Eat lower on the seafood chain for vital nutrients, says Harvard professor of nutrition: Here’s what that means

More and more people are adding fish into their diets for the heart-healthy omega-3 fatty acids. But it may be time to skip the salmon and tuna, and reach for foods lower on the seafood chain like sardines and clams instead.

Shifting your seafood diet to incorporate mainly smaller fish and bivalves can up your intake of micronutrients that people are typically deficient in, including zinc, iron, vitamin B12 and omega-3 fatty acids, says Christopher Golden, professor of nutrition and planetary health at the Harvard T.H. Chan School of Public Health.

“Of all of the different equestrial and aquatic-based foods, small fish are the best source of nutrients for these types of things on a per-weight basis,” Golden tells CNBC Make it. “So, although they are underutilized, they’re really good at delivering those sorts of nutrients.”

Bivalves, like mussels, are also a “really healthy choice,” Golden notes, and they’re great sources of zinc and calcium. Bivalves are “a type of mollusk, such as an oyster, that has its body inside two connected shells.”

Here’s what Golden recommends adding to your diet to replace foods like red meat and farmed salmon.

1. Herring
2. Mackerel
3. Sardines
4. Anchovies
5. Clams
6. Oysters
7. Mussels
8. Scallops

That being said, eating lower on the seafood chain is something you should consider for more than just nutritional value. There are other important reasons why it’s a healthy decision to make, says Golden.

Smaller fish and bivalves may have lower levels of mercury

While Golden is actively researching if there’s a significant difference between the mercury levels in smaller fish and larger fish, scientifically it is shown that when you eat foods that are higher on the seafood chain, “you’re going to have a greater risk of mercury toxicity within the foods that you eat and mercury exposure,” he says.

“Eating the smaller fish, you’re more likely to have a lesser mercury load than some of the larger carnivorous fish,” says…