A2 milk has emerged as an intriguing new option among the diverse milk varieties available – though the scientific backing for its purported advantages remains hazy.
The distinction lies in the A1 and A2 proteins found in cow’s milk, with their proportions varying based on the cattle breed.
Initial claims suggested that the conventional A1 milk might contribute to conditions ranging from autism and schizophrenia to type 1 diabetes and heart disease.
This assertion hinged on the idea that A1 could break down into a potentially harmful peptide called beta-casomorphin-7 (BCM-7).
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The Peptide Puzzle: BCM-7
Both A1 and A2 belong to the casein protein family, comprising around a third of human milk proteins but a whopping 80% in cow’s milk.
These two proteins are nearly identical, each consisting of 209 amino acids – the building blocks of proteins.
The sole difference is at the 67th amino acid position, where A1 has a histidine while A2 has a proline.
This single amino acid variation in A1 is the crux of the proposed issue, as it allows the creation of the BCM-7 peptide during digestion.
BCM-7 is related to opiates and has exhibited a wide array of effects in animal studies when injected directly into the bloodstream, from pain relief to enhanced learning.
However, while BCM-7 has shown some minor impacts on gut motility and inflammation in animals, these effects have not been conclusively demonstrated in humans.
The A2 Emergence
In 2000, the a2 Corporation was founded to commercialize the A2 protein in a branded milk product.
They patented a genetic testing method to identify cattle producing A2 milk, which commands a higher price due to this process.
The corporation pursued legal action against a major New Zealand dairy cooperative in 2002, accusing it of concealing the potential harmful effects of A1 milk.
Reviews and Responses
Independent researcher Stewart Truswell’s 2005 investigation found no “convincing or probable evidence” linking A1 beta-casein to type 1 diabetes or heart disease, labeling the autism and schizophrenia link as “more speculative” and “unsubstantial.”
The European Food Safety Authority’s comprehensive 2009 review echoed these conclusions more definitively.
Food Standards Australia New Zealand (FSANZ) concluded no need to distinguish between A1 and A2 milk in 2009, and its milk information contains no A1/A2 advisory.
New Zealand’s food safety summary states further research, especially human trials, is needed to confidently establish the A1/A2 milk composition’s health significance.
Gut Comfort Claims
Today, A2 milk markets itself as an alternative for those experiencing gut discomfort from regular milk, though experts note studies are small and require improvement.
Ultimately, milk remains a nutritious, calcium-rich food source with high bioavailability. Whether the premium for A2 milk is worthwhile is a personal choice.
Resources:Â
https://www.tandfonline.com/doi/full/10.1080/10942912.2012.712077
https://academic.oup.com/advances/article/8/5/739/4772179
https://en.wikipedia.org/wiki/The_a2_Milk_Company
https://www.nature.com/articles/1602104
https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2009.231r
http://www.ausfoodnews.com.au/2009/03/03/fsanz-says-no-need-to-distinguish-a1-and-a2-milk-based-on-research-available.html
http://www.foodstandards.gov.au/consumer/generalissues/milk/Pages/default.aspx
http://www.foodsafety.govt.nz/elibrary/beta-casein-A1-A2-in-milk.htm
https://theconversation.com/science-or-snake-oil-is-a2-milk-better-for-you-than-regular-cows-milk-62486
