Something Fishy Going On
Supplements no better than placebo in preventing heart attacks
A patient asks: “I know fish is good for my heart, but I don’t like it. Can’t I just do fish-oil supplements instead?”
The doctor responds: “You’re right about fish. Fish oil is another matter.”
I tell my patients to eat at least two 3-ounce servings of fish a week. Even if fish isn’t your favorite food, that’s about a pack-of-cards size serving twice a week, and with a little creativity, fish can often be tucked into other meals.
If you don’t like fish (or, as I often find with my patients, you have it in your mind that you don’t but haven’t really tried it much), then you probably haven’t ventured in varieties. Should you go to a sampling — and I recommend you do — you may also want to take into account other nutrient factors:
Salmon: Highest in omega-3 fats and lowest in mercury. While wild salmon is preferable (it’s free from some toxic chemicals and colorants found in the farmed variety) the benefits of eating farmed salmon far outweigh any risks. The “color added” sign refers to color additives in salmon feed, and while it sounds strange, it’s harmless. Take it from an avid fisherman. They’re the same additives found in many juices, ketchups, salad dressings, and such. Smoked salmon is fine, and I buy it in 1-pound quantities, and eat about 1/4 pound a night on thin Wasa or other crisp crackers.
So far, the universal and essentially unanimous opinion of all the research I have reviewed, is that fish-oil supplements have been a big disappointment.
Sardines: Packed with omega-3, just two tiny sardines give you as much calcium as 1/3 cup of milk, as well as a full day’s supply of B-12.
Flounder, cod, haddock: Low-fat, low-calorie protein and low in mercury. Flounder is high in omega-3, while haddock and cod have less.
Shrimp and scallops: Other low-mercury options, low in calories and fat. Bonus: Shrimp helps you meet your daily iron requirements.
Proceed with caution on this:
Highest in mercury: Swordfish, shark, king mackerel, tilefish, grouper, and fresh tuna. These should be avoided by small children, nursing and pregnant women, as well as those trying to conceive. Other fish relatively high in mercury include mahimahi and red snapper are best if consumed occasionally. Canned tuna is generally lower in mercury, though “light” tuna is lower than albacore.
Tuna fish salads, sandwiches — or better yet, substituting canned salmon for such recipes — is an easy way to easily fold fish into your diet. Other suggestions are fish tacos, fish chowder, or sardines tossed into your salads. If you’re a jerky fan (beef or turkey), try salmon jerky. You’ll be hooked, pardon the pun.
Now, back to your original question: Can you get much of the same benefits of fish from a supplement? So far the universal and essentially unanimous opinion of all the research I have reviewed is that fish-oil supplements have been a big disappointment.
Between 2005 and 2012, over 20 high-quality studies of fish oil were published in top medical journals. The findings were monotonous. Fish oil, no matter what the dose or source — salmon, krill, and such — was no better than a placebo in preventing heart attack or stroke.
One study published in the New England Journal of Medicine looked at the effects of omega-3 fatty acids (fish oil capsules) on adverse cardiovascular outcomes (heart attack, stroke and death from a heart-related cause) in more than 12,000 patients with abnormal blood sugar (either overt diabetes, or simply elevated blood sugar) and other risk factors for heart disease.
Patients were randomized to receive either 1 gram (1000 mg) of omega-3 fatty acids daily, or a placebo. At the end of six years of follow-up, there was no difference between the fish oil and the placebo groups.
The authors admit that a higher dose — 2-4 grams daily — might have made a difference, but they could find no benefit of one capsule per day. Actually, other studies with higher doses have also failed to find much in the way of protection.
What disturbed me was that despite the evidence, at least 10 percent of Americans take fish oil regularly — indeed the percentage of my new patients is about twice that. Granted, they’re coming to see me because they’re keen on improving heart health!
The power of advertising? Perhaps. Though if my patients, who include some of the most sophisticated, well-informed, successful entrepreneurs in the country, are misinformed, then clearly some education is in order.
The explanation for the persistent popularity of fish oil is that most of the experts agree that eating fish, especially salmon, is good for cardiovascular health. If this is so, it seems logical that there is something in fish that is protective, and the fish oil is an attractive candidate.
So, for people who do not enjoy eating fish, it is comforting to believe they can get the health benefit just by taking a couple of fish-oil capsules daily. Unfortunately, although this may be comforting, it does not seem to be true. And in this case, what people don’t know could be harmful.
For example, some research has linked fish-oil supplements to an increased risk for prostate cancer overall, and a 71 percent increased risk for aggressive prostate cancer. While such findings are preliminary, the research on fish-oil supplements irrelevance is, in my opinion, fairly conclusive.
So, eat fish, especially salmon, which does seem to protect against heart attack and stroke, and save your money at the register.