Research from China published this month into the health effects of A2 milk lends support to the sales efforts of NZX-listed market darling a2 Milk, although some scientists remain unconvinced.
Thepaperpublished in theJournal of Pediatric Gastroenterology and Nutritionearlier this month concludes: “Replacing conventional milk with A2 milk reduced gastrointestinal symptoms associated with milk intolerance in Chinese preschool children, with corresponding improvements in aspects of cognitive performance.”
However, Otago University professor of human nutrition Jim Mann expressed doubts about the study.
“Every paper I have reviewed (and there have been many) relating to A2 science and human health has been either garbage or a totally unacceptable overinterpretation of the data,” he said.
“The company advertising has been grossly irresponsible.”
A2 milk contains only the A2 form of beta casein, while standard milk typically contains both A1 and A2 beta caseins.
The Chinese research hypothesised that lactose intolerance, which is prevalent in ethnic Chinese people, could be affected by inflammation of the small intestine reducing the presence of lactase, an enzyme required to process lactose.
Lactose is the form of sugar present in milk.
The theory suggests gastrointestinal inflammation may be linked to the release of a peptide known as beta-casamorphin-7, or BCM7, in digesting A1 milk, which does not occur to the same extent in digesting A2.
The research was done in September and October 2016 by Xiaoyang Sheng and Zailing Li of Shanghai and Beijing universities respectively, Jiayi Ni of consultancy firm Sprim in Shanghai and Greg Yelland of Monash University in Melbourne.
The paper notes the study was funded by A2 Milk and the company “had insight into drafting the manuscript.”
The paper also noted a conflict in Yelland’s role as a director of Neurotest, the company that owns the Subtle Cognitive Impairment Test used in the study.
The SCI test shows subjects a pair of lines and asks them to decide which one is shortest in a process repeated many times.
According to the Neurotest website, “children as young as eight years old have been successfully tested.”
The Chinese study used 80 children aged five to six, of whom 68 were confirmed deficient in lactase, the enzyme required for processing lactose.
NBRemailed Yelland via Neurotest and Monash to ask whether the test had been validated for children younger than eight but received no response.
In the double blind study, two groups of subjects were given 250ml of milk twice daily over a five-day period, followed by a nine-day “washout” period and another five-day period of milk intake.
The groups alternated A1 and A2 milk consumption.
Positive results
The researchers reported children drinking the A1 milk had higher levels of BCM7 and more gastrointestinal symptoms such as bloating, abdominal pain or flatulence.
They also reported improvements in the accuracy of SCIT responses in children taking the A2 milk.
“These data suggest that consumption of A2 milk has a positive effect not only on the gastrointestinal system, but also on cognition in preschoolers,” they said.
Otago University’s Edgar Diabetes and Obesity Research Centre researcher Andrew Reynolds.
Andrew Reynolds, a researcher at Otago University’s Edgar Diabetes and Obesity Research Centre said in his view the research was a small study that didn’t mean much.
“They gave milk to lactose intolerant people and noticed an increase in gastrointestinal symptoms. The difference in cognitive behaviour measured means nothing…
“The most interesting thing is the potential immune response differences – that would need to be better explored with a different study for it to mean something.”
Reynolds also said the wording on a2 Milk’s role in which it had insight into drafting the manuscript but “the authors had full responsibility for, and decided about, manuscript content”was “suspicious.”
In a statement explaining the wording, a2 said: “The a2 Milk Company sponsored the study – if companies did not sponsor studies it would be difficult for clinical research to occur.
“The a2 Milk Company provided background information to the authors with respect to previous beta casein science. The company did not provide any analysis of the results.
“The reference to drafting relates only to guidance that the a2 Milk Company provided as to how to refer to its brand within the manuscript.
“As cited in the publication: ‘… the authors had full responsibility for, and decided about, manuscript content.’
“All research papers go through a comprehensive peer review process prior to publication.”
Shares in a2 are up about 60% over the past year to trade above $17, valuing the company at $12.7 billion.
In a presentation in May, a2 said its revenue for the nine months to March was $938 million, up 42% on the same period a year earlier.
The company said it had 5.7% of the infant formula market in China and a 10.8% share by value of the Australian liquid milk market.
Net profit for the six months to December was $152.7m, up 55% on a year earlier.
Despite its strong performance, the share price appreciation has attracted significant short selling, with more than 6% of its stock sold short as of July 22, according to data from the Australian Securities and Investments Commission.
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