While red food dye may still be a problem in young humans, for roundworms a commonly used lab dye remarkably increases their longevity. Basic Yellow 1, aka Thioflavin T is used in laboratories around the world. Apparently, for the commonly experimented on worm C. elegens, it provides a substantial lifespan boost. Healthy nematodes treated with the dye lived 50% longer, and those bread to have symptoms mimicking Alzheimer's showed slowed disease progress.
The dye is thought prevent the breakdown of protein homeostasis, the process by which an organism maintains the proper structure and balance of its proteins. Maybe humans who want to live forever should be guzzling yellow dye 1 along with vitamins.