The findings are more nuanced than you might expect.
Reviewed by Dietitian Madeline Peck, RDN, CDN
- Omega-3-rich fish may lower mortality risk in women, per new research.
- Unsalted fish and shellfish intake was linked to lower cerebrovascular mortality in men.
- Adding more fish and seafood to meals can support a balanced diet.
If you’re anything like us, you probably feel a magnetic pull when you pass by the fish counter or tinned fish section at your grocery store. After all, fish has long been touted for its myriad health benefits, from supporting heart health to providing omega-3 fatty acids that play a role in brain health.
Fish is also a rich source of protein, vitamins and minerals, and the Dietary Guidelines for Americans recommend eating seafood regularly as part of a balanced diet. But while it may seem like any type of seafood is a healthful addition to your plate, new research suggests that the type of fish you eat may matter when it comes to mortality risk.
In fact, in a new study published in The Journal of Nutritionresearchers investigated whether different types of fish, including omega-3-rich fish and unsalted fish, were associated with mortality risk among Japanese adults. And what they found is a bit more nuanced than you might expect.
How Was the Study Conducted?
Researchers used data from the Japan Public Health Center-Based Prospective Study, a large research project that investigates health outcomes among adults in Japan. For this analysis, they included data from more than 90,000 adults who completed a food frequency questionnaire between 1995 and 1998.
The questionnaire assessed participants’ usual intake over the previous year for 138 food and beverage items. Participants reported how often they ate each food, ranging from never to multiple times per day, along with their typical portion size. In terms of what researchers were looking at in this particular study, the questionnaire included 19 fish and shellfish items, including salted fish, salmon, canned tuna and sardines.
Of those 19 fish items, four were classified as salted products, while the remaining 15 were categorized as unsalted fish and shellfish. Five of those 15 items were further classified as omega-3-rich fish, including salmon, trout, sea bream, horse mackerel, sardines and eel.
Researchers also tracked participants’ health outcomes over several years and were particularly interested in examining deaths from all causes as well as specific causes, including cerebrovascular disease, which includes conditions affecting blood flow to the brain, such as stroke, aneurysms and vascular malformations.
What Did the Study Find?
After analyzing the data from 90,944 Japanese adults, researchers found that a moderate intake of fish and shellfish was associated with a lower risk of all-cause mortality among female participants. Interestingly, they found that the associations between fish intake and mortality differed depending on the type of fish, the cause of death and even participants’ sex.
Specifically, higher intake of omega-3-rich fish was associated with lower all-cause and cerebrovascular disease mortality among females. Meanwhile, among males, higher intake of unsalted fish and shellfish was associated with lower cerebrovascular disease mortality. In other words, researchers found that different types of fish may be associated with different mortality outcomes.
While researchers were unable to explain why the sex-specific differences occurred, they hypothesized that differences in smoking and alcohol consumption habits could play a role, although their analysis did not clearly establish these factors as an explanation.
Though these findings are promising and add to existing research on the potential health benefits of seafood, there are some limitations to keep in mind. First, researchers assessed dietary intake at a single time point, so changes in participants’ eating habits over the follow-up period may not have been captured. Additionally, although researchers adjust for several potential factors, other unmeasured factors could have influenced the results.
How Does This Apply to Real Life?
As this study and previous research suggest, fish can be a nutritious addition to a balanced diet. But if seafood doesn’t regularly make it onto your plate, you may be wondering how to incorporate more into your weekly meals.
And while baked, sautéed or grilled fish is great on its own, there are plenty of other ways to make it more appealing, even for the pickiest of eaters. Here are a couple of ideas:
- Try adding it to one of your favorite dishes. If you love ground beef tacos or salad with chicken, try swapping your usual protein for fish or shellfish. White fish like cod or mackerel works well in tacos, while salmon, trout and shrimp can make a great addition to salads.
- Don’t sleep on canned fish. Fresh fish can be expensive, but you don’t need to buy it fresh to reap the nutritional benefits. Canned tuna, salmon and sardines are budget-friendly, shelf-stable options that make it easy to add more seafood to your meals.
- Give it a flavorful marinade or sauce. If fish tastes too “fishy” on its own, try seasoning it with garlic, lemon, herbs or spices—you might even try serving it with a sauce you love. Pesto, salsa and yogurt-based sauces, like tzatziki, are all simple options.
- Keep frozen seafood on hand. Frozen fish fillets and shrimp can be convenient alternatives to fresh seafood. Keep a few portions in your freezer so you have a protein option ready when you need a quick meal.
Our Expert Take
A recent study published in The Journal of Nutrition found that the associations between fish consumption and mortality differed by fish type and sex. Among females, higher omega-3-rich fish intake was associated with lower all-cause and cerebrovascular disease mortality. Among males, higher unsalted fish and shellfish intake was associated with lower cerebrovascular disease mortality. These findings reiterate the fact that fish provides important nutrients for overall health, including protein and omega-3 fatty acids. Incorporating a variety of seafood into a balanced diet can be an easy way to support your health.