Viagra for Alzheimer’s?

A new study suggests that Viagra could help protect against Alzheimer’s, reports BBC.com. In a bid to identify approved pharmaceuticals that could potentially treat conditions for which they weren’t developed, a team of researchers examined how 1,600 drugs interacted with more than 350,000 different proteins. They found that sildenafil, the chemical name for the erectile dysfunction drug Viagra, may be effective at targeting proteins that contribute to the development of Alzheimer’s. The researchers also looked at the medical insurance records of more than 7 million Americans. Over a six-year study period they found that only 1 percent of those taking Viagra—almost all of whom were men—developed the neurological condition, compared with 5 percent of those not on the drug. This amounts to a 69 percent reduced risk. Lead investigator Feixiong Cheng, from the Cleveland Clinic, cautions that the findings don’t prove that Viagra is responsible for this lowered risk, only that people who take the drug are less likely to develop Alzheimer’s. He says his team is now planning a “randomized clinical trial to test causality.”

Laetoli have been dated to 3.6 million years ago and are thought to have been made by Australopithecus afarensis—the same species that left behind the famous “Lucy” skeleton. But Lucy’s relatives might not have been the only humans strolling around Laetoli. A new study suggests that another set of prints found at the site in 1976, which were long thought to have been left by a bear, were in fact made by a different early human species. The researchers began to doubt the bear theory after analyzing footprint data from humans, chimpanzees, and bears. So they went back to Laetoli and dug down to the prints. Their analysis confirmed that these couldn’t have been made by a bear or a chimpanzee, and that they had very different characteristics to the A. afarensis footprints. That left another hominin species as the only plausible possibility. “There were at least two hominins, walking in different ways, on differently shaped feet, at this time,” co-author Jeremy DeSilva, from Dartmouth College, tells CNN.com. “[This shows] that the acquisition of human-like walking was less linear than many imagine.”