Read The Starch Solution Online
Authors: MD John McDougall
Diminishing supply has caused the price of fresh, wild-caught salmon to triple over the past decade. Because of the rarity of bluefin tuna, the Japanese are now making some of their sushi with beef. In order to avert, or at least delay, the extinction of salmon, fishing for them in California waters is now often prohibited.
When I returned to my beloved coral reefs in the Florida Keys in 2002, I found them no longer brimming with life as I remembered, but rather bleached white and barren by the loss of coral and fish due to environmental stresses and the ocean’s warming temperature. By the year 2048, we are warned, all fish and seafood species will have collapsed, meaning that they will be either extinct or on the precipice of extinction.
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We might justify eating sea creatures if it improved our health and saved our lives, even if doing so would devastate the oceans and kill off their inhabitants. But what if the opposite were true? What if eating fish in the amounts commonly recommended by health professionals posed a health hazard rather than a benefit to us?
Omega-3 and omega-6 fats are called
essential
because we need them but cannot manufacture them ourselves. That means we must get them through the foods we eat. These plant-derived fats have many important functions, such as forming cell membranes and synthesizing hormones. These fatty acids are named for their carbon-to-carbon double bond on a carbon chain; omega-3 fatty acids have their double bond at the third carbon position from the omega (methyl) end of the chain and
omega-6 fatty acids have theirs at the sixth carbon position. What’s important about this is that only plants are able make a double bond at the third or sixth carbon position. Neither fish nor animals nor humans can create their own omega-3 or omega-6 fats.
The basic omega-3 fat made by plants is alpha-linolenic acid, abbreviated ALA. Linoleic acid (without the second “n”) is the basic plant-generated omega-6 fat. Small fish take in ALA by eating seaweed and algae, then converting some of it into long-chain fats, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which they store in their body fat. You may have heard that humans need to eat fish to obtain these elongated fatty acids because we cannot manufacture sufficient amounts on our own, but that simply is not true. Research has demonstrated that men, women, children, and pregnant women convert small but perfectly adequate quantities of ALA into EPA and DHA without any help from fish.
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The omega-3 fatty acid DHA is highly concentrated in the nervous system, leading some people to believe that fish and fish oil can improve our mental health and protect us from neurological diseases. However, there is no evidence that dementia or any other condition of mental deficiency occurs in populations that take in all of their essential fats from plants and have a low intake of EPA or DHA from fish or supplements.
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Furthermore, research shows that those who eat plenty of fish have about the same risk of developing dementia and Alzheimer’s as those who eat no fish at all.
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Consider this reassuring observation: People on vegetarian diets characterize themselves as being in a “better mood” twice as often as meat eaters, and are half as likely to suffer from dementia.
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Many nutritionists and doctors worry about meeting the needs of the unborn during early development. Infants born to mothers who have taken supplements of DHA during pregnancy have been found to show no improvement in neurologic function as assessed by their visual development early in life.
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A critical review of the scientific literature on essential fats by John Langdon, a professor of biology and
anthropology at the University of Indianapolis, concluded: “There is no evidence that human diets based on terrestrial food chains with traditional nursing practices fail to provide adequate levels of DHA or other [omega] n-3 fatty acids. Consequently, the hypothesis that DHA has been a limiting resource in human brain evolution must be considered to be unsupported.”
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Meaning that if we eat natural plant foods we will always, during all stages of life, get enough DHA and other omega-3 fats.
The recommendation to consume more fish began with observations of populations worldwide that have traditionally favored fish. These populations have lower rates of heart disease than populations that eat primarily beef, chicken, or pork. The most notable fish-eating country is Japan. But are we certain that fish holds the key to their good health?
Look a little closer and you will find that the Japanese diet is based largely on rice. In fact, it is their significant consumption of this starch, not of fish, that explains their better health, trimmer figures, more active lifestyle, youthful appearances, and greater longevity. Look at a traditional Japanese meal and you will see that only small amounts of fish are eaten as a condiment atop a bowl of rice. In the United States, where Japanese restaurants serve a little rice with a large plate of fish instead of the traditional opposite, we lose these health benefits. This explains why Japanese people who move to the United States and slowly transition to a Western diet begin to lose their immunity, soon looking more like Americans; that is, fatter and sicker.
Health organizations worldwide, including the American Heart Association, the American Medical Association, the American Diabetic Association, the British Dietetic Association, and Australia’s leading health research body, the National Health and Medical Research Council, among others, recommend that we eat fish primarily because it is a reliable source of the “good” omega-3 fatty acids. Yet these same groups
warn about the hazards of methylmercury and other environmental contaminants in fish. This information has us stuck between a rock and a coral reef: In order to protect our hearts we must consume chemicals that put us at risk for brain damage and cancer.
While there is no danger in avoiding fish sources of omega-3 fatty acids, there is certain danger in consuming fish or fish oil.
Eating fish and taking fish oil capsules exposes you to mercury, a natural element found in the earth and released as industrial pollution during certain manufacturing processes. As mercury is dumped into our rivers, streams, and oceans, it is converted into highly toxic methylmercury, which becomes ever more concentrated as it accumulates up the food chain. Fish at the top of the food chain have the greatest mercury contamination levels. Which fish swim at the top of the food chain? Freshwater pike, walleye, and bass are examples, along with saltwater tuna, salmon, swordfish, herring, mackerel, and sardines.
These saltwater fish are also the ones with the highest concentrations of EPA and DHA. In other words, the fish that give you the most of those fatty acids come packaged with the highest mercury levels. Not just the few specific species listed here, but all fish and shellfish are contaminated with potentially dangerous environmental chemicals.
Mercury-contaminated seafood is almost the sole source of chronic human mercury poisoning. Serious health risks from mercury poisoning include damage to the heart, kidneys, and immune and nervous systems. In the brain, mercury poisoning can cause motor dysfunction, memory loss, learning disabilities, and depressive behavior. Even if eating fish fat or taking fish oil supplements did reduce your risk of nervous and motor disorders (they do not), that benefit would be more than offset by the toxic effects of mercury. In addition to mercury, fish and fish oils contain other toxins that promote cancer and have damaging effects on the reproductive system.
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FOOD | CHOLESTEROL (MG/100 CAL) |
Bass | 60 |
Crab | 55 |
Cod | 53 |
Mackerel | 51 |
Salmon | 40 |
Egg | 272 |
Chicken | 36 |
Pork | 28 |
Beef | 32 |
Grains, vegetables, and fruits have no significant amounts of cholesterol.
The fact that fish is high in blood-thinning omega-3 fatty acids has led to the belief that fish protects us from heart disease. After all, thinner blood reduces the chance of forming a clot in an artery leading to the heart, and thus prevents heart attacks. The mercury that can poison the brain and kidneys also affects blood vessels, causing the formation of free radicals, inflammation, blood clots, and muscle dysfunction of the blood vessel walls.
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In addition to the environmental chemical contamination problem, fish share similar nutritional qualities with other muscle-derived foods like beef, pork, and chicken. Muscles are high in protein, fat, cholesterol, methionine, and dietary acids, and contain no carbohydrate or dietary fiber. (See
Chapter 3
to review the five major poisons found in animal foods.) Cholesterol in fish elevates blood cholesterol,
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with even small doses of fish oils raising “bad” (LDL) cholesterol.
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Research published in respected medical journals showing that fish offers no benefit to the heart, and may even be a step in the wrong direction, has failed to influence medical schools, doctors, dietitians, and health organizations to change their tune from promoting fish and fish oil supplements as a cornerstone of good health. Doctors are taught almost nothing about nutrition during medical school and rarely pursue it on their own, leaving them easily swayed by what they are told by individuals and organizations representing themselves as authorities.
Perhaps the animal food—centered diets of most doctors, dietitians, and scientists have clouded their perspective, too. Barraged by research findings suggesting that they shun beef, pork, chicken, eggs, and cheese due to their high levels of saturated fat and cholesterol, these learned professionals are left with just one animal food option that continues to be held up as healthful: fish.
You needn’t look far to find an abundance of studies promoting a very different point of view from the one you may have heard in your doctor’s office or read about in the papers. Following are a few to whet your appetite. (The italic emphasis is mine.)