Real Food: What to Eat and Why - Nina Planck (2016)

Chapter 4. Real Fish

HOW OUR BRAINS GREW FAT ON FISH

What would you say to a six-year-old who asked: where do farmers come from? Perhaps you would tell a bedtime story like this: Back in the Stone Age, our ancestors were skillful hunter-gatherers. They gnawed on marrow bones, dug tubers, gathered seeds, cracked nuts, and speared fish. Life was good. Over time, however, the smarter ones perceived that a little planning and organization would yield a more reliable food supply, one that could be more easily stored for a rainy day and shared with others. These innovative deer hunters and berry pickers began to tame smaller wild cows and, later, to plant larger seeds of wild grass. Eventually, the tribes who were best at these new tricks put aside their restless ways and settled down in villages to harvest grain and herd animals for milk and meat. They became farmers.

Richard Manning has a subtly different take on what he calls the “just so” story of the rise of agriculture. He believes fishing, not farming, was the second-oldest profession. In Against the Grain, Manning imagines early humans were keen to be near a steady supply of eels, salmon, and other oily migrating fish. They looked for neighborhoods with good water and rested there to wait for hordes of fat seasonal fish; only then did they start to tend, guide, herd, and harvest wildlife in the backyard. While waiting for the river mouth to disgorge fish, the Cro-Magnon had time to paint the mighty salmon on cave walls, a sure sign of its importance.

Fishing man—call him Homo piscator—fills in part of the story of the transition from swinging in the trees (like our fruit-loving primate cousins) to becoming hunter-gatherers and, eventually, farmers. Paleoanthropologists have long puzzled over the “missing link”—the ancestor we share with chimpanzees and gorillas, whose bones (mysteriously) are not found in the fossil record. Where did they live, how did they move about, what did they eat? No one knows.

In 1960, the marine biologist Alister Hardy offered a novel theory about the era after we came down from the trees and before we settled on the plains. Suppose we spent a few million years living in the shallow waters of the sea, like aquatic mammals including the dolphin, hippo, and sea cow? According to Elaine Morgan in The Descent of Woman, the quasi-aquatic ape hypothesis could explain a number of downright peculiar human features: nude skin, subcutaneous fat, permanently plump breasts, how newborns love to swim, why we have sex face-to-face … I could go on about the ways we are unusual among primates. But for our (nutritional) purposes, the most compelling thing about the idea that our ancestors once lived in the water is our dramatic and indisputable dependence on fish.

If you’ve glanced at a biology text recently, you’ll know that the river ape idea is not widely accepted. However, the experts do agree our taste for fish is ancient. Many fossils tell us that some two million years ago, at least three hominid species lived near the huge freshwater lakes of the East African Rift Valley. Each had its niche. The ones with broad, flat molars apparently ate a plant-based, high-fiber diet; another group, with smaller teeth, ate mostly small fruit, berries, and the occasional egg or rodent. The third species, of course, was our very own ancestor, Homo habilis. Dubbed “handy human” for the tools they used, including fishing gear like spears and nets, they were omnivores who loved fish.

Whether we lived in it or near it, water offered easy access to DHA and EPA, omega-3 fats essential to visual, mental, metabolic, and hormonal function, fats found only in fish. The body can make its own DHA and EPA from another omega-3 fat found in plants, Alpha-linolenic acid (ALA), but the conversion of ALA to DHA and EPA is inefficient. Making DHA and EPA requires vitamin B₆, magnesium, calcium, and zinc; it is hindered by trans fats, cortisol, alcohol, and sugar.¹ Moreover, the plant sources of ALA—walnut, flaxseed, and canola oil, and a weed called purslane—were probably not abundant in the Stone Age. Then, as now, the best source of these vital fats is fish. This is a dilemma for vegans and vegetarians; some take DHA and EPA supplements made from algae and fungus.

DHA and EPA are vital to the brain. Like bone marrow, which helped our brains grow much bigger and faster than the brains of leaf eaters, fish was brain food. Recall that the brain is 60 percent fat; half the fat is DHA.² Dr. Andrew Stoll puts it bluntly in The Omega-3 Connection, “Without large amounts of DHA … we might not have evolved at all.” No wonder the search for fish and seafood is universal. The overwhelming bulk of the human family has settled near sea shores and river mouths. The exceptions—landlocked and mountain people—go to great lengths to trade with fishing groups for seafood.³ Like the bonobo—our closest relative, a playful creature that likes to catch shrimp with its hands—Homo sapiens is a water-loving ape. A naked one.

LIFE AFTER SALMON

The Klamath River runs through the mountains of northwest California, passing through the town of Happy Camp, home of the Karuk tribe. Once the Klamath River ran thick with salmon, which the Karuks devoured at every meal, each one putting away more than one pound of fish daily along with deer, bison, and acorns. Then, in the 1960s and ’70s, hydroelectric dams stopped the water, the salmon disappeared, and the Karuks turned to industrial foods.⁴

When wild salmon were plentiful, diabetes and heart disease were rare. Not now. The percentage of tribe members with diabetes rose from near zero to 12 percent, almost twice the national average. Forty percent of the tribe has heart disease—three times the national rate. “You name them, I got them all,” Harold Tripp, a Karuk fisherman, told the Washington Post. “I got heart problems. I got the diabetes. I got high cholesterol. I need to lose weight.”

That’s what can happen when people lose access, almost overnight, to traditional foods and then resort to poor-quality foods. Like the Karuks, many indigenous Americans have swapped a wholesome diet for cheap, ubiquitous industrial foods. The new industrial diet causes the very health problems traditional foods can ward off. In this case, the nutritional mechanisms are well understood. Omega-3 fats in wild salmon prevent the trio of modern diseases—obesity, diabetes, and heart disease—in multiple ways.

Let’s look first at the effects on metabolism, because metabolic disturbances are in many ways the root of all three conditions. Omega-3 fats regulate blood sugar levels and fat burning. DHA and EPA in particular are directly involved in activating the expression of genes controlling fat metabolism. For example, mice fed the same number of calories from fish oil are leaner than those fed corn oil, which is rich in omega-6 fats. People whose muscles are low in omega-3 fats are more likely to be obese.

Obesity, in turn, leads to diabetes. In the United States today, diabetes and metabolic syndrome—or prediabetes—are epidemic. “In medical school, I was taught that if you can understand diabetes, you will understand all of medicine,” says Dr. Andrew Stoll, author of The Omega-3 Connection, “because those with diabetes fall prey to many other disorders, from cardiac disease to kidney failure to stroke.”

What is diabetes? When blood sugar rises, the pancreas secretes the hormone insulin, which signals the muscles to take sugar from the blood. Once in the muscle, the sugar has two uses: as immediate energy or as short-term, stored energy, in the form of glycogen, which marathon runners draw on. In type 1 diabetes, the pancreas does not produce insulin at all. In type 2 diabetes, which accounts for 90 to 95 percent of cases, the pancreas does produce insulin, but the muscles don’t respond; they are “insulin resistant.” When the muscles are deaf to insulin, sugar, which is toxic at high levels, gathers in the blood. Until recently, type 2 diabetes was viewed as an adult disease, and it is still most common in overweight people over fifty-five, but the rising number of cases in children is a distressing trend. Diabetes, it seems, is not a disease of age, but of diet. Fish is important, because omega-3 fats decrease insulin resistance.

EAT FISH TO BEAT INFLAMMATION

In type 1 diabetes, the body attacks its own pancreatic cells. Other autoimmune diseases include arthritis, psoriasis, Crohn’s, lupus, colitis, and asthma. A common symptom is chronic excessive inflammation. Omega-3 fats prevent inflammation, and omega-6 fats promote it. Dr. Artemis Simopoulos (The Omega Diet) says the protective effect of omega-3 fats on autoimmune kidney disease is “one of the most dramatic effects of omega-3 fats on any pathology.”⁵

Diabetes, in turn, leads to heart disease. According to the cardiologist Dr. Arthur Agatston, author of The South Beach Diet, half of heart disease patients have metabolic syndrome first. Omega-3 fats reduce the risk of a first heart attack and reduce the risk of sudden death during a heart attack by 20 to 40 percent.⁶ The Physician’s Health Study, which followed twenty thousand doctors, found those eating fish once a week were half as likely to have a fatal heart attack as those who ate fish less than once a month.⁷

If you’ve survived one heart attack, eating fish may prevent another. The Lancet reported a study of more than two thousand men who had recovered from a heart attack and were given various instructions on diet. Advice to reduce total fat made no difference in mortality, but men told to eat fatty fish two or three times a week had 29 percent fewer deaths from all causes—the most important measure in epidemiology. Researchers called the effect “significant,” even after adjusting for ten potentially confounding factors.⁸

It’s clear from the experience of the Karuk and other tribes, such as those Weston Price studied, that traditional diets have a strong effect on health. But there is disagreement about whether fish oil supplements can prevent or treat heart disease, especially the high-risk groups. From 2005 to 2012, a spate of studies on fish oil supplements in high-risk populations found that fish oil provided no benefit compared to a placebo. Happily, many cardiologists, such as Dr. James Stein at the University of Wisconsin, are now advocates for whole foods, urging patients to eat fatty fish twice a week. If you’re lucky enough—as the Karuks once were—to live near a source of wild salmon, enjoy. If not, buy frozen seafood from a large, healthy fishery such as the cold Alaskan waters.

OMEGA-3 FATS SUPPORT THE HEART

✵Raise HDL

✵Reduce LDL and VLDL (very low density lipoprotein)⁹

✵Reduce blood pressure by dilating the blood vessels

✵Reduce clotting, inflammation, and triglycerides

✵Reduce lipoprotein (a),(Lp(a)) which promotes atherosclerosis and blood clots¹⁰

✵Reduce risk of death during and after heart attack by reducing irregular heartbeat (arrhythmia) through the actions of sodium, calcium, and potassium ions in heart muscle

ARE YOU DEPRESSED?

Muscle and bone are made of protein and minerals, while the brain is the house that fat built. Our brain is particularly hungry for the omega-3 fats found in fish. While other organs can manage (if not ideally) on a ratio of one to four parts omega-6 to one part omega-3 fats, the brain appears to require equal amounts of each.¹¹ Why? Unlike other body tissues, the brain can’t make DHA and EPA from plant oils like walnuts and flaxseed. In nutrition jargon, the brain has an “absolute need”—as opposed to a conditional one—for DHA and EPA, which, as we’ve seen, are found only in fish. Without adequate DHA and EPA, brain cell membranes don’t function properly. In 2005, for example, the Archives of Neurology reported that older men and women who eat more fish have sharper minds and better memory. Fish is food for thinking.

Mental health is one of the most exciting therapeutic applications of fish oil. Omega-3 fats may be as powerful as the drugs a psychiatrist prescribes, even for serious depression. Population studies, lab work, and clinical experience with depressed patients all suggest that fish oil can prevent and treat depression. The omega-3 expert Dr. Joseph Hibbeln has found that differences in depression rates across countries can be predicted by the quantity of fish in the diet. Lab analysis shows that the brains of depressed people have less omega-3 and more omega-6 fats. Finally, clinical evidence is mounting: doctors have prescribed omega-3 fats for major depression, postnatal depression, bipolar disorder, and schizophrenia.

The risk to mental health of omega-3 deficiency starts in the womb and continues throughout life. The baby has massive needs for DHA and EPA, especially in the second half of pregnancy, when growth is mostly due to fat.¹²Formula-fed babies and those nursed by omega-3-deficient mothers may fail to develop proper visual and mental function. Premature babies are particularly vulnerable because they are poor converters of ALA to DHA and EPA. In one study, premature babies fed corn oil had underdeveloped eyes and poor vision, while premature babies fed fish oil were virtually identical to full-term, breast-fed infants. Thus, even when the situation is not ideal—preterm infants are at greater risk in many ways—fish oil can make a difference.

OMEGA-3 FATS IN BREAST MILK

In addition to infant mental and visual problems, lack of omega-3 fats can cause preeclampsia, eclampsia, premature birth, low birth weight, difficult labor, and postnatal depression. The quantity of omega-3 fats in breast milk varies, presumably with fish consumption.

* Two studies were conducted in the United States.

SOURCE: Andrew Stoll, The Omega-3 Connection.

In children, omega-3 fat deficiency is linked to dyslexia, poor motor skills, and attention deficit hyperactivity disorder.¹³ Deficient teenagers and adults are prone to anger, hostility, and violence. Pregnant and nursing women who don’t replenish omega-3 stores face the risk of postnatal depression.¹⁴ (Omega-3 fat depletion is also cumulative; that is, if the mother’s diet lacks these essential fats, deficiency grows with each pregnancy and each generation.) In older people, lack of omega-3 fats is linked to Alzheimer’s disease and dementia.

Fish oil prevents depression in several ways. Omega-3 fats make up nerve cell membranes, which affect the transmission of nervous system signals. ALA, DHA, and EPA regulate calcium, sodium, and potassium ions, which control electrical activity in the brain. Omega-3 fats directly activate receptors for neurotransmitters including dopamine and serotonin, chemical messengers for mood, sleep, appetite, and libido—symptoms altered or crippled by depression. Omega-3 eicosanoids also have a vital (though poorly understood) effect on mood.

Schizophrenia is one of the more distressing and intractable mental illnesses. The traditional treatment, which is more than fifty years old, employs drugs to alter levels of dopamine and serotonin. This works for about 30 percent of patients—not impressive. Moreover, the drugs are costly and cause side effects. A radical new approach begins with the observation—first suggested by Dr. David Horrobin in the 1970s—that the brain is made of fat.¹⁵Neurotransmitters are carried in pouches made of fats called phospholipids, which the body can make from plant-based sources of omega-3 fats or (ideally) obtain directly from fish. In the schizophrenic brain, however, the complex metabolism of fatty acids is damaged, so that neurons and neurotransmitters don’t work properly. Early clinical trials suggest that fish oil supplements might be as effective as drugs, without the side effects.¹⁶

If fish can prevent or treat obesity, diabetes, heart disease, and depression, the muscular salmon immortalized by Cro-Magnon artists begins to look like a delicacy and wonder drug all wrapped up in one speckled silver package. Eating fish is a good thing. If only deciding which fish to eat were as simple.

THE TRUTH ABOUT FISH FARMING

Fishing is fun, but—famously—it involves a fair bit of waiting around for the fish to fall into the trap, whether it’s a net, basket, or hook. If you fish for fun, simply watching the water rush by is pleasant enough, but it would quickly seem inefficient if dinner depended on it. One day, perhaps, a clever Homo piscator (his brain swollen by omega-3 fats) began to wonder whether there wasn’t a quicker, more reliable way to gather the tasty protein he was now accustomed to eating every day. His idea was to trap, feed, and breed fish. In Asia, carp farming is an ancient form of agriculture; the book Fish Culture Classics was printed in 460 BC.

Alas, traditional fish farming is all but forgotten. The marine equivalent of cattle feedlots, confinement dairies, and battery egg barns, fish feedlots present the all-too-familiar problems of intensive food production: crowding, disease, parasites, pesticides, antibiotics, excess manure, environmental damage, and—did you guess?—less nutritious food. Just as beef, milk, and eggs raised on grass contain more omega-3 fats than those fed grain and soybeans, wild fish contains more omega-3 fats than farmed fish.

These undesirable effects were little known in the 1970s, when the Norwegians pioneered salmon farming. Quickly taken up by Scotland, Chile, and Canada (countries blessed with long, indented coastlines), fish farming was an immediate hit. “By the late 1980s, salmon had gone from being a luxury fish to an absolute steal,” writes Gina Mallet in Last Chance to Eat. No doubt that seemed like progress, but the effects on salmon, the sea ecology, and nutrition were less savory.

WILD FISH VS. FEEDLOT FISH

SOURCE: Artemis P. Simopoulos, “Omega-3 Fatty Acids in Health and Disease and in Growth and Development.” American Journal of Clinical Nutrition, Vol 54 (1991): pp. 438-63.

The insults start at birth. To stock fish feedlots, female and male salmon are anesthetized before farmers squeeze out their eggs and sperm. Like the animals on factory farms, farmed salmon is fattier than wild fish—by design. The feedlot diet of fish meal and growth-promoting antibiotics is deliberately fattening. Wild fish also get a lot more exercise, which produces firm, well-toned flesh, not the flabby, greasier version found in feedlot fish.

Wild salmon is measurably cleaner than feedlot fish. In 2004, Science published research showing that farmed salmon contains “significantly” more toxins, including PCBs and dioxin, than wild fish. Similar problems occur in other farmed seafoods. Imported farmed shrimp may contain the drug chloramphenicol. This potent antibiotic drug is used in therapeutic doses for treating serious infections in humans. The United States does not permit chloramphenicol to be used on animals or in animal feed.

Thanks to its natural diet of shrimp, wild salmon is a rich pink color. The species called sockeye is the richest in the carotenoid astaxanthin, a powerful antioxidant. Feedlot salmon, however, is naturally gray. To give farmed salmon the hue we crave, fish farmers rely on a dye called canntaxanthin. “The color is chosen from Salmofan,” says Mallet, “a color swatch from the chemical giant Hoffman-La Roche.”

It was first thought that aquaculture would protect wild fish, but it turned out to be the other way around. Today more than half the world’s salmon is farmed, and the majestic species known as Atlantic salmon is hanging by a thread. In the icy waters of Alaska, on the other hand, where salmon farming is banned, the result is a world-famous, thriving wild salmon fishery. Crowded industrial fish are more susceptible to parasitic sea lice, which (despite routine pesticides) easily spread to wild fish. Each year, millions of salmon escape from feedlots and breed with wild fish, reducing genetic diversity.

Fish farming also causes collateral ecological damage. Feedlots produce chemical runoff from antibiotics, pesticides, and detergents, and tons of fish feces, too much to be cleared by ocean currents. In Asia, Latin America, and Africa, shrimp farming is destroying the complex and vital ecosystem found in mangrove swamps.

The industry defends fish farming as a source of cheap, high-quality protein. However, like other industrial crops, fish feedlots represent a net loss of energy. About three pounds of wild fish are consumed to produce one pound of farmed salmon or shrimp. In Against the Grain, Richard Manning describes the unfortunate logic of the industrial fish food chain.

The protein that supports this practice comes from what we call “trash” fish, such as sardines and herring … Many of these species, however, are not trash at all, but a key link in the ocean’s food chain and an important part of local fisheries and diets in the developing world. Left to their own devices, wild fish (especially salmon) eat the fish that factory trawlers are now scooping up and grinding into fish meal to feed to farmed fish. Absent the trawlers, local fishers in skiffs … would catch a few anchovies to feed local protein-starved communities. Instead, this protein is sucked up, reduced by a factor of three, and shipped to Red Lobsters across suburban America.

The fish we should farm are herbivores (carp, catfish, tilapia) and mollusks (oysters, mussels). But there is money in the carnivores (cod, salmon, shrimp, tuna). Happily, today there are more environmentally sound alternatives to industrial fish. Scotland and Ireland raise organic salmon without antibiotics and pesticides; they use lower stocking densities, organic feed, and a natural pink dye, typically made from ground-up shrimp. Scotland also offers sustainable farmed cod, and shrimp from Ecuador are certified organic by Naturland. In my neighborhood, a brand-new urban indoor shrimp farmer, Jean Claude Frajmund, brings to market fresh, head-on Pacific White shrimp raised in clean, recycled salt water without antibiotics, hormones, or chemicals. Conservation organizations, including the Blue Ocean Institute and the Audubon Society, rate fish and seafood by its abundance and the ecological impact of fishing methods.

Most American wild salmon comes from the Pacific. The premier species is sockeye, whose rich ruby color signals high levels of the natural antioxidant astaxanthin, but some people prefer the milder and richer king salmon. From the Lower Fraser River in Washington State comes the marble chinook, the only really regionally distinct species, which is caught by hook and line or trolling, often by Makah and Nootka tribes. The best-quality fish is frozen on the boat, ideally before rigor mortis—when enzymes begin to break down the flesh—sets in. Fish “frozen at sea” is regarded by people in the know as superior to never-frozen fish—unless, of course, you live near water and your fish goes straight from the sea to the skillet.

Here in New York City, I often buy local seafood, but I also cook delicious wild Alaskan salmon from small independent boats, a choice I regard as socially and environmentally sound. It is certainly preferable to any farmed salmon. I’ve been treated to red sockeye from the Tommyknocker, the boat of Rosemary McGuire, who fishes Alaska’s famous Copper River Flats. Filets and steaks from Vital Choice arrive frozen in vacuum packs and taste of the sea. The hot smoked salmon in jars is exquisite. I also love wild Alaskan sablefish. Sometimes called black cod or butterfish, it’s common in Jewish delis. Ivory and flaky, sablefish has a buttery texture, delightful flavor, and 50 percent more omega-3 fats than salmon. Filets frozen at sea are superb, but for every day, I eat a lot of canned wild salmon, which is not expensive.

It’s sensible to eat fatty fish two or three times a week—and when you do, be generous with the butter and cream. Saturated fats extend the body’s supply of omega-3 fats; hence classics like Dover sole with butter sauce, lobster claws dipped in melted butter, and creamy clam chowder. Cold-water, oily fish (mackerel, herring, bluefish, salmon, tuna) have the most omega-3 fats. A 3.5-ounce (100 gram) portion of sockeye salmon contains more than 1,200 milligrams of DHA and EPA. Sardines—a catchall term for any young fish, often herring—contain 500 percent more omega-3 fats than tuna.

A word of caution about wild fish, however. Mercury is an environmental pollutant known to cause brain damage. Like other metals, mercury accumulates in tissue as it moves up the food chain, which means larger, carnivorous fish contain more mercury than smaller ones. Thus the FDA advises children and pregnant women not to eat swordfish, shark, king mackerel, or tilefish. But it’s unwise to avoid fish altogether.

Why? The benefits of fish to mother and baby are “enormous,” says Dr. Michel Odent, an expert in prenatal nutrition.¹⁷ Odent is concerned that more women fear excess mercury than understand how important fish oil is. In 2005, a study by the Harvard School of Public Health confirmed this view, arguing that the mercury warnings could cause pregnant women to eat too little fish, not only for the baby’s brain but also for their own health. “I think we’ve got two messages,” said Joshua T. Cohen, who led the research. “If you’re not pregnant and you’re not going to become pregnant, eat fish. If you are pregnant or you are going to become pregnant, you should still eat fish, but you should eat fish low in mercury.’¹⁸

Like the FDA, Odent advises pregnant women to avoid the big carnivorous fish, and encourages women to eat plenty of the small, fatty ones, like the anchovy, pilchard, herring, and common mackerel. Mostly herbivorous, farmed fish such as catfish, carp, trout, and tilapia are also good choices if mercury is a concern. The jury is out on tuna, a carnivore; the cautious pregnant woman might prefer to avoid it. If you don’t care for fish, do take a high-quality fish oil, in capsules or liquid.

WHERE FISH KEEP OMEGA-3 FATS

Oily fish (salmon, tuna, mackerel) store omega-3 fats in muscle. The soft brown flesh beneath salmon skin is a particularly rich source. Flaky white fish store omega-3 fats in the liver. I can buy monkfish liver, a Japanese delicacy, at my local farmers’ market. Sauté it in butter and put a slice on toast. The French call it le foie gras de la mer. The traditional favorite of old-school nannies, cod-liver oil is rich in vitamins A and D and contains some omega-3 fats. Fish oil should be wild and unrefined. Quality fish oil supplements don’t contain mercury or PCBs.¹⁹

Should you eat fish raw? Yes—traditional diets include a lot of raw fish. The Inuit eat mostly raw seafood and blubber, the Japanese love sashimi, the Spanish make seviche, and Scandinavians have gravlax (salmon cured with sugar, salt, and dill). These recipes make nutritional sense because polyunsaturated omega-3 fats are very sensitive to heat. When you cook a piece of fish gently, the omega-3 fats are partially protected by lower temperatures in the middle. Nevertheless, the less heat the better. Serve salmon and tuna medium or rare, if that’s to your taste, or try seviche, sashimi, and cold-smoked lox. I adore these dishes, but if you don’t, eat fish the way you like it. My guess is that for most people, any fish is better than none.