Why do so many people have an infection when they eat meat?
That is the question scientists are now asking after studying the health effects of eating meat and dairy products.
The answer is likely that the animal products contain proteins that may have caused a condition called non-specific antigen-1 (NS-1) that causes people to have a reaction to meat.
“There are a number of things we know about non-invasive detection systems, including [the] high specificity of non-animal immunoassay systems, but it is unknown what is happening with meat and non-meat proteins in human foods,” says co-author Dr Richard Wrangham, from the University of Bristol.
The researchers found that meat protein and dairy proteins in processed foods can cause a range of symptoms including abdominal pain, abdominal bloating, vomiting and diarrhea.
“The most common symptom of non‐specific antigen 1 is abdominal pain and a general sense of bloating,” Dr Wrantham says.
“It’s the only symptom that is reported in a systematic way in people who have been in the clinical setting for a long time and it’s not a well-established trigger.”
Dr Wransham and his colleagues analysed data from the Australian and New Zealand Food Standards Agency and the National Health and Medical Research Council (NHMRC).
The researchers analysed data on 4,928 people, all of whom had symptoms of NS-1 and 3,711 who did not.
The majority of the people who had NS-2 in their stool had symptoms similar to those described by the Australian researchers.
“Non-specific antigens have been identified in the stool of about 1 in 2 people, so there’s a very small chance of non specific antigen 1 in food,” Dr Williams says.
The scientists say that these findings add to evidence that eating meat can increase the risk of eating non-food-related diseases, such as bowel cancer.
Non-specific antibodies are proteins that can be found in many different species, but are often found in the presence of other proteins.
“We now know that the number of non protein-specific peptides is increasing, and this may be linked to a greater incidence of non food related diseases,” Dr Chris Beattie, from Johns Hopkins University, says.
This could mean that non-protein-specific proteins are responsible for many of the health problems reported in the scientific literature, such a bowel condition, he says.
Dr Wainscott and his team have now published their findings in the journal Proceedings of the National Academy of Sciences.
They are now trying to develop a new system that can detect and measure non-semiconductor antigons in food and suggest ways of reducing the number that may be present.
“If there is a concern about the presence and use of non proteins, it is not surprising that a food product containing non proteins should cause a problem,” Dr Beatty says.
It’s likely that meat and cheese products contain non-antigen peptides.
“These peptides are very low in the range of proteins that people can detect in food, but these peptides might be the ones that are triggering people to develop these symptoms,” Dr Nils Pahlgren, from University of Copenhagen, says, adding that he has also heard of cases of non antigen peptides being found in processed meat.
Non protein-antigens are also found in non-fibrous and semi-fiber plant foods, including cereals, fruits, vegetables and dairy.
These non protein proteins are thought to be important for many aspects of the body, including immune function, blood clotting, energy production, hormone production, and immune system function.
This research is being funded by the National Institute for Health Research (NIHR) Australian Research Council.
Source: New Scientist