They're called "trace" elements for a reason: Tiny amounts of the right stuff can boost your health and save your life... while even a drop of the wrong stuff can end it.
Now, the latest research shows how these same trace elements can play a major role in your risk of getting or avoiding one of the deadliest forms of cancer on the planet -- the pancreatic cancer that's claimed Steve Jobs, Luciano Pavarotti and Patrick Swayze in recent years.
Let's start with the good stuff: selenium and nickel.
Selenium is already a proven cancer-beater, and it can almost guarantee that you won't get pancreatic cancer: It can slash your risk by 95 percent, according to the study in Gut.
The best source of selenium is Brazil nuts -- but since it's generally hard to get from diet alone, either take a supplement or make sure it's included in your multivitamin.
Nickel didn't quite pack the same punch -- but it still managed to reduce the risk of pancreatic cancer by a third, according to an analysis of toenail clippings in 518 people, including 118 who had pancreatic cancer.
Yes, toenail clippings -- and while that might sound a little bizarre, that's actually one of the best ways to measure trace elements... including the ones you already know you should avoid.
We all recognize how dangerous lead is, for example -- but the new study finds yet another reason to steer clear: a 600 percent boost in pancreatic cancer risk. Cadmium, another heavy metal, boosted the odds by 350 percent, while arsenic doubled the risk of the disease.
Now, you might not think those last three are worth worrying about. You're avoiding them already, right?
Don't be so sure.
All three, for example, can be found in cigarettes. In some areas, they've been found in the groundwater. And arsenic and lead have been turning up in apple juice, according to recent tests from Consumer Reports.
Arsenic might even be in your chicken dinner. Until recently, it was considered perfectly acceptable to add arsenic to chickenfeed -- in part because poisoning chickens gives their meat that "healthy" pink glow consumers love so much.
The FDA recently issued a temporary ban on the main source of arsenic in chickenfeed -- but the poultry industry has been aggressively lobbying for its return, and no one would be too surprised if they got their way on this.
Call it one more reason to go organic.