• Look for light-colored, cottony spots on the fish—they’re freezer burns. Sometimes frozen fish is allowed to thaw and then is refrozen, sometimes several times. Also look for ice crystal coatings—and walk away if you find them. These are fish you don’t want to buy. The highest-quality frozen fish are caught at sea and then quick-frozen individually on board the ship. (Often, there’s a label to this effect, saying that the fish was “frozen at sea.”)
What about Farm-Raised Fish?
It’s called “aquaculture.” Many species of fish and shellfish—including salmon, trout, catfish, tilapia, carp, eels, shrimp, and crayfish—are produced in closed waters and ponds and fed soy-and cereal-based chows. This is similar to the situation of feedlot-fed cattle. What they eat causes their own meat to be low or deficient in the beneficial omega 3 fatty acids that help make fish so good for us. Numerous scientific studies have demonstrated the omega 3 fatty acid inferiority of farmed fish compared to wild fish.
Farmed fish are usually cheaper to bring to market than wild fish. In the United States, trout—unless you have caught it yourself in the wild—is almost always farmed. Fresh, wild salmon has a marvelous flavor; most farmed salmon is bland-tasting. Decide for yourself. Note: Some farmed fish is labeled as such; most is not. If you don’t know, ask your grocer.
Should You Eat Canned Fish?
Canned tuna is America’s favorite fish by far. But the canning process causes a number of problems, the least of which is a loss of fresh flavor. This is what happens: the tuna is cooked at high temperatures and then sealed in a can containing salt, vegetable oil, water, or a combination of these three ingredients. The canning process removes 99 percent of the vitamin A found in fresh tuna, 97 percent of the vitamin B1, 86 percent of the vitamin B2, 45 percent of the niacin, and 59 percent of the vitamin B . It also increases the level of oxidized cholesterol in the fish, specifically a molecule called “25-hydroxycholesterol” that is extremely destructive to the linings of arterial blood vessels—so destructive that oxidized cholesterol is routinely fed to laboratory animals to accelerate artery clogging in order to test theories of heart disease. In animal models of atherosclerosis and heart disease, only 0.3 percent of the dietary cholesterol needs to be in the form of oxidized cholesterol to cause premature damage to the arterial linings.
To complete the degradation of this formerly healthy food, the tuna is packed with salt water or vegetable oils, which usually are high in omega 6 fatty acids. If you have the choice, always choose fresh or frozen fish over canned fish. If you do eat canned tuna, try to find brands that are packed in water only (no salt) or in more healthful oils, such as olive. (Most water-packed tuna contains added salt, but this can be removed by soaking the tuna in a shallow pan filled with tap water and then rinsing the fish in a colander under a running tap.)
Eggs: Good or Bad?
Eggs are healthful foods; our Paleolithic ancestors ate them seasonally, because they just weren’t available all the time. Several recent studies have shown that eating one egg a day has no discernible effect on your blood cholesterol level and does not increase your risk of heart disease. So go ahead—enjoy a couple of eggs for breakfast every few days.
There’s more good news on the egg front: you can buy chicken eggs that, like the wild bird eggs our ancestors ate, have high levels of omega 3 fatty acids. These enriched eggs—produced when chicken are fed omega 3-enriched feeds—are nutritionally superior and are available at many supermarkets and health food stores.
Because eggs are one of our richest dietary sources of cholesterol, the way they’re cooked influences the level of oxidized cholesterol—which can damage the cells lining your arteries and increase your risk of developing atherosclerosis and heart disease. High heat—like that of a griddle—produces more oxidized cholesterol than slow cooking: poaching, hard-boiling, or baking. When you have the choice, avoid fried eggs.
A recent study demonstrated that eggs from free-range hens had up to 1/3 less cholesterol, ¼ less saturated fat, 2/3 more vitamin A, 2 times more omega 3 fatty acids, 3 times more vitamin E, and 7 times more beta-carotene, than battery-cage eggs.
Similar to the situation with grass-fed, free-range meats, eggs produced from chickens allowed to live and forage freely are more nutritious and healthful than are their factory-produced counterparts. One of the first poultry farmers to recognize the superiority of free-range eggs was my friend George Bass. You can sample George’s eggs at his Web site for the Country Hen below. I also recommend that you visit Jo Robinson’s Web site, www.eatwild.com, to find a local producer of free-range eggs near your home.
The Country Hen
P.O. Box 333
Hubbardston, MA 01452
Phone: (978) 928-5333
countryhen.com
How to Make the Most of Fruits and Vegetables
One of the first changes you’ll notice when you start the Paleo Diet is the large amounts of fresh fruits and veggies that you will need to keep on hand. Note: To help produce stay fresh longer, keep fruits and vegetables covered in plastic bags in your refrigerator.
The constant need to replenish your fresh produce supply gives you a good excuse to explore new venues. Try going to local farmers’ markets in your area. They’re wonderful sources of wholesome, fresh, and delicious fruits and vegetables. They may even inspire you to try growing your own vegetables at home. Also, take this opportunity to try out-of-the-ordinary fruits and vegetables (many are included in the recipes and meal plans in this book). You may want to look for exotic produce in Asian, Far Eastern, and ethnic markets if there are any in your community. As you gradually wean yourself from salty, sugary, and starchy foods, your taste buds will become attuned to the subtle flavors and textures of wonderful real foods.
To be on the safe side, be sure to wash all produce before you eat it (even if it comes in a bag that says it’s been washed). Like fish, fresh produce can contain trace residues of pesticides, heavy metals, or other pollutants. The Food and Drug Administration has monitored the levels of contaminants in the U.S. food supply for almost forty years in a program called the Total Diet Study (you can read about it on the Web at: vm.cfsan.fda.gov/~comm/tdstoc.html). The study, which began in 1961, periodically examines more than 230 foods from eight regional metropolitan areas to determine which hidden ingredients—and how much of them—we’re getting in our food. Since its inception, the study has found that our average daily intake of all toxic contaminants—including pesticides, industrial chemicals, heavy metals, and radioactive materials—is well below acceptable limits. Of course, it would be even better if our average daily intake of contaminants were zero, and we could rest assured that our food was completely free of any pollution—but it’s pretty safe to say that this will not happen any time soon.
The bottom line is that fruits and vegetables have much to offer—antioxidants, vitamins, minerals, and all the healing benefits we’ve discussed in this book. We can’t do without them; more than that, they need to play a starring role in our diet.
If you are concerned about pesticide exposure, artificial fertilizer, and other food safety issues, you may want to seek organically grown produce whenever possible, although it’s a bit more expensive
Nuts and Seeds
Nuts and seeds are a good adjunct to the Paleo Diet, but they’ve got a lot of fat, so you need to eat them in moderation. Too many fatty foods—even beneficial nuts and seeds—can rapidly upset your balance of essential dietary fats and derail your weight-loss progress. Throughout the book, we’ve talked about the omegas—omega 6 and omega 3. One kind—omega 6 fats—is not good for you when eaten in excess. The other kind—omega 3 fats—can make you healthier in many ways. The ideal ratio of omega 6 to omega 3 fats should be between 2 and 3 to 1. For most Americans, unfortunately, it’s between 10 and 15 to 1. All nuts and seeds—except for walnuts and possibly macadamia nuts—have unacceptably high omega 6 to omega 3 ratios. This is why you must eat them in small amounts.
O
mega 6 to Omega 3 Fat Ratio in Nuts and Seeds
Nut or Seed Omega 6 to Omega 3 Ratio
Walnuts 4.2
Macadamia nuts 6.3
Pecans 20.9
Pine nuts 31.6
Cashews 47.6
Pistachio nuts 51.9
Hazelnuts (filberts) 90.0
Pumpkin seeds 114.4
Brazil nuts 377.9
Sunflower seeds 472.9
Almonds extremely high (no detectable omega 3 fats)
Peanuts (not a nut but a legume) extremely high (no detectable omega 3 fats)
But nuts are part of the Paleo Diet. They’re high in monounsaturated fats and have been shown in numerous clinical trials to lower cholesterol. This is why they’re on the diet in moderate amounts, so that you can benefit from the good things nuts have to offer. But the high quantities of omega 6 fats in these nuts can also predispose you to heart disease—because they displace the omega 3 fats, which are known to prevent fatal heartbeat irregularities, decrease blood clotting, lower blood triglyceride levels, and reduce the inflammatory profile of prostaglandins and leukotrienes (hormonelike substances that control the inflammation process). Omega 3 fats have also been shown to lessen the symptoms of many inflammatory and autoimmune diseases, including arthritis and inflammatory bowel disease.
Peanuts are forbidden. As mentioned, they are not nuts at all; they’re legumes—and legumes contain lectins and other antinutrients that can adversely affect your health, particularly if you are suffering from an autoimmune disorder.
Important note: Many people are allergic to nuts, and pine nuts can be particularly troublesome for some people. Listen to your body carefully as you begin the Paleo Diet and fine-tune the diet to your specific health needs. Although nuts and seeds are true Paleo foods—and were certainly part of the diets of our ancient ancestors—they were not the staples.
When you shop for nuts:• Try to buy raw, unsalted nuts. You can find them in their natural state at most supermarkets in the late summer and early fall when they come into season.
• If you don’t like cracking nuts, you can find packaged, hulled nuts at some supermarkets and most health food stores. However, read the package label. Hulled nuts are sometimes coated with trans fat-containing oils to increase their shelf life.
• When in doubt, go for walnuts. They have the best omega 6 to omega 3 ratio and are your healthiest choice for a snack food or to use in other dishes. Other nuts should be considered garnishes in salads and other dishes, rather than eaten in quantity.
Purchasing Oils
Vegetable oils were obviously not a component of any pre-agricultural or hunter-gatherer diet, simply because the technology to produce them did not exist. Oils made from walnuts, almonds, olives, sesame seeds, and flaxseeds were first produced using crude presses between 5,000 and 6,000 years ago. However, except for olive oil, most early oil use was for nonfood purposes, such as illumination, lubrication, and medicine. It wasn’t until the beginning of the twentieth century, with the advent of mechanically driven steel expellers and hexane extraction processes, that vegetable oils started to contribute significantly to the caloric content of the Western diet. Today vegetable oils used in cooking, salad oils, margarine, shortening, and processed foods supply 17.6 percent of the total daily energy intake in the U.S. diet. The enormous infusion of vegetable oils into the Western diet, starting in the early 1900s, represents the greatest single factor responsible for elevating the dietary omega 6 to omega 3 ratio to its current and unhealthful value of 10 to 1. In hunter-gatherer diets, the omega 6 to omega 3 ratio was closer to 2 to 1. If we use the evolutionary template exclusively, vegetable oils should probably constitute a minimal part of modern-day Paleo diets.
So, if this is the case, why should we not eliminate all vegetable oils from our diet?
I still believe that certain oils can be used to cook with and add flavor when making condiments, dressings, and marinades. Simply stated, there are four oils (flaxseed, walnut, olive, and avocado) that can promote health and facilitate your getting the correct balance of good fats into your diet. Because hunter-gatherers ate the entire carcasses of wild animals (tongue, eyes, brains, marrow, liver, gonads, intestines, kidneys, and so on) and relished fatty plant foods (nuts and seeds), they did not have to worry about the correct balance of fatty acids in their diet. It came out correctly in the wash.
For most of us, the thought of eating organs is not only repulsive, but is also not practical as we simply do not have access to wild game. Consequently, by eating lean meats, fish, and seafood, along with healthful oils, nuts, and seeds, you can get the correct balance of fatty acids in your diet.
As you can see from the table on page 134, only three vegetable oils have omega 6 to omega 3 ratios of less than 3. These are flaxseed (0.24), canola (2.0), and mustard seed (2.6). Although I originally recommended mustard seed oil in the first edition of The Paleo Diet, I can no longer make this recommendation because of its high erucic acid (a long-chain monounsaturated fatty acid) concentration of 41.2 percent. Consumption of large quantities of erucic acid in laboratory animals causes adverse changes in their heart structure and function and other organs.
This leaves only two vegetable oils (canola and flaxseed) that do not contribute to an elevated intake of omega 6 fatty acids. A number of epidemiological (population) studies have shown a higher risk of developing prostate cancer with an increased consumption of alpha linolenic acid (ALA), a major fatty acid found in both canola and flaxseed oil. However, epidemiological studies are notorious for their conflicting results. For every six studies that support one nutritional concept, you can often find half a dozen more that conclude precisely the opposite. Such is the case linking ALA and flaxseed oil to an increased prostate cancer risk. A series of the most recent epidemiological studies was unable to statistically show that ALA consumption increased prostate cancer risk. More important, in experiments in which animals were fed flaxseed oil, the flaxseed actually inhibited the growth and development of prostate cancer. The case supporting flaxseed oil as a promoter of prostate cancer is currently based solely on epidemiological evidence and therefore remains inconclusive because of the total lack of confirming experimental evidence. Because the majority of epidemiological studies support the notion that ALA is protective against cardiovascular disease, flaxseed oil should still be viewed as healthful.
Since the original publication of The Paleo Diet in 2002, I have reversed my view of canola oil and can no longer support its consumption or use. Let me explain why. Canola oil comes from the seeds of the rape plant (Brassica rapa or Brassica campestris), which is a close relative of broccoli, cabbage, Brussels sprouts, and kale. Clearly, humans have eaten cabbage and its relatives since prior to historical times, and I still strongly support the consumption of these health-promoting vegetables. The concentrated oil from the seeds of Brassica plants is another story.
In its original form, rape plants produced a seed oil that contained high concentrations (20 to 50 percent) of erucic acid (a monounsaturated fatty acid labeled 22:1n9), which I have previously explained is toxic and which causes a wide variety of pathological changes in laboratory animals. In the early 1970s, plant breeders from Canada developed a strain of rape plant that produced a seed with less than 2 percent erucic acid (hence the name canola oil). The erucic acid content of commercially available canola oil averages 0.6 percent. Despite its low erucic acid content, however, a number of experiments in the 1970s showed that even at low concentrations (2.0 percent and 0.88 percent), canola oil fed to rats could still produce minor heart scarring that was considered “pathological.”
A series of recent rat studies of low-erucic canola oil conducted by Dr. Ohara and colleagues at the Hatano Research Institute in Japan reported kidney injuries, as well as increases in blood sodium levels and abnormal changes to a hormone, aldosterone, that regulates blood pressure. Other negative effects of canola oil consumption in animals at 10 percent of calories include decreased litter s
izes, behavioral changes, and liver injury. A number of recent human studies of canola/rapeseed oil by Dr. Poiikonen and colleagues at the University of Tempere in Finland have shown it to be a potent allergen in adults and children and indicate that it may cause allergic cross-reactions from other environmental allergens in children with atopic dermatitis (skin rashes).
Based on these up-to-date studies in both humans and animals, I prefer to be on the safe side and can no longer recommend canola oil.
Both olive oil and avocado oil are high (73.9 and 70.6 percent, respectively) in cholesterol-lowering monounsaturated fatty acids but have less than favorable omega 6 to omega 3 ratios of 11.7 and 13.5. Consequently, excessive consumption of both of these oils without adequate intake of long-chain omega 3 fatty acids (EPA plus DHA) will derail an otherwise healthy diet. I recommend that you get 1.0 to 2.0 grams of EPA and DHA per day in your diet from either fish or fish oil capsules. Because avocado oil is difficult to find and expensive, that pretty much leaves olive oil as the staple for cooking, salad dressings, and marinades.
If you can afford it, I recommend that you always choose extra-virgin olive oil, because this grade of oil is produced by physical means only, without chemical treatment, and it contains the highest concentrations of polyphenolic compounds, which protect against cancer, heart disease, and inflammation.
Although peanut oil has been promoted as a healthy, cholesterol-lowering oil because of its high monounsaturated fat content (46 percent of total fat), it has turned out to be one of the most atherogenic (artery-clogging) of all oils. In fact, it is routinely used to induce coronary artery atherosclerosis in monkeys and other laboratory animals. It’s not clear exactly why this happens. Some scientific evidence suggests that peanut lectins (proteins that bind to carbohydrates) may be responsible for this effect.
The Paleo Diet Page 15