The following is an excerpt from The Perfect Protein: The Fish Lover’s Guide to Saving the Oceans and Feeding the World, by Andrew Sharpless and Suzannah Evans.

In his foreword, Bill Clinton wrote:

The specter of ever-growing numbers of hungry people, especially malnourished children, hangs over our heads. Already, close to 1 billion people go to bed hungry. I’ve never heard anyone else propose the simple solution Andy Sharpless and Oceana are making here: to replicate the success we’ve had in the United States by putting in place effective, conservation focused, scientific fisheries management in the 25 countries that control most of the world’s seafood catch. This is — relatively speaking — a practical, inexpensive, and quick way to make sure our planet has lots more nutritious food in the future, when we’ll really need it.

But is eating fish really such a healthy and sustainable food source? The Perfect Protein explains why we should all be eating more seafood — for our own health and that of the oceans.

It’s the one animal protein that’s rarely mentioned in the endless reports about big agriculture and hunger crises. It’s the protein that’s healthiest for your body: low in cholesterol, brimming with brain-boosting omega-3 fatty acids and nutrients like riboflavin, iron, and calcium. It’s one of the most ancient foods, and it’s most likely the last wild creature that you’ll eat, the last pure exchange between Earth and your dinner plate.

Seafood’s role in heart health was discovered after early 20th century studies on Arctic peoples. Soon, other indicators emerged suggesting that seafood was helpful in avoiding heart disease. Norway experienced a steep decline in fatal heart attacks during the German occupation of 1941 to 1945. In these years, Norwegians could not obtain much in the way of meat, eggs, or whole milk, and instead began eating more fish, skim milk, and cereals. After the war, Norwegians returned to their red-meat diet, and the rate of heart attacks rose again.

Similarly, scientists began to notice that the Japanese, who eat up to 13 times as much seafood as Americans, had much lower rates of heart disease as well. One study found that the Japanese were 20 times less likely than Germans to die of heart attacks.

One of the landmark studies on seafood consumption and heart health took place in the Netherlands from 1960 to 1980. Over those two decades, scientists tracked a group of adult men from the town of Zutphen who ate a consistent amount of fish throughout their lives. The result? The more fish the men ate, the less likely they were to die of heart disease. After the results of the Zutphen study were published in 1985, the knowledge of seafood’s role in heart health went mainstream. Now, just about every authority from the American Heart Association to the World Health Organization recommends eating seafood at least twice a week.

Since the 1980s, “omega-3” has been a nutrition buzzword, found everywhere from margarine labels to fad diet cookbooks. Omega-3 fatty acids are found in some plants, like walnuts, but the best sources are fish and seafood. They, too, ultimately derive their omega-3s from plants — the phytoplankton that support all ocean life.

The more important nutritional benefits that we get from consuming omega-3s come from two types of omega-3 fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are found almost exclusively in marine sources and egg yolk, and yet they are critical to our health, having particular importance in fetal development and maintenance of brain, retina, heart, and immune system health.

Scientists now agree that consuming omega-3-rich seafood two times a week can cut your chance of dying from a heart attack by 30 percent or more.

Seafood is also the only food with which we still have — mostly — the same hunter-trapper relationship as early hominids cracking open clamshells. We may be evolutionarily disposed to enjoying seafood, but as our population has grown and grown, our collective appetite for wild-caught seafood has outstripped the oceans’ ability to provide it — and there’s no question that we can’t afford to decimate all wild seafood.

Fish and shellfish are integral parts of our diets, and they should be. And they don’t come with the massive baggage of industrial pork, poultry, and beef, animal proteins that produce tons of waste and pollution, destroy thousands of acres of land, use huge amounts of water, and are often too costly for the world’s poorest people. The modern industrial agricultural system has mechanized food production in a way that’s nothing short of awe inspiring for sheer effort. But we’re paying a huge, often hidden price. And our planet may not be able to conceal the true costs of agriculture much longer.

When people ask us which seafood is sustainable, it’s hard to give such a pithy response. But if you really pressed us for it, this is what we might say: “Eat wild seafood. Not too much of the big fish. Mostly local.”