By Dr. Mercola

reprint from drmercola.com

Entire books are written about the subject of digestion. The current science of how your body breaks down and specifically utilizes nutrients is still in its infancy.

This article is meant as an overview, talking about the physical process at work in the act of digestion, and some possible causes of why your digestive system may become unbalanced, and what to do if it does become unbalanced.

Unless you are dependent on a tube for nutrition, the reason you have survived to this point in your life is because your body is able to extract what it needs from the food you eat by properly digesting it.

So the short definition of digestion — you put food or liquid into your mouth, swallow it, and then your body breaks these molecules down into a size it can absorb. What your body doesn’t use is excreted as waste.

Fairly basic, right?

Is Digestion Really That Simple?

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, duodenum) and the lower gastrointestinal track (small intestine, 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.

So what exactly makes up the digestive system and how does it work?

Everything Starts With What You Put in Your Mouth

Once you select something to eat, your mouth goes to work, using your tongue and teeth to turn large pieces into smaller pieces (mastication) and using enzymes from the salivary glands to begin chemically breaking down food molecules into a size 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! If you often find your stomach feels like a big knot after you’ve eaten, you’re probably swallowing your food whole.

There’s a reason baby food is mashed into mush. They have no teeth to break the food down themselves into smaller molecules.

And yes, 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 instantly 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 slower.

In my opinion, it’s also a good idea to swallow foods that are neither too hot nor too cold. Foods and liquids are best taken into your body at the temperature of your body, so it’s beneficial to let warm foods cool in your mouth and let cold foods warm in your mouth — as an aid to digestion.

The exception to this would be water — which is most highly structured and beneficial when cold — and seems to be far better at quenching your thirst when cold.

Also, the first major problem with digestion starts with what you choose to put in your mouth!

In our modern world, inexpensive processed foods, often loaded with sweeteners, artificial colors, artificial flavors, artificial preservatives, cheaply processed unhealthy fats and artificial colors are designed to be appealing to all of your senses, including your tastebuds.

And the advertising never betrays that this food can literally kill you!

Processed foods can lead to a whole host of health troubles, and many people today are getting a majority of their calories from these highly processed, low nutritional value foods.

If you are one of these people getting a majority of your calories from fast and processed foods you can face three major problems you may not be aware of:

• Processed foods may be broken down by your body into one or more toxic molecules (ie. Aspartame, Splenda).
• Processed foods may produce undesirable biological effects (ie. trans fats, high fructose corn syrup).
• Your body may treat processed foods as a foreign invader.

When your body consumes processed foods you may be triggering the release of powerful antibodies meant to fight off foreign invaders, which can actually cause collateral damage to your body’s cells. In fact, eating a diet rich in processed foods and junk foods can cause an ongoing mistaken internal attack on very necessary components of your digestive system.

Everyone is affected differently by this constant internal antibody attack, otherwise we’d all have autoimmune diseases. But it is known that macrophages, one of the more powerful tools your immune system uses to fight foreign invaders can also do indiscriminate damage to your body’s tissues.

What Goes on Inside Your Stomach

Back to the digestive process. Once food makes it past your mouth and is swallowed down past your esophagus, the acid wash inside the stomach begins, and not surprisingly, another host of problems can start to occur.

The environment inside your stomach is highly acidic (pH 4) and this acid acts as the next defense mechanism against harmful pathogens that might have slipped past your first line of defense. A protective mucous lining protects your stomach from all this acid.

When I talk about acids in your stomach I am referring to hydrochloric acid and pepsin. When you are young your body usually will produce enough acid to properly digest your food, but as you age, reduced stomach acid comes along with the territory. Many people begin experiencing stomach acid problems in their 30’s and 40’s when stomach acid starts to drop off from youthful levels.

Compromised stomach acidity is a common hindrance to optimum digestion, and can frequently be aided by supplementing with hydrochloric acid ( Betaine HCL) or digestive enzymes. But HCL or enzyme supplementation requires following some basic rules of chemistry.

Your entire digestive tract ranges from strongly acidic (pH4 in your stomach) to slightly acidic (5.7-6.7 pH in your small intestine, and pH7 in your colon). If HCL or enzymes are used as an aid to digestion, it is imperative to not add any unnecessary alkaline disturbances to the acidic environment.

This includes water and especially alkaline water.

So as you age, it is common to experience heartburn, indigestion and GERD-type diseases, and contrary to what you may think, these diseases are almost typically caused by a reduction in stomach acid, not the overproduction of stomach acid.

This is news to many, because the drug companies spend loads of marketing money to convince you that heartburn and acid reflux are caused by too much stomach acid.

Digestive aids, natural or man-made chemicals that affect digestion, generally fall into two categories:

• Help produce more stomach acid, more enzymes and more beneficial bacteria
• Help produce less stomach acid

Digestive aids like hydrochloric acid (HCL) , enzymes and probiotics can actually be powerful tools to maintain a more acidic and beneficial environment in your stomach and intestines that will help your digestive system work optimally.

Dangers of Anti-Ulcer Drugs

The other so-called digestive aids, including the class of drugs called proton pump inhibitors, and H2 blockers (Pepsid AC, Prilosec, Zantac, etc) will actually take you in the opposite direction of optimal health because they shut down acid production, making your problem worse.

So if drug industry into has fooled you thinking drugs like Pepcid AC and Zantac are addressing the problems in your stomach, or even if you’re taking the common calcium tablets to reduce stomach acid, you’re doing your body three huge disservices:

• You are reducing stomach acid even further, the opposite direction that your body actually needs to move.
• You are worsening your already malfunctioning digestive system.
• You are compromising your absorption of the vitamin B-12

Also, the FDA recommends taking these stomach acid reducing drugs for only THREE 14-day periods each year! Taking these drugs longer than that is dangerous, because long-term effects are not well understood and longer-term use is not recommended. So these acid reducing drugs aren’t even meant to be a real solution for your chronic poor digestion in the first place! 

On top of all this, short-term use of acid reducing drugs like Prilosec have a long list of possible side effects, including:

• Insufficient elimination of pathogenic organisms
• Decreased bone density
• Severe abdominal pain
• Rash
• Dizziness
• Depression
• Liver disease
• Chest pain
• Dark urine
• Sever Diarrhea
• Swelling of the hands, ankles, or feet
• Unusual bruising or bleeding
• Unusual tiredness; vision changes
• Yellowing of the eyes or skin

So clearly it’s in your best interest to address the cause of digestive imbalances by properly increasing the acid in your stomach, not decreasing it.

For more in-depth information, I highly recommend reading Dr. Jonathan Wright’s excellent book Your Stomach: What is Really Making You Miserable and What to Do About It.

Make Sure Your Vitamin B12 Levels are Good

B-12 is a vitamin that can only be digested by your body through high stomach acid content, because it takes a lot of acid to break down this essential B vitamin. If you are shutting down your stomach acid production, your body is not going to get the B-12 it needs from the food you eat.

And oral B-12 supplementation will not address this issue as they will not break down in your stomach if acid production is low.

In fact, if you are one of the people taking these proton pump inhibitors or H2 blockers, the primary way your body can effectively absorb the B-12 that it needs is through inter-muscular injections.

So why is getting B-12 so important?

Here are some common symptoms of B-12 deficiency:

Neurological Symptoms

• Mental confusion
• Delusions
• Paranoia
• Headaches
• Depression
• Impulse Control
• Pins and needles in the extremities

• Balance issues

Gastrointestinal Symptoms

• Nausea
• Vomiting
• Heartburn
• Bloating
• Loss of Appetite
• Weight Loss
• Diarrhea

• Constipation

Other Symptoms

• Fatigue
• Paleness
• Shortness of breath that results from only very light exertion
• White spots on the skin (typically the forearm) due to decreased melatonin

Clearly, keeping your body’s natural B-12 absorption mechanism functioning well is vitally critical for optimal health. Without proper B-12 absorption, a whole host of seemingly inexplicable health problems can result, which a conventionally trained doctor will have trouble linking to low levels of B-12.

The Importance of Good Bacteria

Now, moving a little bit further down your digestive tract to the small intestine, there are about 100 trillion microorganisms living in your gut. That’s 10 times more than the total number of cells in your body (about 10 trillion). These tiny creatures make up between 3-5 pounds of your body weight!

Your body receives help breaking down foods into their component parts from the organisms that live in your gut (intestinal flora). These bacteria, yeasts and fungi can produce beneficial waste products as they feast on your digesting food, such as B and K vitamins that your body needs. They also function to break down some foods that your body cannot absorb by itself (they change carbs into simple sugars and proteins into the component amino acids).

But when you eat too many grains, sugars and processed foods, these foods serve as fertilizer for the bad bacteria and yeast and will cause them to rapidly multiply.

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 fact, millions of people currently suffer from yeast overgrowth and a host of maladies related to the rapid spread of the bad bacteria in your intestines. And most conventional doctors will not be able to identify the cause of your symptoms if you suffer from bad bacteria or yeast overgrowth.

Estimates are that as many as 80 million people, mostly women, are currently suffering from harmful yeast overgrowth.

Symptoms of this yeast overgrowth include:

• Irritable bowel syndrome
• Migranes
• PMS
• Cancer
• Vaginitis
• Asthma
• Fibromyalgia
• Weight gain
• Food allergies
• Chronic fatigue
• Yeast infections
• Depression

As you can see the list is long and varied, and the symptoms mimic those caused by many other diseases. If you think you may be suffering from yeast overgrowth, see my free report here.

So the key to good intestinal health, especially in your small intestine, is keeping an optimum balance of the helpful and harmful microorganisms. This is why probiotics (for life) supplements are so important, because they increase the ratio of “good” bacteria in your gut, and why antibiotics (against life) can interfere with the delicate balance in your gut.

In fact, contrary to what you might have heard about probiotics not surviving in the highly acidic wash of your stomach, the helpful bacteria like acidophilus thrive in an acidic environment and not only survive the stomach environment, but acidophilus will actually also create lactic acid to maintain a more acidic condition in your small intestine.

Some examples of health problems that you may face if your gut microorganisms stay out of balance for long periods of time include:

• bad breath
• foul gas
• toxemia
• Candida yeast overrun
• chronic fatigue
• brain fogginess
• lowered immunity
• impaired digestion and absorption

This is why it pays dividends to eat some fermented foods like:

• Sauerkraut
• Kimchi
• Black garlic
• Miso
• Natto
• Kefir
• Lassi
• Tempeh

If you are unable to find quality fermented foods, then supplementing with a high quality probiotic product will also serve the function of multiplying the “good” bacteria found in your digestive tract.

When searching for probiotic supplements, be sure to buy the highest quality you can find, because when it comes to feeding your beneficial bacteria, not all products are created equally.

The Truth about Soy

Another food I want to talk about in relation to good digestion is soy. More specifically, I advise you to avoid all unfermented soy products.

Soy is widely touted today as a health food, mostly through slick food company advertising and marketing. The soy industry’s propaganda likes to point to the high levels of health in Japan, where soy is claimed to be a main component of the diet. But the truth is a little more complicated.

The types of soy popular in Japan are mostly variations of fermented soy, including tempeh, soy sauce, miso and natto are better but still have isoflavones which can act as powerful goitrogenic or thyroid harming influences. So if you have issues with your thyroid you should not consume large quantities of these.

Non-fermented soy products, including tofu, soy milk, soy oil, soy protein powder and soybeans present a more complicated picture, and in my opinion non-fermented soy is definitely not a health food and should be avoided.

Unfermented soy contains natural toxins known as “anti-nutrients”. Soy also contains other anti-nutritional factors such as saponins, soyatoxin, protease inhibitors, and oxalates.

Some of these factors interfere with the enzymes you need to digest protein.

While a small amount of anti-nutrients would not likely cause a problem, the amount of soy that many Americans are now eating is extremely high.

Soy is also one of the most widespread GMO foods in America, with over 91 percent of all soy grown with GMO seeds. I consider eating GMO soy to be like taking part in a giant laboratory experiment, and I recommend you avoid unfermented soy for the anti-nutrient reasons and the GMO reasons if you want to be optimally healthy.

Chewing Gum Fools Your Digestive System

Your body was designed to activate your digestive process through chewing. This is a good thing as your body needs the enzymes and acid to digest your food. However chewing without eating food can be counterproductive.

When you chew gum, you send your body physical signals that food is about to enter your body. The enzymes and acids that are activated when you chew gum can cause bloating and overproduction of stomach acid. Besides this, chewing gum can cause jaw muscle imbalance (if you chew on one side more than the other) and even TMJ in your jaw, which can be a painful chronic condition.

The bottom line is you shouldn’t chew gum or if you do use gum, use if very rarely or right before a meal where the acid and enzyme stimulation may actually be beneficial …

Gallbladder Problems

Your gallbladder stores bile produced by your liver, and releases it into the digestive tract as needed. Sometimes, the gallbladder becomes diseased and must be removed.

Rather than lose the mechanism that regulates bile secretion into your digestive tract, it is far better to address a malfunctioning gallbladder by looking at dietary imbalances. Addressing digestive issues at the source of the problem, the food you eat, is always a more direct way to intervene in disruptions in your body’s digestive mechanisms.

However, if the condition is advanced, gallbladder removal occasionally becomes necessary. When this happens, or if you have previously had your gallbladder removed, you can expect fats in particular, may have trouble breaking down in your digestive tract, and diarrhea may also become a problem. With the mechanism for bile regulation removed, your GI tract may receive either too much bile, or too little. So, adjust your diet before it’s necessary to remove your body’s bile regulator.

But if you do lose your gallbladder, you can combat poor digestion with HCL and enzyme.

The best enzyme to supplement would be an enzyme that breaks down fat or a lipase. This is because you will not be producing much bile, which typically aids in fat digestion.

One key thing to keep in mind with gallbladder problems, and even after gallbladder removal, is that your body still needs to take in “good” fats. So getting a good source of omega three fat (like krill oil) is still essential to good health, even though your body may have some trouble processing all fats if you have gallbladder problems.

Some Final Thoughts

Hopefully this trip through your digestive system has helped you to a better understanding of why it is vitally important to provide your body with the good fuel and good digestive aids it needs, and why providing too much of the wrong kinds of foods or the wrong kinds of digestive aids can lead to problems.

You should also understand why a diet too rich in simple sugars can lead to a whole host of negative consequences from unhealthy yeast overgrowth (which can lead to leaky gut syndrome, irritable bowel syndrome, poor absorption of nutrients, excess gas, weight gain and craving carbs).

Also, a diet rich in food-like substances containing man-made chemicals may also be the cause of other digestive maladies, such as:

• acid reflux
• indigestion
• heartburn
• abdominal pain
• vomiting
• diarrhea

Remember, your digestive system is an extremely complex dynamic system that protects you through a strong defense mechanism against harmful invaders from the external environment.

Some proactive steps you can take to aid in your digestion and help the beneficial microorganisms to flourish and keep digestive disorders away include:

• consume foods as close to their natural state as possible
• consume raw foods regularly
• consume fermented foods
• consume a balance of different types of foods
• avoid man-made chemicals
• avoid pharmaceutical drugs
• avoid a diet rich in simple sugars
• avoid GMO foods

Every day you are presented with a vast array of food choices, and our modern world has found some truly innovative ways to present food to you that appeals to all your senses (smells great, looks great, tastes great). However, relying on your senses alone to choose the nutrients your body needs can lead you down a slow path of self-destruction, chronic diseases and shortened lifespan for not just yourself but for future generations as well.

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.