Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
FDA Orders Heart Risk Warning Labels on Testosterone Drugs
Testosterone-boosting drugs taken by millions of American men have never been proven to be safe or effective for treating aging-related problems such as low sex drive and fatigue, the U.S. Food and Drug Administration says.
On Tuesday, the agency also said the drugs can increase the risk of heart attack and told manufacturers they must add that caution to the warning labels on the products, the Associated Press reported.
A similar warning about testosterone drugs was issued last summer by Canadian health officials.
The agency also told drug companies must clarify that the drugs are only approved to treat low testosterone levels caused by injury or disease.
For years, testosterone pills, patches, gels and injections have been marketed as treatments for low testosterone levels, and sales of the drugs have risen to more than $2 billion.
"There's been a very successful advertising campaign to make men feel that whatever their problem is, the answer is to buy more testosterone," Dr. Sidney Wolfe, of the consumer advocacy group Public Citizen, told the AP.
Last February, the group petitioned the FDA to have testosterone drugs carry a boxed warning -- the most serious type -- about heart risks, but the FDA said there was "insufficient evidence" for such a warning and rejected the petition.
The FDA launched a safety review of testosterone drugs in January 2014 after two federal studies linked them with higher rates of serious problems such as heart attack and stroke. However, other studies have suggested an association between testosterone replacement and longevity, the AP reported.
Men's testosterone levels naturally decrease after age 40, but there is disagreement on whether this actually causes problems such as lower bone density and less energy.
McDonald's Reducing Antibiotics in Chicken and Growth Hormones in Milk
McDonald's says it will start using chickens that are free of certain antibiotics and milk from cows that aren't given the artificial growth hormone rbST.
Chicken suppliers will not be allowed to use antibiotics important to human health, but will be able to use ionophores, a type of antibiotic that keeps chickens healthy and isn't used in people, the Associated Press reported.
The milk change will occur later this year and the chicken change will take place within the next two years, according to the company.
"Our customers want food that they feel great about eating -- all the way from the farm to the restaurant -- and these moves take a step toward better delivering on those expectations," Mike Andres, head of McDonald's U.S.A., said in a statement, the AP reported.
Two More NFL Veterans Will Donate Brains for Concussion Research
Two more former NFL players say they'll donate their brains to science after they die in order to help researchers learn more about concussions and how to prevent them.
Former Seahawks wide receiver Sidney Rice and Giants punter Steve Weatherford said they want scientists to see the effects of the concussions they suffered while playing football, NBC News reported.
Rice believes he suffered 8 to 10 concussions while in the NFL, but said his first one occurred when he was just 8 years old.
He said teams are taking head injuries more seriously, but it can be hard to convince players to take themselves out of a game after suffering a hit to the head, NBC News reported.
"It's just the way we're brought up. I guess it's the culture," Rice said. "You feel like you have to be out there on the field. It's the competition that's instilled in you. You love it, you want to be out there, but it's very important that you pay attention to what goes on when you get a concussion."