You may have come across the numerous headlines this week alleging that taking vitamins can give you cancer. The vast majority of us have read so many scaremongering stories about cancer to even remember, but that didn't stop the likes of the Mail, the Guardian or the Mirror jumping at the chance to report on the latest ‘major study’ intended to strike fear into the UK population.
After endless articles on the dangers of cars, deodorant, mobile phones and even left-handedness, this week it was the turn of vitamins to become the target of irresponsible and lazy journalism.
Among the findings were a number of very scary sounding statistics, such as “Taking too many vitamin E tablets increased the risk of developing prostate cancer by 17%”, and “Taking more than the recommended daily dose of beta-carotene was found to increase the risk of developing lung cancer and heart disease by up to 20%”. The key phrase here is obviously “taking too many”.
As even the conductor of the study, Dr Tim Byers, admitted: “this is not to say that people need to be afraid of taking vitamins and minerals. If taken at the correct dosage multivitamins can be good for you”. And while it may seem as if we have picked two examples of ‘vitamins causing cancer’ at random, these were actually the only two references of this kind that appeared in the research. Of course, this did not stop the big news stories from implying that all vitamins could be harmful to our health. Another nutrient to face criticism was folic acid, which is thought to increase the number of precancerous polyps in the colon.
However, folic acid supplements are incredibly important for pregnant women as it has been proven to (very different from ‘thought to’) help prevent spina bifida and other birth defects affecting the brain and spine. The results were supposedly taken from a decade-long study conducted at the University of Colorado by Dr Tim Byers. But in fact, there was no study. The findings were taken from a commentary published almost three years ago and was merely a subjective review of available studies. A biased summary of science does not constitute science.
Things to Look Out For
The next time you are reading an article that claims to show the harmful effects of vitamins, watch out for these three common tactics employed by the researchers to distort science and make their results seem more sensational:
1. Firstly, researchers will almost never use natural, food-sourced vitamins in their studies. By using synthetic forms of vitamins to generate their results, researchers can still call them ‘vitamin A’ or ‘vitamin E’ despite the fact that they have very little resemblance to the real vitamins that occur in nature.
2. A second, and more obvious, way that researchers can manipulate their findings is to simply cherry-pick the results that they wish to include and discard the ones that they don’t. This means that when they analyse the final results, they end up with exactly the answer they were looking for. If the researchers seem to have a hidden agenda, then it is safe to assume that their results are dishonest.
3. Finally, and most relevant in this case, is the way in which researchers attempt to confuse the public by using ‘relative risk’ instead of ‘absolute risk’ when presenting their findings.
This means that we are told about how much more likely it is that the disease will develop, without ever being told about the overall likelihood of it happening. For example, take a study finding that vitamins increased lung cancer and heart disease by 20%.
If 10 people out of 100 normally developed lung cancer and heart disease, then 12 people out of 100 may develop the disease when taking vitamins. Crucially, when written this way 20% does not sound as scary.