FOS and dementia: Interestingly, these interaction loci were more likely to exhibit genetic associations in the FOS subgroup: 13 of the 15 loci (87%, P = 0.0074) for all-cause dementia and 12 of the 15 loci for vascular dementia (80%, P = 0.035) showing suggestive significance exclusively in the fish oil users but not in the nonusers.