Due to the popularity of Dr Geoff’s ‘Behind the Headlines’ series, this page will be devoted to his reactions to recent news headlines.
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In this rolling section, I have written short comments upon some reports of “new research findings” that have appeared in the health or science pages of the media. I am often critical of the way research reports are portrayed in the media as they tend to be over hyped. My commentaries are not researched or referenced but my personal assessment based upon my existing knowledge and experience. Where it is accessible for free then I have read the original paper. In some cases I have refrained from posting comments because I cannot readily access the paper. If I have commented without seeing the full paper then this is stated before the comments. I only regularly read one newspaper and the BBC news web-site so if readers find stories elsewhere that they think I might be able to comment upon then please send a link to email@example.com .
Posted on 22/05/2018
Trans Fats Should be Eliminated Worldwide by 2023, W.H.O. Says
REview dietary sources of industrially-produced trans fats and the landscape for required policy change.
Promote the replacement of industrially-produced trans fats with healthier fats and oils.
Legislate or enact regulatory actions to eliminate industrially-produced trans fats.
Assess and monitor trans fats content in the food supply and changes in trans fat consumption in the population.
Create awareness of the negative health impact of trans fats among policy makers, producers, suppliers, and the public.
Enforce compliance of policies and regulations.
WHO estimate that up to 500,000 deaths are caused annually by eating these artificial fats. Trans-fatty acids are only subtly different from natural cis fatty acids and they are mainly produced during the process of hydrogenation of vegetable oil which was the used to make solid margarine and vegetable shortening from liquid vegetable or fish oils. Small amounts of trans fatty acids occur naturally in some fats from ruminant animals like cattle and sheep e.g. in beef, lamb and especially dairy products like butter, cheese and cream. It is the artificially generated trans fatty acids that the WHO is targeting.
The subtle difference in structure greatly affects the properties of trans-fatty acids e.g. oleic acid, a ubiquitous cis-fatty acid, has a melting point of 13o whereas its trans equivalent/isomer elaidic acid has a melting point of 45o and is solid at room temperature. Unsaturated fats are normally the healthy option but trans-fats are worse than saturated fat at raising the “bad cholesterol” (LDL) in the blood and they also lower the “good cholesterol” (HDL). They may have other adverse effects like triggering inflammation. Intakes of trans-fatty acids increased from the 1950s as consumers were persuaded to replace saturated spreading and cooking fats like butter and lard partly with “healthier” hydrogenated margarine and vegetable shortening as part of efforts to lower blood cholesterol levels. In 1986, the average intake of trans fatty acids in the UK was estimated at around 5g/day or 2.2% of food energy but some individuals may have been taking in 25-30g/day (i.e. well over 10% of food energy). 1991 UK dietary guidelines suggest that no more than 2% of food energy should come from trans-fats and in 2018 the WHO recommended no more than 1%.
Margarine manufacturers responded to criticism of trans fatty by altering the way it is made and none of the spreading fats now sold in the UK contain hydrogenated oil. Many affluent countries have taken measures to eliminate hydrogenated oils from food. Denmark led the way in 2003 and effectively banned the sale of products containing artificial trans fats. By 2014, similar legislation had been enacted in Austria, Hungary, Iceland, Norway and Switzerland. However, the WHO suggested that in 2014 intakes in some Eastern regions might still be 30g/day. In 2013, the US FDA announced that partially hydrogenated oil was no longer “general recognised as safe” and in 2015, food manufacturers were given 3 years to re-formulate their products to eliminate them. In March 2012, many major UK food producers, retailers and fast food chains agreed to voluntarily phase out partially hydrogenated oils from their products by the end of that year.
Recent data from the National Diet and Nutrition Survey found that intakes of trans fatty acids had fallen to just 0.5% of food energy and almost all of that may be natural trans fatty acids. The position in many other countries is much less encouraging, with particularly high intakes in South Asian countries; many Indian street foods and packaged snacks are high in hydrogenated vegetable oils with no warning for consumers. The WHO announcement was welcomed and supported by the International Food and Beverage Alliance, a grouping of 12 major multinational food companies including Danone, Coca-Cola, Kellogg’s, McDonald’s, Mars, Nestle and Unilever.
Posted on 11/7/2017 Measles “tragedy” kills 35 across Europe
This headline was taken from the BBC news web-site (11/07/17) and discusses findings by the WHO that 35 people across Europe (31 in Romania) have died as a result of measles in the past year. Italy has had 3300 cases and the death of a six year old boy is the most recent of these European measles deaths. Measles deaths have also been reported in Germany and Portugal in the last year. The WHO regional director for Europe is quoted as saying that “every death or disability caused by this vaccine-preventable disease is an unacceptable tragedy”. If 35 people have died then many more will have experienced a serious illness and some of these are likely to have suffered permanent impairment as a result of their measles.
This BBC report is one of more than a dozen BBC reports over the past year dealing with local outbreaks, attempts to control them and attempts by governments to improve vaccination rates. Several of these reports highlight the role of Andrew Wakefield’s discredited claim that the MMR jab is linked to autism, as a major reason why vaccination rates have fallen below the 95% rate necessary to achieve herd immunity. This Wakefield case, the anti-vaccination movement and its impact has been the subject of one of my earlier full blog articles. Some of the other measles-related articles from the BBC news web-site in the past year:
22/06/17 600 children get MMR jab after measles outbreak in Newport
26/06/17 Germany vaccination: Fines plan as measles cases rise This article reports that the German government is planning fines of up to ϵ2500 for parent who fail to seek medical advice on vaccinating their children. Although it will not be an offence to refuse vaccinations.
19/05/17 Italy makes 12 vaccinations compulsory for children This is a report that the Italian government has ruled that children must be vaccinated against 12 common illnesses (including measles, mumps and rubella, MMR) before they can enroll at state schools. Rates of vaccination against measles have fallen to below 80% in Italy.
9/06/17 Parents eye Austrian asylum in Italy vaccination dispute This describes threats by some anti-vaccine parents in the German-speaking Tyrol region of northern Italy to seek asylum in Austria rather than allow their children to be vaccinated.
28/06/17 Italian father in passionate vaccines plea to Veneto governor This describes a letter written by an Italian father, whose daughter has low immunity after chemotherapy, pleading with the regional governor of Veneto to abandon his legal challenge to this Italian government ruling making vaccinations compulsory.
28/03/17 Measles outbreak across Europe
10/10/16 Vaccination offer after Edinburgh measles outbreak
23/09/16 Carmarthenshire measles outbreak linked to festival
8/08/16 Measles spreading at music festivals
The effects of this discredited paper involving at least partially fabricated results from just 12 subjects are still being felt across Europe and the rest of the world.
Posted on 21st June 2017
Good fats as helpful as statins against heart disease, group says
This headline is from NBC News 16/06/17 and was prompted by an authoritative report on “Dietary Fats and Cardiovascular Disease” commissioned by the American Heart Association (AHA). Many media comments on this report have focused upon its conclusions about coconut oil and this was dealt with in the previous post in this “Behind the headlines” section.
Since the 1960s, it has been the generally accepted scientific and medical wisdom that dietary saturated fats from meat fat, milk fat and tropical oils like coconut and palm oil raise the “bad cholesterol” (LDL) in the blood. A raised LDL-cholesterol level leads to furring up of arteries (atherosclerosis) and this in turn increases the risk of cardiovascular diseases like heart attacks and strokes. Cardiovascular diseases are the biggest cause of death in affluent countries like the USA and account for over 17 million deaths per year globally. Official dietary guidelines in most western countries thus usually suggest strict limits on the intake of saturated fats. They also usually suggest limits on total fat intake (e.g. to reduce obesity risk) and this means that if total calorie intakes remain the same, that these fat calories are often replaced by carbohydrate calories; ideally from unrefined starchy products which are also rich in dietary fibre.
It is certainly possible to achieve substantial reductions in saturated fat intakes and LDL-cholesterol levels by diet modification in motivated subjects when good dietary counselling and monitoring support is provided. This high level of support and monitoring would be likely, for example, in well-designed clinical trials of dietary interventions. It is much less effective if patients are simply told that their cholesterol is a bit high and they are just given a generic diet sheet.
Statins are a class of drugs that inhibit cholesterol synthesis in the body and they are very effective in reducing LDL-cholesterol levels and in clinical trials they reduce cardiovascular events and both cardiovascular and total mortality in subjects with raised LDL-cholesterol levels or who have already had a heart attack. They are the cheap, simple and effective option for lowering blood cholesterol levels, requiring little effort from either patient or practitioner. Up to 7 million people in the UK take statins regularly and recent changes in NICE guidelines might more than double the number eligible to be prescribed them.
The AHA report was commissioned in response to some contradictory findings from recent meta-analyses (amalgamations) that seemed to question the traditional model i.e. saturated fats raise LDL-cholesterol and raised LDL causes increased furring up of arteries (atherosclerosis) and cardiovascular disease. This they say has created confusion amongst patients, physicians and the general public. Their report is intended to clarify the situation and reduce this confusion. In the UK there have been a number of media reports, based upon scientific publications, that have questioned this traditional wisdom e.g. reports that eating dairy products, even high fat dairy products does not increase risk of strokes or heart attacks and that saturated fats do not increase heart attack risk . The AHA report identifies several meta-analyses that produce apparently contradictory conclusions i.e. that replacing dietary saturated fats does or does not reduce cardiovascular disease events. In a meta-analysis there is a weighted amalgamation of studies with similar design, intervention strategies and outcome measures to essentially produce a single study of greater statistical power and thus to get a consensus finding from all of the studies. One reason why different meta-analyses addressing an apparently single question come up with different conclusions is because of differences in the criteria they use for selecting studies to include. The AHA report suggested that it was differences in what replaced the saturated fat that resulted in differences in outcomes from meta-analyses, clinical trials and observational studies. Those studies that replaced saturated fat with polyunsaturated fat led to bigger reductions in LDL- cholesterol and to reductions in cardiovascular disease whereas those that replaced the fat with “carbohydrate” did not produce significant reductions in cardiovascular disease. There was an indication that replacing saturated with monounsaturated fats was less effective than polyunsaturated fat. Much of the evidence upon which the conclusions of this report are based is from experimental studies (like clinical trials) rather than from less valid observational studies. I am particularly unimpressed by observational studies that look at the associations between crude estimates of intakes of particular foods and particular diseases. For example, the claimed lack of association between eating dairy products and cardiovascular diseases mentioned above especially as some of the authors have affiliations to or sponsorship from the dairy industry.
Essentially this AHA report, reinforces and refines some of the longstanding beliefs about diet, blood cholesterol and cardiovascular disease risk. This report is mainly focused upon cardiovascular disease which is understandable as it is produced by an organisation primarily concerned with the prevention and treatment of cardiovascular diseases. Some of the conclusions from this report:
- All saturated fats, from both animal and vegetables sources, tend to raise LDL-cholesterol levels
- In clinical trials, replacing saturated fats with unsaturated fats, especially polyunsaturated fats from vegetable oils, reduces both LDL-cholesterol and prevents cardiovascular disease
- In observational studies, diets that are low in saturated fat and high in polyunsaturated and monounsaturated fat are associated with lower rates of cardiovascular disease and death from all causes
- In both clinical trials and observational studies, when saturated fat is largely “replaced” by unspecified carbohydrate there is no reduction in cardiovascular disease or all-cause mortality
- Their findings suggest the strategy for reducing cardiovascular disease should be to reduce saturated fat intakes and replace them mainly with polyunsaturated fats from vegetable oils.
Persuading 15 million UK adults to take statins may produce similar or only slightly bigger reductions in LDL-cholesterol, cardiovascular and all-cause mortality than those that could be produced if these suggested dietary changes were universally implemented. It may be seen as the cheap and easy (lazy?) strategy that requires little effort or commitment from either health practitioners or patients. Producing dietary changes amongst the least health conscious and most vulnerable section of the population will be a long and difficult process requiring considerable commitment and resources. Dietary change may be the preferred option but mass use of statins may be the pragmatic, easy option likely to do the greatest good to the largest number in the immediate future.
Posted on 20th June 2017
Coconut oil “as unhealthy as beef fat and butter”
This headline appeared on the BBC news web-site on 16/6/17 and similar headlines appeared in other UK newspapers like The Sun and in the American national newspaper USA Today . These news reports relate to an authoritative review by an expert panel on “Dietary Fats and cardiovascular disease” released as “A Presidential Advisory” from the American Heart Association (AHA) . The report reviews the current case for reducing dietary saturated fat intake and whether it is better to replace it with carbohydrates or with unsaturated fats. The report covers more than 20 pages and yet, despite the media headlines, the section dealing with coconut oil covers less than half a page. I will therefore split this post into two and comment in this post on the specific findings in relation to coconut oil and in second post (to follow shortly) on the wider conclusions of the report using a headline from NBC News .
Sales of coconut oil and coconut containing food products have been increasing very rapidly in the UK and other countries and many coconut-based cosmetic products are also available. Coconut oil/milk is widely used as an alternative to milk, butter and cream in many recipes and in many prepared savoury products and desserts. It is widely used in a range of dairy-free alternatives to conventional foods. Coconut oil is known to be very high in saturated fats and saturated fats are known to raise the “bad cholesterol” (LDL) in blood. This, in turn, increases atherosclerosis and the risk of heart attacks, strokes and other cardiovascular diseases. A huge volume of experimental evidence stretching back over 6 decades shows that diets high in saturated fats lead to raised LDL-cholesterol levels but that diets with similar amounts of unsaturated fats, especially polyunsaturated fats from vegetable oils, result in lower LDL-cholesterol levels and reduced cardiovascular risk (see next post in this section). Table 1 shows the breakdown of the fatty acids in six common food fats.
Table 1 The percentage of total fatty acids that are saturated, monounsaturated and polyunsaturated in six food fats.
Fat Saturated % monounsaturated % polyunsaturated %
Sunflower oil 14 34 53
Rapeseed oil 7 60 33
Lard 45 44 10
Palm oil 48 44 8
Butter 63 33 3
Coconut oil 91 7 2
Milk and meat fat are high in saturates and low in polyunsaturates whilst most common vegetable oils like sunflower oil, corn oil, soy oil, safflower oil and peanut oil are low in saturates and high in polyunsaturates. Olive oil and rapeseed oil are low in saturates but particularly high in monounsaturates rather than polyunsaturates. As can be seen from the table the two tropical oils, palm oil and coconut oil, have fatty acid profiles that are more like meat and milk than other vegetable oils and so high intakes might be expected to raise LDL-cholesterol levels and predispose to cardiovascular disease. Thus promoting coconut oil as a “healthy alternative” to dairy fat seems to be difficult to reconcile with these figures although its supporters rightly point out that the saturated fatty acids in coconut oil are different to those seen in most other fats. Most of the saturated fatty acids in coconut oil have shorter chains (14 or less carbon atoms) whereas in most other fats and oils those with 16 or more carbon atoms predominate. It has been suggested that coconut oil fatty acids might raise the “good cholesterol” (HDL) in the blood although the AHA report suggests that this is not a significant beneficial effect. In the AHA review it is concluded that the common individual saturated fatty acids, including those in coconut oil, raise LDL-cholesterol and replacing them with unsaturated fatty acids lowers LDL-cholesterol. A meta-analysis (weighted amalgamation) of seven clinical trials comparing the effects of coconut oil upon LDL-cholesterol with other oils rich in monounsaturated or polyunsaturated fatty acids have unanimously reported that coconut oil raises the LDL-cholesterol. There is also no difference between coconut oil and other highly saturated oils (like butter and palm oil) in their raising effect upon LDL-cholesterol, hence the headline conclusion that coconut is as unhealthy as beef fat or butter.
My assessment is that coconut oil raises LDL-cholesterol just as one would expect from its fatty acid profile shown in table 1. There seems to be no rational case based upon blood cholesterol and heart disease risk for replacing saturated dairy and animal fats with saturated coconut oil or palm oil. Coconut oil is, however, a palatable and very useful alternative to dairy fat in many recipes and provides a good alternative for those who for a variety of cultural, ethical and allergy reasons want or need to avoid dairy products. Treat it like butter or cream, something to enjoy in moderation. If you want ice cream, a tiramisu, a creamy curry sauce or “cheese” without milk then products made from coconut enable good dairy-free versions to be made but they are not “healthier” unless you are intolerant to a component of milk. As will be seen in the next posting, the main health message from this AHA report is to replace as much of the saturated fat in your diet as you reasonably can with unsaturated vegetable oils, especially those high in polyunsaturated fatty acids.
Posted on 24/4/2017
Dairy-free diets warning over risk to bone health
This headline appeared on the BBC new web-site on 12/04/2017 and was prompted by a warning from the National Osteoporosis Society issued in response to a survey that they had conducted involving 2000 UK adults. Dairy products (milk, cheese and yoghurt) have for many years been the biggest source of calcium in the British diet so they suggest that their finding from this survey that many young people are restricting their intakes of dairy produce threatens their calcium adequacy and long-term bone health i.e. increased risk of osteoporosis in later life. Osteoporosis is a serious loss of bone mineral that affects almost half of older woman and a fifth of older men and increases the risk of wrist, vertebral and hip fractures. As bone mineral is a calcium compound then the seemingly reasonable rationale is that lowered calcium intake reduces deposition of bone mineral in childhood and early adulthood so that when bone starts to thin in older people the bones will become weaker quicker.
The BBC article also quotes from a Food Standards Agency survey that indicates that almost half of 16-24 year olds claim to be intolerant to cow’s milk although most of them had no medical diagnosis to support this belief. This self-reported level of intolerance is many times higher than reported by older adults. As the article implies, this is almost certainly a massive overestimate of the true level of cow’s milk intolerance in young people. Of course, a proportion of people will be intolerant to cow’s milk products and as these are consumed by most Briton’s this is well documented and often reported as a reason to avoid cow’s milk. It seems likely that if goat’s milk, soya milk or some other alternative were consumed on the same scale then the real level of intolerance to these might be at least as high as that for cow’s milk.
The article notes that the recommended adult intake for calcium is 700 mg/day but rises to 1000 mg/day for those aged 11-18 years. These are the estimated needs of those in the group with the highest requirement and are set as intakes that should guarantee adequacy for everyone in the group. The high values for adolescents reflect the rapid skeletal growth; during the five years of adolescence boys accumulate an average of 200 mg/day of extra calcium in their skeleton. The article quotes from UK surveys which suggest that a quarter of teenagers consume less that 400 mg/day of calcium which is the value set by an expert panel as the threshold below which intake is assumed to be inadequate. As a nutritionist, I would regard intake of any essential nutrient that is below this minimum threshold value as a significant problem even if it does not lead to immediate, obvious symptoms of deficiency. I would also regard avoidance of a whole category of foods like dairy products as undesirable. However once someone has made a considered decision to avoid dairy then the role of the nutritionist or dietitian is to make suggestions and recommendations that allow this personal choice to be healthily implemented. The wide commercial availability of many fortified dairy substitutes has made this a relatively easy task.
I would take issue with this BBC article on three grounds:
- The role of most dairy substitutes as good sources of calcium and vitamin D is underplayed
- The role of vitamin D in ensuring efficient utilisation of dietary calcium and as a requirement for bone formation and maintenance is underplayed
- The link between dietary calcium intake and bone health is not as clear-cut as this piece implies.
The article does list several non-dairy sources of calcium like nuts, seeds, fish and fortified white flour. It does say also that almond and soya milk may contain calcium if fortified. On a recent visit to the supermarket, I looked at labels on a number of dairy substitutes and all of those I looked at, including those of the best know UK brand, had been fortified with calcium and also importantly with vitamin D. The manufacturers’ web-sites also indicated that most of their products were fortified with calcium and vitamin D. This means that people who, for whatever reason, choose to replace dairy foods with the most common commercial alternatives will probably not reduce their overall calcium intake and may well increase their vitamin D intake because ordinary UK milk is not a good source of vitamin D. If dairy avoidance is just part of a whole range of avoidances or one aspect of a bizarre diet then this may threaten calcium adequacy but probably also threatens the adequacy for other nutrients. Severe and poorly planned calorie-restriction to achieve an unhealthy level of leanness, especially in female adolescents, is one such scenario.
Vitamin D is probably a more critical determinant of bone health than calcium intake. Vitamin D is necessary for the efficient absorption of dietary calcium and in severe vitamin D deficiency (rickets), insufficient calcium is absorbed to allow proper bone mineral formation even if dietary calcium levels are not low. The average UK diet probably only provides about a quarter of our vitamin D needs. We rely upon production in our skin when it is exposed to summer sunlight to produce most of our vitamin D needs. Poor vitamin D status is common in many sectors of the UK population because of a combination of low dietary intake and inadequate sunlight exposure. People who simply swap dairy foods for non-dairy substitutes may actually increase their vitamin D intake and in other posts on this blog (for example) I have advocated the fortification of a staple UK food or foods with vitamin D. Weight-bearing exercise is known to increase bone mass in children and young adults – so increased outdoor activity has two benefits for bones as it also increases exposure to sunlight. (Note that outdoor grown or wild mushrooms are a good vegetarian source of vitamin D. Bulk-produced UK mushrooms do not contain vitamin D if grown in the dark, although even these will produce good amounts of vitamin D if left in direct sunlight for an hour or so).
The link between dietary calcium intake and bone health is complicated by factors like the need for good vitamin D status to absorb calcium efficiently and the increase in bone mass caused by weight-bearing exercise. In some populations where consumption of milk by adults and older children has not been the cultural norm, there has been little or no problem with osteoporosis despite relatively low calcium intakes. In some other western countries, osteoporosis is a major public health problem despite calcium intakes that are relatively high. Relatively high calcium intake is no guarantee of good long-term bone health and good bone health can be associated with relatively low calcium intakes if other dietary and lifestyle factors are favourable.
Posted on 17/4/2017
The problem with scientific publishing and how to fix it.
This headline appeared in the “Economist explains” section of The Economist magazine on 30th March 2017. It was brought to my attention by my daughter Kate Webb. Scientific journals have been used to disseminate scientific information dating back at least as far as 1665 when Philosophical Transactions (of the Royal Society, London) was first published. Peer review is now seen as the main method of quality control used for selecting which papers are worthy of publication but it has only been the norm for most journals since the middle of the 20th century. Journal editors send submitted papers to one or more anonymous experts in the field to evaluate the paper and make recommendations about whether the paper should be published or not and any modifications needed before publication.
The author of the Economist article points out that journal publications now serve another major purpose that is often more of a priority than simple dissemination. The number of peer-reviewed papers, especially those published in the top journals, is used as the key indicator of a scientist’s research prowess and thus a major determinant of their career progression. S/he argues that this unintended role of journal articles means that scientists have an incentive to withhold their results until they can publish a more complete and powerful piece. S/he argues that such delays in release of important data might be harmful and cites the recent Zika crisis where s/he claims that research sponsors had to persuade publishers to declare that scientists would not be penalised for early release of their data.
The article author goes on to highlight the large rise in the number of flawed and retracted papers in recent years and notes that the rates of retraction are higher in the top international journals like Nature and Science. S/he says that this shows that they are no longer the guardians of quality that they claim to be. One probable reason for retraction rates being higher in the top journals is that published articles will be subject to much greater critical scrutiny than those published in low-level journals that may never be read, sometimes not even read properly by the peer reviewers. Any flaws in major papers published in top journals are thus more likely to be exposed and reported to the editor and these editors may be much more willing to retract papers shown to contain irretrievably flawed or fabricated data. Higher retraction rates could thus be seen as a sign of better quality control in these top journals. Seriously flawed or fabricated data published in low level journals are likely to go unnoticed, unreported and unretracted
In a rather throwaway sentence, the article author also suggests that papers published in elite journals are no more statistically robust than those in lesser journals. In a previous post, I have discussed some of these statistical issues and I am sure that they are not confined to papers in lesser journals, for example:
- Small underpowered studies, which makes falsely statistically significant results more likely
- Small effect sizes which may be just a measure of the inherent bias in the study
- Multiple testing, e.g. correlating multiple variables until one gets a statistically significant association (by chance!)
- Multiple modelling i.e. sequential correcting for confounding variables until results become or remain statistically significant
- Slight manipulation of results so that they reach the magic “<5% probability of occurring by chance” so that they can be claimed as “statistically significant”.
The author of this Economist piece suggests three reforms which s/he believes would improve and accelerate science and allow health agencies to respond more quickly to epidemics and speed up the development of new treatments:
- Scientists should put their academic papers into publicly accessible repositories before they are published
- Peer reviewers should no longer be anonymous and the reviews should also be published
- Alternatives to journal publications as the path to career advancement for scientists should be sought. S/he mentions number of views of preprints and whether clinical data has been used in guidelines for doctors as possible examples.
I have some issues with these specific suggestions such as those below.
- If peer reviews are to be published then without strict safeguards they may simply become an opportunity for reviewers to promulgate their own views and theories in lengthy essays without the need for supporting data or peer review.
- Science, like most human activities, is competitive and competition may be a major motivating factor fuelling scientists’ creative energies. To persuade scientists to prematurely release their “new early exciting data” for others to exploit is going to require a major cultural shift.
- Using published papers as the measure of a scientist’s worth is undoubtedly a distorting influence on scientific publishing. As in any other field, once a metric of “success” is accepted it ceases to become an incidental objective measure and starts to define the way that activity is conducted and managed. Acquiring peer-reviewed publications becomes a major objective in its own right rather than their being primarily a vehicle for disseminating high quality research data. To find better measures of the quality of a scientist’s research output is a desirable objective but to find something that is both objective and suitable for mass application is not easy. This is why paper counting has been the standard tool for so long.
My main criticism of this piece, however, is not in the suggested solutions but in the writer’s identification of the problem with scientific publishing. Delay in the publication of important data may be an occasional problem in specific circumstances. However, the major problem with scientific publishing is the deluge of poor quality data often published after only nominal peer review. Rather than holding back important data, many scientists are guilty of prematurely publishing inadequately substantiated data or splitting up data sets into small parcels that yield multiple publications rather than one substantial paper. A large proportion of what is published either cannot be reproduced by other scientists or is not of sufficient interest to persuade others to even try to reproduce it. A high proportion of the 2 million papers published each year will never be cited by any other scientist and many will have few, if any, readers. Release of unsubstantiated and potentially false data may open up research blind alleys that soak up research effort and resources possibly for decades afterwards (see previous post on yogurt as a proposed cause of ovarian cancer). I would be looking for ways of persuading the majority of scientists to wait until they are confident of the reproducibility and value of their data before rushing into print. Fewer but better papers would be my desired outcome.
Posted on 02/04/2017
“Fake research” comes under scrutiny
This headline appeared on the BBC news web-site on 27/03/2017 . The main point of the piece was that official data on the incidence of research fraud allegations underestimates by at least ten fold the number of cases revealed in a BBC survey of 23 of the UK’s research intensive universities. The article may well have been prompted by the start of an inquiry into research integrity by a House of Commons committee. The author notes suggestions that the UK should have an official regulatory body to oversee publicly funded research, modeled on the Office of Research Integrity (ORI) in the USA. Dr Ivan Oransky who helped found the web-site RETRACTION WATCH is quoted as confirming that in general only a tiny fraction of cases of research fraud identified by universities and funding agencies get reported. He says that in one frequently cited survey about 2% of researchers admitted to having committed some act of research misconduct. This is much higher than the amount of research misconduct that is actually reported and recorded.
The term research misconduct covers a spectrum of misbehaviour including data fabrication or falsification and plagiarism. Fabrication is the invention of data and falsification involves manipulating real data so that what is reported no longer reflects what was actually found.
2% sounds like quite a low figure but it is almost certainly an underestimate. Even in a survey said to be anonymous, how many people will admit to doing something that is regarded as the worst professional crime that a scientist can commit? Evidence from those found guilty of research fraud, is that they are usually multiple offenders and some have built long and successful careers based almost solely upon fabricated data (see for example Ranjit Chandra and Diederik Stapel on this blog). If we accept 2% as a minimum estimate then this means that at least 40,000 of the 2 million scientific papers published annually involve some form of misconduct. This is not confined to papers in low quality journals because the best journals have the highest rates of retracted papers (more intense scrutiny means that exposure of fake data is more likely).
Some scientists take a fairly relaxed or complacent view of bad and fraudulent research because they believe that it will be exposed or discredited when other scientists are unable to reproduce it. However, very few fraudulent scientists are exposed by this route and some churn out publications based upon fabricated data for decades before being exposed.
Why does “fake research” matter so much?
- It undermines the credibility of science and public trust in research. The realisation that “pop star” psychologist, Diederik Stapel’s reputation was founded upon a mass of fabricated data threatened for a time to undermine confidence in his field of social psychology research about the psychological processes underlying individual choice and economic decision-making.
- It is a misuse of scarce resources of the host institution and research funders. In 2005, world-renowned obesity researcher Eric Poehlman of the University of Vermont acknowledged that he had used fabricated data in 17 funding applications and pleaded guilty in a court in Vermont to defrauding the US National Institute of Health of $547,000. Prosecutors believe that he actually defrauded the NIH of $2.9million. He was sentenced to a year and a day in prison, one of the very few research fraudsters to receive a jail sentence or indeed any legal sanction.
- It damages the careers and lives of collaborators and research students. Ten of Diederik Stapel’s graduate students had their theses tainted by the public acknowledgement that they contained fabricated data and one young woman, who had just submitted her thesis, felt obliged to withdraw it. One of Haruko Obokata’s distinguished research supervisors, Yoshiki Sasai, hanged himself in his laboratory in August 2014 just a few months after the retraction from Nature of the two papers that he co-authored with her.
- Fraudulent data hinders the progress of research. It persuades other researchers to try to reproduce the false findings or leads them into unproductive areas. An editorial in the American Journal of Physiology in 2007 bemoans the amount of time, money and energy that had been expended by other groups around the world in trying to replicate the falsified data of Jatinder Ahluwalia about the way in which white blood cells kill ingested bacteria. The eminent geologist Sir Arthur Smith Woodward FRS is said to have spent the last 21 years of his life trying unsuccessfully to unearth further fossils and artefacts from the area where Charles Dawson claimed to have found the Piltdown man skull.
- Policy decisions, choice of medical treatment or public behaviour can be based upon false data and false conclusions. Scott Reuben’s fabricated data on the benefits of the COX-2 type of painkillers probably increased sales of these compounds by several billion dollars worldwide and influenced the pain management protocols of many physicians and surgeons around the world. The false data of Werner Bezwoda helped encourage the use of high dose chemotherapy (HDC) in cases of advanced breast cancer. It became difficult to recruit subjects onto clinical trials comparing HDC and conventional chemotherapy (in case they were allocated to the conventional treatment group) and so delayed the completion of these clinical trials by several years. Many thousands of patients underwent this expensive, gruelling and potentially life-ending treatment partly as a result of his fake positive data.
- In extreme cases false data can kill people. The fabricated data of German anaesthesiologist, Joachim Boldt, helped to increase and prolong the use of certain hydroxyethyl starch preparations (HES) as fluid replacers in seriously sick or injured people. They are now listed as contraindicated for many procedures and are known to be associated with increased risk of adverse events and with higher risk of death. The falsified data of Boldt thus probably contributed to extra patient deaths through their unjustified use. As a result of the highly positive false data relating to HDC of Werner Bezwoda published in 1995, a small trial that sought to replicate Bezwoda’s treatment protocol was started in Seattle, Washington. Four of the six patients recruited, before the trial was abandoned, suffered serious and permanent cardiac damage (heart failure) because of the treatment and two died as a result of this.
Is it now time to consider whether research fraud should be made a specific criminal offence?
Posted on 24/03/2017
“Fish oil does not benefit baby intelligence, study finds”
This headline appeared in the “Australia” section of the BBC news web-site on 22/03/2017.
The headline was prompted by a research letter published in the Journal of the American Medical Association (JAMA). I have only read an extended summary of this letter which is a 7-year follow-up of a study published in 2010. I have been able to access and read this original report . These articles report the results of a controlled clinical trial of the effects of fish oil supplements given in the second half of pregnancy. They show that the supplements do not reduce postnatal depression nor improve the cognitive development and intelligence of the babies.
Maria Makrides and her Australian colleagues (2010) recruited 2400 women who were less than 21 weeks into their pregnancy. Half were given a fish oil capsule containing 800mg of DHA and half were given a placebo (vegetable oil). Almost all of these mothers were assessed for postnatal depression and 726 babies were assessed for cognitive and language development at 18 months old. A proportion of the babies were also assessed at 4 years old and 7 years (about 540 babies) – it was the letter reporting the results from this last follow-up that prompted the title headline. In the 2010 paper the authors found that the fish oil supplement made no difference to rates of postnatal depression in the mothers. The fish oil also made no difference in composite scores for cognitive (intelligence) or language development in their babies. The 7 year follow-up essentially confirms the findings at 18 months old. When they broke down the composite scores then there were a couple apparent small positive effects in the fish oil group but this was offset by small negative effects on behaviour in the supplemented group. Small differences in odd individual measures where multiple measures have been made should anyway be treated very sceptically. There was some evidence that gestation was slightly prolonged in the fish oil women and although firm conclusions were difficult to reach from this particular study, it is in line with other reports of the effects of fish oils.
Fish oil and cod liver oil supplements represent around 40% of the £400 to 500 million UK supplement market. People take these oils because they are a rich source of the long chain omega-3 fatty acids known as EPA and DHA. Cod liver oil also contains vitamins A and D and this is the historical rationale for its widespread use, especially in children.
Other than oily fish (like salmon, mackerel, herrings and sardines) and maybe meat from animals fed fish-meal, sources of EPA and DHA in the diet are scarce. Some vegetable oils like rapeseed oil and particularly flaxseed oil do contain substantial amounts of other shorter chain omega-3 fatty acids. In theory our bodies are able to make EPA and DHA from these short chain omega-3s. Our capacity to make EPA and DHA may, however, be limited, especially if our diets contain copious amounts of omega-6 fatty acids which are abundant in many vegetable oils and spreading fats. Large intakes of omega-6s may inhibit the conversion of short chain omega-3s to EPA and DHA.
There is reasonably convincing evidence that fish oil from food or supplements may slightly reduce the risk of having a heart attack. The best of this evidence is from studies with heart attack survivors where fish oil seems to reduce the risk of a second fatal heart attack. Some of this evidence comes from before the mass use of statins and any small, beneficial, population-wide effect of fish oil may be swamped by the impact of statins. Statins are taken by 6 million British adults and there are suggestions that this number should double.
Many people take cod liver oil or fish oil to “lubricate their joints” and alleviate or prevent the symptoms of osteoarthritis. There is a plausible mechanism for how fish oil might do this, but there is little or no substantial evidence of efficacy. There is some evidence that huge doses of fish oils may have some limited benefits for patients in relatively uncommon rheumatoid arthritis.
Fish oil supplements are also taken in the hope that they may alleviate the symptoms of depression. One of the original aims of the Makrides paper was to see if they reduced the risk or severity of postnatal depression. There is no convincing evidence for any beneficial effect upon depression or postnatal depression. There has been much SPECULATION about whether fish oil supplements might improve behaviour, attention span and academic performance in schoolchildren but there is no real evidence to support these claims. The work of Makrides and her colleagues indicates that antenatal fish oil does not improve a baby’s intellectual development.
Posted on 17/3/2017
B vitamins may have “protective effect” against air pollution
Note: I have only read the author’s summary of their work as it requires a payment to read the full paper.
The title appeared as a headline on the BBC new web-site 14/03/2017 and similar headlines were used by media outlets around the world . These 16 researchers exposed 10 subjects to either clean air or air polluted with small particulates known as PM2.5 for periods of 2 hours. They performed these exposures after pre-treatment for a month with either a B vitamin mixture or a placebo. They assessed changes in DNA in blood cells involved in human immunity after each of these four exposure situations. Exposure to the particulate pollutants produced a measurable change in DNA (increased methylation) which was apparently prevented by the vitamin supplement.
The doses of vitamins were extremely high, over 12 times EU Recommended Daily Allowance (RDA) for folic acid (B9), 30 times the RDA for vitamin B6 and 400 times the RDA for vitamin B12. The folic acid and B6 doses are over the Tolerable Upper Limit recommended by the European Food Safety Authority (no upper limit is set for B12). Any changes seen with these doses may be unrelated to the normal vitamin activity of the substance. Unless similar effects are seen at more normal vitamin doses this would undermine any practical application for these findings. Massive doses of vitamins are not harmless and severe toxicity associated with overdose of some is well established.
They used very short-term changes (2h) in a marker for DNA change. The implication is that this DNA change is a reliable predictor of likely long-term health damage (e.g. cancer) that might result from prolonged exposure to these particulates.
This was only a pilot study with just ten volunteers. The measured effect of the pollutant was only just statistically significant but did seem to be completely blocked by the supplements. Small scale studies with results that are anywhere near the borderlines of statistical significance should always be treated with extreme caution.
These authors have actually shown that massive doses of these B vitamins seemed to block short-term changes in an assumed marker for long-term harm (DNA methylation in white blood cells) in a very small pilot study.
This study is widely reported as if it were a major breakthrough rather than some very preliminary indications of a possible future research area. The authors themselves did caution about the limitations of their study.
As an analogy, high doses of antioxidant vitamins (e.g. A, C, and E), minerals (e.g. selenium) and antioxidant-rich foods (e.g. watercress) reduce short-term measures of oxidant damage to cells, including DNA damage. This has been widely interpreted for decades as an indication that increased antioxidants might reduce the risk of cancer and/or heart disease. Yet high quality clinical trials of antioxidant supplements lasting many years have found no indication that they reduce cancer, heart disease or total mortality risk. Several studies have reported that some of these supplements, particularly those that contain beta-carotene (vitamin A), cause net harm.
Posted on 20/3/2017
Obesity crisis: Is this the food that is making us all fat?
This headline and a picture of vegetable oil appeared in the business section of the BBC News web-site on 15/03/2017 ;an unexpected source for one of these posts.
My first reaction
I wrongly assumed after reading this headline that the rise in consumption of vegetable oil in the UK since the 1960s and 70s was being suggested as the reason why UK obesity rates had quadrupled over this period. There has undoubtedly been a major shift in our sources of fat:
- In 1975, 68 % of spreading fats sales were butter but two decades later this was just 25%
- In 1975 just 22% of cooking fat sales were vegetable oil but by 1996 this was 77%
- In 1975, 78% of cooking fats were animal fats (mainly lard) and this was down to 23% by 1996.
Since 1996, vegetable oil has increased to over 80% of cooking fat sales and reduced fat spreads (not readily available in 1975) now account for 60% of spreading fat sales. These changes in our sources of fat resulted in a substantial reduction in our consumption of saturated fat and an increase in polyunsaturated fat consumption. All fats, whether saturated or unsaturated are concentrated sources of calories. They all provide about 9 Kcal/g compared to around 4 for sugar, starch and protein. What about total fat intakes? The contribution of fat to our calorie intake rose during the years after WW2 as post-war shortages and rationing eased. From 1975 to the early 1990s, the fat contribution to total energy intake remained constant at around 40% despite the switch from saturated to unsaturated fat. Although the absolute amount of fat (grams) dropped during this period, this was in line with the overall reduction in calorie intake recorded over this period. Since the early 1990s the contribution of fat to the energy in our diets has actually fallen to around 35%. Therefore vegetable oil and spreading fats made from oil, initially replaced other fats and since the 1990s overall fat consumption has been falling in real terms. It does not seem logical, therefore, to blame rising sales of cheap vegetable oil for our current obesity crisis.
What triggered the headline?
The BBC article was prompted by a report produced by a Professor Benton at Leeds University about sources of UK food and the impact of globalization. This independent report sponsored by the supermarket chain Morrison’s is not primarily about nutrition but about where our food comes from. Some of the chapter headings illustrate the general nature of its content:
- The food we eat: where is it sourced?
- Is more food trade a good idea?
- The benefits of local production
- The UK capacity for greater self-sufficiency.
In his conclusions, Professor Benton argues that globalization drives diets towards major commodity crops including vegetable oils leading to a loss of diversity and a drive towards calorie rich but low nutrient diets. He argues that the global food trade means that rich countries are able to export some of the environmental costs of food production to other countries. He argues that whilst the UK cannot hope to be self-sufficient in food we could become much less reliant on imported food. Reading further into the BBC article it was not explicitly argued, except in the headline, that the UK obesity crisis was caused by eating more vegetable oil.
After a brief skim through Benton’s 36 page report, I find it difficult to see how it generated the BBC headline. Of course, Professor Benton was probably interviewed for the BBC article and this may have led to the strong suggestion of a link between vegetable oil and obesity. One could interpret the first part of this BBC report as suggesting that globalization and the massive production and trading in high calorie vegetable oils has allowed increased consumption of high calorie, low nutrient diets that have helped to create a climate, in many countries, where obesity increases.
Is wide availability of calorie rich foods really the cause of the global obesity epidemic?
If the BBC news story had been solely related to Professor Benton’s report then I might have abandoned my intention to post this commentary. However the reporter (Katie Hope) then goes on to talk about a study produced by a group at the London School of Economics entitled “Globesity”? The effect of globalization on obesity and caloric intake. Joan Costa-Font and Nuria Mas reported that globalization as determined by a OECD index is associated with a rise in both obesity and calorie intake. However, they concluded that “social globalization” i.e. changes in the way we work and live is a much stronger driver of obesity than increases in the availability of cheap calorie rich food. To put it simply obesity is increasing because people are expending less energy in working, shopping, socializing, travelling and doing household chores rather than because they are eating more.
In the UK, data from government sponsored surveillance reports like the old National Food Survey, The Family Expenditure Survey and their subsequent replacements have suggested that we eat, or at least buy, many fewer calories than we did in the late 1950s or early 1960s; perhaps a quarter to a third less. Yet over this same period, obesity rates have at least quadrupled. Almost a quarter of the UK adult population are now obese and around two-thirds are currently classified as either overweight or obese. We are getting fatter and yet apparently eating less which suggests that reduced activity and reduced energy expenditure are the major drivers of these obesity increases. There have also been big rises in the number of children who are classified as obese or overweight.
Cross sectional studies have found that when one classifies people as low, medium or high activity then obesity rates rise with decreasing activity. Several studies from around the world have found that number of hours of TV watching in children is not only linked to their current obesity but also predicts the future likelihood of becoming obese. Future studies will obviously have to widen the definition of “viewing” to include all activities that involves sitting and watching the screen of an electronic device.
Whilst the availability of a plentiful supply of cheap calorie rich foods is an essential prerequisite for rising obesity levels, it is decreased activity and reduced energy expenditure that is the main driver of rising obesity and especially the rising level of childhood obesity.