Biological Energy, Digestive Enzymes, and Metabolic Enzymes
last updated 4.24.06

What is a 'systemic' enzyme?
What is a 'brain enzyme'...or 'liver enzyme'?

What is a 'systemic' enzyme?

It's tricky to follow at first because a few terms have very different meanings. Here is an organizational structure for the general categories of enzymes. While all enzymes are proteins that do work in nature, the categories are based on the enzymes source and function.


  • 1. Food enzymes - comes natural in food as in raw food (makes food rot away).
  • 2. Digestive enzymes - produced by living organisms that aren't plants (can be from of animals, humans, bacteria, yeast, etc). This category includes enzymes made by the pancreas, in saliva, stomach, and intestinal cells). Enzymes produced by various microbes are refined and purified, and made into supplements. Pancreatin is pancreas enzymes from ox, pig, or possibly other animals. These enzymes specifically breakd down nutrition for the organism to use for nourishment.
  • 3. Metabolic enzymes - these enzymes are produced in the body on an as needed basis and are not supplemements. These enzymes do work in nature. These enzymes build various tissues, transfer compounds from one molecule to another, oxidize things, reduce things, etc.


Within #2, the category of digestive enzymes, there are two subcategories based on how the digestive enzymes are USED.

  • 2a. Used for food breakdown - digestive enzymes used in this way are taken with food to break foods into pieces.
  • 2b. Used to clean things out in the body - digestive enzymes used in this way are taken between meals (may be enterically coated or may not be). The idea is so the digestive enzymes get in the body to help reduce inflammation, breakdown yeast, bacteria, or virus elements, remove harmful plaque and fibrin, and clean out immune complexes and gunk.


I've noticed that the term 'systemic enzymes' are used to describe both #3 and #2b. This makes it confusing. When talking about #3, the person means to talk about enzymes working in the system besides digestive enzymes (metabolic enzymes). When talking about #2b, the person means to talk about digestive enzymes used to do cleaning and healing in the body 'system.'

To add to the confusion, there are some pop diets called the Metabolic Diet which talks about using digestive enzymes. You are not swallowing metabolic enzymes directly as supplements to improve metabolic function. However, taking digestive enzymes can improve metabolism indirectly.

  • 1. This can happen by better digesting food to make nutrients better available in the body so it has the raw materials it needs to run better.
  • 2. Improved digestion puts more energy into your body. Having more energy in the body improves metabolism, lessens fatigue, and helps you function better overall.
  • 3. Taking enzyme supplements keeps gunk and pathogen levels down.
  • 4. Taking enzyme supplements to help digest your food and keep the body cleaned out means that your own metabolism doesn't have to do this. Your immune system and metabolism can focus on better on other areas of running the body when they aren't bogged down with food digestion. (a correlation is when you get really sick. The body needs all the energy and raw materials it can muster to fight off the the person temporarily looses their appetite and lays low temporarily).

Taking enzyme supplements between meals faciliates this over taking them with meals (this part helps reduce inflammation too). Some people feel this is the use of digestive enzymes that prolongs age.

It is confusing particularly when terms are used interchangeably but have different meanings.

What is a 'brain enzyme'...or 'liver enzyme'?

These refer to metabolic enzymes which are everywhere in the nature and your body, and make everything 'work'. Metabolic enzymes are things like the enzymes in the liver function, as in "the test showed elevated liver enzymes"...or phenyl sulphotransferase, the enzyme that helps with processing out phenol compounds. There may be millions of different types because a different enzymes because each has a different job.

Metabolic enzymes are different than digestive enzymes (which digest or breakdown organic matter - we call it 'food'). When digestive enzyme action breaks down organic matter in our bodies, we call it 'eating food'. At times when it happen outside our bodies, such as in a compost pile, we call it 'rotting' or 'decaying'. These two categories of enzymes are not interchangeable. Just about all the time, you cannot supplement metabolic enzymes. They need to be produced by the body internally. Digestive enzymes can be supplemented all day long.

Some of the genetic problems involving enzymes are talking about metabolic enzymes. One of these is Fabry Disease:

"Fabry's disease is a fat storage disorder caused by a deficiency of an enzyme involved in the biodegradation of lipids. The gene for this disorder is on the X-chromosome, so only the mother needs to be a carrier to produce an affected child. "

On the surface, it sounds like you could fix Fabry's disease by simply supplementing lipase to breakdown fats. While this may help, the enzyme in question is a metabolic enzyme that is truly 'deficient'...not lipase.

The guy may be trying to say that a metabolic enzyme in the brain is what is really lacking and not a digestive one.

Since we really can't add in metabolic enzymes, what do we do when a metabolic enzyme is lacking or not working well? One way is too supply the raw materials and energy that the body needs to make all enzymes to begin with.

  • Enzymes are composed of amino acids, so we definitely need those. This means that thorough digestion of protein foods is required to supply those amino acid (and what amino acid supplements may try to target).
  • Some enzymes require co-factors, usually a mineral such as magnesium and zinc. If the mineral is not present or deficient, the metabolic enzyme cannot function.
  • The metabolic enzyme and enzyme function needs energy which is provided from the digestive enzymes breaking down food.

In animal science, energy is always a factor. Feed ration calculations include a variable for finding out how much energy the feed will provide to the animal to help it grow and function. It is talked about as "digestible energy".

I have noticed in human nutrition, this appears to be a lost variable. It is like trying to make the equation 'a +b + c = ?' balance without variable 'c'.

It is common to hear when a person starts digestive enzymes they have soooo much more energy, and their fatigue is gone. This may be why some kids seem 'hyper' in the first days or weeks after starting enzymes. They are getting a boost in energy to the system they need to adapt too. Part of this energy is going to the metabolic enzymes so they can start functioning much better.

There are other aspects too, like needing oxygen from breathing, vitamins and other raw materials. However, this is why digestive enzymes may be a great help even if the fundamental problem involves a metabolic enzyme.



Selecting Products
Which Enzymes?
Dosing Guidelines
Mixing Suggestions
Interactions w/ other things
What to Expect Starting
General Trends
At School
Getting Started Step-by-Step
Enzyme Safety

Sensory Integration
Digestive Disorders
Food Sensitivities

Leaky Gut
Bacteria / Yeast

PDD/Autism Spectrum

Autoimmune / Neuro Cond.
Heart/ Vascular Health
Sports Medicine

This independent site is for education and information about digestive enzymes. There is a large need to provide practical and general information on enzyme therapy for a wide range of uses.

Enzymes have been around a very long time. Hopefully this site will help reduce the learning curve.

Ideas, comments, and questions are welcome.

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