Along with the classic advice to get plenty of vitamin C and wash your hands often, there’s a new tip that’s all the rage on TikTok: onion water.
By not eating the fiber in the onion, you are missing out on the prebiotic fiber that is naturally found in a whole onion. These prebiotic fibers help maintain a healthy and diverse intestinal microbiota. Not getting these prebiotics means not getting support for gut health, which in turn can influence certain aspects of immune health. Also, it is not clear how many of the micronutrients that support immune health will be present in the water once we drink it.
There is no evidence that drinking onion water can boost immune function leading to faster clearance of colds or flu. The benefit of onion water is primarily water, which provides hydration.
So despite popular belief, drinking onion water will not prevent you from getting sick this winter. In fact, it might even increase your risk of foodborne illness. At the very least, the drink could be irritating and unpleasant. Fortunately, there are plenty of other evidence-backed (and better-tasting) ways to boost your immune system.
Is it risky to drink onion water?
Drinking onion water might sound like a low-risk remedy to explore, especially if we want to take a more natural approach to cold and flu prevention. With that said, there are a few words of caution to consider before trying it. Many fruits and vegetables can become contaminated with bacteria such as salmonella or listeria. So we could fall ill if we ingest these organisms.
There are also health risks when combining fresh produce and water, especially if the mixture has not been pre-refrigerated. Soaking them in water for a long time could carry a similar risk as soaking avocados, especially if the onion was not washed well and the water was not refrigerated during the infusion process. In addition, experts warn that onion water could cause irritation in some people when eaten thanks to the sulfur-containing compounds found naturally in the vegetable.