Collagen. Copper. Alpha-hydroxy acids. Petrolatum. Retinoic acid.
You can be forgiven if you thought I was talking about a chemistry course. Beauty is as much about looking young as it is about looking, well, beautiful, and today's beauty products promise to reduce wrinkles and cover up age spots and protect from UV rays and do all but wash out the kitchen sink.
There is, alas, no real way to stop looking older. Collagen creams are a hot item, but if you stop and think about it, it's highly improbable that they work the way the ads say they do. It is true that, as you get older, the collagen levels in your skin decrease. It is not true, however, that collagen creams work by "replenishing" collagen levels in your skin. Perhaps they will temporarily, thanks to the addition of retinoic acid. Even more depressing is that simple, inexpensive moisturizers are just as effective at temporarily reducing the appearance of wrinkles than the $30/jar stuff sold at cosmetics counters.
There is sad news for anti-aging diets, too: they don't work. That's not to say that eating tons of fruits and veggies are bad for you--au contraire--but rather, that the aging process is more genetic than anything that you can control.
But what about the magic of calorie-restriction diets? I would posit that, if you're eating tons of fruits, vegetables, and nuts, you're probably not eating as many calories as the person who dines regularly at Big 'n Fatty. I would also posit that, because most healthy foods--such as those found in Japanese and Mediterranean cuisines--tend to be high in fiber, you'll probably get full eating less of it. But neither of these truly illustrate a calorie-restricted diet, which is cutting your caloric intake to 1000-1200 cal/day.
What happens to your body--and, perhaps more importantly, to your mind--when you drop 25-50% of your regular caloric intake (I tend towards the low end, at around 1600/day--it's usually recommended that a man take in 2000 cal/day)? Epigentic changes are almost inevitable when the body takes punishment long enough; there is nearly indisputable evidence that most, if not all, psychiatric illnesses are due to how the genes are changed in response to environmental stressors. It only follows that the body's responses to constant near-starvation would be to go through some changes, too. The science is still terribly convoluted as to exactly which genes get turned on and off and to what extent, but epigentic changes in response to calorie restriction happens, in yeast and mice, and, presumably, humans.
It is unlikely that calorie restriction will ever enter a clinical trial on the scale that would be required to produce meaningful results. Not only do humans tend to live an inconveniently long time, the genetic backgrounds of the participants would need to be far better understood than they are today if we are to avoid the devestating effects of the Minnesota Starvation Experiment. While most of the men came though the experience intact, it's a gateway to anorexia in those who are prone to it. Anorexia, with it's 20% mortality rate, is by far the more deadly, whereas even if you're doing everything right with a calorie-restriction diet, you could get hit by a bus tomorrow.
How long you live matters far less than what you do with your life, and how you look while doing it matters far less than whether you enjoy doing it. If you're paying for your wisdom with age, you may as well get the most for your time.