More Reasons to Swap Steak For Salmon and Other Seafood
Research finds new concerns about red meat, and evidence that omega-3 fatty acids found in fish may reduce cardiac mortality risks.
You’ve no doubt been warned about the dangers of eating too much red meat, a source of unhealthy saturated fats. Well, a recent Cleveland Clinic study has found another reason to skip the hamburgers at your next summer cookout.
Researchers, led by Stanley Hazen, MD, PhD, vice chairman of Translational Research for the Lerner Research Institute and section head of Preventive Cardiology & Rehabilitation at Cleveland Clinic, found that bacteria living in the human digestive tract metabolize a compound called carnitine, turning it into trimethylamine-N-oxide (TMAO), which has been linked to atherosclerosis. Carnitine is abundant in red meat, and is often added to popular energy drinks. The research was published in the journal Nature Medicine.
“The bacteria living in our digestive tracts are dictated by our long-term dietary patterns,” Dr. Hazen explains. “A diet high in carnitine actually shifts our gut microbe composition to those that like carnitine, making meat eaters even more susceptible to forming TMAO and its artery-clogging effects. Meanwhile, vegans and vegetarians have a significantly reduced capacity to synthesize TMAO from carnitine, which may explain the cardiovascular benefits of those diets.”
Reduce Red Meat Intake
Indeed, the study underscores the idea that less red meat in the diet is better, particularly if you are already at risk for cardiovascular disease, says dietitian Julia Zumpano, RD, LD, with the Cleveland Clinic Preventive Cardiology Nutrition Program.
“I think this study is very interesting, and only proves the importance of reducing intake of red meat for heart health,” she says. “The saturated fat and cholesterol in red meat can lead to high levels of LDL (“bad”) cholesterol. Also, processed red meat, such as salami, pepperoni, corn beef, hot dogs, sausage or bacon are not only very high in saturated fat, but sodium as well, which can also increase blood pressure.”
However, Zumpano says that occasional consumption of red meat is probably okay, provided it’s infrequent and that you choose a lean piece of meat. “What I would suggest is, when possible, choose the leanest cut possible, such as a sirloin, tenderloin, flank, or rib roast with all visible fat trimmed,” she advises. “If ground beef, choose 90 to 95 percent lean. Also, keep the portion down to four ounces, which is about the size of a deck of cards.”
More About Carnitine
Carnitine is naturally found in red meats, including beef, venison, lamb, mutton, duck and pork. But it’s also a dietary supplement that’s available in pill form, or as an additive to sports energy drinks, because of its association with boosting energy for muscular activity. The body actually produces carnitine in the kidneys, and Dr. Hazen suggests that in light of this research, further study is warranted to determine the safety and benefit of carnitine supplementation.
“Carnitine is not an essential nutrient,” Dr. Hazen says. “Our body naturally produces all we need. We need to examine the safety of chronically consuming carnitine supplements, as we’ve shown that, under some conditions, it can foster the growth of bacteria that produce TMAO and potentially clog arteries.”
If you’re looking to reduce your red meat intake, there’s more evidence to support the switch from beef steak to salmon steak. A recent study published in the Annals of Internal Medicine found that older adults who have higher blood levels of omega-3 fatty acids, such as those found in fatty fish, may be able to lower their overall mortality risk by 27 percent and their mortality risk from heart disease by about 35 percent.
“This just reinforces our current recommendations of replacing most if not all of your red meat meals with omega-3 fish,” Zumpano says. She recommends that adults try to get two to four servings of fish per week, with a serving size of three to four ounces. She suggests that limiting fish consumption to no more than 12 ounces per week is wise, out of concerns for fish that may be higher in mercury.
Though salmon is most often thought of as a great seafood source of omega-3s, Zumpano lists tuna, sardines, herring, anchovies, mackerel, lake trout, swordfish, and haddock as other good sources.
“Omega 3 fatty acids come in the form of EPA and DHA,” she explains. “Fish is the best usable source of these acids. The plant based sources of omega-3 come in the form of ALA, which then needs to be converted to EPA and DHA. Some of the benefit is lost in the conversion.”
She also notes that dietary supplements are not regulated therefore caution must be taken when choosing a omega-3 supplement. “Be sure to read the EPA and DHA on the label and add these values together to obtain the actual quantity of omega-3 that you would be receiving from that supplement. Don’t forget to check the serving size as well.”