Eating Fish Can Lower Cardiovascular Disease Risk, Study Shows

Salmon meal

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Key Takeaways

  • Fish is high in protein, iron, and vitamin D, and certain oily fish contain important omega-3 fats.
  • A new study found that having two servings of fish each week is associated with a lower risk of cardiovascular disease (CVD) events in people with existing vascular disease.
  • The association of fish being protective against CVD was not found in the general population, but fish is still a healthy choice.

A new study shows that eating at least two servings of fish each week is associated with a lower risk of major cardiovascular events, including heart attack, stroke, and congestive heart failure. The research, published in in JAMA Internal Medicine, also found that fish is associated with lower mortality from cardiovascular disease (CVD) events. 

The links between fish and heart health have been studied for many years, but this is the first study to specifically look at how associations vary between those who have pre-existing CVD and those who do not have any vascular disease.

Interestingly, the study found that while fish is associated with a lower risk of CVD events for people with existing vascular disease, it does not have the same effect for people without vascular disease.

The strongest association for CVD protection was found specifically in people who choose oily fish such as salmon, tuna, sardines, and mackerel. That’s because these types of fish are highest in omega-3 fat, which has long been studied for its links to heart health.

Dr. Andrew Mente, PhD

Eating at least two servings of fish each week (175 g) appears to lower your risk of future cardiovascular events and death if you have pre-existing cardiovascular disease.

— Dr. Andrew Mente, PhD

The Study

This large study was a pooled analysis from four individual cohort studies from around the globe. The total population being studied included 191,558 participants in the 21-county PURE (Prospective Urban Rural Epidemiology) study, a cohort where the majority of participants had no pre-existing CVD.

The other three cohorts were participants with pre-existing vascular disease, and included 43,413 participants from 40 countries.

The researchers gathered data on fish intake based on food frequency questionnaires.

Unfortunately, only one of the four cohort studies specifically identified the exact type of fish that were eaten. This information is important, since previous studies have shown that oily fish with more omega-3 fats are more cardio-protective than leaner types of fish.

The participants were segmented into four groups, based on their fish intake:

  • Less than 50 grams of fish per month
  • 50 grams a month to 175 grams per week
  • 175 grams to 350 grams of fish per week
  • More than 350 grams of fish per week

For the PURE study, where most participants had no prior vascular disease, the results showed that, compared to low fish intake of 50 grams or less per month, the participants who ate more than 350 grams of fish each week were not associated with the risk of major CVD events.

The findings were quite different in the three cohorts where the participants had pre-existing vascular conditions. In these cohorts, the researchers found that:

  • CVD events were lowest in participants whose fish intake was at least 175 grams per week.
  • Total mortality was lowest in participants whose fish intake was at least 175 grams per week.
  • There was no enhanced protection of heart health with fish intake higher than 350 grams a week.

“Eating at least two servings of fish each week (175 g) appears to lower your risk of future cardiovascular events and death if you have pre-existing cardiovascular disease,” says Dr. Andrew Mente, an associate professor in the faculty of science at McMaster University in Hamilton, Ontario, and one of the researchers on this study.

In the cohort where types of fish were noted, the researchers found that fish with the highest amounts of omega-3 fats were more strongly associated with a lower risk of CVD events.

“The protection of fish is seen mainly for fish that contain high amounts of omega-3 fats, or so-called oily fish, such as herring, mackerel, sable, salmon, tuna (steak or can), and sardines,” says Mente. “Other types of fish that contain low amounts of omega-3 fats are generally neutral.”

Dietitian Ale Zozos, founder of the Mediterranean Nutrition School, wasn’t surprised that eating fish correlated with a reduction of CVD incidents in high-risk patients, but was surprised that the same interventions were not significant for general populations.

“Of course, there is still so much research to be done, but modest amounts of fish once or twice a week is an excellent source of omega-3s and protein, and the overall positive effects should not be ignored,” says Zozos.

Fish and Heart Health

Mente says one reason why eating fish is good for heart health is the beneficial effects on blood lipids, such as lowering triglyceride levels.

“Such beneficial effects on triglyceride levels are more pronounced in people with elevated triglyceride levels, a common characteristic of people at high risk of vascular disease,” says Mente.

Certainly, past studies have attributed the benefits of fish to the omega-3 fats in oily fish, which have been linked to lowering triglycerides and improving HDL cholesterol levels.

Dr. Andrew Mente, PhD

The protection of fish is seen mainly for fish that contain high amounts of omega 3 fats, or so-called oily fish, such as herring, mackerel, sable, salmon, tuna, and sardines.

— Dr. Andrew Mente, PhD

What If You Don't Have Vascular Disease?

“If you're generally healthy, there's no clear protection, although fish is probably a safe choice for you as well,” says Mente.

As part of any healthy eating plan, fish fills the protein portion of the plate. With a variety of vitamins and minerals including iron, calcium, and vitamin D, fish contain many essential nutrients that are important for maintaining good health.

Even in the absence of vascular disease, it’s still a good idea to have fish on your plate at least twice a week.

“Since the study did find that fish intake was associated with lower incidence of cardiovascular events in patients with vascular disease, and because it does not suggest any adverse effects of fish consumption among the general public, I stick by my usual recommendation of 2-3 servings of fish per week for my clients,” says Nicole Stefanow, a dietitian in Ramsey, New Jersey.

She notes that since vascular disease often goes undiagnosed or is diagnosed too late, it’s always a good idea to eat fish.

Which Fish Should I Choose?

This study did not drill down into the details of how fish are prepared (i.e. baked vs. deep fried), or whether the fish that participants are consuming may contain mercury or polychlorinated biphenyls (PCBs), two known environmental contaminants in fish. Future studies will have to focus on these details to help inform future recommendations about fish.

Currently, the most popular types of fish and seafood consumed in the U.S. include shrimp, salmon, and canned tuna. Of these, salmon is the highest in omega-fats and lowest in mercury, so it’s a great choice. While not as popular, trout, herring, Atlantic mackerel, and sardines are also low-mercury and high omega-3 options.

Canned tuna also contains lots of omega-3 fats, but may contain mercury, depending on which variety you buy. If you are pregnant, nursing, or feeding young children, look for lower-mercury canned skipjack tuna, rather than higher-mercury albacore tuna.

How Should I Prepare Fish?

If the idea of baking a salmon fillet isn’t appealing, it’s time to be creative!

“At my house we love to steam fish on the grill in a tin foil packet with herbs,” says Stefanow. “There are so many flavor combinations, but two to try are parsley, garlic & lemon, or ginger, garlic, chili & lime.”

She also suggests trying fish tacos topped with fresh cilantro, avocado slices, and a crisp veggie slaw, or making simple salmon cakes. You can used canned salmon for these, too.

Zozos says that you also can cook your fish in an air-fryer. “There is something about the added crunch to the filet that makes this a tasty alternative to baking or broiling,” says Zozos.

“Find a go-to way to make tuna or salmon salad to top your favorite crackers, veggies, or be the star of your sandwich. Some of my favorites include using avocado or Greek yogurt as a base, plus tons of different combinations with herbs and spices—the sky is the limit,” says Zosos.

Sushi and sashimi also are popular options.

If you have vascular disease and just can’t stomach fish, talk to your doctor about taking an omega-3 supplement.

What This Means For You

If you have vascular disease, make sure to include two servings of oily fish in your diet each week to help reduce your risk of heart attack, stroke, and other vascular conditions. If you don’t have vascular disease, fish is still a great choice, since it’s high in protein, iron and vitamin D. Choose options that are high in omega-3 fat but low in mercury.

8 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Cara Rosenbloom, RD
 Cara Rosenbloom RD is a dietitian, journalist, book author, and the founder of Words to Eat By, a nutrition communications company in Toronto, ON.