Are You Digesting Your Food? and Why It Matters

digestion is necessary for a healthy body

The digestive process

Eating a healthy diet is necessary for a healthy body, but proper digestion of food is equally important because the digestive process breaks down our food into smaller parts that are then used. 

Our digestive system begins in the mouth and continues through the esophagus, stomach, small and large intestines (1).  These organs of the gastrointestinal (GI) tract are hollow, allowing for food to pass through (2).

the digestive system

https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works

When digestion is working well, the body breaks down proteins into amino acids, fats into fatty acids, and carbohydrates into simple sugars. It uses these building blocks to create organs like our skin and cell membranes, and to generate energy.  Digestion also separates micronutrients such as calcium from the foods we eat so they can be used to build structures like our bones and for body functions like muscle contraction (3).

If digestion is not working optimally, we can become nutrient insufficient and, over time, deficient.  Nutrient deficiencies lead to an unhealthy body, especially when deficiencies occur in essential nutrients like calcium.  We must consume calcium in our daily diet for proper muscle and nerve function, eyesight, blood clotting, and healthy bones and teeth (3).

Symptoms of poor digestion (4)

·       Heartburn, reflux

·       Uncomfortable full feeling shortly after a normal meal

·       Food intolerances or sensitivity

·       Abdominal pain

·       Bloating, excessive gas

·       Nausea, vomiting

·       Altered bowel habits like diarrhea or constipation, greasy, smelly stools

·       Skin issues like psoriasis, eczema, and acne

·       Fatigue, unintended weight loss, and loss of appetite

Two important factors for digestion

Hydrochloric acid (HCl) is a primary component of gastric juice in the stomach, responsible for breaking down food, killing pathogenic bacteria to protect the GI tract, activating enzymes, triggering bile release, and facilitating nutrient absorption (5). 

When stomach acid is low (hypochlorhydria), we can experience symptoms such as feeling full quickly, reflux, bloating, gas, and bowel changes, such as diarrhea or constipation (6).

If low stomach acid persists, we can become nutrient-deficient, intolerant of foods, and experience chronic infections that can lead to conditions like SIBO (7).

Bile is a digestive fluid produced in the liver, stored and concentrated in the gallbladder, and used by the body to break down dietary fats, absorb fat-soluble vitamins like vitamins A, D, E, and K, excrete waste products, alkalize the acidic contents of the stomach as it moves through the digestive tract, and acts as an antimicrobial protecting the intestines from pathogens (8).

When bile production, secretion, or flow is reduced, we can experience symptoms from nutrient malabsorption, like reduced control of body movement (vitamin E deficiency), night blindness (vitamin A deficiency), fractures, osteoporosis (vitamin D deficiency), and bleeding problems (vitamin K deficiency) (9) (10) (11).

What’s the nervous system got to do with it?

The vagus nerve (10^th cranial nerve) originates in the brainstem and is responsible for parasympathetic (rest, digest, detoxify, heal) control of most internal organs, like the heart, lungs, and digestive tract (12).

The vagus nerve plays an important role in increasing gastric juices, stomach acidity, and gut motility (13).  A key element of the gut-brain axis, the vagus nerve sends signals in both directions, about 80% of the information is transmitted from the body to the brain, and 20% is transmitted from the brain to the body (12).

As a conduit between the brain and the immune system, one job of the vagus nerve is to shut down the inflammatory process once it has served its purpose.  Chronic inflammation is a common sign of poor vagus nerve function, or low vagal tone (12).

Vagal tone can be estimated using heart rate variability (HRV), the measurement of time between consecutive heartbeats, with a high HRV indicating more adaptability and better vagal tone (14).

Tips to improve the digestive process

If you experience symptoms of poor digestion, improving your digestive process can help avoid health complications.

Improving the digestive process involves investigating each factor of digestion (e.g., stomach acid, bile, enzymes, and motility).  Do you have sufficient stomach acid to break down food, bile to emulsify fats, enzymes to begin the digestive processes, and healthy vagal tone?

Improving stomach acid:

·       Consume protein first at each meal

·       Avoid refined carbohydrates and fried food

·       Chew each bite well

·       Avoid fluids during meals

More steps to improving stomach acid and what to watch for here.

Improving bile flow:

·       Beets (betaine) can thin bile

·       Bitters (chicory, dandelion, arugula) can thin bile

·       Apple cider vinegar (diluted) can thin bile

Improving vagal tone (14):

·       HIIT exercise can improve vagal tone

·       Walking can improve vagal tone

·       Slow breathing (5.5 breaths/minute) 10-20 minutes/day

·       Singing and humming can improve vagal tone

·       An anti-inflammatory, nutrient-dense diet can improve vagal tone