Taking fish oil supplements may help boost a protein in the brains of older mice that stops brain cells from dying, which could help keep their brains healthier.

We analyzed the available evidence on whether fish oil increases Bcl-2 protein in the brains of aged mice, and what we’ve found so far leans toward a possible connection. One assertion suggests that taking fish oil supplements may help boost a protein in the brains of older mice that helps prevent brain cells from dying, which could support healthier brain function [1]. This single assertion is supported by nine reports or observations, and none of the evidence we reviewed contradicts it. Bcl-2 is a protein that plays a role in keeping cells alive by blocking signals that trigger cell death. In aging mice, lower levels of this protein have been linked to increased brain cell loss, so anything that might raise its levels could be relevant to brain health. But it’s important to note that this finding comes from studies in mice — not humans — and the evidence we’ve reviewed doesn’t specify the dose, duration, or type of fish oil used. We don’t know if this effect happens in all aged mice, or if it’s consistent across different conditions. There’s also no information on whether the increase in Bcl-2 actually leads to measurable improvements in memory, movement, or other brain functions in these animals. The evidence is limited to one broad claim with no detailed studies attached, and we haven’t seen any data on how strong or lasting this effect might be. What we’ve found so far doesn’t prove fish oil raises Bcl-2 in aged mice, but it also doesn’t rule it out. The current evidence is sparse and not detailed enough to say how reliable or meaningful this effect might be. If you’re considering fish oil for brain health in aging, this is one small piece of a much larger puzzle — and it’s based on animal research. More studies with clear methods and measurements would be needed to understand what, if anything, this means for real-world use.