 500.)"

Despite a lack of evidence supporting taking them, the fish oil business continues to grow,  buttressed by multiple internet sites promoting various types of fish oil (and more recently krill oil)  for any and all ailments and a belief in the power of “omega-3 fatty acids”.

Another Meta-Analysis Concludes No Benefit To Fish Oil Supplements

A publication this month evaluated the 10 randomized controlled trials involving 77 917 thousand individuals that have studied fish oil supplements in preventing heart disease. The writers concluded that fish oil supplements do not significantly prevent any cardiovascular outcomes under any scenario.

It was written by a group with the ominous title of “The Omega-3 Treatment Trialists’ Collaboration.”

The Omega-3 Treatment Trialists’ Collaboration was established to conduct a collaborative meta-analysis based on aggregated study-level data obtained from the principal investigators of all large randomized clinical trials of omega-3 FA supplements for the prevention of cardiovascular disease, using a prespecified protocol and analysis plan. The aims of this meta-analysis were to assess the associations of supplementation with omega-3 FAs on (1) fatal CHD, nonfatal MI, stroke, major vascular events, and all-cause mortality and (2) major vascular events in prespecified subgroups.

The authors conclusions:

. Randomization to omega-3 fatty acid supplementation (eicosapentaenoic acid dose range, 226-1800 mg/d) had no significant associations with coronary heart disease death (rate ratio [RR], 0.93; 99% CI, 0.83-1.03; P = .05), nonfatal myocardial infarction (RR, 0.97; 99% CI, 0.87-1.08; P = .43) or any coronary heart disease events (RR, 0.96; 95% CI, 0.90-1.01; P = .12). Neither did randomization to omega-3 fatty acid supplementation have any significant associations with major vascular events (RR, 0.97; 95% CI, 0.93-1.01; P = .10), overall or in any subgroups, including subgroups composed of persons with prior coronary heart disease, diabetes, lipid levels greater than a given cutoff level, or statin use.

Nothing. Nada. No benefit.

There is clearly no reason to take fish oil supplements to prevent cardiovascular disease!

American Heart Association Sheepishly Recommends Fish Oil Supplements

If the science was conclusive on this in 2013 why did the American Heart Association (AHA) issue an “advisory” in 2017  suggesting that the use of omega-3 FAs for prevention of coronary heart disease (CHD) is probably justified in individuals with prior CHD and those with heart failure and reduced ejection fractions?

The AHA advisory is clearly misguided and relies heavily in its discussion on a 2012 meta-analysis from Rizos, et al. published in 2012.

Oddly, this is the study that prompted me to write my first fish oil post in 2013

The AHA advisory totally distorts the completely negative conclusions of the Rizos meta-analysis, writing:

A meta-analysis published in 2012 examined the effects of omega-3 PUFA supplementation and dietary intake in 20 RCTs that enrolled patients at high CVD risk or prevalent CHD and patients with an implantable cardioverter-defibrillator (total n=68 680). That meta-analysis demonstrated a reduction in CHD death (RR, 0.91; 95% CI, 0.85–0.98), possibly as the result of a lower risk of SCD (RR, 0.87; 95% CI, 0.75–1.01).11

Strangely enough, if you look at the conclusions of Rizos, et al. they are

No statistically significant association was observed with all-cause mortality (RR, 0.96; 95% CI, 0.91 to 1.02; risk reduction [RD] -0.004, 95% CI, -0.01 to 0.02), cardiac death (RR, 0.91; 95% CI, 0.85 to 0.98; RD, -0.01; 95% CI, -0.02 to 0.00), sudden death (RR, 0.87; 95% CI, 0.75 to 1.01; RD, -0.003; 95% CI, -0.012 to 0.006), myocardial infarction (RR, 0.89; 95% CI, 0.76 to 1.04; RD, -0.002; 95% CI, -0.007 to 0.002), and stroke (RR, 1.05; 95% CI, 0.93 to 1.18; RD, 0.001; 95% CI, -0.002 to 0.004) when all supplement studies were considered.

Nothing. Nada. No significant benefit!

The AHA was so confused by their own advisory that in the AHA news release on the article they quote Dr. Robert Eckel, a past AHA president as saying he remains “underwhelmed” by the current clinical trials.

“In the present environment of evidence-based risk reduction, I don’t think the data really indicate that fish oil supplementation is needed under most  circumstances.”

The end of the AHA news article goes on to quote Eckel as indicating he doesn’t prescribe fish oil supplements and the science advisory won’t change his practice:

Eckel said he doesn’t prescribe fish oil supplements to people who have had coronary events, and the new science advisory won’t change that. “It’s reasonable, but reasonable isn’t a solid take-home message that you should do it,” he said.

AHA: Wrong On Coconut Oil and Fish Oil

It’s hard for me to understand why the AHA gets so many things wrong in their scientific advisories. In the case of the recent misguided attack on coconut oil , their ongoing vilification of all saturated fats, and their support for fish oil supplements I don’t see evidence for industry influence. The authors of the fish oil supplement advisory do not report any financial conflicts of interest.

There is, however, one bias that is very hard to measure which could be playing a role: that is the bias to agree with what one has previously recommended.  The AHA issued an advisory in 2002 recommending that people take fish oil. Changing that recommendation would mean admitting that they were wrong and that they had contributed to the growth of a 12 billion dollar industry serving no purpose.

Personally, I am aware of this kind of bias in my own writing and strive to be open to new data and publications that challenge what I personally believe or have publicly recommended.

In the case of fish oil supplements for preventing cardiovascular disease, however, the most recent data supports strongly what I wrote in 2013:

Don’t take fish oil supplements to prevent heart disease.

Americans want a “magic-bullet” type pill to take to ward off aging and the diseases associated with it. There isn’t one. Instead of buying pills and foods manipulated and processed by the food industry which promise better health, eat real food (including fish) eat a lot of plants and don’t eat too much.

Piscinely Yours,

-ACP

N.B. I have no patients on the two prescription fish oil supplements available, Lovaza and Vascepa. I wrote about Vascepa here

Below is an excerpt:

Like the first prescription fish oil available in the US, Lovaza, VASCEPA is only approved by the FDA for treatment of very high triglycerides (>500 mg/dl).

This is a very small market compared to the millions of individuals taking fish oil thinking that  it is preventing heart disease.

The company that makes Vascepa (Amrin;$AMRN)would also like to have physicians prescribe it to their patients who have mildly or moderatelyelevated triglycerides between 200 and 500 which some estimate as up to 1/3 of the population.

The company has a study that shows that Vascepa lowers triglycerides in patients with such mildly to moderately elevated triglycerides but the FDA did not approve it for that indication.

Given the huge numbers of patients with trigs slightly above normal, before approving an expensive new drug, the FDA thought, it would be nice to know that the drug is actually helping prevent heart attacks and strokes or prolonging life.

After all, we don’t really care about high triglycerides unless they are causing problems and we don’t care about lowering them unless we can show we are reducing the frequency of those problems.

Data do not exist to say that lowering triglycerides in the mild to moderate range  by any drug lowers heart attack risk.

In the past if a company promoted their drug for off-label usage they could be fined by the FDA but Amarin went to court and obtained the right to promote Vascepa to physicians for triglycerides between 200 and 500.

Consequently, you may find your doctor prescribing this drug to you. If you do, I suggest you ask him if he recently had a free lunch or dinner provided by Amarin, has stock in the company (Vascepa is the sole drug made by Amrin and its stock price fluctuates wildly depending on sales and news about Vascepa) or gives talks for Amarin.

If he answers no to all of the above then, hopefully, your triglycerides are over 500.

.

 

 

 

 

Cioppino and Cholesterol in the City by the Bay

IMG_2812
Crab cioppino from Sotto Mare. The crab is quartered and you must use utensils to get at it.

The other night  I had the best cioppino I have ever had. I’ve had variations of this wonderful tomato-based seafood stew  all over the world (including the legendary bouillabaisse in Marseilles) but I left my heart with the Dungeness crab cioppino served at Sotto Mare Oysteria and Seafood restaurant in North Beach, San Francisco. It makes sense, since cioppino was invented by Genoan fishermen from the SF Bay Area in the 19th century who threw together the freshest catch from their day at sea.

The recipe for Sotto Mare’s cioppino is actually available online as follows:
¼ cup olive oil
1 tsp. crushed red chile flakes
8 cloves garlic, finely chopped
3 cups fish stock
1 ½ cups whole peeled tomatoes in juice, crushed
10 leaves basil
1 lb. cod, cut into 2″ chunks
1 lb. cleaned calamari, bodies cut into ½″-wide rings
12 oz. medium shrimp, deveined
12 oz. bay scallops
16 clams, cleaned
16 mussels, cleaned
2 2-lb. Dungeness crabs or snow crab legs, halved
Kosher salt and freshly ground black pepper, to taste

It involves a lot of shellfish: calamari, shrimp, scallop, clams, mussels, crabs and I think a large part of what made it so good was the freshness of the shellfish obtained from the nearby Pacific Ocean.

Shellfish, Dietary Cholesterol and Cardiovascular Risk

Shellfish contain a lot of cholesterol and many of my patients have been told to minimize or avoid shellfish, especially shrimp, due to concerns they will exceed the (completely arbitrary) 300 mg daily limit suggested by the American Heart Association and the USDA nutritional guidelines.

There is no scientific basis for being concerned about the amount of cholesterol one consumes when eating shellfish (or for any food for that matter, as I previously wrote about with regard to eggs here)

But there are definitely warnings out there on the internet and traditional new media from seemingly responsible authorities.

This blurb from  the Physician Committee for Responsible Medicine is typical of the misinformation:

“Since our bodies make plenty of cholesterol for our needs,we do not need to add any in our diet. Cholesterol is found in all foods that come from animals: red meat, poultry, fish, eggs, milk, cheese, yogurt, and every other meat and dairy product. Choosing lean cuts of meat is not enough; the cholesterol is mainly in the lean portion. Many people are surprised to learn that chicken contains as much cholesterol as beef. Every four-ounce serving of beef or chicken contains 100 milligrams of cholesterol. Also, most shellfish are very high in cholesterol. All animal products should be avoided for this reason. “

The Physician Committee for Responsible Medicine appears to be a front for vegan-promotion. They go on to state that every 100 mg of cholesterol you consume raises your cholesterol by 5 mg/dl and that

“Every time you reduce your cholesterol level by 1 percent, you reduce your risk of heart disease by 2 percent.  For example, a reduction from 300 mg/dl to 200 mg/dl (i.e., a one-third reduction) will yield a two-thirds reduction in the risk of a heart attack”

A Fox News publication simultaneously extolls the virtues of shrimp consumption (noting that “three ounces of shrimp (or about seven medium-sized shrimp) has a mere 84 calories, 1g of fat, and an impressive 18g of lean protein” and that they are a great source of selenium, “an antioxidant that fights cancer-causing free radicals in your body”) and warns you against eating it (“If you are watching your cholesterol, it’s best to go easy on shrimp because four large shrimp have 42.5mg of cholesterol”)

Other publications advise those with high cholesterol or higher risk of heart disease to choose low-cholesterol varieties of shellfish over shrimp.

The Science Supporting Shrimp

Let’s look at what is actually known about consuming shrimp and shellfish.
A study of over 13,000 subjects (the ARIC study) found no increased risk of cardiovascular disease in the high shellfish consumers versus the low shellfish consumers.

A study in 1996 compared consuming a diet with 300 grams (about 10 oz.)  of steamed shrimp/day (providing 590 mg of cholesterol daily) versus a baseline diet of 107 mg/ cholesterol in 18 individuals without cholesterol problems.  The shrimp consumers compared to baseline had a 7% higher LDL or bad cholesterol but a 12% higher HDL or good cholesterol. Thus, the ratio of total to good cholesterol went down. We now know that this ratio is a much more important risk marker for cardiovascular disease than the total cholesterol. Triglycerides dropped significantly when subjects were consuming shrimp versus the baseline, low cholesterol diet.

A 1990 study looked at multiple different types of shellfish substituted for meat, cheese and eggs, and found that oyster, clam, crab and mussel diets (with lower cholesterol and higher omega-3 fatty acid profiles) lowered VLDL triglycerides and VLDL cholesterol.  These shellfish diets, except for the mussel diet, also lowered LDL and total cholesterol. Shrimp and squid had no effect on the lipid profiles.

 Benefits of Shrimp and Shellfish Consumption

I’ve focused on shrimp in this post because it has the highest cholesterol content of all shellfish and therefore is the most likely to be considered bad for heart patients or patients with high cholesterol. I’m presuming if I can convince you that shrimp are heart healthy, then you will believe that all shellfish are.

shrimp contentsTake a look at this chart of the nutrient composition of shrimp and you can understand that, once you eliminate  unsubstantiated fears of the cholesterol content, this a great food.

I am not a big advocate of examining the macronutrient composition of foods in order to predict their health benefits. This approach to nutritional science resulted in the development of highly processed low-fat monstrosities that currently sit in boxes and bags and line the most prominent parts of supermarket shelves. The overall effect of foods on the cardiovascular system depends on an incredibly complicated interaction of food components, bacteria in the gut and genetic predispositions: areas we are only beginning to understand. However, for those readers who are concerned about such things there is reassurance.

Start with the fact that there are no carbohydrates in shellfish: since carbs and added sugar are likely the biggest culprits in our obesity epidemic, shrimp and shellfish are great tools in helping to manage weight.  Shrimp have a very high percentage and quality of protein content for muscle building.

Some avid shrimp promoters insist that shrimp should be consumed regularly to reduce the risk of both cancer and heart disease.  The fat in shrimp is mostly polyunsaturated fat with a high ratio of omega-3 to omega-6 which is considered optimal . Eating 100 ounces of shrimp daily gives you 180 mg of EPA and DHA (considered the most important of the omega-3 fish oils for heart health) daily, close to the 250 mg daily the USDA recommends for most adults.

Astaxanthin has been found to be a potent natural antioxidant, exceeding ten times the antioxidant activity of β-carotene and 500 times that of α-tocopherol. The astaxanthin level of wild shrimps has been reported to vary between 740 and 1400 μg/100 g in edible meat portions.

If I were a vegan or vegetarian I would consider slipping shrimp into my dishes instead of tofu.

Adulterated Shrimp

The cioppino recipe above doesn’t add a lot to the shellfish and fish: a little olive oil and tomatoes, basil and garlic-these things are not going to jack up the calories, sugar or fat content.

Depending on how you cook shrimp, the resulting dish will have markedly different nutrient composition compared to the raw nutrients listed above.

Breading and deep frying the shrimp takes 3 oz from 60 calories to 206 and the fat grams from 1 to 10.  I suspect that you or your body will figure this out and eat less later. Given the fairly low fat and carbohydrate content of the Sotto Mare cioppino, I am ashamed to admit, I ate that whole bowl pictured above (which the menu said could be shared between two).

The SOSC doesn’t share my love of cioppino; she ordered the linguine with clam sauce. Three ounces of clams have only 26 mg of cholesterol but it seems to me the majority of calories in this dish are coming from the carbs in the pasta and whatever the composition of the sauce is. In any event, the SOSC pronounced it the best she has ever had.

Mercury in Shellfish

The level of mercury is a concern in all the fish that we consume.  Fortunately a recent study from Maine University found that shrimp is very low in mercury.mercury by type of shrimp This included varieties from Thai shrimp farms, Maine shrimp farms and the Gulf of Mexico. In comparison to other types of fish, shellfish are universally on the low end of the mercury level graph as shown below.mercury in fish

 

 

 

Fear neither the  cholesterol nor the mercury in shrimp and consume your cioppino with gusto and without guilt!

 

Should I Take Aspirin To Prevent Stroke or Heart Attack?

 

Aspirin is a unique drug, the prototypical  two-edged sword of pharmaceuticals.  It has the capability of stopping platelets, the sticky elements in our blood, from forming clots that cause strokes and heart attacks when arterial plaques rupture, but it increases the risk of serious bleeding into the brain or from the GI tract. Despite these powerful properties, aspirin is available over the counter and is very cheap, thus anyone can take it in any dosage they want. 

Who Should Take Aspirin?

For the last five years I’ve been advising my patients who have no evidence of atherosclerotic vascular disease against taking aspirin to prevent heart attack and stroke. Several comprehensive reviews of all the randomized trials of aspirin had concluded by 2011 that

The current totality of evidence provides only modest support for a benefit of aspirin in patients without clinical cardiovascular disease, which is offset by its risk. For every 1,000 subjects treated with aspirin over a 5-year period, aspirin would prevent 2.9 MCE and cause 2.8 major bleeds.

(MCE=major cardiovascular events, e.g. stroke, heart attack, death from cardiovascular disease)

Dr. Oz, on the other hand, came to St. Louis in 2011 to have  lunch with five hundred women and advised them all to take a baby aspirin daily (and fish oil, which is not indicated for primary prevention as I have discussed here). When I saw these women subsequently in my office I had to spend a fair amount of our visit explaining why they didn’t need to take aspirin and fish oil.

After reviewing available data, the FDA this week issued a statement recommending against aspirin use for the prevention of a first heart attack or stroke in patients with no history of cardiovascular disease (i.e. for primary prevention). The FDA pointed out that aspirin use is associated with “serious risks,” including increased risk of bleeding in the stomach and brain. As for secondary prevention for people with cardiovascular disease or those who have had a previous heart attack or stroke (secondary prevention), the available evidence continues to support aspirin use.

Subclinical Atherosclerosis and Aspirin usage

As I’ve discussed previously, however, many individuals who have not had a stroke or heart attack are walking around with a substantial burden of atherosclerosis in their arteries. Fatty plaques can become quite advanced in the arteries to the brain and heart before they obstruct blood flow and cause symptoms. In such individuals with subclinical atherosclerosis aspirin is going to be much more beneficial.

 

Guided Use of Aspirin

zerilloplaque
Large, complex atherosclerotic plaque in the carotid artery found by vascular screening in an individual with no history of stroke, heart attack, or vascular disease. This patient will definitely benefit from daily aspirin to prevent stroke or heart attack
We have the tools available to look for atherosclerotic plaques before they rupture and cause heart attacks or stroke. Ultrasound screening of the carotid artery, as I discussed here, is one such tool: vascular screening is an accurate, harmless and painless way to assess for subclinical atherosclerosis.

In my practice, the answer to the question of who should or should not take aspirin is based on whether my patient has or does not have significant atherosclerosis. If they have had a clinical event due to atherosclerotic cardiovascular disease (stroke, heart attack, coronary stent, coronary bypass surgery, documented blocked arteries to the legs) I recommend they take one 81 milligram (baby) uncoated aspirin daily. If they have not had a clinical event but I have documented by either

  • vascular screening (significant carotid plaque)
  • coronary calcium score (high score (cut-off is debatable, more on this in a subsequent post)
  • Incidentally discovered plaque in the aorta or peripheral arteries (found by CT or ultrasound done for other reasons)

then I recommend a daily baby aspirin (assuming no high risk of bleeding).

There are no randomized trials testing this approach but in the next few years several large aspirin trials will be completed and hopefully we will get a better understanding of who benefits most from aspirin for primary prevention.

Until then remember that aspirin is a powerful drug with potential for good and bad effects on your body. Only take it if you and your health care provider have decided the benefits outweigh the risks after careful consideration of your particular situation.

Time to Stop Taking Worthless Vitamins and Minerals

As I pointed out in an earlier blog , individual vitamins and multivitamins have been proven over and over to have no benefit for heart disease.
A recent series of articles in the Annals of Internal Medicine summarized in this accompanying editorial, confirms this and further shows that multivitamins have no benefit on preventing cognitive decline with aging.
The U.S. Preventive Services Task Force reviewed all studies on multivitamins, single and paired vitamins and concluded that there was no benefit of taking these on overall mortality, cardiovascular mortality or cancer.
Hopefully this series of articles will start the decline of the multibillion dollar Vitamins and Supplement industry in the U.S.
For my patients, I recommend a healthy diet that includes, fruits, vegetables, and fish which will provide all the micronutrients and vitamins they need. There is no evidence that you can substitute taking industry-processed micronutrients or fish-oil and expect the benefits to be the same

Omega-3 fatty acids, and heart disease: Do fish oil supplements prevent heart attacks or death from heart disease

In recent years, a steady stream of experts, including the ubiquitous Dr. Oz, Screen shot 2013-01-26 at 9.47.51 AMhave advised every one to take fish oil supplements to protect their heart health

In fact, there is little to no evidence that fish oil supplements or fish oil enhanced foods should be consumed for any health purpose.
Omega-3 fatty acids (also known as  ω−3 or n−3) are polyunsaturated fatty acids (PUFA) that can be derived from marine or plant oils. They are considered essential fatty acids in humans, vital for normal metabolism but not synthesized by the human body.

The long chain omega-3 fatty acids eicosapentanoic acid (EPA) and docosahexanoic acid (DHA)  are felt to be the most beneficial. The best food source of DHA and EPA is cold water fatty fish and shellfish. The fish highest in these fatty acids are salmon, sardines, mackerel, herring and tuna.

Alpha-linolenic acid (ALA) is an omega-3 fatty acid which is predominantly found in plant oils (flaxseed, canola, and soybean oils) and walnuts. It can, to a limited extent, be converted in human bodies  to EPA and DHA, thus can be considered a precursor.

There is some evidence that consuming fish on a regular basis is associated with lower risk of coronary heart disease and stroke. Therefore, I can agree with current AHA and USDA guidelines which recommend consumption of fatty fish at least twice a week and I advise this for my patients.

Predominantly on the basis of one very positive study performed in Italy in 1999 (the GISSI study, which gave EPA/DHA to heart attack survivors), most cardiologists, the AHA, and the supplement industry had concluded by 2005 that fish oil reduced mortality and cardiac morbidity. The best evidence then was that the fish oil supplement was helpful after a heart attack (so-called secondary prevention). However, there was a very powerful urge to extrapolate this recommendation to patients without heart disease (so-called primary prevention).

Such expanded recommendations were reflected in the media. For example, Forbes proclaimed

“One Supplement That Works:

A lot of nutritional supplements are quack medicines. Not fish oil”

By 2009 sales of OTC fish oil supplements had risen 18% in one year to 739 million and Americans were buying 1.8 billion worth of foods (such as margarine and peanut butter) fortified with extra omega-3s. By  2011, Americans were spending 1.1 billion on supplements.

GlaxoSmithKline developed and patented a high-concentration fish oil (Lovaza) that gained an indication for treating high triglycerides which had global sales of 1 billion dollars in 2008. Supported by heavy advertising and promotion to physicians (through dinner lectures, lunches and other promotions), this expensive version of fish oil is widely prescribed by physicians for reasons other than the very high triglyceride elevations it has an indication for.

Forbes wrote

“In the history of nutritional supplements there’s something striking about omega-3: the fact that it works. Much of the $25 billion a year that Americans spend on supplements is money down the drain”

While the second part of that sentence is true (the vast majority of supplements/nutraceuticals/minerals that Americans take in a search for longevity or arthritis relief are worthless) the first part is not true.

The subsequent  hype for the benefits of fish oil supplements, especially in the world of nutritional supplement has been outrageous and inaccurate.

A typical product description reads as follows.

“We believe this is the highest quality Omega-3 available.
This highly concentrated Pharmaceutical Grade Omega-3 Fish Oil delivers 800mg of EPA and 600mg of DHA.
The important benefits of Omega-3 have been proven in thousands of independent studies by universities, governments, and health organizations. Because of such research, people around the world are now taking fish oil for reasons ranging from brain development, mild depression and heart function to arthritis and our immune systems.
It causes NO fishy or un-pleasant after taste.
This Omega 3 has been verified by a 3rd party to be Mercury Free.”

If one reads further down the page, however, the most important sentence is the following (and this is true for all supplements_






These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease

So , the fish oil pushers  make a series of totally unsubstantiated claims about the benefits followed by the statement that it is not intended to benefit any one in any way.

The most recent systematic review and meta-analysis of omega-3 fatty acid supplementation and the risk of major cardiovascular events (published Sept. 2012,) concluded:

“overall, omega-3 PUFA supplementation was not associated with a lower risk of all-cause mortality, cardiac death, sudden death, myocardial infarction,  or stroke based on relative and abolute measures of association”

Studies performed in the last 5 years of omega-3 PUFA supplementation do not support a role for them in reducing heart disease, either in high risk individuals without documented heart disease or those who have already had heart attacks.

Most of my patients continue to take fish oil supplements because they think that there may be a benefit without any down side. However, there are a number of potential down sides that should be considered.
1. There is no government regulation or measurement of the contaminants in fish oil supplements.
According to Consumer Reports

“Most tested pills are claimed to be “purified” or “free” of PCBs, mercury, or other contaminants, claims that have no specific regulatory definition, the Food and Drug Administration says. The agency has taken no enforcement action against any omega-3 maker over PCBs or other contaminants, an FDA spokeswoman said, because it has seen no public-health risk”

2. A major source of the fish oil in fish oil supplements, menhaden, is being over fished. Menhaden are a sardine-like forage fish that range in huge schools from Canada to Florida and into the Gulf. As filter feeders, they form an important base of the marine food chain. They have historically been harvested for food and later, for use as fertilizer and more recently for use in aquaculture and in omega-3 supplements. This fish, which has been called “the most important fish in the sea,” feeds on phytoplankton and is essential for a healthy marine ecosystem. The Atlantic States Marine Fisheries Commission (ASMFC) recently approved a 20% decrease in fish catch for the Atlantic Coast menhaden bait and reduction fisheries, The numbers of these fish have declined by 90% in the last 4 decades. Without doing extensive research on your particular fish oil supplement you can’t be sure you aren’t contributing to  this problem.

So, the bottom line on fish oil supplements is that  the most recent scientific evidence does not support any role for them  in preventing heart attack, stroke, or death. There are potential down sides to taking them, including contaminants and the impact on the marine ecosystem. I don’t take them and I advise my patients to avoid them (unless they have triglyceride levels over 500.)

Americans want a “magic-bullet” type pill to take to ward off aging and the diseases associated with it. There isn’t one. Instead of buying pills and foods manipulated and processed by the food industry which promise better health, I advise following Michael Pollan’s simple advice

“Eat food. Mostly plants. Not too much”