Medical Services | Health Information | Appointments | Education and Research | Jobs | About

Connect with an expert

Nutrition-wise blog

With Mayo Clinic nutritionists Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.
Back to posting index
July 17, 2008
Catfish and tilapia: Healthy or harmful?
9 comments posted
Read comments | Post a comment
By Jennifer Nelson, M.S., R.D. and Katherine Zeratsky, R.D.

There's an interesting discussion in this month's "Journal of the American Dietetic Association." What it boils down to is this: Is the fatty acid mix in catfish and tilapia healthy or harmful? The debate has even reached the popular press. Why all the fuss?

First off, since 2000, catfish and tilapia rank as two of the most popular fish consumed in the United States thanks mainly to their taste and relatively low expense. And both contain heart-healthy omega-3 fatty acids.

Consumption of these types of fatty acids is thought to be associated with reduction in blood pressure and reduced risk for certain cancers, inflammatory conditions such as rheumatoid arthritis, and even mental decline.

You may not have heard so much about a second ingredient they contain, omega-6 fatty acids. Like omega-3s, these are polyunsaturated and help lower blood cholesterol levels, however they are thought to play a role in clotting function, are inflammatory and susceptible to oxidation — thereby possibly increasing risk for blood clots, arthritis, inflammatory bowel disease and cancers.

The National Institutes of Health funded study by Weaver and colleagues looked at the favorable omega-3 fatty acid content and unfavorable omega-6 contents of commonly eaten fish and found that while catfish and tilapia contain both, they contain a high amount of unfavorable omega-6 fat.

They report that a 3-ounce portion of catfish or tilapia contains 67 and 134 milligrams respectively of the bad fat (the same amount of 80 percent lean hamburger contains 34 milligrams, and bacon 191 milligrams).

Does this mean you should give them up? No! The rebuttal by Harris is in the same journal. He says the logic of judging fatty fish by the amounts of omega-3 and omega-6 fat contents is flawed. Governmental and professional organizations haven't used such a ratio for years.

He also says that to think that eating catfish or tilapia — because of its high omega-6 content — is more risky in terms of heart disease than eating bacon or hamburger is "flawed."

My take? I'm going to continue to eat fish — at least twice weekly. I'm going to choose a variety of fatty fish — including tilapia and catfish along with others especially high in the good fats such as salmon, tuna and mackerel.

P.S. When you see this on the evening news you can say that you got the scoop here.

9 comments posted
Read comments | Post a comment
Back to posting index
September 16, 2008 7:46 a.m.
All the factors mentioned when taken into consideration can affect the final outcome. My family has enjoyed Tilapia every Tuesday as a tradition for several years now. I've never found a safer, more versatile or affordable fish to prepare. It's amazingly simple to fix, always yummy & delicious & everyone loves it. We even take turns planning how we'd like it cooked when it's "our week". Now maybe if I bought the fish from China I'd be worried since it's always the cheaper quality frozen or previously frozen,then thawed crap labeled "refreshed" but for a few more pennies a pound I can usually buy fresh. Our fishmonger turned me on to the fact that usually the best place to buy fresh is Publix though typically nothing is branded. I even found the website of the largest supplier for North America & ripped off this info blurb: Tropical Aquaculture's tilapia is the world’s leading source of fresh premium tilapia.Our tilapia are grown naturally, with no antibiotics, without hormones to promote growth, & no additives or preservatives to improve appearance or extend shelf life. Because tilapia is an herbivore fish & can be raised on grain it's one of the most eco-friendly, sustainable fish available today.Our tilapia is always fresh, never frozen, harvested around the clock & delivered to the market within 24hrs of harvest. Tropical Brand Tilapia is farm-raised in low density ponds,our pristine waters keep our Tilapia safe from any
- Michael Corleone (No relation)
July 24, 2008 7:30 p.m.
Chris O. raises an important and often-overlooked point -- where food comes from is often significant, especially if it comes from China (alas, most stores do not provide this information so you are on your own). How it is prepared is significant, too, and so is one's susceptibility to various illnesses. Good luck.
- Vic
July 24, 2008 12:07 a.m.
It would be more helpful had the reasons been included as to why the arguments are "flawed". Without explanation, it's hard to be persuaded, no?
- Donna
July 23, 2008 2:38 p.m.
I really enjoy Tilapia. Since most Tilapia is farmed, it is relatively affordable. However, I recently found, by reading the package for origin of the Tilapia, that the fish was farmed in China. Due to the pollution in China the Environmental Working Group(EWG) states that Tilapia from China should not be consumed due to the high levels of pollutants found in the fish.
- ChrisO
July 23, 2008 1:55 p.m.
It would be helpful if the Mayo did a piece on mercury content of fish. Members of my family recently tested so high for mercury that we were contacted by the state department of health. We have since stopped eating high mercury fish like tuna and yellowtail (we previously ate a lot of sushi, which included a lot of high mercury fish). Thank you.
- Linda
July 23, 2008 10:48 a.m.
Hurray for sanity!!!!
- Marcia
July 23, 2008 4:31 a.m.
lease address the issue of toxins in fish. Is Tilapia/catfish high in toxin and how harmful to one's health is this. Ronnie,Nigeria
- No name given
July 23, 2008 12:14 a.m.
WEN YOU EAT FISH LOOK FOR A TRAZABILITY OF THE FOOD BECOUSE IT MAKES CERTIFICATION OF GOOD QUALITY OF FOOD IF THE FISH IS MAKE IT IN FARM FISH
- WWW.ACUICULTURA.COM.MX JORGE ROJAS A.
July 22, 2008 7:34 p.m.
I think the question was more in regard to toxins that may be in these two types of fish, like mercury. I know the benefits of eating fish, but what about the toxins in fish.
- Cynthia
Post a comment

NUTRITION-WISE


Nov 21, 2008