Why It Seems Like Scientists Are Constantly Changing Their Minds
Is coffee this week good or bad? The oil is still okay, right? Are we in a “diet coke will kill you” or “diet coke is good” cycle? This can be difficult to keep track of. But the headlines don’t tell the whole story. Behind the scenes, scientists are constantly disagree and disagree.
Remember, health is a complex thing: there are so many different foods, different people, and different things that we worry about. No study can answer all the questions about, say, coffee. So, each group of scientists looks at the problem space – I picture it as a big shiny cloud filled with question marks – and cuts off a tiny piece that they think they can handle. (Even “large” studies do solve a small issue; they just do it by studying a large group of people.)
There are tons of scientists working on oil, coffee and wine because these are common enough products and many people care about the answer. So you have hundreds or thousands of teams making little pieces out of this cloud, each coming back with its own answer. They might not always agree, but they didn’t initially ask the same question.
Take wine, for example. It contains the antioxidant resveratrol, which may have some health benefits, which is why some scientists are studying it. They may even do research using pills containing resveratrol rather than wine. But wine also contains alcohol, which has its potential risks and benefits, so other researchers will look into this.
And each team of scientists will apply their own approach when designing their experiments. Maybe feed resveratrol to mice. Maybe someone else will ask people how much wine they drink. And scientists can focus on different results: someone can look at premature death, someone can count heart attacks, and someone can simply take blood samples to check their cholesterol levels.
With all this, you could expect a lot of positive and negative results, right? But if you are not a researcher, you will probably go through every news article and use the information you learn to add red wine to the “good for you” or “bad for you” box in your brain. You are not lazy, you are just an ordinary person trying to figure out whether it should be good or bad for you to drink wine at dinner.
Even when scientists study the same question, the results will not always be the same. Think about your favorite sports team: they don’t win all games. You can feel a little rollercoaster of emotions from their victories and defeats, but you don’t look at victory and don’t say: aha, it proves! The Pirates are the best team in baseball! You may hope so, but you won’t believe it until you start seeing more wins than losses. In science, the equivalent of a record of wins and losses is a systematic review that evaluates and summarizes previous research. And, unfortunately, they rarely make headlines.