In my last post I published some good news about cancer survival rates, so I thought it was important to highlight a big problem with our recent success against this disease. This issue is flagged up in a study published at the end of January.It addresses the fact that the gains we have made in cancer diagnosis and treatment are very unevenly spread around the world. To analyze this is greater detail, the scientists studied the differences in survival in different countries, and the results are somewhat predictable.If, for example, you are an Australian or American with breast cancer, you have a 90% chance of surviving. If you are Indian however, you only have a 66% chance.If a child is diagnosed with acute lymphoblastic leukaemia in Finland, they have a 95% chance of beating the disease; in Ecuador, the rate is only 50%.So, over the period of this study (2000 to 2014) roughly 200,000 Indian women died from breast cancer who wouldn’t have died if they were living in the US. Almost 1,000 Ecuadorian children died from acute lymphoblastic leukaemia who wouldn’t have if they were in Finland. The same pattern is seen for all cancers, so it is clear that millions are dying from cancer in less developed countries who would not be if they were born somewhere else.This is even more staggering when you realise that this study did not even include countries at the bottom end of the global poverty index. This excluded nearly one third of the global population, as the records and reporting from these areas is just too unreliable to use.It is clear from the numbers that if you are from a less well-off country, you are far more likely to die after being diagnosed with cancer. This isn’t entirely surprising, as the detection and treatment of the disease changes quickly and can prohibitively expensive.Unfortunately, it is also likely get worse in the coming years. Due to a lack of tobacco regulation in poorer countries, lung cancer is set to increase. The WHO has pointed out that smoking still appears to be increasing in Middle Eastern and African regions, and it is known that the tobacco industry has actively been targeting young people in these countries.Additionally, as our treatments for cancer get more sophisticated, they also get more expensive, something I have written about in the past. When combined with less well supported health systems, and other more pressing public health issues, the picture looks bleak for cancer patients in many low- and middle-income countries.Of course, there are plenty of other public health improvements that can be made around the world that would have a bigger impact on people’s lives than providing better access to cancer treatments. Access to clean water, anti-malarial programs, and HIV and TB treatment programs would be far wiser investments than cancer therapeutics. However, as we in cancer research congratulate ourselves on our successes, it is always worth keeping in mind just how unevenly that success is distributed.
Are cancer rates rising?
Cancer is so prevalent in life now that it is easy to think that the rates are skyrocketing. However, the numbers don’t back this up. In actual fact, we are slowly but surely advancing our response to the disease, and recently published data underlines this progress.The publication was the annual report of the American Cancer Society. In that article, they compile all the recent data to see what trends there are in cancer rates and deaths.The report delivers some good news.Although cancer kills more people in the US than anything except heart disease, the incidence of the disease (the percent of the population diagnosed) is stable or declining, and survival is increasing. This is a steady trend we have seen over the last decade, and it looks like it will continue into the future.To be clear, because the population is increasing we are seeing more cancers, so the total number is rising, but the incidence (which is relative to the population) is not changing. For example, if there are 200 cases of cancer in a population of 100,000 (0.2%), that is the same incidence as 20,000 cases in a population of 10 million (0.2%). The number of cases is different (200 compared to 20,000), but the incidence is the same.Also remember that the older you are, the more likely you are to be diagnosed with cancer. And that people are now surviving longer with the disease than ever before. So, when this increased survival is combined with the rising and older population, it is perfectly understandable that we come into contact with more and more people who have had the disease, and thus think that the rate is increasing.What the data actually shows us is that this is not the case. In women, the overall incidence of cancer is neither increasing nor decreasing. While there are drops in colon and lung cancer, there are increases in breast and skin cancers that offset these, so overall, there is no change.In men we have also seen a drop in colon and lung cancers, but also a large decrease in prostate cancer, which means that overall, male incidence of cancer has dropped by around 2%. The decrease in prostate cancer is largely down to changes in how we screen for the disease, so is probably not a true decrease (before we changed the screening we were detecting lots of cancers that would never have progressed. We no longer count them in the numbers). In reality, the male situation is probably like the female situation, and there has been little change in the numbers.When we look at the survival from cancer, the picture is more optimistic. Since 1991, the overall death rate from the disease has decreased by 1.5% per year, which means that in the last 36 years we have seen a decrease of over 26% in cancer deaths. That means that the likelihood of you dying from cancer has drastically decreased.In 1975, 50% of patients were dead after 5 years. By 2012 this had decreased to 34%, and this trend is continuing, with more people surviving for a longer time after being diagnosed with cancer.There have been several major advances in the last few years, and we are yet to see the real benefit of these, so it looks like this trend for increased survival will continue. It is slow progress, but the numbers certainly give us cause to be optimistic!
Ultra-processed foods and cancer
This story was all over the news today:
“Ultra-processed foods may be linked to cancer, says study”The Guardian, 15th Feb. 2018
The news comes from a French study that looked into whether cancer was associated with highly processed foods. As usual, the question is whether the actual results of the study warrant the hysteria currently playing out in the media? (Spoiler: the answer to that is almost always an emphatic NO!)First things first; this is an excellent study, with well carried out data collection and good analysis of the results. The authors looked at 104,980 people, and asked them to fill out a daily survey about their diet. Using that data they compared cancer rates to the people’s self-reported diets.The study found that high consumption of “ultra-processed foods” was associated with a 12% increased risk of cancer. In men, no one cancer type was specifically increased, in older women the foods were associated with an 11% increase in breast cancer.These studies are notoriously difficult to interpret, mainly because, aside from their diet, there are numerous differences between people. In this study for example, the participants who consumed a higher amount of ultra-processed foods were more likely to be smokers, and less likely to be physically active.Clearly, what people eat is only part of a larger lifestyle. People who eat healthily tend to be healthier in other areas of their lives, so it is very difficult to say that a specific dietary choice is actually causing cancer. The authors of this study tried to correct for things like this, but that is extremely difficult to do, something that was acknowledged by the authors in their paper.It is also worth saying that the definition of “ultra-processed” is a hard one to pin down. The definition used in this study was based on a food classification system called NOVA, but this is still not very clearly defined, which means it is difficult to draw any practical conclusions from it. Unfortunately, in the media the term is wielded to mean anything that isn’t “natural”, despite this being wrong. For example, according to the classification used in this study, gluten-free artisanal bread is ultra-processed, as are vegan health shakes, and organic protein bars.While this is a solid piece of research, the public reaction to it is likely to be misplaced. Unfortunately, it is likely to play into the “clean eating” fad, which is largely nonsense. It is now clear that the fashion for “clean eating” has legitimised eating disorders, and may in fact be doing far more harm than good.However, as global consumption of processed food increases, it is very important that we understand their impact on health. This research clearly warrants more study, but these findings alone cannot offer practical advice to consumers. As always, if you have a varied diet and get a bit of exercise, there isn’t much to worry about!
Cancer vaccine breakthrough?
Every once in a while I see a paper that makes me sit up and say “Wow”. They are rare, but when they happen they let us really see the progress that is being made. This week one of those papers was published in the journal Science Translational Medicine.The study built on recent work that is focused on the immune system, and the potential that we can make it attack a cancer (something which doesn’t normally happen). There has already been some excellent results in this field in human trials, but this study took the work in a slightly different direction. The work was carried out in mice, so is still at an early stage, but the a small clinical trial is starting this month, and that will tell us how optimistic we should be.What these scientists have developed is a clever way to activate the immune cells specifically within the tumour by injecting it with a tiny amount of DNA and another compound. When they did this they found that the tumours shrank and disappeared. It gets better though: they tried the same approach in breast cancer, colon cancer, and melanoma, (three very different cancer types) and saw the same effect across the board.
Perhaps the most exciting part of the work was that when they injected one tumour, the immune system attacked all the tumours in that mouse, which means that this is an approach that may work in late stage patients, who are typically very difficult to treat.The technique itself makes use of a trick that is already used in patients: by injecting a tiny amount of DNA into a patient’s cancer, we can improve responses to chemotherapy. It works by making the immune cells in the vicinity express a marker on their surface, which has the effect of priming them for action. The insight that these scientists had, was that by using a second compound to recognize this marker, they could activate the cells to attack the tumour. Because the injection is directly into the cancer, only the immune cells that recognize the tumour are activated. Some of these then leave the original tumour and attack other ones throughout the body.This approach proved to be remarkably effective. In total, the scientists treated 90 animals with the therapy. Eighty seven of those were cured. Additionally, in some of the mice the tumours became resistant and began to grow again, which is typically what happens in human patients. However, if they then injected this new tumour with the therapy, they saw the same shrinking as before, which is extremely encouraging.It was a startlingly successful study, but as I mentioned above, this work was in mice, so we can’t be sure the results will translate to humans. It’s possible that there will be toxicity to humans, or that there will be issues with stimulating the immune system like this, but it is also very possible that we will see some real benefits of this therapy.It’s an exciting time to be in cancer research!
Is coffee bad for you?
People have an undying love for coffee. Around the world, it’s estimated that 2 billion cups are drank every single day. Lots of people can’t start the morning without one, and there’s now a coffee shop on every corner in every city. 
Considering this popularity, it is perhaps unsurprising that the health benefits/health damaging effects of coffee are never far from the news. This year alone has seen 25 different articles on the Daily Mail Online, detailing why the drink is going to make you live longer or shorter, depending on the article. Of those 25, 14 were extolling the benefits of coffee, while 11 were describing the opposite.On one particularly impressive week the site published six separate articles on the topic, claiming among other things that coffee is nature’s Viagra, that it protects against liver cancer, and that it can cause miscarriage and birth defects. If you were to ask somebody whether coffee was good or bad for them, I sincerely doubt that they would know. So what does the evidence say?Quite a lot actually. There have been many studies on the role that coffee may play in different diseases, which I will get in to below. As is almost always the case however, the first thing to say is that there’s probably no need to change your habits. Whether coffee is good for you or bad for you, the effect seems to be minor. If you love your coffee, there’s no need to cut back. If you’re not a drinker, there’s no need to start.Before I get into the health implications of coffee, it is worth mentioning that aside from the drink itself, people should really think about the way they drink their coffee. It is thought that at least 58 billion paper cups are thrown away each year, made from 32 million trees, and requiring a staggering 100 billion litres of water for their production. It is an extraordinarily wasteful industry, and something as simple as buying a reusable cup can make a significant difference, particularly if it is not made from plastic.
Below I have described what the current literature has to say regarding coffee consumption and various diseases. Ultimately, it is safe to say that for a healthy person with no underlying conditions, normal coffee consumption is probably good for you. The benefit is small in all cases, so it is not something to worry about. As always, there are caveats involved (whether you take sugar in your coffee, whether you drink decaffeinated, how hot it is when you drink it…), but I have tried to answer the major questions below. It is worth pointing out that although an individual coffee drinker is unlikely to see any benefit from their habit, due to the large number of drinkers around the world coffee drinking could potentially have a large impact on the overall health of the population.
Ultimately, it is safe to say that for a healthy person with no underlying conditions, normal coffee consumption is probably good for you.
Q: How much coffee is too much?In general, various safety authorities suggest that 2 – 3 cups of coffee in one sitting is perfectly fine, provided that people don’t drink much more than 6 in a day. For most people, 8 – 10 cups will begin to produce negative side effects, including migraine, anxiety, nervousness, trembling, insomnia and an increased heart rate. These side effects are all caffeine related, and this seems to be the main culprit in the coffee-related problems. Obviously the amount of caffeine differs in different coffee brands and brews, and the numbers above relate to roughly one shot of espresso per cup. There has not been any study confirming or refuting long-term detrimental side effects of regularly drinking more than 6 cups per day (apart from extreme cases when people far exceed this), so we can’t really say either.A: 6 cups seems to be the recommended daily limit for a healthy person, but this is largely precautionary. Q: Does coffee change your risk of dying?The simplest thing we can look at is whether coffee makes you live longer. There have been numerous studies into this, and their results have been mixed. It is pretty clear that coffee doesn’t in general shorten life. Several studies have found no correlation between coffee consumption and longer life, however some have found the opposite. The most recent work I could find suggests that those drinking more than 4 cups a day were at a lower risk of dying, however this was only true in people over 45 years of age. This work was presented at a conference and has yet to be published, so I haven’t been able to have a look at their analysis. However, confusingly, other studies have found that those who drink small amounts of coffee (1 cup a day) get a benefit, but that benefit disappears if you drink more than 4 cups. Some studies claim that women benefit more than men, and others that the benefits depends on what ethnic group is being studied. All in all, the literature is mixed, which is a clear sign that if there is an effect, it is a tiny one. It is interesting to note though, that the scientists who carried out the most recent study found that even people who drank decaffeinated coffee got some of this benefit, meaning that the effect may only partially be as a result of caffeine intake.A: Coffee may extend life in certain circumstances, but if it does, the effect is tiny. Q: Are coffee and cancer associated?As coffee drinking and smoking often went hand in hand in the past, it is difficult to separate the two in studies. What is clear is that the results are mixed. A Japanese study suggested that high coffee consumption (over 5 cups a day) had a protective effect. Another recent analysis suggested that coffee is not associated with the large majority of cancers, with a few exceptions. Coffee seems to have a protective effect against liver cancer, but the size of this effect is debatable. However as most liver cancers are related to either smoking or obesity, there are far bigger interventions that can be made to protect against this cancer. There have been studies showing a slightly reduced incidence of endometrial, skin, gallbladder, oral, and kidney cancer in coffee drinkers, but these studies have yet to be confirmed. Finally, there was a suggestion that coffee drinkers were more prone to prostate cancer, but recent studies have cast doubt on this.A: Coffee seems to have a protective effect against liver cancer, and potentially against several others. Q: Does coffee affect heart health?It was thought for a long time that coffee was associated with cardiovascular diseases, hypertension, and heart failure. This makes intuitive sense; when people have too much coffee, they often feel like their heart is racing. Several studies seemed to show this was the case, however none of the studies were thorough enough to tell for sure. More recent studies have shown that this is not the case, and that coffee has either a neutral or a beneficial effect on heart health. For example, some studies show that coffee is protective against coronary heart disease in women, and reduces the risk of death in patients who have had a heart attack. Other studies show no change or an increase in coronary heart disease risk, so any effect is likely to be small.A: Coffee has a neutral or slightly beneficial effect on heart health. Q: How about the effect of coffee on mental health?The number of studies looking at this is smaller than in the previous paragraphs. However, those that have been done do show that coffee has a slight protective effect on depression risk, although some of those studies were of poor quality. Due to the sleep disturbing effects of excess caffeine, there is reason to think that this may also have a detrimental effect on mental health, but the evidence has not backed this up.A: Coffee seems to have a slight beneficial effect on mental health Q: Does coffee play a role in neurodegenerative diseases like Alzheimer’s and Parkinson’s?Lifelong coffee consumption seems to have a protective effect on the development of Alzheimer’s and Parkinson’s. In both cases the effect was more pronounced in the early stages of the disease, and in the case of Parkinson’s, it the effect was bigger in men than in women.A: Long-term coffee drinking has a slight protective effect in age-related dementia Q: Does coffee protect your liver?It is in liver disease that we see the biggest protective effect of coffee. Liver enzymes tend to be lower in coffee drinkers (which is a good thing). Interestingly, this tends to be more pronounced in patients at the highest risk of liver disease, such as alcoholics. It is also beneficial in non-alcoholic liver disease and other metabolic syndromes. Coffee inhibits the Hepatitis C virus, and drinkers show lower levels of damage in their livers, and as mentioned above, coffee seems to have a protective effect against liver cancer.A: Coffee has a slight but significant protective effect against almost all kinds of liver disease and damage Q: Does coffee affect fertility?There is very little evidence that coffee consumption has a measurable effect on fertility. Several studies have shown a slight decrease in semen quality with high caffeine intake, and others show a very slight increase in the time to pregnancy for caffeine drinkers. This study included energy drink consumption have far higher levels of caffeine than coffee, so the results were probably skewed by that population. Several larger studies have found no correlation between coffee consumption and an increased time to pregnancy.A: Coffee drinking does not decrease fertility. Q: Is coffee safe in pregnancy?Many women avoid caffeine during pregnancy, preferring to err on the side of caution in this case. The WHO recommends limiting caffeine intake during pregnancy to 3 cups or fewer per day, and the evidence supports this conclusion. Studies have shown that high caffeine intake is associated with a slightly higher risk of pregnancy loss and developmental defects. If drinking fewer than 3 cups per day however, there is no evidence of an increase in foetal malformation, neurodevelopmental defects, or miscarriage.A: High coffee consumption may cause issues in pregnancy, but no problems have been seen for those drinking 1 – 2 cups per day.
Milk and Parkinson's
As the population has been getting older, there has been increased attention paid to neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. These are diseases that cause a progressive loss of mental function (dementia), or problems with movement, such as tremors. The causes of these diseases are still relatively unknown, so there is a lot of public interest in studies that look at this. This week a paper was published that suggests there may be a link between high consumption of low fat dairy (particularly milk), and Parkinson’s. This was picked up by numerous media outlets, with predictable headlines.
Do you eat 'low-fat' branded food? Parkinson’s disease could be triggered by THISThe Express, 12/06/17
It has been known for a few years that there may be a link between dairy consumption and Parkinson’s. However, this link has always been weak and controversial, so the benefits of drinking milk have far outweighed the potential harm. This week’s study took this further by analysing this link in a huge number of patients, far more than have ever been studied before.So what have they found? Well firstly, there’s no need to give up drinking milk. The study did NOT find that low fat milk causes Parkinson’s. That’s not to say the headlines were entirely wrong, but the study was not designed to find whether milk causes Parkinson’s. It was designed to see whether people who drank lots of low fat milk were more prone to the disease. This is a subtle distinction, but an important one. I have written about this in the past (correlation vs causation), but it is worth repeating. Just because two things are happening together, doesn’t mean that one is causing the other. On top of that, milk is full of nutrients, so cutting it out or the diet may have unintended consequences.This study was a big one, including nearly 130,000 people. Of those 1,036 people developed Parkinson’s over the course of the study. When they looked at how much milk these people drank compared to the rest, they found that there was no difference. However, if they specifically looked at the consumption of low fat milk, they found that people who drank 3 or more glasses per day were more likely to develop Parkinson’s. The association wasn’t very strong, with the general population having a 0.8% chance of getting the disease, and those who drink lots of low fat milk having a 1% chance. It’s a small difference, but with an aging population, this could mean significantly more people with the disease.The authors of the paper are careful to emphasise that they are not showing that milk causes Parkinson’s. They make several alternative suggestions themselves, including the possibility that Parkinson’s itself affects dietary behaviour, causing people to drink more milk. However, it must be considered a possibility that low fat milk is increasing the rate of Parkinson’s.So is it advisable to limit your milk consumption? At present, the answer to that is no. Milk contains nutrients we need, including calcium and potassium, and has significantly less sugar than other drinks. Per glass (240ml), it has 2.6 teaspoons of sugar, compared to 5.2 teaspoons in orange juice, and 6.4 in Coca-Cola. Additionally, those at risk drank 3 or more glasses per day, which is quite a lot.In short, there is no need to start drinking black tea and putting water on your cereal. Paranoid people might want to limit their consumption to less than a litre a day, but I won’t be changing my habits on the back of this evidence!
Eggs, cancer, and motivated reasoning
The following headline in the The Daily Express caught my attention this week:
“Ovarian cancer - could EGGS be the cause of disease? Vegan charity research REVEALED”Express.co.uk 14th March 2017
The article goes on to explain that a Bristol based charity called Viva! Health has urged consumers not to eat eggs, claiming that one egg a week increases cancer risk by up to 70%. According to their own website, Viva! Health is a science-based health and nutrition charity, and being “science-based” you would expect them to have sufficient evidence to make a claim as eye-catching as the one above. So is this the case?
Viva! Health claim that eggs are linked to ovarian and prostate cancer in two ways. First, the high cholesterol levels promote these cancers; and second, choline in eggs is linked to prostate cancer. They give references to scientific publications as evidence, but these publications show nothing of the sort. The journal article they point to regarding cholesterol explicitly states that any association between egg consumption and ovarian cancer risk is not due to the cholesterol in eggs. A quick look at the literature also shows that if there is any link between egg consumption and breast or prostate cancer, it is tiny. A similar pattern holds true for the link between choline and prostate cancer. The research that Viva! Health use to support their claim actually shows the opposite, that choline from eggs is not associated with cancer. It’s pretty clear, there’s nothing to worry about.It took me roughly six minutes to debunk both of these claims, using the identical publications that Viva! Health used to support their claims, so an obvious question is how a charity that clearly thinks of itself as “science-based” could come to the opposite conclusion to me. There is a well-known phenomenon in psychology called motivated reasoning. It describes a process by which someone who holds a particular belief seeks out information that confirms what they already believe, rather than rationally assessing the evidence.It is a fascinating mental trick that we are all guilty of. We all cling to different beliefs with different strengths. If I was to tell you that plastic bags are more environmentally friendly than cloth bags (unless the cloth bag is used more than 130 times), you are likely to look at the evidence and relatively quickly change your view without a huge amount of argument. On the other hand, if I was to say that immigration is economically bad for a country (or good depending on your point of view), you are far more likely to argue with me and ultimately reject that argument. Although both the plastic v cloth and the immigration arguments are contentious and depend on the studies you look at, the likelihood is that you reacted differently to each.A lot of recent research has started to dissect these distinct types of beliefs. We have normal beliefs that change with additional information, but we also have a set of beliefs that form the core of our identities. These often take the form of religious or political views, and when these beliefs are challenged we don’t take a rational approach. Instead we employ motivated reasoning, dismissing awkward facts and cherry picking the ones that agree with us. Indeed, if one of these core beliefs is challenged, it is likely that the belief will be ultimately strengthened rather than weakened by the challenge, something called the backfire effect.Motivated reasoning is extraordinarily common in pseudoscience. Topics like climate change and vaccine safety have decades of reputable research behind them, but despite this, deniers ignore the body of evidence and scientific consensus, deciding to rely on small bits of circumstantial evidence or simple untruths to “prove” their points. There seems to be very little we can do to convince people who hold these beliefs so tightly. However, the majority of the population doesn’t have beliefs like this at the core of their identity. They may have heard the arguments and be unsure about the topic, but with clear evidence and explanation, most people will make the right decisions. This is exactly why it is so important to talk about science and to educate people in how to recognize false claims.Motivated reasoning may be behind the Viva! Health claim that eggs cause cancer. They are a charity dedicated to promoting veganism, so it is entirely plausible that their beliefs regarding non-vegan foods are central to their identity. Alternatively however, they may just understand that if you link something to cancer (whether it is true or not), you are far more likely to make it into the papers, and have random bloggers talk about you!
Using stem cells to treat cancer
There are many scam artists around nowadays proclaiming the benefits of their particular unproven stem cell therapy, for anything from curing cancer to making paralysed people walk again. It’s not surprising really; stem cells are a pool of cells in every organ that are almost eternally youthful and can regenerate themselves and all other cells in the organ. They sound almost magical. However, last year the FDA (the US Food and Drug Administration) had to move to crack down on these clinics, citing the of lack of evidence that any of them work and a number of serious complications reported following treatment. Complications including patients in Florida dying, a woman developing bone fragments in eyelids following a stem cell facelift, and another developing nasal tissue in her spine after a doctor promised to cure her paralysis with stem cells.It is a field ripe for abuse partly because it is one with so much potential. Stem cells do have fascinating possible applications, and there is a lot of research going in to them at the moment. Unfortunately, most exposure people have with them is in science fiction or alternative medicine. Which is why it was very interesting to see a study published last week that underlined how much real potential this field of research has. The study used mice instead of humans, so is still at an early stage, but is very promising nonetheless.Scientists from North Carolina were studying a deadly form of brain cancer called glioblastoma (GBM), which has extremely poor prognosis for patients diagnosed with it. The work builds on the bizarre finding that these tumours somehow attract stem cells to them. So if you look at a GBM in humans, there are stem cells inside them that shouldn't be there. Scientists had previously used this fact to load some stem cells with chemotherapy and could show that in mice, the stem cells were attracted by the tumour as expected, but they could also release their therapy while they were there. The problem with this is that we have very few stem cells in the brain so finding them and loading them with drugs is very difficult.In this case the scientists overcame that problem by turning skin cells into brain stem cells. They took skin cells from mice into the lab and, because skin cells originally comes from the spinal cord which is technically part of the brain, were able to trick them into reverting back into that state. They could then give these cells their chemo payload and inject them back into the mice. When they did this the stem cells made their way to the brain and reduced tumour size to almost nothing, which is obviously a very impressive response.There are two key advantages of this approach: 1) we have lots of skin stem cells, so they are easy to get; and 2) you can do it with a patient’s own cells, meaning that you wouldn’t have to worry about rejection, which can cause severe complications. This work still has to undergo significant testing to ensure it is safe for humans, but studies so far have been positive. A group in California have carried out a clinical trial which showed that apart from tissue rejection (which isn’t an issue in this case), stem cells can be a remarkably safe form of therapy.This work is still at an early stage, but it is very encouraging. Considering that the average survival time for a patient with GBM is only a year, any new therapeutic avenues are welcome. The stem cell field is one that is on the cusp of large-scale application, and this could be one of the first in an array of new therapies for cancer and many other diseases. At present however, 95% of clinics offering these therapies are charlatans looking to make money off vulnerable people.
Does Nutella cause cancer?
On a recent cycling trip in Canada, I ate an obscene amount of Nutella. It works as a great lunch, and dipping fresh bread in it is a delicious snack. When you are exercising all day every day, a tasty, spreadable, dippable energy source like this is extremely useful. Don’t get me wrong, it is a very unhealthy food, but despite this, I’m a fan.Which is why I was surprised this week to see Ferrero (the makers of Nutella) defending their product against claims that it causes cancer. A quick internet search revealed the problem. As the Tech Times put it: “Nutella Can Cause Cancer, Study Warns”. The Huffington Post ran with: “Stores Are Pulling Nutella After Report Links It To Cancer”, while the Daily Mail asked “Could Nutella give you CANCER?”. So what is this all about, and should you stop eating Nutella?As I’m sure you can guess, the simple answer is no, there is currently little evidence to suggest that you need to avoid Nutella. This panic was based on a study released by the European Food Safety Authority (EFSA) last year which suggested that when palm oil is refined at above 200°C, it releases something called glycidyl fatty acid esters (GE). Previous work has shown that at high levels this chemical can cause cancer in rats. Ferraro do indeed use palm oil in Nutella, so people have made an assumption that it therefore contains GE. However, Ferrero have clearly stated that they do not process their palm oil at 200°C, so no GE is produced in the process. Case closed.But for the sake of argument, lets pretend they do refine their palm oil at 200°C. Would the hypothetical amount of GE in Nutella be a cause for concern? In the EFSA report they quote the levels of GE that cause tumours in 25% of rats (10.2 mg/kg/day in case you are interested). Now obviously we would want to play it safe, and wouldn’t want to consume anywhere near that amount. So for argument’s sake, lets see how much Nutella we would need to eat to get 1/10,000th of that amount (thanks to this article for calculating the numbers). It turns out that the average adult would need to eat nearly 100g of the stuff every day to reach 1/10,000th of the amount that gives rats cancer. That’s over two jars a week, and if you are eating that much Nutella, then cancer is the least of your problems. The same amount of Nutella (800g) contains over 450g of sugar, which is double what your TOTAL sugar intake should be for a week.Simply put, concerns about cancer are a terrible reason to stop eating Nutella. Their use of palm oil has many other problems associated with it, including the devastating environmental impact, but that is another argument. As always, this is a case of poor journalism. The study itself didn’t mention Nutella, and was just focused on the GE. Some simple fact checking would have shown that Nutella does not process their palm oil in a way that produces GE, but there is nothing like a food scare to attract clicks.
Royal College of Physicians recommends e-cigarettes for smokers
A few months ago I wrote here about the rise of e-cigarettes. In that post I pointed out that e-cigarettes are far less harmful than tobacco, and should be marketed as a safer alternative to smoking. There has been an interesting update on this topic today, with the Royal College of Physicians (RCP) recommending that all smokers be offered and encouraged to use e-cigarettes.You can read my previous post for some of background, but put simply, e-cigarettes vaporise nicotine to allow it to be inhaled (hence it being known as “vaping”). This differs from smoking, where tobacco is burned and the smoke inhaled. This accounts for the primary difference between vaping and smoking; tobacco burning creates thousands of chemicals, 10% of which are known to cause cancer. People inhale far fewer chemicals when vaping, making it 95% safer than smoking.The RCP released a report today (April 28th) stating that
"e-cigarettes are likely to be beneficial to UK public health. Smokers can therefore be reassured and encouraged to use them, and the public can be reassured that e-cigarettes are much safer than smoking"
They go on to state that current evidence shows:
- E-cigarettes are not a gateway to smoking.
- E-cigarettes do not result in the normalisation of smoking.
- E-cigarette use is likely to lead to quit attempts that would not otherwise have happened.
- The dangers of long-term e-cigarette are unlikely to exceed 5% of those associated with smoked tobacco products, and may well be substantially lower than this figure.
An excellent Cancer Research UK blog post on this topic points out that this reduced harm of vaping is something we should focus on. They emphasise that a significant number of people may be unable, or simply not want, to give up smoking. For these people, the aim should be to reduce the danger of their habit by encouraging them to use e-cigarettes rather than traditional cigarettes. This harm reduction strategy has worked well in other cases, such as needle exchanges for intravenous drug users.This is what the NHS already recommends, in the form of nicotine replacement therapy. It has been shown, however, that the delivery of nicotine to the brain via vaping is far more similar to smoking than in nicotine replacement therapy. As a result smokers seem to prefer vaping, and e-cigarettes have now replaced nicotine patches and gum as the most popular aid in quitting smoking in the UK.It has been shown that an overwhelming majority of e-cigarette users are ex-smokers, or current smokers who are trying to cut down or quit. Considering the human toll of smoking (270 deaths in the UK every day), it is commendable that the RCP have recommended e-cigarettes to smokers. While there are still problems with vaping (particularly in marketing to children), the advantages for current smokers are undeniable. The use of alternative sources of nicotine is safer, and should be part of any strategy to reduce the harm of tobacco.
Acupuncture no longer recommended for back pain
NICE (the organisation that provides guidance to doctors in the UK) recently updated their recommendations regarding lower back pain. In the updated guidance, they say that exercise, in all its forms (for example, stretching, strengthening, aerobic or yoga), is the most important step in managing back pain. Previously, NICE also recommended acupuncture or massage, but this has now been altered. Massage can still be used alongside exercise, but the guidelines no longer recommend acupuncture, as "evidence shows it is not better than sham treatment".This is not entirely surprising as, despite widespread acceptance of acupuncture, the evidence that it works for any illness or disability is very scant (as I have described in a previous post). Most studies are poorly carried out, and many show no difference between it and sham acupuncture.Unfortunately, the authors of these studies often conclude that both acupuncture and sham acupuncture work, rather than the actual conclusion (that acupuncture doesn't work). If a medicine works no better than a sham medicine (a sugar pill for example), we cannot conclude that both the medicine and the sugar pill work.For those suffering from back pain, the new recommendations also encourages people to continue with normal activities as far as possible, and recommends that non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or aspirin should be tried. Unfortunately, at present there is no evidence to back up other interventions.A recent study found that back pain caused more disability than any other condition, and is also responsible for 37% of all chronic pain in men and 44% in women. While it is understandable that people seek relief from their symptoms, it is obvious that the NHS can't fund a treatment that does not work.
Recent advances in cancer therapy
First off, sorry for the lack of writing in the last few weeks; I’ve been in the middle of a job hunt, so my time has been limited by that. In the time I have taken off however, there have been some major news stories about cancer.The week of the 15th February brought some pretty sensational headlines. These were about a trial of a new immunotherapy, which both The Times and the Independent proclaimed “a cure”, and The Guardian labelled as “unprecedented”.Immunotherapy is an extremely promising branch of cancer therapy that has recently been getting a lot of attention. I have previously written about it here, so I won’t go into detail about how exactly it works. Simply put, it involves taking some of a cancer patient’s immune cells, teaching them to recognise the tumour, and then putting them back into the patient. These immune cells can now identify the cancer, attack it, and hopefully clear it from the system.
These results have not been published yet (they were presented at a conference), so we can’t say for sure how reliable they are. We do know however, that the trial had just 36 patients on it, and that it was looking at a cancer we can already treat with a high degree of success (acute lymphoblastic leukaemia (ALL)), so the headlines were far more sensational than the work deserves. That being said, it does appear to be a very encouraging study. However, as I have previously written, claiming something is a “cure” for cancer is likely to be wrong.This treatment appears to be very effective for ALL, and it may eventually become part of the standard therapy for this disease. However, ALL is just one of a large number of different types of cancer. Couple this with the ability of the disease to develop resistance to therapy and it becomes unlikely that this (or any other therapy) will ever be a “cure” for cancer. So while this is certainly an exciting advance, claiming it is a cure is unfortunately incorrect. It may have the potential to cure some patients, but without long term testing, we just don't know if this is the case.This problem of resistance brings me to the second big cancer story that’s been in the news recently. Coincidentally, it is also to do with immunotherapy. In this study, scientists found that a patient’s cancer carry markers that the immune system could be primed to attack, as I described above.However, it has always been assumed that as a tumour develops, it would change and evolve, resulting in some cells that no longer have these markers, and would therefore be resistant to the immune cells taught to target those markers. What is interesting about this study is that the scientists showed that this may not always be the case, and that all of a patient's tumour cells may still carry the markers, meaning they would all be attacked by the immune system. The video below (from CRUK) describes this very nicely.https://www.youtube.com/watch?v=ZPwrvPerxIkThe potential that a patient won't develop resistance to a therapy is one that scientists and doctors can only hope for. If this study holds, and is extended to other cancers, this dream may become a reality for some people. Again, this is a study on very few patients, but it gives us a tantalising glance at a potential weakness in cancer that could be exploited.It is an exciting time to be a cancer researcher!
Trust in science
As with every other week, the last 10 days has brought a slew of tabloid stories, linking various things with causing or curing cancer:GOOD: antacids, Chinese herbal remedy, berries and tea, anthrax, frying foodBAD: being tall, tonsils, artificial football pitches, The RAF, oral sexAs always, these stories are largely nonsense, suitable only for the bin. Unfortunately, they are reported credulously and are widely read, and this saturation of health-related articles has several negative consequences.The constant bombardment of people with often-contradictory health information can drown out real health advice, making people think that eating some nuts can offset the effects of a terrible lifestyle for example. There is an enormous industry based on the peddling of cancer-preventing foods and supplements, often with a thin veneer of scientific respectability, and thanks to tabloid reporting, a much wider reach than should be allowed. It’s infuriating.However, the most insidious problem with poor media portrayal of science is the gradual erosion of trust in science. This may not seem like a significant issue, but it may be the most important. The rejection of vaccines, denial of climate change and resistance to genetic modification of foods, for example, are all rooted in science denial.This is an issue with many causes. Both political and religious beliefs play a major role in our view of the evidence, as does self-interest, meaning that arguments are often politicised or financially motivated. When Andrew Wakefield, for example, “found” a link between vaccines and autism, he personally profited from people not using the MMR.
The driving force behind denialist movements are often organisations that stand to gain from the confusion (climate change denial has largely been funded by groups that will suffer most from restrictions on fossil fuels). There has been a deliberate drive to manufacture controversy in many areas, most famously by the tobacco industry, whose tactic was not to win the debate, but to “foster and perpetuate the illusion of controversy in order to muddy the waters around scientific findings that threaten the industry”. A leaked memo to George W Bush on climate change tactics from 2002 suggested that although the scientific debate was closing, it was important “to continue to make the lack of scientific certainty a primary issue in the debate”. Media organisations are often complicit in this, and there are many examples of the deliberate undermining of the scientific process, most notably by Fox News in the US.That being said however, the large majority of people who subscribe to denialist views are people who have no such motivation. These people appear to have a basic mistrust of science, and are swayed by the anti-science rhetoric. It is easy to understand why parents hesitated to vaccinate after the initial reports of a link to autism, but despite this link being definitively shown to be false, vaccination rates in large parts of the world are still suffering. Be it the left-wing embracing of alternative medicine, the right-wing support of climate change denial or religious creationism, the anti-science movement is a pervasive one, largely based on the mistrust of science.There are several roots of this mistrust. An obvious one is that science can undermine deeply held beliefs. When this happens, people are likely to reject the evidence, rather than give up their belief. In fact, when challenged on such a belief, people are more likely to strengthen their belief rather than the other way around (known as the “backfire effect”). This needn’t be a religious belief, and is something that has been observed in many areas of life, such as the belief in superstition or alternative medicine. If science continuously challenges these beliefs, then people stop believing in the science.It is also the case that a misunderstanding of what science actually is also contributes to this issue. Many people see science as an “institution”, something that is telling us what to do. The reality is that it is a process. This misunderstanding of science makes it much easier for people to rationalise the rejection of valid conclusions, regardless of the strength of the evidence. The power of anecdotal evidence is a classic example of this: “my father smoked 20 a day, and he lived ‘til he was 90”. This view of science as an “institution” also feeds into an anti-establishment mentality that can also result in science denial. This is the same mentality that is behind the belief in grand conspiracies.And this brings me back to the tabloids. If you are told every day that random things are making you sick, or are essential to health, it is likely that you will become desensitised to them. It is easy for people to reject science-based advice, because tabloid reporting makes science appear far more confused than it actually is. The reporting of preliminary findings, or of badly carried out science, leads to a confused picture of our current understanding. Scientists are constantly studying and learning, working towards the truth. Bad science and incorrect results are inevitable in science, but it is a self-correcting process that gradually works to show what is real and what is not.Our entire civilisation is based on scientific innovation and progress. While that progress cannot be halted, it can be slowed by the mistrust of the public in the scientific process. That can only be a bad thing.
Smoking vs Vaping
Vaping has become remarkably popular in the UK over the last few years. Estimates now suggest that over 2.5 million people in the UK use e-cigarettes and that number is rising. However, as a recent conversation with my wonderful sister-in-law showed me, people are divided over whether this is a good thing or not.Smoking is one of the most damaging habits we can choose to take up, being the single biggest cause of preventable death in the UK (as I described in a previous blog). We have known for years that people “smoke for the nicotine, but die from the smoke”; standard cigarettes burn tobacco, generating over 7,000 different chemicals, at least 72 of which are known to cause cancer.In contrast, e-cigarettes vaporise nicotine to allow it to be inhaled. This difference is perhaps the biggest argument for vaping that can be made, as most current evidence suggests that it is far safer. Public Health England (a UK governmental body) estimates that e-cigarettes are “around 95% less harmful that tobacco”, leading 53 experts to recently write a letter to the WHO, urging them not to classify e-cigarettes the same as regular cigarettes. Furthermore, the Royal College of Physicians has also called for e-cigarettes to be marketed as a less harmful alternative to smoking.However, it is important that e-cigarettes are seen as the lesser of two evils, rather than as something “good” or “safe”, a fact that seems to be ignored by advertisers, who benefit from a lack of marketing regulation that applies to other addictive substances like cigarettes, alcohol or gambling.There is pretty good evidence now that several cancer causing agents can be found in e-cigarettes. Some of the flavourings added to e-cigarettes have been found to contain high levels of chemicals known to cause lung cancer. Furthermore, the well-known carcinogen formaldehyde has been identified at levels 5 times higher than in normal cigarettes. This study has not been replicated however, but it is worth keeping an eye on.Additionally, nicotine itself is a poisonous substance, particularly in pregnancy, as it can both cross the placenta and is present in breast milk. While the dose of nicotine supplied by an e-cigarette is lower than that supplied by a regular cigarette, it is overwhelmingly clear that people should neither smoke or vape during pregnancy.Finally, it is important to discuss the potential of vaping as a gateway drug to smoking. Do people who would otherwise not smoke take up vaping? There isn’t a huge amount of data to answer that question right now, and the data we have is mixed.Some studies suggest that this may not be the case, and the increased e-cigarette use is resulting in a decreased in the number of new smokers. However, other studies have shown the opposite, that many teens that use e-cigarettes do so for the novelty and flavour. The two biggest studies show that only a subset of those considered “gateway smokers” will move on to be regular smokers however, meaning that it is likely that further follow-up studies “will be unable to demonstrate a major gateway to heavy tobacco use”.E-cigarettes have only been on the market for a few years, so it is impossible to tell what the long-term effects of their use will be. While there still isn’t sufficient evidence to be sure, indicators suggest that vaping is a lot less dangerous than smoking, so it probably makes sense to market e-cigarettes as a safer alternative for nicotine addicts.However, making e-cigarettes attractive to teenagers and children should obviously be banned. It is extremely worrying that many flavours currently available are targeted at kids (including “cotton candy” and various fruit flavours). After all, nicotine is an extremely addictive substance, so the normalisation of vaping in this group should be prevented.This current lack of regulation needs to be corrected, but it must be acknowledged in any regulation that e-cigarettes are less harmful than regular cigarettes, and that excessive regulation may drive people to smoking in order to get their nicotine fix. Given the horrendous toll of tobacco smoke, this is something we cannot allow.
Should children eat rice cakes?
I’ve seen this story pop up on my newsfeed a few times recently, so I thought I’d have a look and see if there is much to it.It is an article about some new guidelines in Sweden regarding arsenic in rice products. They state that due to high levels of arsenic, some rice products can be harmful to children, and that many of them should be rationed, or even avoided altogether.In case you don’t want to read the rest of this blog post, I’ll give you my take on it first. We are already aware that there are high levels of arsenic in rice products, and the US FDA (Food and Drugs Administration) has been monitoring it for years. Long-term exposure to low levels of arsenic has been associated with various cancers, including those of the kidney, bladder and liver. Some in the press have also reported neurotoxicity in children, but there is little reliable evidence for this in the literature.While the link with cancer may be real, the level and time of exposure required to see such effects would suggest that the Swedish Food Safety Authorities are going overboard with this advice, and the possibility of harm is only in extreme cases. So as always, the key is to exercise moderation in all things.The article reports that the Swedish National Food Agency tested 102 rice products for arsenic levels, and recommended that:
"children should not eat rice or rice products such as rice porridge, rice noodles, or breakfast cereal made of puffed rice, such as Rice Krispies, more than four times a week. And with regards to rice cakes, children should completely avoid these."
This advice is slightly puzzling, as it has been known for a long time that there is inorganic arsenic in much of our food, but particularly in rice products. The US FDA has been monitoring arsenic levels in rice products for the last 25 years. In their most recent tests, they analysed over 1300 products, and found results similar to those in Sweden. However, the FDA did not reach the same conclusions regarding safety, something I will go into more later.Unfortunately there isn’t much advice available as to what constitutes “safe” levels of arsenic in food. There are fairly clear guidelines about arsenic in drinking water, but comparing levels in food to those in water is difficult, so the following should be taken with caution.The World Health Organisation (WHO) recommends a limit of 10ug (10 millionths of a gram) per litre of drinking water. They report that there is some evidence of toxicity if the level is 50 – 100ug per litre, which is 5 – 10 times above their recommended limit. Furthermore, they report that from 10 – 50ug per litre there is a possibility of adverse effects, but that these would be at such a low incidence that they would be difficult to detect.Taking the WHO guidelines as reasonable, small children (aged 5 to 8, who drink around a litre of water per day) can expect to stay healthy ingesting 10ug of arsenic per day from their drinking water. This doesn’t take into account the additional arsenic they get from food. However, let’s go with the WHO and take 10ug per day as the safe dose.Many of the rice products tested contain a significant portion of that. Rice cakes, for example, have 4ug of arsenic, while Rice Krispies have 2.2ug. So if a child was to have rice-based cereal for breakfast, rice for dinner and snack on rice cakes, you can see how they could easily exceed our safe dose.This isn’t a problem if it happens irregularly; however, if a child is getting this dose of arsenic every day, then, using the cautious WHO estimates, there is a small possibility of future problems.As I mentioned above, the US FDA have also been keeping an eye on arsenic in rice products. Their testing has been far more comprehensive than that in Sweden, and their findings have been very similar. However, they do not have the same recommendations as the Swedish National Food Agency. The FDA recommends the following:
"Eat a well-balanced diet. All consumers, including pregnant women, infants and children, are encouraged to eat a well-balanced diet for good nutrition and to minimize potential adverse consequences from consuming an excess of any one food. This advice is consistent with the guidance of the American Academy of Pediatrics, which has long stated that parents should feed their infants and toddlers a variety of foods as part of a well-balanced diet.Consider diversifying infant foods: The FDA recognizes that children routinely eat rice products and that by tradition many infants are fed rice cereal as their first solid food. According to the American Academy of Pediatrics, there is no medical evidence that rice cereal has any advantage over other cereal grains as a first solid food and infants would likely benefit from an array of grain cereals."
In conclusion, it is probably right to say that the levels of arsenic in rice may be a problem for children who eat very large amounts of rice products every day. Feeding children 5 rice cakes per day probably isn't the best idea either. However, recommending an outright ban on rice cakes for children seems very extreme, and un-needed. In moderation, they are a perfectly good snack. Parents have enough to worry about, and if a child is getting a balanced diet, then arsenic should not be another thing on that list.
