Your Personal Paleo Code: The 3-Step Plan to Lose Weight, Reverse Disease, and Stay Fit and Healthy for Life (16 page)

Notes for this chapter may be found at ChrisKresser.com/ppcnotes/#ch7.

As we’ve looked closely at food on a biochemical and molecular level (micronutrients, macronutrients, fatty acids, and toxins), you’ve learned why certain foods should be a part of your Personal Paleo Code and why others don’t make the cut. Now that you have a good grasp of what should be on your plate, it’s time to take a step back and consider food quality. Before you head out to the market to collect ingredients for your next meal, I want to help you understand the importance of eating what I call real food. Real food is:

Let’s look at each of these in turn.

Industrial food processing has had more detrimental effects on human health and well-being than any other factor in the past few hundred
years—and possibly in the entire history of humankind. Food refining has brought us food toxins that destroy health: wheat flour, industrial seed oils, artificial trans fats, and table sugar and high-fructose corn syrup. It has also brought us chemical additives and preservatives, some with known negative effects and others with effects still unknown.

Almost every day, new research is revealing the harm these newfangled processed foods have on us. A study in 2011 found that emulsifiers used in packaged foods ranging from mayonnaise to bread to ice cream increased intestinal permeability (causing a leaky gut, which you’ll learn more about in
chapter 10
) and caused a chain reaction of inflammation and autoimmune disease. Another study showed that diet-soda consumption increases the risk of stroke and causes kidney damage, possibly because of the phosphoric acid used as an acidifying agent to give colas their tangy flavor. High intake of phosphoric acid is associated with premature aging, kidney and vascular disease, and cardiovascular complications in patients with chronic kidney disease. To avoid the harm caused by processed and refined foods, a good general rule is “If it comes in a bag or a box, don’t eat it.” Of course, not all foods that come in bags or boxes are harmful, so this isn’t meant to be taken completely literally. It’s just a helpful guideline. Butter is often packaged in a box, and some fruits, vegetables, and salad greens are sold in plastic bags. High-quality frozen organic produce is boxed or bagged. That doesn’t mean you shouldn’t eat butter, fruits, and vegetables. But in general, if you follow this guideline, you’ll avoid most common food toxins. And that’s more than half the battle.

Organic plant foods contain, on average, 25 percent higher concentrations of micronutrients than their conventional counterparts. In particular, they tend to be higher in important polyphenols and antioxidants like vitamin C, vitamin E, and quercetin. Even more relevant in determining your produce’s nutrient content is where it comes from, and, more
important, how long it’s been out of the ground. Most of the produce sold at large supermarket chains is grown hundreds—if not thousands—of miles away, often in areas with longer growing seasons (in warmer states like California, Texas, and Florida, or in countries with year-round tropical climates). This is especially true when you’re eating foods that are out of season in your local area, like a South American tomato in midwinter in New York. Possibly weeks have passed since that tomato was picked (hard and unripe, so that it could be shipped without bruising), after which it was packaged and transported thousands of miles through a maze of artificially refrigerated distribution centers before it finally arrived at the store, where it sat on the shelves even longer.

The problem with this (besides producing inferior taste and quality) is that food starts to change as soon as it’s harvested, and its nutrient content begins to deteriorate. For example, total vitamin C content of red peppers, tomatoes, apricots, peaches, and papayas has been shown to be higher when these crops are picked
ripe
from the plant. The vitamin C content of supermarket broccoli in May (in season) has been shown to be twice as high as supermarket broccoli in the fall (shipped from another country). Without exposure to light (allowing photosynthesis), many vegetables lose their nutrient value. If you buy vegetables from the supermarket that were picked a week ago, transported to the store in a dark truck, and then stored in the middle of a pile in the produce section, and then you put them in your dark refrigerator for several more days before eating them, chances are they’ve lost much of their nutrient value. For example, a study at Penn State University found that spinach lost 47 percent of its folate after eight days.

This is why buying your produce at local farmers’ markets or, even better, picking it from your backyard garden is preferable to buying conventional produce shipped from hundreds or thousands of miles away. Fruits and vegetables from local farms are usually stored within one or two days of picking, which means their nutrient content will be higher. And as anyone who’s eaten a fresh tomato right off the vine will tell you, local produce tastes so unlike (and so much better than) produce shipped in from afar that it could well be considered a completely different food.

A main benefit of organic produce is that it’s grown without pesticides, herbicides, or other harmful chemicals that have been shown to cause health problems, especially in vulnerable populations like children. A study published in the journal
Pediatrics
concluded that children exposed to organophosphate pesticides at levels typically found in conventional produce are more likely to develop attention deficit hyperactivity disorder (ADHD) than children who aren’t.

In 2010, scientists who had been studying possible links between environmental toxins and cancer concluded that Americans should eat organic produce grown without pesticides, fertilizers, or other chemicals. Their report stated that the U.S. government had grossly underestimated the number of cancers caused by environmental toxins. They also highlighted the risk to unborn children of the toxins in conventionally grown foods. Fetal exposure to harmful chemicals (through a pregnant woman’s consumption of produce grown with toxins) can set a child up for a lifetime of endocrine disruption, hormone imbalances, and other problems.

Local produce has more nutrients and fewer chemicals than imported produce, but there are other, non-nutritional reasons to eat it. These
were summarized well in Cornell University’s Northeast Regional Food Guide:

How can you argue with that? I’ve also found that forming relationships with the people who grow my food leads to a greater sense of community and connection. In an increasingly techno-obsessed, hyperactive world, that is especially welcome.

While the reasons to eat pasture-raised-animal products and wild-caught fish span social, political, economic, and health considerations, I’m going to focus on health factors. Several studies have been done comparing the nutrient content of pasture-raised-animal products to that of grain-fed-animal products (that is, animals raised in concentrated animal feeding operations, or CAFOs). Pasture-raised-animal products are superior to CAFO products in two primary respects: (1) they have a better fatty acid profile, and (2) they have higher levels of vitamins and other micronutrients.

Studies have shown that grain-fed animals have decreased omega-3 levels, thus raising the omega-6-to-omega-3 ratio. As you’ll recall from
reading about these fats in
chapter 5
, too much omega-6 and not enough omega-3 can be problematic. The more grain in a cow’s diet, the lower the omega-3 levels in the beef. A 2010 paper published in the
Nutrition Journal
reviewed seven individual studies comparing omega-6 and omega-3 levels in grass-and grain-fed beef. Every study found significantly higher levels of omega-3 in grass-fed beef, and in some cases the difference was almost tenfold. On average, grass-fed beef had an omega-6-to-omega-3 ratio of 1.5:1, compared to 7.7:1 for grain-fed.

Another study compared the omega-6-to-omega-3 ratio of several different types of meat, ranging from pasture-raised bison and beef to wild elk to conventional chicken. They found the following ratios (expressed as parts of omega-6 to one part omega-3):

What is apparent from both studies is that pasture-raised beef is much closer to the historical omega-6-to-omega-3 ratio of between 2:1 and 1:1 (what our Paleo ancestors consumed) than beef raised in concentrated animal feeding operations. In fact, the ratio for pasture-raised beef is even better than for wild elk. This means that pasture-raised beef falls within evolutionary norms for the fatty acid content of animals that humans have eaten throughout their history. CAFO beef does not.

You may also have noticed that the ratio of omega-6 to omega-3 of chicken is about nine times higher than that of pasture-raised beef. I don’t see this as a reason to avoid chicken, but it does suggest that the fatty acid profile of beef and lamb are superior, and they should be favored in the diet. Studies have shown that meat from pasture-raised animals can actually raise levels of EPA and DHA in the blood, making it the only dietary source of these important long-chain omega-3 fats other than cold-water, fatty fish.

We see a similar difference between eggs from hens raised on pastures and eggs from those raised in confinement. Eggs from pasture-raised hens contain as much as ten times more omega-3 than eggs from factory hens. Pastured-chicken eggs are higher in B
₁₂
and folate. They also have higher levels of fat-soluble antioxidants, like vitamin E, and a denser concentration of vitamin A.

Farmed fish contain more omega-6 than wild-caught fish. Tests conducted in 2005 show that wild-caught salmon contain ten times more omega-3 than omega-6, whereas farmed salmon have only about four times more omega-3 than omega-6 (despite having more omega-3 fat overall). Another study found that subjects who consumed standard farmed salmon, the kind raised on diets high in omega-6, had higher blood levels of inflammatory chemicals linked to increased risk of cardiovascular disease, diabetes, Alzheimer’s, and cancer. Wild salmon also contains four times as much vitamin D than farmed salmon does, which is especially important since up to 50 percent of Americans are deficient in this important vitamin.

Meat, fat, and dairy that comes from pasture-raised animals are the richest source of another type of good fat, called conjugated linoleic acid (CLA). CLA may have anti-cancer properties, even in very small amounts. In animal studies, CLA at less than one-tenth of 1 percent of total calories prevented tumor growth. In a Finnish study on women, those who had the highest levels of CLA in their diet had a 60 percent lower risk of breast cancer than those with the lowest levels. In another study, people with the highest levels of CLA in their tissues had a 50 percent lower risk of heart attack than those with the lowest levels.