Countless books have been written about digestion, yet the science—and therefore our understanding—of how your body breaks down and utilizes nutrients is still in its infancy. This section is a mere overview of what we know to be accurate at the time of this writing: the physical processes at work in the act of digestion, some possible causes of imbalance in your digestive system, and what to do if it does become unbalanced.
What is digestion exactly? The short answer is that it is the act of breaking down the food or liquid you consume into constituents of a size that your body can use as fuel or a structural component for your body.
Fairly basic, right? And yet, digestion is actually a complex combination of biological interactions and chemical reactions taking place at every stop along the extensive digestive tract, which is generally split into two halves—the upper gastrointestinal tract (mouth, esophagus, stomach, and duodenum) and the lower gastrointestinal tract (small intestine and large intestine).
Your gastrointestinal tract is also home to the largest part of your body’s immune system, protecting you against foreign invaders by producing acids and housing colonies of beneficial bacteria that act as a defensive army fighting to protect you from pathogens that find their way inside your body.
Once you select something to eat, your mouth goes to work, using your tongue and teeth to turn large pieces of food into smaller pieces (mastication) and using enzymes from your salivary glands to begin chemically breaking down food into molecules that your body can absorb.
This is why nutrition experts are always advising you to eat slowly and chew your food thoroughly (at least 20 chews per bite): because your digestion actually begins in your mouth! Taking your time when eating and chewing your food properly has a number of beneficial side effects. For example, chewing your food twice as long as you normally would will help you control your portion sizes, which naturally decreases calorie consumption.
Another benefit of chewing longer is that your food is digested better. The majority of your digestive enzymes are actually in your mouth, not in your stomach. Therefore, chewing your food longer allows the food to be broken down better. You’re also likely to find that you actually enjoy the taste of the food more if you eat more slowly. Additionally, chewing your food helps stimulate the production of enzymes to help digest it.
Also, the first major problem with digestion starts with what you choose to put in your mouth! Clearly, though, because you have picked up this book, you are dedicated to choosing healthy, natural, whole foods rather than the plethora of processed so-called foods available on the market today. You’re doing yourself and your health a powerful favor by doing so.
WHAT GOES ON WHEN FOOD REACHES YOUR STOMACH
Moving down your digestive tract, once food is swallowed, it travels down your esophagus and enters your stomach. The environment inside your stomach is highly acidic (pH 4), and this acid—composed of hydrochloric acid and pepsin—acts as a defense mechanism against harmful pathogens that might have slipped in with your food. A protective mucous lining protects your stomach tissues from all this acid.
When you are young, your body usually will produce sufficient acid to properly digest your food, but as you age, reduced stomach acid comes along with the territory. This explains why, as you get older, it is common to experience heartburn, indigestion, and conditions associated with gastroesophageal reflux disease (GERD). Contrary to what you may think, unpleasant symptoms associated with acid reflux and heartburn are typically caused by a reduction in stomach acid, not the overproduction of it. This is news to many, because the drug companies spend loads of marketing money to convince you that too much stomach acid is the problem and their drugs are the simple solution.
Digestive aids like hydrochloric acid (HCL), enzymes, and probiotics can actually be highly effective tools to maintain a more acidic and beneficial environment in your stomach and intestines, helping your digestive system work optimally.
Moving further along, after leaving the stomach your food enters the small intestine. Recent estimates suggest that there are about 30 trillion microorganisms living in your gut.1 These tiny creatures make up three to five pounds of your body weight!
These microorganisms—bacteria, yeasts, and fungi—help your body break down foods into their component parts. They can produce beneficial waste products as they feast on your digesting food, such as B and K vitamins. They are also able to break down some foods that your body cannot absorb by itself. For example, they change carbs into simple sugars and proteins into their component amino acids.
But not all intestinal organisms are helpful. This is yet another way that the food you eat impacts your health. Some foods, like the indigestible fiber in vegetables, are metabolized to short-chain fatty acids in your gut, which nurture good bacteria and starve the bad. But some foods, like processed foods and sugar, have the opposite effect.
One of the best things you can do for your health, including your digestive health, is eliminate sugars and processed foods as much as possible! In doing so, you can avoid being one of the millions of people who currently suffer from disease-causing organisms like yeast overgrowth.
Estimates are that as many as 80 million people, mostly women, are currently suffering from harmful yeast overgrowth. Symptoms include:
The key to good intestinal health, especially in your small intestine, is maintaining the ideal balance of helpful and harmful microorganisms. (You may be wondering, why would anyone want any harmful microbes? The fact is, they are part of life and impossible to completely eradicate. So long as you have plenty of friendly bacteria to keep them in check, they aren’t likely to negatively impact your health.) The approach to eating that I outline in my book Fat for Fuel, and that the recipes in this book follow, is a powerful way to do just that.
Other symptoms you may face if your gut microorganisms are out of balance for long periods of time include:
Nowadays, it truly does take an act of will to train your body to recognize whole natural foods as delicious and nutritious, when the alternative is food-like substances that have been processed, designed, crafted, and marketed to appeal to all of your senses and to your intellect.
If you love the convenience and taste of packaged foods, don’t despair. Once you start cooking and enjoying the recipes included in this book that are based on the whole-foods, low-carb, high-fat approach, you’ll quickly see that eating healthy isn’t an act of deprivation. Quite the opposite—as the body starts burning fat as its primary fuel, most people notice that their cravings actually disappear.
Additionally, real foods are so delicious and energizing (and the high-quality fats so satiating) that you will soon stop thinking about the processed stuff. Your taste buds as well as your beneficial bacteria will thank you.
WHEN DIGESTION STARTS EATING YOU UP: LEAKY GUT SYNDROME
The lining of your gut is very thin, only one cell thick, and it is quite easy and very common for disruptions in the cellular connections to occur. When there’s a disruption in the interconnections between the cells in your intestines, this allows undigested food particles to enter your bloodstream. This is known as leaky gut syndrome, a serious problem that can contribute to an autoimmune response.
If your gut lining is leaky or permeable, partially undigested food, toxins, viruses, yeast, and bacteria have the opportunity to pass through your intestine and access your bloodstream. When your intestinal lining is repeatedly damaged due to reoccurring leaky gut, cells called microvilli become damaged and unable to process and utilize the nutrients and enzymes that are vital to proper digestion.
Eventually, digestion is impaired and absorption of nutrients is negatively affected. As more exposure occurs, your body initiates an attack on these foreign invaders leaking from the gut. It responds with inflammation, allergic reactions, and other symptoms we associate with a variety of diseases.
Leaky gut is the root of many allergies and autoimmune disorders. Combine it with toxic overload and you have a perfect storm that can lead to neurological disorders like autism, ADHD, and learning disabilities.
NOURISH YOUR INTESTINAL FLORA TO RESTORE GUT HEALTH
Keeping your population of favorable intestinal bacteria healthy is the key to optimizing your digestive well-being, but the benefits don’t end there. These organisms perform a wide variety of vital functions, and we’ve now come to realize that they need to be properly balanced and nourished if we want to maintain multiple facets of physical as well as mental health.
Researchers are now realizing that your microbiome may be among the most important factors in preventing as many as 90 percent of diseases. We used to think that DNA was the most important factor in disease development, but now we know that while genes do play a role, the actual expression of their code is in large part regulated by which microbes are present! Emerging science also shows that your microbiome can be rapidly altered, for better or worse, by factors such as diet, lifestyle, and chemical exposures.
This is a double-edged sword, no doubt. On the one hand, many of our modern conveniences (such as processed foods, antibiotics, chlorinated water, and pesticides) turn out to be extremely detrimental to our gut flora. On the other hand, your diet is one of the easiest, fastest, and most effective ways to improve and optimize your microbiome. So the good news is that you have a great degree of control over your health destiny.
Bacteria appear to influence human health in two important ways. While an overabundance of pathogenic (disease-causing) bacteria has been linked to various diseases, other microbes appear to be actively involved in preventing certain disease states. When they’re lacking, you end up losing this protection, which allows the disease process to set in.
Studies have linked certain bacteria to several diseases, including obesity.2 This in no way changes the fact that certain foods will make you pack on the pounds; it just means that the bacteria these foods nourish likely play a major role in facilitating that process. The foods known to produce metabolic dysfunction and insulin resistance (such as processed foods, fructose/sugar, and artificial sweeteners) also severely impair your beneficial gut bacteria, and this may well be a key mechanism by which these foods promote obesity.
Chemicals may also contribute to a weight problem by way of the gut microbiome. For example, a study published in Environmental Health Perspectives found that persistent organic pollutants (POPs) found in food altered the gut microbiome in mice, thereby contributing to the development of obesity and metabolic dysfunction.3 Conversely, another study found that one microbe called Akkermansia muciniphila helps ward off obesity, diabetes, and heart disease by lowering blood sugar, improving insulin resistance, and promoting a healthier distribution of body fat.4 However, it’s still not known whether A. muciniphila produces these effects all on its own, or whether it helps promote other beneficial bacteria.
Research has also shown that gut microbes specializing in fermenting soluble fiber play an important role in preventing inflammatory disorders, as they help calibrate your immune system.5 The inflammatory response actually starts in your gut and then travels to your brain, which subsequently sends signals to the rest of your body in a complex feedback loop. So in order to address chronic inflammation and inflammatory diseases, it’s important to nourish your gut flora.
Researchers have also linked diets high in processed sugar to memory and learning impairments, courtesy of altered gut bacteria.6 Impairments in your microbiome not only promote neurological diseases but can also have a powerful impact on your general mood. Depression is increasingly being viewed as a symptom of poor gut health, and therein may lie the real cure as well.
For example, in one recent study researchers found that fermented foods and drinks helped curb social anxiety disorder in young adults.7 Previous trials have also demonstrated that probiotics can help ease both anxiety and depression. For example, one study found that in certain brain regions, the probiotic Lactobacillus rhamnosus had a marked effect on levels of GABA, an inhibitory neurotransmitter that is significantly involved in regulating many physiological and psychological processes.8 It also lowered the stress-induced hormone corticosterone, resulting in reduced anxiety- and depression-related behavior.
In another study, people who took a multi-strain probiotic for at least four weeks reported a lessening of rumination—recurring, persistent thoughts about something distressing that has happened or may happen, which tends to create anxiety.9
Because the news is out about the beneficial impact of probiotics, there are many food products on the market that claim to be good sources of beneficial bacteria. One of the most popular is yogurt. But most commercially available yogurts are nothing more than creamy junk food.
Commercial yogurts often contain upwards of 25 to 30 grams of sugar per serving, which meets or exceeds the recommended amount of sugar for the whole day! The amount of probiotics you’ll get from commercial yogurt is also far lower than what you’d get from a high-quality probiotic supplement. A commercial yogurt might give you a million probiotic cells, which sounds like a lot, but if you take a quality supplement you’re getting tens of billions of probiotics—four orders of magnitude greater amounts. So in that respect, a supplement is clearly easier and more cost-effective. Another option is to make yogurt at home.
To find out how your favorite brand of yogurt rates, use the Cornucopia Institute’s Yogurt Buyer’s Guide and Scorecard, which is available at http://cornucopia.org/yogurt-scorecard/.
OPTIMIZING YOUR MICROBIOME IS A POTENT DISEASE-PREVENTION STRATEGY
You will be pleased to know that supporting your microbiome isn’t very complicated. However, you do need to take proactive steps to implement certain key strategies while actively avoiding other factors. To optimize your microbiome both inside and out, consider the following recommendations:
THE ROLE OF PROBIOTIC SUPPLEMENTS IN GUT HEALTH
One of the best and least expensive ways to optimize your gut microbiome is to change your diet by eliminating sugars and processed foods and eating real food, preferably organic, including plenty of fiber and traditionally fermented foods. But probiotics can also be beneficial.
Probiotics are supplements designed to increase the population of beneficial bacteria in your gut. You might imagine that you need to take the supplements for only a little while and then the bacteria grow, reproduce, and live happily after. But that’s actually not the case. Your intestinal tract is a challenging environment with lots of competition. Probiotics have developed the ability to withstand a lot of difficult conditions, including stomach acid and bile, but they don’t live and thrive forever.
Rather, when you stop taking probiotics, your populations of friendly bacteria will gradually decline. So it’s really important to continue consuming probiotics. If you can’t commit to eating fermented foods—particularly vegetables—regularly, probiotic supplements are a good alternative.
Not all probiotic supplements are created equal, however. You’ll need to choose your supplement well. Factors to consider include the following:
I hope you’re coming to see that nurturing your digestion through dietary choices has powerful and wide-ranging effects on numerous aspects of your health. Eating clean and natural foods, nourishing your gut, and having a healthy intestinal community are really at the core of wellness.