CNN put out a release today on Dr. Sanjay Gupta’s “Changing Life” special airing Saturday and Sunday April 14th/15th at 8pm/11pm ET…

Advocates for stem cell therapy, human growth hormone therapy and dietary supplements all claim those efforts help people live longer, healthier lives; yet, there’s only one scientifically proven method to prolonging life. CNN chief medical correspondent Dr. Sanjay Gupta reveals it and tells what works and what does not in a surprising new documentary CNN: Special Investigations Unit – Chasing Life, premiering on Saturday, April 14, and Sunday, April 15, at 8 p.m. and 11 p.m. (ET).

The special is based on Gupta’s first book, Chasing Life, which will be released on Monday, April 9.

“I’ve always been fascinated by the endless quest for immortality and extending youthfulness,” Gupta says. “This book and special allow me to shed light on some of the myths behind claims of long life and report on some of the hot spots where reaching 100 is more common than the rest of the world.”

Scientists have known for more than 70 years that calorie-restriction diets show remarkable results in the laboratory for extending life. For example, rats following this regimen live 30 percent longer. Yet, these strict, near-starvation diets have not caught on. Gupta sits down for a 639-calorie meal with a couple who swears by the health benefits and possibilities of fighting off degenerative diseases that a calorie-restriction diet provides.

Stem cell research in the United States remains a hotly debated political issue and is illegal in most countries, but claims of body rejuvenation and mind reanimation are compelling to those wishing to find a virtual fountain of youth. Gupta reveals the facts behind these claims by traveling to Russia to get a rare glimpse inside a Moscow clinic that offers these controversial – and possibly dangerous – stem cell treatments and introduces one doctor who swears by them. Alexander Tepliashin, who runs the clinic, shows Gupta how it operates and explains why millions of dollars could be made in offering stem cells to the public.

Dr. Andrew Weil, an expert on alternative forms of medicine and avid user of dietary supplements, offers his viewpoints on the ones he feels are most beneficial. However, even Weil admits that he has second thoughts about which supplements and how many to take. To date, an estimated 15 to 40 percent of Americans take supplements as a part of their daily regimen, even though there is no concrete evidence that they work any better than eating a healthy diet.

Gupta also investigates whether the hype behind human growth hormones may be putting users at a higher risk for complications such as joint pain or, worse, cancer.

In addition to the special, an online report (www.CNN.com/chasinglife) features user-generated iReports and photo galleries, a longevity health quiz, a sample menu and recipe for a calorie-restriction diet, and a special drawing for viewers to win free copies of Gupta’s book, Chasing Life. Viewers will also have an opportunity to watch online as Gupta ages 10 years each night during the week of April 9.