Understanding Your Blood Type

Your Genetic Markers

Blood types are genetic markers that we inherit. Each blood type evolved in a different part of the world at a different time. Your blood types tell you where your ancient ancestors evolved.

  • Blood Type A1 — European gene.
  • Blood Type A2 — Arctic gene.
  • Blood Type B — Asian gene.
  • Blood Type O — Tropical gene.
  • Blood Type AB — Mid-East genes.
  • Blood Type Rh-negative &ndash Basque gene.

What are Blood Types?

What are blood types? Blood types are surface markers (called antigens) on red blood cells and on most other cells in our bodies. They consist of many small sugar or sugar-protein molecules that stick up from the cell surface, and together with other markers, form the cell coat. These markers have two main functions. They help the cell communicate with other cells through messenger molecules (called cytokines). They also help the cell interact with the immune system. This can help the cell protect itself, but it can also lead to reactions with food allergens.

The ABO blood types were first discovered by Dr. Carl Landsteiner in 1900. Since then many other blood groups have been discovered, including the Rh, Duffy, Kell, Kidd, Louis, MNS, P, and others. Each group consists of several types. But the two most important blood groups are the ABO group and the Rh group (also called positive and negative or CDE). These are the most reactive, and are the two blood groups that we will be working with in the Biotype Diets.

In addition to ABO there are a dozen subtypes of A. Subtypes A1 and A2 are the most prevalent in the United States and Europe (constituting 99% of type A), and are employed in the Biotype Diets. However, there are other prevalent subtypes in Scandinavia (A-finn) and Africa (A-bantu and A-intermediate, which is intermediate between A1 and A2). In addition there are: A3, A-x, A-m, A-end, A-el, A-lae, and Australian A). Your ancestors might be one of these of these subgroups!

Where do we have ABO types? The ABO markers appear on cells throughout almost the entire body, not just on red blood cells. In fact, some scientists now believe that ABO types originally appeared on our bodies' tissue membranes before they appeared on red blood cells. In this way ABO markers can help cells all over the body communicate and protect themselves, but they can also react with allergens. ABO markers are present on many allergy-sensitive tissues, and in this way relate to food allergy symptoms. For example: ABO types are expressed on all the epithelial cells (skin, eyes, nose, mouth, ear-tubes, throat, lungs, esophagus, stomach, intestines, bladder, urethra, and vagina). They appear on the synovial membranes lining the joints. They are expressed on all the endothelial cells (these line the blood vessels, lymph channels, and body cavities around the heart, lungs, abdomen and pelvis). They are also present in food-related secretions, including: saliva, digestive juices, nasal mucus (smell), and breast milk -- and even in tears, sweat, semen, and vaginal fluids. However, ABO types are not expressed on white blood cells, which are the main components of the immune system (T-cells, B-cells, eosinophils, mast cells, and others).

How Are Blood Types Inherited?

Each person inherits one dominant blood type called the phenotype (how we appear). These are: A, B, O, or AB. But in actuality each of us inherits two blood types, one from each parent, called the genotype (genetic type). Examples are: AA, AO, BB, BO, OO, and AB. But only one gene will be dominant (except with AB). In addition, blood type A can be subdivided into subtypes A1 and A2, where A1 appears dominant.

Table 1: The ABO Blood Group







(underlying genetic patterns)

A1 A1
A1 A2
A1 O

A2 A2
A2 O



A1 B
A2 B

USA Population
(millions of people)











We also inherit an Rh blood type (positive), or we do not inherit it (negative). The other name for Rh is blood type D. We inherit D or we do not. In a small percentage of people a genetic mutation called Du replaces the D antigen. When this happens, a person's blood type will mistakenly appear as "negative", but further testing will show it to be Du-positive. If you are Du-positive, you should follow Rh-positive diet guidelines.

Table 2: The Rh Blood Group




(underlying genetic patterns)



USA Population
(millions of people)



Source: American Red Cross

Where to Get Your Blood Typed (ABO, Rh, A1/A2)

In order to use the Biotype Diets book, you will need to know your blood type. If you do not know it, here are some suggestions on how to find it or have it typed. It is usually simple and inexpensive.

For the Layperson

You may already have had your blood type taken, and have it on file somewhere. Anyone who has donated blood is given a Red Cross Card with their blood type. Anyone who has had surgery usually has had their blood type placed in their hospital file. Infants are often typed at birth. In addition, women can obtain their blood type from their obstetricians. Men can get theirs from their military records or dog tags. And students often have theirs taken in their science classes. If you do not know your blood type, your health care provider can identify it with a simple inexpensive test. You can also purchase a blood type kit at many health food stores. If you are blood type A or AB, and cannot determine your A1-A2 sub-type immediately, then use the A2 diet if you are intolerant of wheat or gluten. Otherwise use the type A1 diet.

For Health Professionals

This is for licensed physicians, osteopaths, chiropractors, nurses, nutritionists and naturopaths. You can order blood type tests from any major corporate laboratory, including ABO, Rh, and A1. If you wish to type blood in your office, it is a simple and inexpensive procedure. You will need: reagents for ABO + Rh, A1, sterile alcohol swabs, lancets, blood typing cards, mixing sticks, sterile gloves, and bandaids. You can purchase all of these blood typing supplies inexpensively from Carolina Biological Supply (800-334-5551), except the A1 reagents. Reagents for type A1 are available from EY Laboratories (800-821-0044) or Immucor (800-829-2553).

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