Posts

Embracing Motherhood The Mysteries of Digestion Unraveled

The Mysteries of Digestion Unraveled

Before I delve into articles about what we should eat and why, I wanted to first take a look at one of the most basic functions of human physiology: digestion. After this, I will explore cellular respiration, which is how we metabolize food to make energy. In doing so, I hope to have a strong foundation of understanding to build future health articles upon.

So often, we hear about foods and ways of eating that are “healthy”, and as a whole, we have held many erroneous beliefs about what should constitute “healthy”. (Although this is changing…just look at the February 2016 issue of Time’s article, “The New Rules of the Heart” which talks about how cholesterol is actually good, why we should avoid statins, how saturated fat is actually good, how weight loss isn’t about calories in/calories out, and how we shouldn’t be taking an Asprin a day!)

The science behind what makes food “healthy” or not is simplified too much and the truth is hidden behind too many corporate slogans rather than actual science. Once we can understand the building blocks of food, how we digest them into individual molecules, and how we metabolize those molecules to make energy, the term “healthy eating” shouldn’t be so debatable or vague.

I have been reading about this information for years in an attempt to search for and serve my family the healthiest foods possible. Reading Sally Fallon’s book Nourishing Traditions was the first thing that changed my view about food and made me realize how misguided we have been about fat and the food pyramid. (Check out the Weston A. Price website to learn more!)

In writing this article, I started with Sally Fallon’s ideas as a framework in my brain, then used a college textbook called Understanding Nutrition by Whitney and Rolfes to really delve into the scientific explanations of carbohydrates, fats, and proteins and how we digest them (throughout this article, my descriptions come from this textbook unless otherwise linked). But even this seemingly benign textbook was not written without bias and made many leaps about what we “should eat” based solely on government recommendations rather than actual science.

So after reading this textbook and using it to explain the facts, I continued to ask my own questions, do my own research, and am now presenting an in depth synthesis of what I’ve learned about the foods we eat and how they are broken down during digestion.

In a Nutshell

When we eat any food, from cookies and cakes to burgers and fries to salad and dressing, it is all broken down into single molecules before being absorbed through the small intestine and sent into the bloodstream to be used as energy, for building, or stored for later use. All food can be categorized as and broken down into:

  • Carbohydrates –> Monosachharides
  • Fat (Triglycerides) –> Monoglycerides and Free Fatty Acids
  • Protein –> Amino Acids
Carbohydrates, Fats, Proteins, and the Smallest Molecules They are Broken Down Into

Carbohydrates, Fats, Proteins, and the Smallest Molecules They are Broken Down Into

*It takes about 6-8 hours for food to pass through the stomach and small intestine. In a study with 21 participants, it took  men an average of 33 hours for the food to be eliminated from the large intestine. It took an average of 33 hours for children too, but an average of 47 hours for women. Interesting!

Digestive System

Here is a picture of the entire digestive system just to give you a visual reference for where we are going. In my drawings, you’ll notice that I have included only what is necessary and exaggerated certain things for the purposes of clarity.

digestive system

Digestive System (Photo Credit: Wikimedia Commons, LadyofHats, 2006)

Carbohydrates

Carbohydrates are primarily an energy source for plants, some animals, and humans.

From Polysaccharides to Monosaccharides

From Polysaccharides to Monosaccharides

Foods with Carbohyrdates

There is a misconception (probably due to that silly food pyramid!) that carbohydrates only refer to things like breads and pastas and not things like fruits and vegetables. But the truth is that lettuce is a carbohydrate, apples are carbohydrates, grain is a carbohydrate, and sugar beets are carbohydrates.

When you look at the nutritional profile of these carbohydrates, however, you’ll notice that the amount of carbohydrates differs greatly among different food sources. Also, keep in mind that carbohydrates (which all come from plants) can be an excellent source of vitamins and minerals if grown properly and not overly processed.

The total carbohydrates measured on nutrition labels include both simple sugars (monosaccharides and disaccharides) and soluble and insoluble fiber (polysaccharides).

Types of Carbohydrates 

types of carbohydrates

Types of Carbohydrates (The numbers refer to the number of molecules.)

  • Monosaccharides: Monosaccharides are one molecule of sugar. Some foods contain monosaccharides and others are created when disaccharides are broken down during digestion. They are small enough to pass through the walls of the small intestine.
    • Glucose: The primary product of photosynthesis, found in all fruits and plants, most carbohydrates that we eat are converted to glucose during digestion
    • Fructose: Found in fruits, some root vegetables, cane sugar, and honey
    • Galactose: Combines with glucose to make lactose (milk sugar), not found on its own
  • Disaccharides: Disaccharides are two molecules of sugar. Some foods contain disaccharides and others are created when polysaccharides are broken down during digestion.
    • Sucrose: Made up of one molecule of fructose and one molecule of glucose, found in the stems of sugar cane and roots of the sugar beet, occurs naturally in some fruits and vegetables alongside glucose and fructose (especially in certain fruits and carrots), table sugar
    • Maltose: Made up of two molecules of glucose, formed during the germination of certain grains, mostly barley which is converted into malt, found in beer
    • Lactose: Made up of one molecule of glucose and one molecule of galactose, a naturally occurring sugar found in milk
  • Oligosaccharides: 3-10 monosaccharides connected together.  They are not digested or absorbed in the small intestine (so they give us no calories yet give us that full feeling). Instead, they pass directly to the large intestine where they are consumed by microflora thus increasing the amount of healthy bacteria. Examples include: artichoke, burdock, chicory, leeks, onions, and asparagus.
  • Polysaccharides: Polysaccharides consist of many monosaccharides connected together.
    • StarchStarches consist of tens to hundreds to thousands of monosaccharides connected together. They are how plants store glucose for future use. About 70% of a plant’s structure is typically made up of the starch amylopectin (which is highly branched making it easy for the plant, and for humans to hydrolyze, or break down in the presence of water) and the other 30% is typically made up of the starch amylose (which has a more linear structure that makes it easy to store, but can’t be broken down without the enzyme amylase).
    • Resistant Starch: Resistant starches cannot be broken down during digestion, and so they are sent to the large intestine where they feed the healthy bacteria residing there. Examples include: green bananas, rolled oats, green peas, white beans, lentils, pearl barley, cold potato and cold pasta (occurs due to retrogradation).
    • Fermentable FiberWe can’t digest the cell walls of plants, but some of them can be fermented in our large intestine like fructans (that occur in agave, artichokes, asparagus, leeks, garlic, onions, and wheat), inulin (occurs mainly in chicory), pectins (occurs mainly in the skins of citrus fruits and in apples, oranges, plum, guavas, and gooseberries), and raffinose (found in beans, cabbage, brussel sprouts, broccoli, asparagus, and whole grains). This fiber is soluble, meaning that it can mix with water, which creates a viscous gel that slows down digestion as it passes to the large intestine to be fermented by the microflora that resides there.
    • Nonfermentable Fiber: Humans do not possess the enzymes to digest some components of cell walls like cellulosehemicellulose, and lignin (which provide plants with the stiffness they need to stand upright), nor do we possess the bacteria to break them down either. (Ruminants and termintes possess symbiotic bacteria that help them to break these elements down.) These types of polysaccharides will pass through us unused. They are what is referred to as insoluble fiber (not soluble in water and NOT digestible or fermentable) and what gives bulk to our stool. Examples include pretty much any part of the plant that is hard to chew such as cucumber skins, the outer hull of grains, the hull of popcorn kernels, potato skins, grape skins, 80% of lettuce, and more.

How we Digest Carbohydrates

The digestion of carbohydrates occurs mostly in the small intestine.

carbohydrate digestion

How We Digest Carbohydrates

  1. In the mouth: The breakdown of carbohydrates begins in the mouth with the salivary enzyme amylase. Amylase works to break up the starch amylose, and hydrolysis begins breaking down the starch amylopectin. Very little digestion actually takes place here, however.
  2. In the stomach: Carbohydrates are churned into a paste in the stomach, but no chemical breakdown occurs during this process. The stomach actually neutralizes any amylase that was swallowed.
  3. In the duodonom: When carbohydrates enter the duodonem (which is the beginning part of the small intestine) the pancreas releases the enzyme amylase which breaks down polysaccharides into shorter glucose chains and maltose. (Babies produce very little amylase until over the age of one, although human breast milk contains a significant amount.)
  4. Throughout the small intestine: The brush boarder that lines the small intestine performs the final breakdown of carbohydrates by releasing the enzymes sucrase, maltase, and lactase that break down the disaccharides sucrose, maltose, and lactose into the monosaccharides glucose, fructose, and galactose.
  5. Absorption: The monosaccharides of glucose, fructose, and galactose are now small enough to pass through the walls of the small intestine and enter the bloodstream. Glucose and galactose need to hitch a ride on a sodium-dependent hexose transporter which will only transport them with a sodium ion. Fructose hitches a ride on another hexose transporter and doesn’t need sodium. As the blood circulates the liver, cells there take up fructose and galactose and covert them to other compounds, mainly glucose. This is why we say that most carbohydrates are converted to glucose in the blood!
  6. In the large intestine: Within one to four hours after a meal, all of the sugars and most of the starches have been digested. What passes into the large intestine are things that could not be digested or absorbed. This includes resistant starch (such as asparagus), fermentable fiber (such as the peel of an apple), and nonfermentable fiber (which includes cellulose, one of the components of cell walls). Resistant starches and fermentable fibers are water soluble and attract water which softens the stool. They are also able to be fermented by the good bacteria that (hopefully) resides in the large intestine releasing water, gas, and short chain fatty acids.
  7. Elimination: The nonfermentable fiber merely “bulks up the stool” and passes through unchanged. (Ever notice whole kernels of corn or popcorn hulls in your poop?)

Fats

Fats are the most efficient source of long term energy storage in both animals and humans.

From Triglycerides to Monoglycerides and Free Fatty Acids

From Triglycerides to Monoglycerides and Free Fatty Acids

Types of Fatty Acids

(*The following description of fats is adapted from Sally Fallon’s book Nourishing Traditions.)

Fatty acids can be categorized by how saturated they are:

  • Saturated: All available carbon bonds are occupied by a hydrogen atom
  • Monounsaturated: Has one double bond in the form of two carbon atoms double-bonded to each other and therefore lacking two hydrogen atoms
  • Polyunsaturated: Has two or more pairs of double bonds and therefore lack four or more hydrogen atoms

In addition, they are also categorized by how long they are:

  • Short-Chain Fatty Acids: Has four to six carbon atoms (always saturated, found mostly in butterfat from cows and goats)
  • Medium-Chain Fatty Acids: Has eight to twelve carbon atoms (found mostly in butterfat and tropical oils)
  • Long-Chain Fatty Acids: Has fourteen to eighteen carbon atoms
  • Very-Long-Chain Fatty Acids: Has twenty to twenty-four carbon atoms (DHA)

How We Digest Fats

In children and adults, fat digestion occurs mostly in the small intestine (although in infants, it occurs mostly in the mouth). Most of the fat in our bodies and the fat we eat is in the form of triglycerides (three fatty acid chains attached to a glycerol molecule).

fat digestion

How We Digest Fats

  1. In the mouth: Fat digestion starts slowly in the mouth. Some hard fats begin to melt as they reach body temperature. A salivary gland at the base of the tongue releases an enzyme (lingual lipase) that plays a minor role in fat digestion in adults and an active one in infants. In infants, this enzyme efficiently digests the short and medium chain fatty acids found in milk.
  2. In the stomach: Once fats hit the stomach, they would float if it were not for the muscle contractions that direct all contents towards the pyloric sphincter at the bottom of the stomach. This churning action emulsifies the fat by dispersing it into large droplets. The gastric lipase enzyme in the stomach (that performs best in an acidic environment) starts to work on breaking these droplets down. But very little fat digestion takes place in the stomach.
  3. Bile in the small intestine: When the large fat droplets enter the duodonem (the beginning part of the small intestine), they are coated with bile. (Bile is made in the liver and stored in the gallbladder. When fat enters the small intestine, it triggers the release of the hormone cholecystokinin which signals the gallbladder to release its bile.) The bile emulsifies the large fat droplets into smaller droplets. This increases their overall surface area making it easier for the next step. (Bile acids in the bile often pair up with amino acids which have one end attracted to water and one to fat. This helps with the emulsification process.)
  4. Lipases in the small intestine: The pancreas secretes a lipase enzyme that hydrolyzes (breaks down in the presence of water) the triglycerides into monoglycerides and free fatty acids. *Infants do not secrete much of this enzyme; this is why the lingual lipase excreted from under their tongues plays more of an active role.
  5. Absorption: Monoglycerides and free fatty acids are now small enough to pass through the intestinal wall.
  6. Elimination: If you are eliminating too much fat in your stool (white poop anyone?), it is a sign of poor health (i.e. your intestines don’t absorb food, your pancreas doesn’t make enough digestive enzymes, or your gallbladder isn’t passing on enough bile).

Protein

Protein is the building block of life.

From Protein to Amino Acids

From Protein to Amino Acids

Foods with Protein

There are both animal and plant based sources of protein. Animal based sources of protein have all of the essential amino acids that we need, including the ones that we can’t make and can only get from dietary sources. Here are some examples of different foods and the amount of protein they contain:

  • Chicken (31 g of protein per 100 g)
  • Hamburger (27 g of protein per 100 g)
  • Salmon (25 g of protein per 100 g)
  • Eggs (19 g of protein per 100 g)
  • Milk (3 g of protein per 100 g)
  • Kidney beans (9 g of protein per 100 g)
  • Tofu (8 g of protein per 100 g)
  • Barley (2 g of protein per 100 g)

How we Digest Protein

The majority of protein digestion occurs in the stomach. *Watch a cool video that explains the entire process here.

protein digestion

How We Digest Protein

  1. In the mouth: Protein (basically a bunch of amino acids all connected and bunched together) are crushed and moistened in the mouth, but no chemical breakdown occurs during this part of the process.
  2. In the stomach: Hydrocholoric acid in the stomach uncoils, or denatures, each protein’s tangled strands so that the digestive enzymes can attack the peptide bonds. Hydrocholic acid in the stomach also converts the inactive form of the enzyme pepsinogen to its active form, pepsin. Pepsin cleaves large polypeptides into smaller polypeptides and some amino acids.
  3. In the Duodonem: When the smaller polypeptides enter the duodenum (the beginning part of the small intestine), proteases are released from the pancreas that hydrolyze them further (break them down in the presence of water) into short peptide chains, tripeptides, dipeptides, and amino acids.
  4. In the Small Intestine: Then peptidase enzymes on the membrane surfaces of the intestinal cells split these tripeptides and dipeptides into single amino acids.
  5. Absorption: These single amino acids are now small enough to be absorbed through the small intestine and enter the blood stream. Only a few peptides escape digestion and enter the bloodstream intact.
  6. Elimination: Only a small amount of dietary protein is lost in the feces.

In Conclusion

I have been reading, learning, making big posters, drawing models, redrawing models, talking to anyone who will listen, synthesizing, and applying all that I have learned about digestion for years in an attempt to understand it as best as I can. I feel like I could keep drawing better diagrams or synthesizing the information better and further, but I have to just stop here and move on knowing that I am going to continue to dig deeper, learn more, write more, and draw more, and keep building on this with future posts.

I think that understanding digestion is one of the fundamental building blocks for understanding health, and I hope that my synthesis of this information can help you understand it better as it has helped me. I am excited to move on and keep learning! I hope you’ll join me!

See it in action! Watch a camera go inside the digestive system to see a 5 minute video of what the process looks like first hand!

 

Why We Drink Raw Milk

2012-06-18_18-13-07_380When I was juggling a full time job and raising a family, I never had the time to do much research about what we ate. We just spent a ridiculous amount of money trying to buy foods that were organic and called it good. But now that I am a stay at home mom, I have made it my JOB to feed my family and do it right. One of the first (and best) changes we made was switching to raw milk. Read on to find out why raw milk is clearly the better option, and why if you’re not going to drink raw milk, you really shouldn’t be drinking milk at all. 

Should Adults Even Be Drinking Milk?

I am a big fan of breastfeeding and its numerous health benefits. A mother’s milk is designed to give her baby all of the nutrients it needs to grow as it begins life. All other mammals do this as well, cows included. Does it strike you as a little odd that in drinking cow’s milk we are essentially drinking what was designed for a baby cow? Most adults (60-70%) don’t even produce the intestinal enzyme lactase (which all baby mammals produce) which is needed to properly digest milk! That coupled with the fact that many adults are allergic to the milk protein casein and I’m surprised that it is even so widely accepted that milk is part of our food pyramid (which is another post in and of itself!). So if you do in fact choose to drink milk, the pasteurized and homogenized milk you find on store shelves is hardly fit to even be called milk.

Confined-animal-feeding-operation

Factory Farms House Freaks of Nature

Every grocery store and gas station advertises the low price of their milk as an enticing factor to draw you in. In order to bring you milk for $1.89/gallon, the milk is obtained by treating these living, breathing, feeling creatures like pieces of machinery in an assembly line. The cows are crowded together in feed lots, fed corn and grain to fatten them up (rather than the grass that their bodies are naturally meant to digest), pumped full of bovine growth hormones in order to produce 3 or 4 times more milk than their bodies are designed, get mastitis, secrete pus, and hence need the routine antibiotics that these conditions create. Did you know that there’s an allowable pus content in store bought milk? That means they know that every cow will produce some pus and so they allow for a certain amount of that to be passed down to the consumer. As a breastfeeding mother, I am meticulous about what I eat because I know it passes directly to my baby. It’s the same with cows! When we drink their milk, we are essentially taking in whatever they did.  Now that I have children, I am mortified to think that these hormones could be passed through to them and actually cause them to hit puberty early.

Pasteurization Destroys Everything Good

When you think about the allowable pus content in store bought milk, does it make you feel a little bit better to know that it’s been heated to a high temperature at least? Heated pus…mmm-mm-mmm! The process of pasteurization is supposedly needed to protect us from infectious diseases, even though as Sally Fallon points out in her book, Nourishing Traditions, “ALL OUTBREAKS OF SALMONELLA FROM CONTAMINATED MILK IN RECENT DECADES – AND THERE HAVE BEEN MANY – HAVE OCCURRED IN PASTEURIZED MILK.” Raw milk has lactic-acid producing bacteria that will naturally protect your body from these and other harmful pathogens. Milk is alive! It is full of enzymes that help our bodies digest and assimilate all of the bodybuilding factors including calcium. Pasteurization kills these enzymes along with altering the amino acids and making the protein less available to us. It also reduces milk’s mineral components, losing at least 50% of vitamin C, destroys the essential vitamin B12, and has even been linked to diabetes because of the unnecessary strain on the pancreas. Are you crossing store bought milk off your grocery list yet? I haven’t even mentioned the unnatural process of homogenization and its link to heart disease because the suspended fat and cholesterol particles are more prone to rancidity and oxidization or the fact that skim milk has a bluish color until powdered milk is added to it, and powdered milk has oxidized cholesterol which can damage the arteries and lead to atherosclerosis! But on to greener pastures!

The Benefits of Raw Milk

  • If you had to, you could live off from raw milk alone. It is a perfectly balanced food.
  • It is an excellent source of saturated fat and cholesterol. Both of these necessary dietary components have been unjustly demonized by mainstream media. Read my blog: The Truth About Fats to learn about how wrong we’ve all been about fats.
  • It is rich in fat soluble vitamins A and D.
  • It is an excellent source of protein with all twenty of the standard amino acids.
  • It has immunoglobulin proteins that provide resistance to many viruses and bacteria.
  • It has a perfect balance of minerals such as phosphorus and magnesium that allows the absorption of calcium.
  • It has sixty functional enzymes that aid in its own digestion giving our pancreas a break.
  • It contains lactobacilli bacteria that digests lactose and may allow people who lack the enzyme lactase to digest it.
  • It is abundant in Conjugated Linoleic Acid (CLA) which is an extremely beneficial polyunsaturated Omega-6 fatty acid that can raise the metabolic rate, help remove abdominal fat, boosts muscle growth, reduces resistance to insulin, strengthens the immune system, and lowers food allergy reactions. Grass fed cows are known to have three to five times more CLA than cows that are grain fed.
  • Drinking raw milk is an excellent way to reverse insulin resistance. There was a recent study done that compared two groups of people. One group consumed four servings of dairy a day and the other group consumed two servings of dairy per day. The group that consumed four servings of dairy per day improved their insulin resistance by 11% over a six month period.

Milk FarmMilk Farm2Milk Farm3The Raw Milk Experience

We get our milk from a little Amish farm in west Michigan. We drive 40 minutes one way to get it fresh every week. The kids get out to stretch their legs and play with the Amish children as my husband pours the milk fresh out of the cooling vat that has been collected within the last few days. We can see the cows grazing in the fields surrounding the farm. Sometimes they are so far away we can’t even see them!  They milk three or four cows at a time using a hand operated electric pump (run off from a generator) and actually bring in the baby cows to feed, which costs them but is better for the baby cows. Their milk is tested regularly and always passes with flying colors. But the best part of all is the taste! The fresh, rich, creamy, ice cold glass of frothy milk is so delicious, filling, and decadent that I almost feel guilty! This is an amazing experience for our kids. They get to see where their milk is coming from and not just assume that everything comes off from the shelves at a store.

2012-06-18_18-16-50_924

2012-06-18_18-13-48_3512012-06-18_18-14-11_17How Much Does It Cost?

Purchasing raw milk is illegal, so we actually own a cow share and pay boarding fees. We own 6 shares, which costs us a refundable deposit of $300 and we pay $120/month in boarding fees which is $5/gallon. This may seem like a lot of money and a lot of milk for one family, but it is an amazing source of nutrient dense food that doesn’t take any time to prepare that we can have with meals, as a snack, or even as a meal substitute when we’re on the run. Our kids can be picky eaters at times, but they LOVE raw milk and drink it all the time. We keep their sippy cups constantly full and they open the refrigerator often to grab their cups and take a drink whenever they choose.

Being on a budget, we have to prioritize many things, but our raw milk is the one thing that we will maintain no matter what happens. If this was the ONLY thing I could do for the health and well being of my family, it would be enough to make a difference.

For More Information…

  • To find a raw milk source near you, check out Real Milk Finder. Their website also has a ton of great information if you would like to learn more about raw milk.
  • To find the latest news about raw milk and lots of other good information, check out the Weston Price Foundation.
  • If you want a really great informative read, check out Sally Fallon’s book Nourishing Traditions.
  • I also got some great information for this post about raw milk in Natural News.
  • Check out this 11 minute video if you want to see a great summary of the benefits of raw milk or this video if you want to see a 2 minute video on Sally Fallon’s perspective.