I often wonder just how much I annoy people when the topic of alternative medicine (alt med) comes up. In general, if someone says something I don’t agree with, I let it slide. When it comes to alt med, however, I don’t seem to have the same restraint. It’s unfortunate really, as it comes up surprisingly often, and my position comes across as pretty extreme.People ask “What’s the harm?”, and point out that “Even if it doesn’t do anything, people feel better having tried it”. I empathise with this position, but completely disagree. The point I try to make is that if we accept the use of alt med, we legitimize it, making people more likely to choose it over conventional medicine.
The focus of this post is cancer patients who put all their trust in alt med. While it's true that most people use alt med alongside real medicine, the popularity of, and belief in, the alt med movement means that it is inevitable that some people will ignore mainstream medicine in favour of alternatives.Unfortunately this does happen, and it happens regularly enough for us to study it. A few months ago, researchers from Yale published a paper looking into the outcomes for cancer patients who chose alt med over conventional treatment.The authors chose four types of cancer to look at: breast, prostate, lung and bowel. Additionally, they chose patients who had early stage disease, so had a good chance of surviving their cancer.Before I get on to the results of their study, one interesting thing to note is that the researchers show that the patients who rejected conventional treatment were more likely to be younger, healthier, more highly educated, and female. These are the patients who would be expected to have better outcomes than other cancer patients, to survive longer and to have fewer complications. However, that is not what the researchers found.Unsurprisingly, the patients who chose alternative medicine were far more likely to die from their cancer than those who didn’t. In the case of breast cancer, alt med users were nearly 6-times as likely to die. In colorectal cancer they were 5-times as likely. In lung cancer they were twice as likely. To put it simply, choosing alternative medicine above conventional therapy kills cancer patients.So, if 100 women with breast cancer were on conventional therapy, 13 would be expected to be killed by their cancer in the 5 years after diagnosis. If the same women were on alternative medicine instead, 41 of them would be expected to be killed over the same time. It is a damning example of the damage alt med can do.
As always, there are a few caveats with this study. One is that these patients completely rejected conventional therapy. Patients who combined it with conventional therapy were included in the conventional arm, so this study can't say anything about the benefits/damage of that situation.It is also likely that these numbers quoted above are an underestimation. Patients who started using alternative medicine, but switched to conventional therapy (when they realise it was not working) will have been counted in the conventional therapy group, meaning that in reality the use of alt med is probably doing even more damage than described in this paper.This all brings me back to my original point. When people give alt med a sheen of validity by claiming it works, it starts to be seen as a true alternative to our tried and tested treatments. The reality is that it simply isn't. As long as it has some legitimacy, a proportion of the population will use it instead of real medicine, at best wasting money, and at worst seriously damaging their own health. I argue with people about alt med because if I don’t, I feel like I am tacitly agreeing that it has some clinical use, when I know it is not true.To paraphrase an old saying, you know what they call alternative medicine that has been shown to work? MEDICINE. And real medicine saves lives.
Disparities in cancer survival
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.
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!
Does a common drug increase stomach cancer risk?
This story was in the papers this week, linking a very commonly used medication with a doubling in stomach cancer risk. A doubling in the risk of anything sounds bad, but what does it mean in reality?
“Acid reflux drug linked to more than doubled risk of stomach cancer”
The scientists, working in London, published a paper linking the use of proton pump inhibitors (PPIs) with cancer. As around 20 million people in the US take these drugs annually, usually to deal with heartburn, it is obviously very important to be aware of any potential harm they are doing. Indeed, several recent reports have emphasised that these drugs are not as safe as their maker’s say, although the levels of side effects is admittedly extremely low.This study found an increased risk of stomach cancer in people taking the drugs. Those on PPIs were 240% more likely to be diagnosed with the disease. However, to understand this properly, you have to realise the difference between relative risk (which this is) and absolute risk.For example, this increase in relative risk of 240% actually means an increase from 0.24% to 0.57% in the chances of an individual patient getting the disease. In other words, the likelihood of you being diagnosed with stomach cancer goes from a low risk to a slightly less low risk. So of the over 60,000 people included in this study, PPI use was associated with an extra 10 cases of stomach cancer. Most people would consider this acceptable for the benefit they get from the drug.While the increased risk for an individual is low, these drugs are among the most commonly prescribed in the world, as I mentioned above. So, for a population this big, a small increase in risk can result in thousands of additional cases of this disease.Extrapolations like this have to be taken with a pinch of salt however, as they are fraught with issues. For one thing, the study only followed people for 9 years, so it’s difficult to say much about a population of people taking the drugs. Most importantly however, these extrapolations make mass generalisations. Not all patients will be long-term users, while some will be on the drug for longer than the 9 years of the study. It is pretty clear however, that PPI use is associated with many additional cases of stomach cancer.It has to be pointed out though that this is a correlation, and we cannot say that the PPIs are causing the increase. I’ve discussed this in the past here, so I won’t go into detail on this.One last thing to mention is that although PPI use has increased dramatically since they were introduced in 1988, the number of stomach cancer cases has decreased by over 25% in the same time, due to other preventative measures we have put in place. This downwards trend is still continuing, so we can expect further drops in the coming years. Absolute risk v relative riskI showed above that even a large increase in risk of stomach cancer doesn’t mean many extra cases, and I have previously discussed the difference between absolute and relative risk in this blog post.Have a look at the diagram below. In both situations you have a 100% increase in relative risk. However, in one case this means your absolute risk goes from 1% to 2%. In the other it goes from 35% to 70%. Understanding this difference lets you be a lot more critical when reading numbers in the media!
Vitamin supplements: unexpected consequences
Over the last number of years, the vitamin and nutritional supplement market has grown phenomenally. It is estimated to be worth over $36 billion in the US, up from $17 billion in 2000. It is thought that nearly 70% of the US population take some kind of dietary supplement, and there is much said and written about their use. One thing that cannot be debated however, is the lack of evidence that they do any good. A prime example of this comes from a study published recently about vitamin B supplements.
The study looked at vitamin B use and lung cancer. They decided to do this because a previous study had reported an increase in these cancers in people taking vitamins B12 and B9, but that study wasn't designed to look specifically at this, so more work was needed.This study looked at over 77,000 people between the ages of 50 and 76, over a number of years. The results were striking. Vitamin B6 or vitamin B12 use was associated with a doubling in lung cancer risk in men, if taken at above the recommended daily allowance. Since people generally have no idea what the recommended daily allowance is, and the levels of these vitamins can be very high in supplements, there may be many people putting themselves at risk. Indeed, the majority of people taking vitamins unknowingly exceeded the recommended daily allowence.There are a few details that are worth noting. First, the effect was only seen in men and not in women. Second, the association was even stronger in smokers, who are already prone to lung cancer. Third, this effect was present for B6 and B12, but not for people taking B9 (also known as folic acid). Finally, the authors found no beneficial effects of vitamin B supplements in any group.So what does this mean in real terms? Of the 37,049 men in this study, 1966 where found to be taking the highest dose of vitamin B. Of that 1966, 36 were ultimately diagnosed with lung cancer. If they had not been taking vitamin B supplements, this would be expected to be 18 lung cancer diagnoses. That suggests that high vitamin B use was associated with roughly an additional 18 cases of lung cancer. When you consider that this study had over 77,000 people enrolled, 18 additional cases of lung cancer may seem quite small, and these numbers are indeed dwarfed by the additional cases caused by smoking, but it is still significant.As always, I have to point out that this study did not show that vitamin B supplementation caused these extra lung cancers, just that men taking high doses were more likely to get it. As I have previously described, correlation is not the same as causation. However, this was a well carried out study, and the authors controlled for as many variables as they could, making it more believable that the vitamin supplementation is contributing to the cancers.What is clear however, is that vitamin B pills give no benefit on any health outcome. Considering that they may even be doing some harm, it emphasises that we should be cautious when supplementing our diet with unnaturally high levels of vitamins. It is generaly assumed that the more vitamins the better, but as this study points out, that is not the case. A healthy, varied diet more than meets our vitamin needs. Why spend money on supplements if we don't need them?
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.
Anti-obesity campaigning and stigmatization
Last year Cancer Research UK launched the latest campaign aimed at reducing obesity related cancers. This is an important issue, with obesity now being recognised as the second biggest preventable cause of cancer, behind only smoking. The evidence for this is extremely solid, and it is expected to cause an additional 15,000 deaths in the UK from cancer this year alone. And the numbers are increasing steadily. In the 20 years from 1993 to 2013, the number of people classed as overweight or obese in the UK increased by 6 million.Looking at these numbers it is very easy to make the case that an anti-obesity campaign is a perfectly acceptable, indeed necessary, part of our strategy to tackle cancer. This was the logic behind the CRUK campaign. However, that initiative was badly received by some people, who described it as “fat phobic” and very insensitive. These objections are easy to dismiss, especially when viewed alongside the obesity related cancer statistics. However, rather than immediately rejecting these arguments, it may be worth considering them for a minute.Let’s get a few things clear first.
- Mental health problems are extraordinarily common and are a huge problem for us as a society. For example, it is thought that 25% of the population will experience mental health issues each year, with the OECD estimating an annual cost to the UK economy of £70 – 100 billion (around €80 – 115 billion). Several reputable sources put the cost as even higher than that. As a comparison, the economic cost of cancer is “just” £15.8 billion (around €18 billion), emphasising just how important an issue mental health is.
- Negative body image is associated with mental health problems. Unfortunately it is an extremely complex and under-studied field, so solid numbers are hard to come by, but it is estimated that 22% of adolescents suffering with depression have clinically significant body image concerns. This does not mean that one causes the other, but it is safe to assume that our societal problem with body image is damaging.
So let's get back to cancer. The above information makes it clear that any anti-obesity campaign must balance the benefit of decreased obesity with the potential of further stigmatizing obesity and increasing body image problems. So does the CRUK campaign do this? This is an image of one of the adverts that drew the ire of body positivity campaigners.
The first question that has to be asked is what is the aim of this campaign? Obviously the charity wanted to draw comparisons between obesity and smoking, emphasising how dangerous it is. The success of the campaign relies on the assumption that people are not aware how dangerous obesity is, and on the second assumption that if they are made aware of this, people will lose weight and crucially, keep it off. It appears that the first assumption is at least partially true. While people are aware that obesity is unhealthy, less than 25% of people are aware of the increased cancer risk. CRUK have identified the need to increase awareness, but it must be pointed out that although the cancer risk is underestimated, people are already aware that obesity is dangerous.The second assumption made by CRUK is that fear of cancer will motivate people to lose weight. Scare tactics have been used in many campaigns, including well-known road safety and anti-smoking drives. The clear intention of this ad is to draw parallels with smoking, and therefore elicit the same response from people. However, there is reason to think that in the case of obesity, negative messaging may not work.A study carried out in 2012 by researchers at Yale University found that messages deemed negative or stigmatizing were seen as the least motivating of all messages. People exposed to these messages were significantly less likely to comply with their recommendations. Furthermore, there is significant evidence that making people feel stigmatized or shamed about their excess weight makes them more likely to eat unhealthily and avoid exercise, thus decreasing the effect of any public health campaign (additional published studies about this can be found here, here, here and here).The sole aim of this campaign is to highlight that obesity is linked to cancer. While this may on the surface seem like a sensible idea, unfortunately it is more likely to stigmatize obesity than have any meaningful effect on weight loss. This demonization of obesity is very prevalent, and studies have shown that society makes extremely damaging assumption about obese people, including that they are lazy, weak-willed, unsuccessful, unintelligent, lack self-discipline and have poor willpower. It is a little acknowledged but extremely prevalent form of prejudice. This stigmatization is known to be extremely damaging to mental health, but also to threaten physical health (through patient's complaints being lazily and incorrectly ascribed to their weight), to generate health disparities, and as I mentioned above, to interfere with effectiveness of obesity intervention efforts.It is clear that we need to do something about obesity. It is one of the most important health interventions we can make as a society, but increasing the stigmatization of obese people is not the way to tackle this issue. Positive, empowering messaging, healthy eating education (especially in childhood), advertising bans and facilitation of exercise have all been parts of successful anti-obesity drives in the past. Normally I think that Cancer Research UK are extremely effective in their campaigning. This time however, I think they got it wrong.
