Fish facts

Fish is a nutritious source of protein and incorporating it into your diet can be beneficial to your overall health. While most fish are low in overall fat, some sources of fatty fish are high in unsaturated fat, which is heart-healthy fat. It is easily digestible and contain omega-3 fatty acids, which are unsaturated, heart-healthy and liver-healthy fats. A dietitian at Baylor College of Medicine provides the pros – and some potential cons – of adding fish into your diet.

Protein sources

Salmon is one of the most popular fish to consume. It is a highly nutritious protein that is high in omega-3 fatty acids. Shrimp is another good source of protein, especially for people with acid reflux or any sort of fat-malabsorptive disorder since it is high in protein and contains no fat. While shrimp are high in cholesterol, studies have suggested that foods high in cholesterol do not affect blood cholesterol. Saturated fat affects blood cholesterol, and shrimp does not contain any saturated fat.

“The way our bodies metabolize cholesterol is not the same as saturated fat,” said Courtney Ford, senior registered dietitian in the Department of Medicine – Gastroenterology and Hepatology at Baylor College of Medicine. “Consuming saturated fat affects our LDL cholesterol, not the cholesterol in that food.”

Mercury

There is a concern with high amounts of mercury in certain types of fish:

• Shark
• Swordfish
• Bluefin tuna
• Sea bass

While these are safe to eat, it is not recommended to have more than two to three servings of high-mercury fish in a week.

Raw fish and seafood

The nutrient content and nutrient bioavailability of fish does not vary much between raw and cooked fish. Ford advises only consuming raw fish that is considered sushi-grade: parasite-free, safe for consumption, temperature controlled and professionally handled. There is no risk to eating raw fish as long as it is a low-mercury fish.

“If a person is pregnant, has liver disease or is a transplant patient, that’s where we may need to draw a line, but as far as the general, healthy individual, there is no risk to eating raw, sushi-grade fish that isn’t high in mercury,” Ford said.

She cautions consuming raw mollusks and shellfish, including oysters, mussels and clams because they have a higher probability of containing parasites or bad bacteria that cause food poisoning.

Bottom-feeding fish

Bottom-feeding fish include shrimp, catfish and tilapia. These fish feed on the bottom of the body of water, which means they eat the excrement of other organisms. This impacts the nutrient quality of that fish or crustacean. While these are safe for consumption, fish like tilapia and catfish are not the highest in nutrient-density compared to other sources of fish.

Wild-caught vs. farm-raised fish

Farm-raised fish are in a controlled environment with little space to swim freely. Wild caught fish are high in fast-twitch muscles because they swim freely, making them more nutritious than farm-raised fish that have a controlled diet and limited space to swim. Farm-raised fish are less healthy fish than wild-caught fish when they are alive, which affects the nutrient quality upon consumption.

“When you look at the wild-caught salmon versus the farm-raised salmon, the wild-caught is bright red and the farm-raised is light, pale pink because the wild-caught produces that pigment swimming freely,” Ford said.

Overall, fish is a healthy protein benefitting the liver and heart.

“When we add fish to our diet and consume it regularly, we’re making a choice between a land animal and a sea animal, and the sea animal is always the most heart-healthy, liver-healthy choice,” she said.

Learn more about gastroenterology and digestive health services at Baylor Medicine. 

By Homa Shalchi