Walk your way to a better memory
Exercise may improve memory as well as or better than medication in older people at risk for Alzheimer’s disease, according to a report in the Journal of the American Medical Association. The study included 138 people over age 50 who had memory problems, but not outright dementia. Half of them walked or did other types of relatively vigorous exercise for 50 minutes, three times a week, and half did not. By the end of the six-month study, the exercisers had about a 1-point memory improvement on a test with a 0 to 70 point score compared to non-exercisers. Yes, it doesn’t sound like much. However, the Australian authors point out that it beats medication, which does relatively little to improve memory in at-risk people. So why is exercise beneficial? It’s unclear, but it may improve blood flow in the brain. However, getting people to exercise—particularly those who are older or who may have arthritis or other health problems—is tough, according to a JAMA editorial. But fear of Alzheimer’s disease “may help motivate older individuals and society to become more physically active,” writes Eric B. Larson, MD. (Read more about the health benefits of exercise for senior citizens, as well as tips for working out.)

If diamonds really are forever, you can be too
You may have heard about the "Bling Is Dead" movement—basically, a backlash in hip-hop circles against the so-called "blood diamonds" harvested in war-torn African nations. Now, as Reuters reports, a Swiss company is making bling from the dead. For as little as $7,500, the chemists at Algordanza (which means "remembrance" in the local Swiss dialect) will take your loved one's ashes, extract the roughly 2% carbon content from them, and subject the purified residue to intense heat and pressure. A couple months later, a cut, buffed, and polished synthetic rock is yours to take home. "Some people find it helpful to go to the cemetery and grieve, and they leave their grief in the cemetery," Algordanza chairman Veit Brimer told Reuters. "There are some people who, for whatever reason, do not want to have this farewell." The company's biggest market so far is Japan, where land is scarce and cremation is common. Meanwhile, U.S.-based LifeGem takes a different approach: It makes diamonds from the carbon-rich hair of deceased loved ones, pets included.

Kids burn more calories with some video games than others
It appears that stamping out ninjas—virtually, that is—burns more calories than dispatching them with a joystick. In a study that parents around the globe should love, University of Hong Kong researchers discovered that children who play an active video game that involves bowling, action, or running burn four times more calories and have higher heart rates than they do playing a conventional video game. The children, aged 6 to 12, used a gaming system called XaviX, which has a mat that allows virtual running and walking on the streets of Hong Kong, in addition to activities like “stamping out ninjas,” according to the report in Archives of Pediatrics and Adolescent Medicine. While encouraging, the study is just a “drop to the bucket of research” needed to figure out how to combat obesity in U.S. children, according to an editorial.

You’ve come a long way, baby
Women who smoke can achieve equality with men—in terms of heart attack, that is. In a study of Norwegian heart-attack patients, women who didn’t smoke tended to have their first heart attack at an average age of 81, and male smokers tended to have a first heart attack around age 72. However, if they smoked, women tended to have their first heart attack at 66 and men at 64, according to a study presented at the European Society of Cardiology. So men lost an average of six years of a heart-attack-free life, while women lost 14 years (after taking into account other risk factors). "Smoking might erase the natural advantage that women have," Robert Harrington, MD, a professor of medicine at Duke University and spokesman for the American College of Cardiology, told the Associated Press. Estrogen is thought to protect women from heart disease before menopause, and smoking may cause earlier menopause, the researchers say. (Take Health.com's quiz: What Kind of Smoker Are You?)

Surgical nano-bots on the march
Johns Hopkins University engineers have unveiled a nano-sized surgical tool that could make minimally invasive surgery even more precise. According to the MIT Technology Review, the hand-shaped, copper and chromium "micro-gripper" (at work in this video) can be controlled remotely by magnets outside the body. The gripper's tiny "fingers" respond to chemical cues or temperature changes and curl around tissues, cells, or tumors that need extracting from the body. The gripper is a mere 500 micrometers in diameter with its claws extended (about the width of 8 human hairs), and 190 micrometers when clenched. David Gracias, the biomolecular- and chemical-engineering professor at Hopkins who led the development of the gripper, says the goal is "to have a machine that you can swallow, or [to] inject small structures that move and can do things" on their own. No word yet on what sort of indigestion a battalion of nano-surgeons duking it out inside your gut might cause.

(PHOTO: GETTY IMAGES)