A Skeptical Look at ALCAT Testing

Stephen Barrett, M.D.
December 25, 2019

The Antigen Leukocyte Antibody Test (abbreviated ALCAT or Alcat)— analyzes the responses of the patient’s white blood cells (leukocytes) when incubated with extracts of foods and other test substances. Proponents claim that the test can detect otherwise hidden allergies and “intolerances” and that avoiding the alleged offenders can lead to improved health. This article explains why the scientific community is skeptical.

Background History

ALCAT testing was launched in the mid-1980s by American Medical Testing Laboratories (AMTL) and has been marketed since 2006 by Cell Science Systems Corporation. of Deerfield Beach, Florida. Roger Deutsch, who runs Cell Science Systems, says that the test evolved from research that began in the 1950s. In a recent podcast, he claimed that researchers found that (a) tests done by challenging cells with substances to which the person was allergic produced results that were correlated with clinical symptoms, (b) the test process, which they named cytotoxic testing, “became very popular and broadly used,” but (c) people don’t like huge paradigm shifts so it fell a little bit by the wayside.” Deutsch also said that cytotoxic testing used a technician to examine cells under a microscope to judge whether there was a reaction, but the ALCAT test improved the process by applying electronic instrumentation to measure and interpret the changes [1].

Cytotoxic testing did more than “fall by the wayside.” Researchers found it was unreliable, professional organizations condemned it, several states obtained injunctions against marketers [2]. In 1985, the FDA banned the sale of cytotoxic test kits and any other devices that use similar methods to diagnose allergy or intolerance to food and ingested substances [3].

U.S, Patent Office records indicate that in 1983, Mark J. Pasula, Ph.D. began filing a series of patent applications for “a method and apparatus for
measuring the degree of reaction
between antigens and leukocyte cellular antibodies.” The first document asserts that the method worked the same way as cytotoxic testing but was better because the many more white cells were tested and the cellular changes or destruction were counted by the device rather than a human operator [4]. The second document states that the test provides “a
method of diagnosis which is capable of diagnosing
maladies caused by foreign entities for which the body
of a subject produces no antibodies.” It further claims:

In this fashion, it may be objectively determined if the subject has a reaction to any of the tested foreign entities, and is therefore suffering from any of the tested maladies. Such a test may be used to test for any malady affecting the immune system, from influenza, to AIDS, to cancer [5].

The third document adds:

It is my theory that most
maladies may be diagnosed by the observation of the
reactions of the body’s immune system, specifically, the
size-distribution of the leukocytes in two samples of a
subject’s blood: a control sample which has no foreign entity added thereto, and a test sample which has at
least one foreign entity added thereto [6].

Pasula is identified elsewhere as AMTL’s research director. The exact way the test is performed was described in a 32-page guide that AMTL distributed to practitioners in 2003 [7].

ALCAT Claims

The therapeutic claims made for ALCAT testing are not modest. Deutsch’s book, Your Hidden Food Allergies Are Making You Fat, claims:

Anywhere from 30 to 90 percent of the population of the United States is intolerant to one or more foods. . . . It’s time to find out whether common foods are causing or exacerbating your health woes and to avoid those foods if one or more of the following symptoms have become a permanent fixture in your life: acne, anxiety, arthritis, attention deficit hyperactivity disorder (ADHD), autism, bedwetting, chronic diarrhea, chronic fatigue, depression, diabetes, ear or other frequent infections, eczema, fatigue, hay fever symptoms (year-round), headaches (tension type and migraine), infertility, inflammatory bowel disease. migraine, muscle aches, obesity, panic attacks, stuffy nose, urticaria.

Although these are some of the most common food intolerance symptoms, food intolerance has been implicated in nearly any symptom imaginable. Like medical conditions, which may present themselves in a wide range of severities and intensities, food intolerance manifests in a wide range of degrees. What’s more, it fluctuates. Sometimes a food-intolerant person will have a good day and be symptom-free. And other days he or she will be totally incapacitated by ill health.

The factors that the book says can cause variability include: (a) airborne allergens that may cross-react with a food constituent and can change according to seasonal patterns, (b) exercise, (c) the “total load” of chemically related substances, (d) inability of the liver to detoxify, and (e) inflammation of the gut, due to spicy food, alcohol consumption, or localized allergic response [8].

Do you think it is possible that the incidence of food intolerance is 30-90%? Do you think it has has been “implicated in nearly every symptom imaginable” or plays an important role in most of the conditions listed above? I do not.

From 2001 through 2005, the ATML Worldwide Web site offered a brochure that said:

The immune system is an intricate structure which, under normal circumstances, protects
the body from the harmful effects of invading elements—viruses, bacteria, other microorganisms
and toxins. However, sometimes the system over reacts to substances,
including foods and food additives, that are not normally harmful. The result: hayfever,
asthma, migraine, skin problems, intestinal disorders, painful joints or muscles, frequent
ear infections and hyperactivity in children, chronic fatigue; and, along with any of these
or other disorders, weight imbalance.
From minor health problems to life-threatening disease, or anywhere
between these extremes, you should find out whether food intolerance
is the culprit [9].

The AMTL site also invited viewers to take the test shown to the right [10].

Health Test
  1. Are you sick and tired of feeling exhausted all the time?
  2. Do you have a difficult time managing your weight?
  3. Are you plagued by annoying gas, indigestion, bowel irregularities, or often feel bloated?
  4. Are headaches, including migraines affecting the quality of your life?
  5. Do you suffer from joint pains or muscle weakness?
  6. Do you crave certain foods or eat the same foods often?
  7. Do you get sick often?

If you answered “yes” to any of these questions, we may be able to help you look and feel better!

Please note these answers will not be used to make a diagnosis. These symptoms may be a sign of serious illness. Therefore, we recommend discussing them with your health care provider.

I eat oatmeal for breakfast and a banana and yogurt for lunch every day. I include them because they contribute to my healthful diet. Yet the “Health Test” suggests that these dietary choices are potentially so serious that I should (a) discuss them with my doctor and (b) take an ALCAT test to see whether they are caused by food intolerance.

In 2011, in an article in The American Chiropractor, Deutsch stated:

Eating healthful food is one thing, but eating in accordance
with your own unique, genetically determined biochemical
makeup is quite another thing. One man’s meat is another
man’s poison. Finding out what foods are right (and which are
wrong) for you is the key to health and performance.
Foods that are compatible with your make up will increase
your strength and energy. Consumption of foods or added
chemicals that YOUR body perceives as harmful will result in
intolerance reactions. Food intolerance induces the excessive
generation of toxic free radicals and inflammatory chemicals.
The damage can result in a wide range of health problems [11].

Test Reports

The Cell Science Systems Web site currently lists 20 test panels that encompass from 50 to 370 items that can include foods, molds, food additives/colorings/preservatives, antibiotics/anti-inflammatory agents, and/or herbs. The tests appear to be prescribed mainly by chiropractors and naturopaths, but they can also be ordered by consumers online. The cost depends depends on the number of items tested and varies somewhat from provider to provider. The 200-food panel costs typically costs between $400 and $600, but other versions can run from $200 to over $1,000.

The reports themselves should make you suspicious. The example below, which is one of dozens I found posted on the Internet, says that (a) 13 foods in the green column should be avoided for at least six months because there is severe intolerance, (b) 24 foods in the orange column should be avoided for a minimum of 3-6 months because of moderate intolerance, (c) 45 foods in the yellow column should be “avoided if possible,” and 105 foods in the green column are acceptable.

The food groupings make no sense to me. The report would have you believe that (a) someone could be intolerant to lamb, beef, pork, turkey, and chicken liver but OK with buffalo, chicken, duck and venison; (b) someone could be intolerant to cow’s milk but OK with goat or sheep milk, (c) someone could be intolerant to peach, pear, raspberry, pumpkin, strawberry, fig, apple, apricot, cranberry, grape, papaya, and honeydew, but OK with avocado, blueberry, grapefruit, nectarine, banana, cantaloupe, lemon, pomegranate, blackberry, cherry, lime, orange, watermelon, date, mango, and pineapple, and (d) someone could be intolerant to bell peppers, black-eyed peas, Brussels sprouts, carrot, corn, kelp, kidney bean, cauliflower, celery, chick pea, endive, fava bean, green pea, portobello mushroom, sweet potato, tomato, turnip, white potato, and wild rice, but OK with the 26 other vegetables listed at the top of the green section. However, there is no logical reason to believe that foods in the red, orange, or yellow columns that are similar to those in the green column will affect the body differently.  


Click to enlarge
Research Status

Although the ALCAT test has been available for more than 30 years, its use has not been established by scientific studies. Cell Science Systems claims that more than 30 studies have established the test’s validity. But Blue Shield of California has summarized the research this way:

There is a lack of published research on the diagnostic accuracy of ALCAT; therefore, it is not possible to determine the sensitivity, specificity, and/or predictive value of the test compared with alternatives. A few low-quality studies have reported improvements in outcomes following the use of ALCAT, but it is not possible to determine whether these changes occurred as a result of the test itself, bias, variation in the natural history of the condition, and/or the placebo effect. The evidence is insufficient to determine the effects of the technology on health outcomes [12].

Another recent reviewer concluded:

A number of publications are cited on the company’s website
reportedly demonstrating the diagnostic utility of the test, but
virtually all are abstracts as opposed to manuscripts in peer-reviewed
journals. The lack of such evidence makes it impossible
to objectively evaluate these claims. It may well be that the
laboratory instrument being used accurately measures white
blood cell volumes. However, it is unclear whether or not any
changes in these cell volumes in response to food exposure would
be physiologic or pathologic or how they would lead to the long
and disparate list of maladies being investigated [13].

In 2009, a South African allergist asked South Africa’s Advertising Standards Authority (ASA) to investigate whether it was proper for Alcat South Africa to claim that its tests could accurately identify food sensitivies that caused a long list or health problems. The ASA concluded: “Given the absence of any independent, credible verification, there is nothing before the Directorate to unequivocally verify that that product is capable of achieving the claimed results.” [14]

In 2010, a naturopath and an immunology researcher reported what happened when they sent four blood samples from the same person for 50-food ALCAT testing. On the first day, they submitted two samples under different assumed names. One week later they submitted two more samples under different assumed names. The results, which should have been identical, were completely random [15]. Even though only one person was tested, the results are a very powerful demonstration of unreliability.

Regulatory Status

The FDA permits the ALCAT test system to be marketed as a device but has not required that it be validated as clinically useful. The agency considers ALCAT to be a “whole human plasma or serum immunological test system,” which it defines as “a device that consists of reagents used to measure by immunochemical techniques the proteins in plasma or serum” and can “aid in the diagnosis of any disease concerned with abnormal levels of plasma or serum proteins.” Such devices are classified as Class I. Marketers of Class I devices are not allowed to make diagnostic or disease-related claims. Many ALCAT promoters make disease-related claims, but I have seen no evidence that the FDA pays attention to them.

Insurance Fraud

Medicare and most insurance programs consider ALCAT testing to be “investigational” (unproven) and do not cover it. Cell Science Systems says that the CPT code for the test is 83516. This number stands for “immunoassay for analyte other than infectious agent antibody or infectious agent antigen; qualitative or semi-quantitative, multiple step method.” In 2012, the National Health Care Anti-Fraud Association notified insurance companies that CPT code 83516 was being used to bill for ALCAT tests. That code has many legitimate uses, but several companies that checked high users of the code found they had unknowingly paid for ALCAT testing. The proper way to report an ALCAT is a single line entry that uses a modifier that indicates the number of substances tested. Thus the code for an ALCAT that tests 320 substances should be 83516-320. But some providers disguised what they did by using four billing lines with 99, 99, 99, and 23 units each. So far, at least six individuals have been charged with insurance fraud [16].

Bankruptcy Proceeding

In June 2018, Cell Science] Systems Corporation filed for Chapter 11 (voluntary) bankruptcy, listing liabilities of $1,966,572 and assets of $410,323. The document stated that the company’s gross income was about $11 million in 2016, $7.8 million in 2017, and $2.9 million from January 1, 2018 through the filing date [17]. In January 2019, the court approved the reorganization plan to settle about $1.7 million of the unsecured debts with payments of 30% of the amounts owed spread over a 4-year period [18].

Why I am Skeptical

To be useful, a test must provide information that enables health outcome to be improved. To demonstrate usefulness, the results must be consistent (reproducible) and clinically meaningful. To demonstrate reproducibility for the ALCAT test, results should be the same when (a) a sample is divided into several portions that are tested separately and (b) samples from a patient are obtained on different days. The evidence of reproducibility put forth by proponents is minuscule compared to what would be needed. In addition, as noted above, they admit that an individual’s day-to-day and month-to-month reactivity can change for many reasons, so I do not believe that reproducibility can be demonstrated. Even if reproducibility could be shown, establishing that ALCAT results are as useful as proponents claim would require hundreds of well designed double-blind studies—far more than the few questionable studies they cite.

The Bottom Line

ALCAT testing has been promoted with a combination of scare tactics and glowing promises. There is good reason why the scientific community regards it as untrustworthy.


  1. Identifying food sensitivity and intolerance. Podcast sponsored by Cell Science Systems. Natural Medicine Journal 11(1), 2019.
  2. Barrett S. Stay away from cytotoxic testing. May 31, 2019.
  3. Cytotoxic testing for allergic diseases. FDA Compliance Policy Guide 7124.27, March 19, 1985. Revised March 1995.
  4. Pasula MJ. Method and apparatus for measuring the degree of reaction between antigens and leukocyte cellular antibodies. Patent No. 4,614,722, filed Nov 1, 1983, granted Sept 30, 1986.
  5. Pasula MJ. Method and apparatus for measuring the degree of reaction between a foreign entity and a subjects blood cells. Patent No. 4,788,155, filed Oct 1, 1986; granted Nov 29, 1988.
  6. Pasula MJ. Method and apparatus for measuring the degree of reaction between a foreign entity and white blood cells. Patent No. 5,147,785, filed June 9, 1989, granted Sept 15, 1992.
  7. Physicians’ guide for using and interpreting the ALCAT Test. AMTL Corporation, Sept 2003.
  8. Rivera R, Deutsch RD. Your Hidden Food Allergies Are Making You Fat. Three Rivers Press, New York City, 2002.
  9. For health, for sport, for slimming . . . for life. (brochure) AMTL Corporation, July 2000.
  10. ALCAT Worldwide home page. Archived 2001-2005.
  11. Food factors and athletic tolerance. American Chiropractor, Sept 2011, pp 41-44.
  12. Antigen leukocyte antibody test. Blue Shield of California Policy 2.01.93, Dec 1, 2018.
  13. ASA ruling: ALCAT. CAMcheck Web site, Nov 9, 2009.
  14. Kelso JM. Unproven diagnostic tests for adverse reactions to foods. Journal of Allergy and Clinical Immunology: In Practice 6:362-365, 2018.
  15. Hodsdon W, Zwickey H. NMJ Original research: Reproducibility and reliability of two food allergy testing methods. Natural Medicine Journal 2(3):8-13, 2010. (The published report does not identify ALCAT by name, but Dr. Zwickey confirmed to me by mail that it the tests were ALCATs.)
  16. Barrett S. Chiropractor prosecuted for false billing for ALCAT testing. Chirobase, June 5, 2019.
  17. Cell Science Systems Corporation. Voluntary petition for non-individuals filing for bankruptcy. U.S. Bankruptcy Court for the Southern District of Florida. Filed June 22, 2018.
  18. Cell Science Systems Corporation. Debtor’s plan of reorganization. U.S. Bankruptcy Court for the Southern District of Florida. Filed Jan 17, 2019.

This article was revised on December 25, 2019.