GM chemicals in cleaning products are 'potent allerg...

"GM enzymes used in household products 'are potent allergens'," reports The Daily Mail following research on the potential for genetically modified enzymes to cause allergies.

Researchers took blood samples from 813 workers routinely exposed to genetically modified (GM) enzymes from working in the food, drinks, chemicals, detergents and pharmaceutical industries.

They found antibodies – proteins produced in response to the presence of the GM enzymes – in just under a quarter of those tested.

The most commonly detected antibodies were derived from exposure to alpha amylase, stainzyme, and pancreatinin, which are predominantly used in detergents and home care products.

However, just having antibodies doesn't prove a person has an allergy.

The researchers examined a subgroup of 134 workers and found around a third of them had possible allergic symptoms such as runny nose, eye irritation or shortness of breath.

One-off tests on these workers do not give conclusive proof that exposure to these enzymes causes allergies.

Also, these workers are likely to have a higher level of exposure through their occupation than the average person may have just by using such products.

Therefore the findings do not give immediate cause for concern for the general public.

Nevertheless, if these findings are verified, further regulation around products containing such enzymes may be required.

Where did the story come from?

The study was carried out by researchers from the University Medical Center Hamburg-Eppendorf. There was no mention of a source of funding for this study.

The report was published in the peer-reviewed journal Occupational & Environmental Medicine and is free to read online.

The media reported on this study accurately. The Guardian provides a good summary of the research and findings, rightfully pointing out limitations of the research such as the possibility of selection bias in the subgroup analysis.

What kind of research was this?

This was a cross sectional study which aimed to investigate genetically engineered enzymes – such as those used in manufacturing fragrances, detergents and food flavourings – as potential allergy-causing substances (allergens).

As this was a cross sectional study, taking one-off allergy tests in staff in the workplace, it cannot prove causation. However, this type of study is useful for providing links for further investigation.

A cohort study, assessing allergic response in people before they started working in these industries, and then following them up over time to see how their allergic response changes, would give better indication of cause and effect.

What did the research involve?

The researchers took blood samples from 813 workers exposed to genetically modified enzymes. Most of the workers were from the food, chemical, detergent and pharmaceutical industries. Two-thirds were men aged 20 to 60 years.

The blood samples were screened for antibodies related to enzyme exposure in their workplace. The specific enzyme antibodies were:

phytase
xylanase
glucanase
cellulose
savinase and/or alpha-amylase

The workers were exposed for between three months and 10 years to two to four enzymes in their workplaces.

For a subgroup of 134 workers at two workplaces, clinical data was collected, including their medical histories, physical examination and lung function testing.

What were the basic results?

Just under a quarter (23%) of all exposed workers had IgE antibodies related to workplace-specific enzymes. These are the antibodies the immune system produces as an allergic response.

The most common antibodies were against the enzymes derived from alpha-amylase (44%), followed by stainzyme (41%) and pancreatinin (35%).The highest individual antibody levels were detected in workers exposed to phytase, xylanase and glucanase.

Alpha amylase, stainzyme, and pancreatinin are predominantly used in detergents, cleaning products and home care products.

The sub group analysis found that 64% were symptom free, 19% had a runny nose and/or conjunctivitis, and 17% had wheezing and/or shortness of breath.

How did the researchers interpret the results?

The researchers conclude: "Our data confirm the previous findings showing that genetically engineered enzymes are potent allergens eliciting immediate-type sensitisation. Owing to lack of commercial diagnostic tests, few of those exposed receive regular surveillance including biomonitoring with relevant specific IgE [tests]."

Conclusion

This cross sectional study aimed to assess the potential for allergy caused by genetically modified enzymes which are abundant across the manufacturing industry.

The researchers showed that such enzymes can cause increased levels of the related antibodies, causing sensitisation for some of those that come in contact. However, just having antibodies to something you've been exposed to doesn't necessarily equate to allergic symptoms such as dermatitis or asthma.

A notable limitation of this study is that it examined and reviewed the medical history of only a small subgroup of people. The majority of these people had no allergic symptoms, despite the high prevalence of antibodies. As these people were only selected from two sites, and were not a randomly selected sample of all workers tested, the possibility of selection bias can't be ruled out.

Another important limitation is that this type of study is unable to prove cause and effect. A prospective cohort study would be the best way of assessing whether non-allergic people subsequently develop allergic sensitivity upon working in environments where they are exposed to these enzymes.

It is also likely that the level of exposure for these workers is higher than for the general public using these products. So the implications for the general population are probably minimal.

Another drawback to the research, acknowledged by the authors, is that commercial secrecy limited access to data, preventing them from gaining access to the chemical formulations used.

Nonetheless, should these findings be verified and suggest that these enzymes lead to allergies, further regulation around products containing such enzymes may be required.