Ah, asparagus. That green vegetable that parents use to terrify their children into frightened obeisance. The mere mention of a dinner cooked with its green, bitter taste is enough to terrify the very soul. The only excuse for its presence is to provide a medium through which we can eat better things, like prosciutto and parmesan cheese.
Also, if you read the news, it can give you cancer.
A new study has come out that links breast cancer metastasis to asparagine, and if that sentence seems painfully wordy you may be one of many journalists who have covered this story with terrifying headlines about how asparagus is coming for your very soul.
News sources from across the globe have combined to scream in one voice that eating asparagus is terrible for you. We have delighted in reading story after story telling us that we were right to throw a tantrum as a child and refuse to eat the nasty-tasting greenery on our plates. Because, you see, asparagus can give you cancer.
Except, of course, it’s a bit more complicated than that.
Asparagus: The Destroyer Of Worlds
The new study that everyone’s talking about is a pretty cool piece of research from a team at the prestigious Cambridge University that was published in the equally-maybe-even-more-prestigious Nature.
You can be reasonably sure it’s good science.
What did the paper find?
Basically, the researchers looked at a mouse model of breast cancer. They were building on previous research that indicated that a chemical called asparagine might be important in the pathway from having one tumour in your breast to having lots all over your body. When they tested different ways of reducing asparagine in the mice — either using drugs to block it from ‘helping’ the cancer cells to metastasize, or preventing the mice from eating it in the first place — they found that reduced amounts of asparagine were associated with chemical changes that would reduce the likelihood of cancer cells spreading around the body.
In other words, asparagine levels could be the difference between a single tumour in the breast and many all over the body.
Pretty big news.
So why aren’t I scared?
There are a few quirks that make this much less scary than you may’ve heard. The most obvious of these is the boring truth that this is a theoretical study in mice that looks at a chemical pathway, not a hard clinical outcome. Asparagine may play a role in the metastasis of breast cancer, but moving from “Mice eat it and then may be more at risk of tumour spread” to “People shouldn’t eat it” is a huge stretch. The researchers even noted that this study was more about demonstrating that a single amino acid could be important in how tumours spread than we thought.
It’s also worth noting that asparagine, despite the name, isn’t only found in asparagus. There might be quite a bit of asparagine in its namesake, but the chemical is also found in a wide variety of other foods, including virtually all meat, most grains, legumes, and a bunch of other vegetables. It’s a pretty common chemical, which means that cutting asparagus out of your diet is even less likely to be of any benefit.
On top of this, most people failed to mention that this was quite preliminary research. There were no ‘hard’ clinical outcomes, like number of tumours or death. The scientists in this experiment only looked at whether asparagine has the potential to cause cancer metastasis, not whether it actually did or whether this actually caused more problems.
The takeaway from this is that science is complicated. Experimental, lab-based science is an order of magnitude more complicated than that. Look at the abstract for this piece of research, and marvel at how difficult the damn thing is to read:
It’s not surprising that many people got it wrong, because it takes either an advanced degree in cancer biology or several hours with a dictionary to pick apart the abstract, never mind the study itself.
The real story here is that science is mind-bogglingly complex sometimes. It’s one of the main reasons that I am in favour of common language abstracts, which are written so that a lay person can understand them.
Bottom line? Every news story about asparagus causing cancer got it wrong. Asparagus doesn’t cause cancer. A chemical commonly found in it might, maybe, potentially, contribute to breast cancer spreading, but there’s no reason to believe that the initial tumour happens because you ate some foot-flavoured stalks. There’s not even much evidence that eating asparagine does anything for cancer spreading, because so far we haven’t tested the idea in actual people.
Don’t worry too much about asparagus. Chances are it’s doing more good for you — because it’s a green vegetable that is 100% better than eating fries — than bad. At the very least, it’s probably not doing any damage to anything other than the overall quality of your salads.
Don’t believe the hype.
Asparagus is fine for your health.