I came across this interesting report of an experiment done at McMaster University. They fed mice a cocktail of vitamins (B-complex, D3), minerals (zinc), and herbal supplements (e.g. garlic, green tea, ginseng). Compared to controls, the mice fed the cocktail lived 10% longer, were spontaneously twice as active in old age, appeared to get smarter as they aged, and, unlike the controls, did not turn gray or bald (at least true of the example animal in the video).
You have to watch the video to see the vast difference between the supplemented and the unsupplemented animals. The supplemented animals don't even look or act aged.
This is the first report I have seen documenting extension of lifespan with nutrient enrichment in animals. The scientists are now testing the combination of supplements on crickets, and those fed the supplements apparently have doubled life spans compared to controls.
This supports the hypothesis that a high nutrient density, equatorial analogue (i.e. herb-enriched) paleo diet might extend lifespan in humans without caloric restriction. Take a look at Art DeVany for an example of the possible results.
CBC News - Health - Old mice run faster with supplements