“Nothing is to be feared, it is only to be understood. Now is the time to understand more, so that we may fear less.”
Marie Curie, an amazing two-time Nobel Prize winner, stated beautifully how we fear what we don’t understand.
Science faces a lot of scrutiny, mistrust, and fear these days. Do cell phones cause cancer? If I don’t eat organic foods, will I get cancer? Why do people think vaccines cause autism? Are GMO foods bad for you?
Many of the headlines we see grab our attention by warning us against something that scares us, usually something health-related. We often turn to these articles to educate ourselves, but sometimes a catchy title can also cause concern.
This is the first in a series of posts in which I want to challenge your fears about science by making the scientific process more accessible. If science scares you, I want to dive in to figure out why, challenge what you think you know about science, and teach you to make your own interpretations by interrogating where your information comes from, and the caveats, biases, and political pressures with which it comes.
With the huge amount of news at our fingertips 24 hours a day, it is important that we think about what we are reading and the motivations behind each news story. While there is a lot of truth out there, there can be just as much over-exaggeration and over-interpretation, leading to general confusion and frustration about what is true and what is not. And if we are trying to figure out if something causes cancer, we would just like to skip the BS and get the answer.
This problem is not just in the hands of journalists who need an engaging title. Scientists have their own set of challenges when it comes to interpreting study results and avoiding inherent biases. Without an understanding of the scientific process, it can be difficult to decipher the results of a study and convey its significance to the public.
Scientists walk a fine line between providing information the public needs without scaring them with findings that may not be conclusive. Additionally, we can’t expect journalists—who may not have a rigorous science background—to get it right all the time.
Scientists approach the world by asking questions. How do cells move? How does cigarette smoke affect the lungs? How do genetic mutations cause disease?
Scientists are data-driven. We answer these questions using graphs, maps, diagrams, and equations. Our graphs have error bars and statistical significance. We interpret our data and make conclusions based on statistical significance, which helps us to rule out the chances that our results are due to random chance. If our data is statistically significant, we can make a reasonable conclusion that the effect we are measuring is real.
This marriage to statistics drastically affects the willingness of scientists to claim that something is true, rather than that something might be true. This distinction is important and is often based on context. It is not uncommon that scientists cannot provide a black and white answer, which can be infuriating and doesn’t always make for a great public interest story.
Let’s explore this with a current health issue: recent news headlines are reporting that a California lawsuit is pressing for coffee to be sold with a cancer warning due to the presence of acrylamide, which is produced when coffee beans are roasted.
If a study suggests that acrylamide in coffee might be associated with cancer, compared to a study that suggests that acrylamide in coffee causes cancer, which is likely to make you drop your daily coffee habit?
These types of questions come down to causation and correlation. If possible, we would like to test causation. Because we cannot ethically perform these types of experiments in humans, we cannot give a person increasing amounts of acrylamide to see if they develop a tumor. If this did occur, we would be able to definitely say that acrylamide causes cancer.
And we would also probably be in jail.
Although we can do this experiment in animals, there are caveats that come with animal research. Acrylamide might cause cancer in a mouse, but since mice are not humans, we’ll never know for sure whether it directly causes cancer in humans.
Additionally, we have to be careful to note the amount of potential carcinogen being tested in animals – is it equivalent to the amount that humans are typically exposed to? Oftentimes, potential carcinogens are tested at levels much higher than what a human would be exposed to.
For example, the American Cancer Society website reports that:
“Acrylamide has been found to increase the risk of several types of cancer when given to lab animals (rats and mice) in their drinking water. The doses of acrylamide given in these studies have been as much as 1,000 to 10,000 times higher than the levels people might be exposed to in foods. It’s not clear if these results would apply to people as well, but in general it makes sense to limit human exposure to substances that cause cancer in animals.”
Although we cannot perform causative studies on humans, we can perform correlative studies, which were performed to help answer this acrylamide question. To do this, scientists can use questionnaires and other surveying techniques about lifestyle to evaluate whether increased exposure to acrylamide results in increased rates of cancer.
The problem with correlation studies is that it can be difficult to rule out compounding factors and obtain a large enough sample size. For example, there are a certain number of people in a study who by chance will develop cancer that is unrelated to acrylamide exposure. Or, in the case of surveys, study subjects might lie or answer in a way that undermines the accuracy of the results.
As far as studies in humans, the American Cancer Society suggests there is no clear direct link between acrylamide and increased risk of cancer, although this is an issue for which they argue more research should be done.
I am not here to tell you about whether you should stop drinking coffee. What I do want to do is explain how scientists approach questions like this to provide some context about why they cannot always come to a definitive conclusion.
Given the limitations on how we are able to study the effects of potential carcinogens, we may only ever have correlative information about the effects of certain compounds on human health. But hopefully now you understand more about how this type of research is done so that you can begin to draw your own conclusions.
If you are still worried and want to learn more about acrylamide and how to limit it in your diet and lifestyle (hint: cigarette smoking significantly increases your exposure), take a look at the American Cancer Society’s website.
How has science made you nervous? Are there headlines that have made you worried about your lifestyle choices? Share in the comments or shoot me an email at outoftheivorytowerscience@gmail.com and we can figure out how to better understand science in the news so we can fear less.
