Keep in mind that if you just want to reap the benefits of a Paleo diet, you need not understand any of the science and technical stuff. The reason I need to go into this level of detail, however, is because many people are confused about topics like saturated fat, cholesterol, and heart disease. Most of our lay populace, and seemingly even more of our medical community, are out to lunch on this topic. This forces me to get fairly detailed so you have an opportunity to understand all this. If I do a good job, it should allow you to read this book, implement the recommendations, track your progress, and, ideally, have few questions because I did my job up front. That"s the idea, anyway. We"ll see how effective I am. I mention this because we have a little more technical material to carve through before you will get your fifth-level "lipid-Jedi" decoder ring and start saving the world from the forces of evil: VEGANS!
What Fats Do What?
Different fats have different physiological roles. To keep things simple, I will only cover the fats most commonly occurring in the diet. Let"s look at these fats from the perspective of the fat"s level of saturation just to keep things tidy. This is also helpful as our first family of fats is more misunderstood than an Emo kid growing up in Arkansas.
Saturated Fats and Their Functions.
Saturated fats have generated a bad rap over the years. Initially, they were saddled with the dubious distinction of being the cause of CVD. Then, researchers tried in vain to attach them to everything ranging from cancer to neurodegeneration. The reality is saturated fats are generally pretty benign, some actually helpful. All of them have been quite misunderstood. Let"s look at the saturated fats starting with the short varieties, and then working our way longer.
Lauric Acid.
Lauric acid is a 12-carbon-long saturated fat commonly found in coconut, palm oil, and, interestingly, human breast milk. Lauric acid has novel antiviral properties that include proven activity against HIV, chicken pox, cytomegalovirus, and many other viruses. Lauric acid also has properties that help to heal gut irritation, which we will see, is an important feature in reversing leaky gut and autoimmune issues. Lauric acid can increase LDL and thus, total cholesterol, but as you have learned, LDL cholesterol is relatively benign if we have low systemic inflammation and low insulin levels via limited carbohydrate intake.
Many populations, such as the extensively studied Kitavans, consume large amounts of Lauric acid, display higher cholesterol levels than other populations, yet suffer little CVD. Yet again it would appear nature has dealt us a paradox, but it was only our a.s.sumption that all saturated fat is bad that led us to this false conclusion.
Palmitic Acid.
Palmitic acid is 16 carbons long, fully saturated, and commonly found in palm oil and animal products, including beef, eggs, milk, poultry, and seafood. Palmitic acid has long been implicated in CVD, as it tends to raise LDL cholesterol. Among the saturated fats, it would appear palmitic acid does pose the greatest likelihood of increasing LDL cholesterol. However, palmitic acid has also recently been shown to be vital both to forming new memories and accessing long-held memories. As we shall see when we investigate how our diet has changed, a Paleo diet supplies an adequate amount of palmitic acid for optimum cognitive function while limiting the intake to levels that are not harmful to the cardiovascular system. It is also important to note that excessive carbohydrate intake leads to palmitic acid production. If you recall from the insulin chapter, when liver glycogen is full, additional carbohydrate is converted to palmitic acid. This process appears to blunt our sensitivity to leptin, which then inhibits our satiety to a normal meal. This is the beginning of insulin resistance and is at the heart of the mechanism of how we cease to respond to food by feeling "full."
Stearic Acid.
The final saturated fat we will consider is the 18-carbon stearic acid. Stearic acid is found in significant amounts in meat, eggs, and chocolate! Stearic acid appears to be neutral with regard to LDL number, but it has been shown to actually increase HDL levels. Stearic acid also decreases a marker of systemic inflammation, Apollo protein-A.
Saturated Fat: The Bottom Line, Please.
Even though this was a quick sprint through the saturated fats, it was likely still enough to send some folks into a fetal position. So, what is the bottom line here? Are saturated fats bad or not? Do they increase the potential for CVD? Well, it depends.
A high intake of saturated fats, in conjunction with a high intake of dietary carbohydrate, is a h.e.l.l of a combo for an early grave. As you saw in previous chapters, elevated insulin levels lead to a shift in the LDL particles to a type that is small, dense, and easily oxidized. This is bad for a number of reasons, but the central feature is increased systemic inflammation and a subsequent increased probability of a cardiovascular event like heart attack or stroke. No bueno. If, however, our intake of saturated fat is kept within ancestral limits, and we also modify our carbohydrate intake to match that of our ancestors (both in amounts and type), we have little if any risk of developing CVD. We will look at the specifics of this after we have tackled mono and polyunsaturated fats.
Monounsaturated Fats.
Really, this section should be t.i.tled "monounsaturated fat" because although there are a number of monos (the acronym is MUFA-monounsaturated fatty acid), we are really concerned with only one variety, called oleic acid. Oleic is an 18-carbon-long MUFA found mainly in plant sources, such as olive oil, avocados, and nuts. Don"t count animal sources out, however! Even grain-fed meat contains a significant amount of oleic. Most people are familiar with the Mediterranean diet, and much of the health benefits ascribed to the diet are centered on the "heart healthy" MUFA"s. Indeed, MUFA"s are pretty impressive with regards to their benefits: Improved insulin sensitivity, improved glucagon response, and decreased cholesterol levels. Most plant sources of MUFA are also accompanied by fat-soluble antioxidants that are incorporated into the membranes of our cells, thus preventing oxidative damage a.s.sociated with aging and most degenerative diseases. MUFAs were the primary fat in our ancestral diet, so if we want to optimize our performance, health, and longevity (and look good naked), we will construct meals that emphasize this cornerstone of the Paleo diet.
Polyunsaturated Fats: AKA the Essential Fats.
As paradoxical as it may sound, there are indeed essential fats. We cannot make them and must consequently get them from our diet. If you do not get enough of these fats or the right ratios, you will have big problems. For our international readers, that"s Problemas Grandes, or Scheissen Grossen! As you will see, they are not only essential, but they also represent one of the largest divergences from our ancestral diet and into our corn-fed catastrophe. The next section will look at two subfamilies of polyunsaturated fats (PUFA) called the omega-3 family and the omega-6 family (abbreviated as n-3 and n-6 respectively). Sit tight folks, if you have not fallen asleep yet, you will soon!
Key Points.
Just to keep you on track, here are the key points that you should take away from the forthcoming section. These bullet points will help you make sense of the science-laden geek-speak that will be poured on you like a scalding beaker full of gra.s.s-fed beef stew.
1. Long n-3/n-6s are good. We get these from gra.s.s-fed meats and wild-caught fish.
2. Ancestral ratios of n-3/n-6 were approximately 1 to 1. Modern ratios are 1 to 10. This is bad.
3. Corn, soy, safflower, and similar vegetable oils are the source of the excessive n-6 fats in our diet.
Give Me a 3!
Alpha-Linolenic Acid (ALA).
ALA is a short (18-carbon) n-3 found in flax, hemp, and other plant sources. It is sub-par for our goals of enhancing performance, health, and longevity. It is adequate to the needs of keeping vegetarian hippies alive (I guess that"s a good thing), but we are much more interested in EPA and DHA, found only from animal sources, such as wild fish and game, certain types of eggs (from chickens fed flax seed), and gra.s.s-fed meat. If you look at the attached diagram, you will notice that ALA can be converted to EPA and DHA, but it is a painfully inefficient process. Like I said, ALA will keep you alive-it will not allow you to thrive.
Eicosapentaenoic Acid (EPA).
EPA is a 20-carbon-long PUFA that is vital to life. Like I mentioned previously, it can be manufactured from the shorter-chain ALA, but it is a slow process and there are downsides a.s.sociated with ALA, which we will discuss in a moment. EPA is a potent anti-inflammatory, decreases platelet aggregation (thins the blood), and blocks angiogenesis (the growth of new blood vessels, one of the mechanisms necessary for cancer to spread). In non-geek speak EPA es muy bueno!
Docosahexaenoic Acid (DHA).
DHA is a 22-carbon PUFA that is critical for fetal brain development and normal cognitive functions throughout life. Mothers who have inadequate stores of DHA are at particularly high risk of deficiency during pregnancy and postpartum. For the child, this can mean stunted neurological development. For the mother, this can mean dramatically increased susceptibility to complications such as preeclampsia, gestational diabetes, and postpartum depression. Similar to EPA, DHA has potent ant.i.tumor and anti-inflammatory actions. Our bodies can interconvert EPA to DHA and vice versa, but we appear to run best when we have ample amounts of both essential fats.
OK, time to look at the omega-6 family of essential fats.
This is a paired-downed graphic representing conversion of short-chain n-3/n-6 fatty acids to longer chain n-3/n-6 fats. Our physiology is wired for a dynamic equilibreum built from n-3/n-6 ratios ranging from 1-1 to 1-2. The n-3/n-6 fats share the various enzymes listed above. An overabundance of one fatty acid family can dramatically impair the conversion of the alternate family. Our modern diet with its Omega 6 dominance impedes the production of the long-chain Omega 3 family and their anti-inflammatory by-products, including Prostaglandins. This is also why some otherwise favorable Paleo foods like nuts and seeds can be problematic, as they frequently have much greater Omega 6 content, which can push your dietary fatty acid ratios to a pro-inflammatory (n-6 heavy) state.
To avoid problems, mainly use nuts and seeds as you would a condiment.
"Red Leader... I"ve Got Your 6!"
Linoleic Acid.
Linoleic acid (LA) is an 18-carbon n-6 PUFA found in high concentration in vegetable oils such as safflower and sunflower. Both LA and its longer metabolites are potent mediators of systemic inflammation (i.e., they are pro-inflammatory). As we will see, this makes some otherwise "Paleo" foods such as certain nuts problematic because LA can block the anti-inflammatory effects of EPA and DHA. This is also why corn, sunflower, and soy oils are so bad for us, as they are loaded with LA. Let"s take a look at the metabolites of LA.
Gamma Linolenic Acid.
Gamma linolenic acid (GLA) is an 18-carbon n-6 PUFA with one more double bond than LA. Dietary sources of GLA include borage, primrose, and hemp oils. The body can convert LA into GLA, but this process can decrease in the case of hyperinsulinism and viral infection. As you will see, the n-6 family of PUFAs tend to be pro-inflammatory. However, GLA can act as an anti-inflammatory agent (as compared to LA) by blocking the production of various prostaglandins. Hang in there, just a few more!
Dih.o.m.o-Gamma-Linolenic Acid.
Dih.o.m.o gamma-linolenic acid (DGLA) is a 20-carbon n-6 PUFA. DGLA regulates the production of several important families of molecular messengers including series 1 thromboxanes and leukotrienes-molecules crucial in the regulation of immune function, inflammation, and pain. DGLA is produced from GLA and can be converted into arachidonic acid, the final n-6 PUFA we will consider.
Arachidonic Acid.
Arachidonic acid (AA) is a 20-carbon n-6 PUFA found predominately in animal products. It regulates a host of metabolic functions via actions on prostaglandins, thromboxanes, and leukotrienes. AA gets a bad rap because it is involved in metabolic pathways largely controlling inflammation. This is a mistake. AA is critical for normal actions such as adapting to exercise, muscle repair, and brain function. Think of AA like daytime television: vital to life, but also toxic in excessive amounts.
OK, So What?
I know this is a ton of information, but like I said previously, I need to cover all of this material for one main reason: I need to answer all the inaccuracies that form the basis of our governmental and academic nutritional recommendations. You are bombarded by government information pushing a grain-based, high-carb, low-fat diet. They are wrong and I need to detail why they are wrong; otherwise you are trading one false G.o.d for another.
In the prescriptive chapter, I will provide concrete guidelines for a.s.sessing just how well a Paleo diet works for restoring health and vigor. I will describe objective lab values that prove a Paleo diet is the best way you can fuel yourself. I wish we could just jump in and hit the "how to" material, but I need to answer questions about saturated fat, essential fats, and these myriad related topics so you can understand just how all this works.
When we consider fats and their potential impact on health and disease, our Paleo Solution can help us by providing guidelines that helps us make sense of dietary fat.
* No trans fats. Our ancestors never saw a trans fat.** The concept of trans fats is only about fifty years old and our metabolism has no idea what to do with them. Trans fats are created when polyunsaturated fats from corn, soybean, and similar oils are exposed to heat, hydrogen gas, and a catalyst. The resulting fat looks and acts similar to saturated fats (it does not go rancid quickly, so it is solid or semisolid at room temperature), but with some serious flaws: Trans fats ruin liver function. They wreak havoc on blood lipids. They destroy insulin sensitivity. Want to die young? Eat plenty of trans fats and high-fructose corn syrup (soda and chips anyone?) and your family can collect on your life insurance in short order.
Trans fats should become less of a problem over time, as they are being phased out of restaurants and prepared foods. The irony is trans fats were used as a replacement for supposedly harmful fats such as coconut and palm oil. The same governmental do-goodery that brought us the high-carb, low-fat diet, also brought us trans fats. Interestingly, both recommendations strongly support the subsidized agriculture scene in the United States. Although palm oil may be high in palmitic acid, and thus not the greatest option, it is far better than Franken-foods like hydrogenated vegetable oils and margarine.
So, trans fats should be: 0%. By the way, when the government comes to help you, run. They are either bringing a firing squad or dietary changes, but the end result is the same.
* Amount of Fat. Total fat intake appears to have little bearing on most health and disease. We see populations with as low as 10 percent fat intake and as high as 50 percent fat intake with similar CVD rates. We will tinker with your intake to see what works best for you.
* Types of fat. Type of fat appears to bear strongly on disease processes, but the key players have changed. Saturated fat has historically been implicated as a causative factor in everything from CVD to cancer. However, closer a.n.a.lysis has shown this a.s.sumption to be largely inaccurate. When we consider our ancestral diet, we see saturated fats tended to account for 1015 percent of total fat intake in most populations. Exceptions to this include populations near sources of coconut (lauric acid). In these populations, we may see intake of saturated fat as high as 40 percent of calories, but none of these hunter-gatherer populations show significant signs of CVD. One key feature of the hunter-gatherer diet is a low total palmitic acid content. So, although palmitic acid does appear to increase LDL cholesterol, other factors appear more important in CVD propagation. The n-3/n-6 fats appear to play the primary role in disease processes such as cancer, diabetes, autoimmunity, and neurodegeneration.
* Saturated fat. Our ancestral diet did have saturated fat, but as you will see, it was seldom a large percentage of calories. Additionally, the saturated fat in a Paleolithic diet tended to be cardio-neutral fats, such as stearic and lauric acids. Due to grain feeding of our meat, we consume far more palmitic acid, which can increase LDL cholesterol. Although this is not the only risk factor in CVD, it is something we can easily modify by emulating a Paleolithic diet using modern foods such as gra.s.s-fed meat and wild-caught fish.
* Omega-3 vs. Omega-6 essential fatty acids. N-3/n-6 fats are important in every aspect of inflammation. N-3/n-6 fats also control elements of cancer, Parkinson"s, Alzheimer"s, and fertility. Anything in which inflammation plays a role. And, that"s actually about everything. If you recall from the description of essential fats, n-3s are broadly categorized as anti-inflammatory, whereas n-6"s are generally pro-inflammatory (there are some exceptions to this, but it works for our purposes). The crux of the problem is this: Our ancestral diet provided about one omega-3 fat for every one or two omega-6 fats. Our genetics are therefore designed for about equal amounts of pro and anti-inflammatory signals from the fats in our diet. Our current diet has a ratio of about one omega-3 fat for every ten to twenty omega-6 fats. The signal to our body has been shifted ma.s.sively toward the pro-inflammatory side of the equation and, not surprisingly, we are not doing so well with the change.
How do we get things right again? Focus on gra.s.s-fed and wild-caught fish, avoid sources of n-6 fats especially some seed and grain oils, and supplement with some fish oil. We will talk about how much fish oil to take a little later.
Fat Wrap.
Hopefully you are getting a sense of why we are so concerned with n-3 and n-6 fatty acids. They are key players in controlling hormone-like substances with s.e.xy names like prostaglandins, thromboxanes, leukotrienes, endocannabinoids, cytokines, and eicosanoids. These substances are the focus of billions of dollars per year in pharmaceutical sales and research because they control cell-to-cell communication throughout the body related to inflammation. Drugs that act on metabolic pathways such as the c.o.x-1 and c.o.x-2 (cyclooxygenase one and two respectively) include Viox, Celebrex, and our old friend aspirin. The c.o.x pathways regulate much of what we perceive as pain and inflammation. It is impossible to overstate how powerful these substances are. They are all controlled by n-3/n-6 fats, insulin levels, and lifestyle issues, such as sleep and stress. What this means is we have significant control over these processes and can use our knowledge to forestall aging, cognitive decline, and a host of other degenerative disease.
Do You Need to Track What Types of Fats You Are Eating?
Not really. If you follow the simple meal plan we have in the book, you will be set. There is no need to micromanage this stuff if you follow the simple and delicious recipes and concepts of the Paleo Solution. As I"ve said before, you do not need to understand these concepts to do them, but you, your family, and your doctor will have questions, so you might as well have answers.
All that silly health stuff aside, if you balance your essential fats you will not only be healthy, you will lose fat, gain muscle (if you want to), have loads of energy, and generally feel good. Or in more compelling terms, your f.a.n.n.y will look great in a bikini. Or board shorts. However you roll!
Below is a list of n-3 super foods. If you want to really broaden your geek fat knowledge, check out Professor Cordain"s website: Wild Alaskan Salmon.
Sardines.
Anchovies.
Mackerel.
Herring.
Trout.
Gra.s.s-Fed Meat.
Omega-3 Enriched Eggs.
** You will notice that a nutritional breakdown of gra.s.s-fed meat shows a small amount of trans fats. Should you panic? Is there some kind of mistake? No, this is normal and, ironically, healthy. The trans fats produced in wild or gra.s.s-fed meat products is naturally occurring and actually healthy. They include fats such as conjugated linoleic acid (CLA), which has proven anticancer and antioxidant activities and improves muscle growth and leanness. The bottom line is that trans fats in gra.s.s-fed meat are not a problem.
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So Robb, this is the fat chapter, but you did not talk a lot about cholesterol. What"s up?
Well, I did mention how palmitic acid can increase LDL count, but the reality is dietary carbohydrates have a much more important influence on cholesterol and overall cardiovascular disease risk. Here are a few things to remember with regard to excessive dietary carbohydrate and consequent hyperinsulinism: * LDL cholesterol is converted to the small, dense atherogenic profile under the influence of excessive carbs.
* Total cholesterol is increased due to the up-regulation of HMG-COA reductase.
* Systemic inflammation is increased by up-regulation of pro-inflammatory prostaglandins, cytokines, and leukotrienes.
When considering cholesterol and CVD, the important points are: * Focus on the amounts and types of dietary carbohydrates, emphasizing vegetables, while saving fruits and tubers to support intense exercise.
* Create an n-3/n-6 profile of 1:1 to 1:2 by eating predominately gra.s.s-fed meats and wild-caught fish, while limiting n-6 intake.
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EIGHT.
Stress and Cortisol.
or Why This Book Should Be t.i.tled: Sleep Ya Big Dummy!
Introductions are always a b.u.g.g.e.r for me because I"m not a linear thinker. I see the world as layers of connections rather than some kind of university-style outline. This is great for making connections and innovation, but it"s a terrible way to introduce new material to most people. If everything is connected, how do you keep the moving parts separated such that one can make heads or tails of the material?
This chapter is a perfect ill.u.s.tration of this challenge, as we begin to look more and more at an integrated approach to our Paleo Solution. We must consider more endocrinology, specifically the adrenal hormone cortisol and its many actions on both wellness and disease. Then we will explore how our modern lives are growing more and more at odds with our ancestral lifeway, and what this means not only for cortisol, but also for (you guessed it) our performance, health, and longevity.
It is this point of divergence from our ancestral lifeway-the separation of how our genetics expect to meet the world vs. how they actually do meet the world-that is the issue. If you want to understand how and why our modern world is killing us softly, you need to understand where we came from. Then, if you want to, you can affect change that complements our genetics and ancestry.
Way Back.
It may test your credulity, but our ancestors had things both harder and easier than we do. Hard things included living without advances such as medicine, centralized government, or advanced communications. If you broke a leg, caught a nasty bug, or got mauled by a large, nasty critter-well, these types of things explain the average lifespan of about thirty to thirty-five years for our hunter-gatherer ancestors. As you will discover in the exercise chapter, our ancestors lived a rough and tumble existence that left their skeletons looking like equal parts Olympic athlete and rodeo clown!
Our forebears had to work quite hard for their food, clothing, and shelter, often at significant risk of bodily harm. Interestingly, however, they did not work as hard or as long as we do. It may come as a shock, but our ancestors only worked about 1015 hours per week. Pause for a moment and let that sink in. Perhaps they worked five hours one day, a few hours the next. Then they took an entire day off to just laze about. This may seem impossible, but it is a common feature of all hunter-gatherer societies studied, and this is why the HG lifeway is often referred to as the "original affluent lifestyle."
Their work varied with the seasons and locations in which they lived. It provided food, clothing, and shelter. A hunter-gatherer"s work also supplied the backbone of Paleo-insurance: a place in the extended family network of a hunter-gatherer tribe. The rest of the time was spent socializing, traveling to see relatives in neighboring groups, and oftentimes playing games of chance. Even cavemen liked to gamble!
Explorers and anthropologists who have studied and lived among various HG tribes describe the people as "very" content and happy. Early to bed, early to rise, and lots of adventure (a little danger can kill you, but oddly enough, it also lets you know you are alive). They had a strong social network, a sense of belonging, variety in their work and, really, not that much drudgery. Now I do not want to paint an overly beatific view of the HG life. They certainly faced a number of stressors: Sickness, injury, and perhaps attack by wild animal, a rival tribe, or even a relative (then, as now, the most likely person to kill you was someone you knew). Although these dangers might shatter the Walt Disney utopia I was painting, our ancestors lived what appears to be remarkably good lives considering the lack of things like medicine, insulated homes, and sitcoms.
The key difference between the stressors our ancestors faced and our modern stressors can be described thusly: frequency and duration. Paleo stress tended to be acute: short in duration and infrequent in occurrence. Modern stress, by contrast, tends to be constant and unrelenting.
In the book, Why Zebras Don"t Get Ulcers, Prof. Robert M. Sapolsky makes the point that wild animals do not show the stress-related illnesses we see in humans. Part of this is due to how the human condition has changed (Paleo vs. present life) and part of this is due to the nature of the human mind. Humans can fret about the future, and review unsettling memories of the past. Psychoneuroimmunology (how the mind influences the immune system and vice versa) has shown that our thoughts are our reality, for good or ill.
A theme Eastern religions share is a recommendation to "be in the now." Kids and other small scampering critters tend to be quite proficient at being present, and it"s little wonder that we a.s.sociate happiness with the simple lives of kids and critters. Modern life, for all its advances and amazing achievements, has opened its own Pandora"s box. Unlike the story of Pandora, however, in which a host of demons have been set loose upon humanity, I think the a.n.a.logy is that we have been thrown into the box and the stresses of modern life a.s.sail us from every angle.
I know, it"s kinda heavy stuff. Here"s the deal though: Until you can recognize the bars of your cage (or the walls of your box?), you do not stand a chance of getting out. In the words of Erwan Le Corre, founder of MovNat, you are a "Zoo Human." Ponder this image for a moment. It is both accurate and unpleasant. Hopefully the imagery motivates you to make some changes, or, again in Erwan"s words, "to find your true nature."
With that in mind, let"s look at modern life with the perspective that our genetics are wired for the acute stressors of the Paleolithic, and then let"s see if we can formulate a plan of escape. I saw a few vegans up the street, maybe we can push them down, take their hemp, and "braid an escape rope!"
Modern Life-Sleep Much?
What better way to chronicle the stressors of modern life than to look at how we greet most days: 1. With an alarm clock.
2. Without as much sleep as we would like to have.
I"ll talk about the physiology of sleep in a moment, but for now I think we can all agree that we feel dramatically better with sufficient sleep. Or, if you are like most people, you have no idea what "well rested" means. "Sleeping in" and being fully rested is our ancestral, genetic norm. Unfortunately, we rarely experience this after infancy. Well, not until we are p.o.o.ping our pants in a rest home.
What would your life be like if you could awaken every day without an alarm and after sleeping as much as you wanted? This is not a rhetorical question. Contemplate.