If you were involved in the revision of the UK's alcohol guidelines, you are the last person in the world who should be criticising others for misrepresenting evidence.
As I've explained before, the benefits of moderate drinking were subjected to the full 'merchants of doubt' treatment by the Chief Medical Officer's guidelines committee. They blatantly cherry-picked the evidence, relying heavily on the work of one sceptic (
Tim Stockwell) while raising a bunch of zombie arguments that have long since been debunked in the literature.
But 'public health' knows no shame and so Mark Petticrew, the activist-academic who helped lead the evidence review -
and who told his colleagues what the conclusion was going to be before it had got started - has
popped up today with a diatribe dressed as a study, claiming that the drinks industry 'appears to be engaged in the extensive misrepresentation of evidence about the alcohol-related risk of cancer.'
His evidence for this comes from the tried and tested quack methodology of doing a Google search and, er, misrepresenting the evidence. Written with three colleagues - although I'll just say 'Petticrew' in this blog post for brevity - he breaks the industry's alleged misrepresentations into several categories.
He starts with what turns out to be his strongest evidence. Under 'Denying, disputing or selectively omitting the relationship between alcohol consumption and cancer', he quotes the International Alliance for Responsible Drinking (IARD) and some Canadian organisation who say:
‘Recent research suggests that light to moderate drinking is not significantly associated with an increased risk for total cancer in either men or women.’ International Alliance for Responsible Drinking
'Some studies show a link between alcohol and breast cancer among both pre-menopausal and post-menopausal women. However, no causal relationship has been shown between moderate drinking and breast cancer.’ Éduc’alcool (Quebec)
The first of these quotes, from IARD, cites
a BMJ study from 2015. The study actually
does show an increase in total cancer risk from moderate drinking for women, but not for men. The IARD quote is badly worded, at best, and is all the stranger because they go on to explain the results of the study correctly in the sentences that follow (Petticrew doesn't quote that bit). The risks are extremely low, amounting to an increased risk of between two to four per cent, but they are not completely absent.
However, there is evidence from other sources that moderate and light drinkers do not have a higher cancer risk. Only last month
a large American cohort study found that overall cancer risk was 0.89 (0.82-0.97) for light drinkers and 0.95 (0.85-1.05) for moderate drinkers. This means that light drinkers were significantly
less likely to die from cancer in the study period. Nevertheless, the source used by IARD does not accurately reflect the statement quoted by Petticrew so it's 1-0 to him.
The second quote depends on what evidence you consider sufficient for a 'causal relationship'. Epidemiology famously cannot
prove causation, but most authorities consider the statistical association to be good enough to infer it in this instance. On that basis, the Quebec organisation could be said to be 'disputing' the evidence, albeit no more than Petticrew and his chums have been disputing the much greater weight of evidence about the benefits of moderate drinking.
This is as good as the study gets as an exposé of industry 'denial'. Everything else in it is drivel, as we shall see. For the most part, Petticrew excoriates the industry for saying things that are patently true.
Under 'Distortion: mentioning some risk of cancer, but obscuring, misrepresenting or obfuscating the nature or size of that risk', he writes
It is commonly stated by these organisations (12/20 SAPROs) that the risk of some common cancers only exists for ‘heavy’, ‘excessive’ or ‘binge’ drinking. For example,
‘Cancer risk associated with the consumption of alcohol is related to patterns of drinking, particularly heavy drinking over extended periods of time.’ Australia, Drinkwise
In what universe is this stating that risk 'only' exists for heavy drinkers? If Drinkwise had meant to say that, they would have done so. As it is, the use of the word 'particularly' clearly implies that there is risk, albeit less risk, for non-heavy drinkers.
Similar statements also appear on the IARD website, such as ‘In general, alcohol-associated cancers have been linked with heavy drinking’ [27].
The scientific evidence suggests that such statements are misleading (Table S1), because the increased risk of some common cancers, such as breast, oesophageal, laryngeal, mouth and throat cancers and cancers of the upper aerodigestive tract, starts at low levels of consumption, even though it is low at those low levels [7,8] (see also Table S3).
Like the Drinkwise quote above, the IARD statement is true. Cancer risk is clearly related to patterns of consumption and heavy drinkers have a greater risk than light drinkers.
IARD's report Drinking and Cancer provides five academic references to support this.
It is an indisputable facts that some cancers, such as liver cancer and possibly pancreatic cancer, are
only associated with alcohol if you're a heavy drinker. For those cancers which are linked to moderate consumption, risk is significantly greater for heavy drinkers. Neither of the sources quoted above suggest otherwise, and the IARD document explicitly discusses the cancers that are - or might be - linked to light/moderate consumption.
It should also be noted that in the press release for this 'study', Petticrew says:
'It's
important to highlight that if people drink within the recommended
guidelines they shouldn't be too concerned when it comes to cancer.'
If IARD had said that, he would doubtless condemn them for downplaying the risks or being 'misleading'.
He continues:
Other industry claims (from three organisations) relate to disputation of the mechanisms, or involve claims about the consistency of the evidence, as in these examples:
‘Recent studies indicate a dose-response relationship between alcohol consumption and breast cancer, although this relationship was not evident in some past studies.’ IARD [27].
‘All the studies show that the knowledge about the causes of breast cancer is still very incomplete and as scientists from the National Institute on Alcohol Abuse and Alcoholism in the USA recently pointed out, some other (possible confounding) factors have not been considered in the research relating the consumption of alcoholic beverages to breast cancer.’ Wine Information Council [28].
This is also a feature of SABMiller materials:
‘The mechanism by which alcohol consumption may cause breast cancer is not fully known.... The relationship... is undergoing vigorous research... If and how these two factors may interact and affect risk is not completely known.’
All of these are uncontroversial statements of fact and plenty of non-industry sources echo them.
Here is the
American Cancer Society, for example:
Exactly how alcohol affects cancer risk isn’t completely understood.
In fact, there might be several different ways it can raise risk, and
this might depend on the type of cancer.
And here is
Cancer Research UK:
According to Dr Ketan Patel,
a Cancer Research UK expert on how alcohol causes cancer: “We don’t
really know. We don’t fully understand why alcohol causes some cancers
and not others.”
Petticrew says that statements like this are examples of the industry tactic of 'Claiming or implying that, as knowledge of the mechanism is incomplete, the evidence of a causal relationship is not trustworthy'. That's rich coming from him. The alcohol guidelines review repeatedly cast doubt on the benefits of moderate drinking by
falsely claiming that there is a 'lack of well evidenced biological processes that could explain the effect' and then presenting this as proof that the benefits do not exist at all.
Petticrew pulls exactly the same trick in his little polemic when discussing non-Hodgkin lymphoma which has been
inversely associated with alcohol consumption. Keen to dismiss any benefits from drinking, he quotes an authority saying that 'there is no immediately obvious mode of action that could explain the association.'
But there is a difference between what Petticrew does and what the industry and cancer charities quoted above are doing. They explicitly state that the risks are real but that the causal mechanisms are not fully understood. Petticrew, by contrast, is claiming or implying that, as knowledge of the mechanism is incomplete,
the evidence of a causal relationship is not trustworthy.
Petticrew then mentions the Portman Group...
The Portman Group’s response to the consultation on the revised UK guidelines (issued in 2016) includes a section in which the evidence is disputed, referring to protective effects. It refers to the ‘increased risk of a small number of cancer types’ and states: ‘Different levels of alcohol consumption have a range of effects on cancer risk including no impact on the majority of cancers, and in some cases, an inverse relationship.’ [11]. As well as misrepresenting the evidence, this statement is misleading as it confuses the number of different ‘types’ of cancer, with the risk of specific cancers.
Again, everything the Portman Group says here is true. The press release that accompanies Petticrew's article correctly notes
that alcohol 'accounts for about 4% of new cancer cases annually in the
UK.' There are more than 100 different types of cancer and
IARC has established that alcohol
consumption could cause seven of them: 'cancers of the oral cavity,
pharynx, larynx, oesophagus, colorectum, liver
(hepatocellular carcinoma) and female breast.' They also noted that 'an association has been observed between
alcohol consumption and cancer of the pancreas'. But that's it.
It is reasonable to describe seven out of 100 as a 'small number' and it is indisputable that alcohol has 'no impact on the majority of cancers'.
It is also true that an inverse relationship between alcohol consumption and a few forms of cancer, including
renal cancer and
non-Hodgkin lymphoma, has been repeatedly found in epidemiological studies. Petticrew asserts that there is a 'lack of evidence for protective effects of alcohol consumption on cancer'. An unbiased reader who reads the meta-analyses (see links in previous sentence) might conclude that he sets the bar of proof higher for evidence that shows benefits than for evidence that shows harm.
The Portman Group is neither 'misrepresenting' nor 'disputing' the evidence. Petticrew chooses not to quote from page 20 of
Portman's consultation response in which they explicitly say:
'The relationship between alcohol consumption and increased risk of certain cancers is clear and we believe it is important consumers are aware of this.'
Moreover, the sentence immediately before the one Petticrew quotes (beginning 'Different levels...') says:
'We fully accept the evidence on the links between alcohol and certain types of cancer.'
Under 'Distraction: focussing discussion away from the independent effects of alcohol in increasing the risk of common cancers', Petticrew cites the following examples of the industry saying things that are 'potentially misleading':
‘Not all heavy drinkers get cancer, as multiple risk factors are involved in the development of cancers including genetics and family history of cancer, age, environmental factors, and behavioural variables, as well as social determinants of health.’ Australia: Drinkwise [26].
‘Alcohol has been identified as a known human carcinogen by IARC, along with over 1,000 others, including solvents and chemical compounds, certain drugs, viral infection, solar radiation from exposure to sunlight, and processed meat.’ IARD [27].
‘For example, the fact that you are female is a risk factor in developing breast cancer. We also know breast cancer is age-related so you’re more likely to develop it as you get older and that you’re more prone to breast cancer if it is part of your family history. These are all factors beyond our control. We also know that risk is related to the ‘hormone environment’ that women experience during the course of early pregnancy, child birth and breastfeeding which all exert a protective effect.’ Drinkaware, UK [32].
These are mundane statements of fact. It seems that Petticrew won't be happy until the alcohol industry's only health message is 'IF YOU DRINK, YOU'LL DIE!!! GET AWAY!!!'
In fact, these 'industry messages' are not very different from that of the
Committee on Carcinogenicity, who say:
Drinking alcohol has been shown to increase the
risk (or chance)
of getting
some types of cancer.
This does not mean that everyone who drinks alcohol will
get cancer, but studies have shown that some cancers are more common in people
who drink
more
alcohol.
The Drinkaware discussion of breast cancer is similar to what you will find on
Cancer Research's webpage about breast cancer. Although Petticrew doesn't mention it, the quote he uses is from
Professor Paul Wallace, an epidemiologist with an impressive CV in alcohol research, who is Drinkaware's Chief Medical Advisor. The full quote runs as follows:
Professor Wallace says it’s important to put this risk into context.
There are many other factors which increase the risk of developing
breast cancer. “I often sit down with my patients and explain that there
are certain factors we can do nothing about,” he says. “For example,
the fact that you are female is a risk factor in developing breast
cancer. We also know breast cancer is age-related so you’re more likely
to develop it as you get older and that you’re more prone to breast
cancer if it is part of your family history. These are all factors
beyond our control."
There is a lot that Petticrew could have quoted from that
Drinkaware webpage but didn't, presumably because it wouldn't fit his narrative of an industry cover up. For example:
When asked to name the main health effects of drinking too much
alcohol, many people will first say liver disease. Others will mention
heart disease. Some will name mental health issues. Cancers are often
low down on the list.
But they shouldn’t be – especially breast cancer.
It is clear from a number of large scale studies that there is a link
between alcohol consumption and cancer. Globally, one in five (21.6%)
of all alcohol-related deaths are due to cancer. Breast cancer is the most common cancer among women and second only to lung cancer as a cause of cancer death in women.
Professor Paul Wallace, Drinkaware’s Chief Medical Advisor, believes
that more people should know that alcohol can increase women’s risk of
getting breast cancer.
I challenge any reasonable person to read this - or, indeed,
any Drinkaware literature - and claim that the organisation is trying to downplay or deny the risks of drinking. I was on a Drinkaware panel once. They are basically a temperance group.
Only a lunatic could think otherwise.
Petticrew says that there are 'two particularly frequent areas of misinformation', namely breast cancer and colorectal cancer. As evidence, he goes back to the Portman Group...
The Portman Group’s response to the UK guidelines includes a section on breast cancer, in which the evidence is disputed. For example, it states that ‘studies associating moderate alcohol consumption are contradictory’.
Is the evidence 'disputed' by the Portman Group? No, it is not. Here is what the Portman Group actually said in their consultation response:
A percentage (6%) of all breast cancer cases in the UK is attributable to alcohol - the links between alcohol consumption and breast cancer are clear and it is right that consumers are made aware of the risks.
As for the studies being 'contradictory', there is some truth in this, but it is not the Portman Group saying it. The Portman Group were only quoting
some (reputable) scientists who said:
'Since studies associating moderate alcohol consumption and breast cancer are contradictory, a woman and her physician should weigh the risks and benefits of moderate alcohol consumption.'
Petticrew misquotes this and wrongly attributes it to Portman, which is sloppy at best. In fact, the point being made by the Portman Group is that risks should be explained in a meaningful way. This is not controversial.
Cancer Research UK have made an effort to explain breast cancer risk in absolute, rather than relative, terms. John Holmes made a similar point in a
journal article this week.
Nevertheless, Petticrew repeats his false claim about Portman disputing the evidence, saying:
...in disputing the evidence on increased breast cancer risk, the Portman Group document does not reference the IARC reviews, other systematic reviews, nor the Committee on Carcinogenicity review.
Not only is the initial claim a lie, but the claim about references is also a lie. The Portman Group document cites the Committee on Carcinogenicity reports several times and uses it as a source for a table which shows 60,000 breast cancer cases a year, of which Portman says alcohol causes 3,600 (see below).
This is a strange way of 'disputing the evidence'.
What is the point of all this flim-flam? Regular readers will have probably guessed. It's all part of creating a narrative of alcohol being the new tobacco and Big Booze being the new Big Tobacco.
And he's good the headlines he wanted.
If you want to know why a 'public health' study has been written you have to head straight to the 'discussion' section where it all comes out...
The most obvious parallel is with the global tobacco industry’s decades-long campaign to mislead the public about the risk of cancer, which also used front organisations and CSR activities to mislead the public.
...These findings therefore have significant implications. They provide evidence that the AI [alcohol industry], like the tobacco industry, misleads the public and policy-makers about the cancer risks of their products. Our findings are also a reminder of the risk which accompanies giving to the AI the responsibility of informing the public about alcohol and health.
...some public health bodies, academics and practitioners liaise with the industry bodies included in this study, for example by acting as advisors or trustees, or by collaborating with them in implementation activities. Despite their undoubtedly good intentions, we suggest that it is unethical for them to lend their expertise and legitimacy to industry campaigns which mislead the public about alcohol-related harms.
The AI, unlike the tobacco industry, still has significant access in many countries to government health departments. It is also active in the international policy arena, with, for example, partner or stakeholder status at World Health Organization and United Nations meetings relevant to alcohol, on occasions when the tobacco industry is excluded. This study shows that the AI uses similar tactics to the tobacco industry, to the same ends: to protect its profits, to the detriment of public health.
There you have it. Petticrew is none-too-subtly telling academics to back away from the alcohol industry if they want to keep their reputations intact in the coming war on drink. He is also sending a signal to politicians that industry always lies while anti-alcohol campaigners, such as himself, are trustworthy. And he is telling governments to lock drinks companies out of the political process as has happened with tobacco under the Framework Convention on Tobacco Control.
Petticrew gets to this conclusion by saying things that are not true and denying things that
are true. His study uses sleight of hand, evasion and downright misrepresentation to create a false narrative that falls apart as soon as you look at the primary sources. He does precisely what he accuses the industry of doing: selectively quoting from research in order to mislead, lying by omission, and making claims that cannot be supported by the weight of evidence.
For all of Petticrew's bluster, the drinks industry is dominated by massive, blue-chip companies with who would get sued if they lied about the harms of drinking. 'Public health' academics have no such incentive to stay honest.
Not for the first time, Petticrew has started with a conclusion and scrambled around for evidence to support it. When he failed to find any evidence, he wrote what he was going to write anyway. If the 'public health' movement had any integrity, the man would be a pariah.
