If you've been in the habit of taking any kind of supplement, it's worth taking a moment to do some research into what it can and can't do for your health. Take fish oil supplements, for example: One of the main benefits of taking fish oil is getting your omega-3 fatty acids, which are found in fish like salmon as well as in nuts and seeds. These are known to be broadly good for your health in appropriate quantities. But believing that omega-3s, or other nutrients found in fish oil supplements, can solve all your health problems isn't really sensible. There are things that omega-3s can help, but in other areas science says it doesn't have an effect — or that it can actually make things worse.
We first discovered what omega-3s were in 1929, and since then they've been the focus of a lot of science to see what purpose they serve in human diets and how they help our bodies. You can't actually produce omega-3s on your own, so they need to be obtained via your diet, and when they're in the body they help form and maintain cell membranes, particularly in places like the brain and heart. But there are limits to their powers, so that shelf full of supplements might not do what you hoped. Here are four things fish oil can do for your health, and two things it definitely can't.