A British professor’s claim in a national newspaper article that aluminium in vaccines may cause autism has been called into question by fellow academics.

The claim, by Chris Exley, a professor of bioinorganic chemistry at Keele University, has been criticised by fellow scientists, who described his research as flawed, said it is “absurd” to draw conclusions from it, and raised concerns over a possible conflict of interest, all of which he denies.

Exley has claimed in the past that aluminium causes Alzheimer’s disease and is linked to breast cancer. His department has received money from a company that sells silicon-rich mineral water, which he thinks “everyone should drink every day to remove toxic aluminium from their bodies and brains”.

The article in question, which was partly taken from a piece Exley wrote for the health blog Hippocratic Post, was published by the Daily Mail and titled “Perhaps we now have the link between vaccination and autism”. It said that in Exley’s research, to be published in the Journal of Trace Elements in Medicine and Biology, “aluminium content of brain tissues from five donors who died with a diagnosis of ASD was found to be extraordinarily high”.

The Daily Mail's online story has had at least 59,000 shares so far, and a story about the research has been written on the anti-vaccination site Age of Autism. BuzzFeed News has previously revealed how false or unevidenced stories linking vaccines to autism are widely shared on the internet.

Earlier unfounded vaccine/autism scares based on fraudulent research by the British doctor Andrew Wakefield that was published in 1998 were linked to a huge drop in vaccination rates and subsequent outbreaks of measles in Britain and other countries.

Exley is quoted as saying: “Perhaps we now have the link between vaccination and autism spectrum disorder (ASD), the link being the inclusion of an aluminium adjuvant in the vaccine.”

However, scientists told BuzzFeed News that Exley’s study is profoundly flawed. The study looks at the brain tissue of two groups of donors who had been diagnosed with ASD and subsequently died.

The first consists of five people between the ages of 15 and 50; the second consists of 10 people, but the details of only five are made available. It found what it said were extremely high levels of aluminium in some of the brains.

But Dorothy Bishop, a professor of neurodevelopmental biology at the University of Oxford, told BuzzFeed News that she would dismiss the study's results, while Jonathan Green, a professor of child and adolescent psychiatry at the University of Manchester who specialises in autism, told BuzzFeed News it was “absurd to draw conclusions” from the study.

The main problem, said Bishop, is that the study lacks controls: It looked at no healthy brains to see whether they were different from the ASD-diagnosed brains. “You always need controls, because you tend otherwise to see what you expect to see, even if there is no deliberate attempt at fudging the data,” she said. “This point is the most serious, in my opinion, and would make me just dismiss the results.”

Bishop said: “When you’re doing that sort of analysis you absolutely have to do it blind and have a set of control brains, and they didn't.” She said it was surprising that this study had been given access to the Oxford Brain Bank’s brains: “These brains are very, very precious and rare.”

Exley told BuzzFeed News that suitable controls were unavailable, and that his earlier studies, done using the same technique, gave them “a very good understanding”. He added that he had taken steps to “find out how much aluminium could conceivably have been added by the process”.

Second, the study didn’t mention how any of the donors died, which both Bishop and Green felt was relevant. “Clearly the cause of death is pertinent to brain findings and needs to be taken into account,” said Green. Exley said that none of them had died of causes which would cause him to expect them to have elevated aluminium levels, and that the reason he had not included the causes of death was to avoid the donors being identifiable. Both Green and Bishop felt that it should have been possible to include the relevant information in a nonidentifiable way.

Third, the study’s results are strange, according to Dr Alice Howarth, a cellular physiologist who works at the nonprofit organisation Merseyside Skeptics. “The very high figures stand out as potentially anomalous,” Howarth told BuzzFeed News. “They’ve taken three pieces of tissue from one lobe of one donor’s brain and measured each separately. One showed a [value of micrograms of aluminium per gram of brain tissue] of 2.44; one was 1.66; and the third was 22.11!”

She says most scientists would remove the third result from their findings because it was so anomalous, or at least carry out the test several more times, and that it was “astonishing” Exley had not. Instead, Exley’s paper adds the three figures together and averages them – and then places great weight on the result, saying “one has to question why, for example, the aluminium content of the occipital lobe of a 15-year-old boy would be 8.74μg/g”.

There are similar strange results in the table, the most dramatic being one with results of 0.01, 0.64, and 18.57, and another of 1.71, 1.64, and 17.10. All are given as averages of the three numbers, and the paper makes no mention of the wide variations beyond a mention of “significant inter-tissue, inter-lobe and inter-subject variability”. Bishop said the use of a mean in this situation is not recommended, “as it would not be representative of any of those in the group”.

Exley said this was because while metals such as iron, which are essential to life, are found homogeneously throughout the brain, “non-essential, toxic” ones are extremely localised, perhaps where there is damage, explaining the difference, and that he only included the mean figure because the reviewers wanted it.

In the introduction to the research paper, Exley claims the “burgeoning use” of aluminium in vaccines “has been directly correlated with increasing prevalence of ASD”, but Green told BuzzFeed News that this was an “old, discredited story with no epidemiological evidence”. Exley strongly disagreed with this assessment. The reference in Exley’s paper is to a study in the Journal of Inorganic Chemistry that the World Health Organisation’s Global Vaccine Safety Initiative describes as “seriously flawed”. But Exley said “most scientists take little notice of non-peer-reviewed documents emanating from the WHO”, and that the paper was published in a reputable journal.

Exley is also facing questions over why he did not declare his involvement with a company called SilicaWaters.com, which sells “a unique, natural silica bottled water”, in the “competing interests” section of the research paper.

The SilicaWaters website says it donates 10% of its net sales to Exley’s research at Keele University “into the benefits to health of drinking silica-rich water”.

Exley has written for the Hippocratic Post (again reproduced in the Daily Mail) that “everyone should drink silicon-rich mineral water every day to remove toxic aluminium from their bodies and brains”.

Exley’s research paper says he and his fellow authors “have no competing interests”.

Green said the SilicaWaters link is something that should “very definitely” be mentioned in the “competing interests” section of the paper, while Bishop agreed that it “probably” should have been. “The general recommendation is that you should mention anything that could be regarded as affecting your judgment,” she said.

Exley told BuzzFeed News he did not make any money from the sales, and that the SilicaWaters company had been set up by a local businessman who wanted to provide money for his research. At the time of writing, he said, the company had given only around £300 to Keele.

He did acknowledge that it might have been a good thing to add to the competing interests section: “Now I’ve had this conversation, maybe I’ll do it [next time].”

As well as previously claiming that aluminium causes Alzheimer’s disease, Exley has also previously claimed that it is found in the breast tissue of women who have had mastectomies.