Follow nutrition guidelines for a few years and you'll learn only one thing is really certain -- recommendations will change. Nearly every food that was once terrible for you, eventually seems to be found to be not so bad, at least as part of a normal, balanced diet.

That's apparently true of coffee, which, if you drink it sugar free, is pretty hard to overdose on, and wine, which we're now told can actually be good for your brain if drunk in moderation. Even chocolate isn't as naughty as your mom told you it was.

But science apparently wasn't satisfied with all this happy news. Nutrition researchers are extending their streak by removing one more super delicious food from the bad boy list. You're prayers have been answered (or mine have been, at least), cheese has now been declared a possible life extender.

The tastiest prescription out there for a long and healthy life.

Indulging in a gooey mac n' cheese may once have made you feel bad about the terrible things you thought you were doing to your cholesterol levels, but thanks to new research published in the journal Nature Medicine, you can now enjoy without guilt. In fact, that deliciousness might even promote heart health and extend your life.

The reason for the good news appears to be a chemical called spermidine, which is naturally found in aged cheeses (as well as mushrooms, some whole grains, and as the name suggests, semen). When the Austrian researchers behind the study gave this substance to middle-aged rats, the results were promising.

"The mice do not only live longer, when we supplement spermidine to the drinking water, but they are also healthier in terms of cardiac function," study co-author Dr. Frank Madeo told Medical Daily.

Of course, it remains to be seen if the effects are the same in humans (and, as such, there's no word on appropriate dosage). The scientific team is planning a follow-up study to investigate, but the current research did find additional evidence that spermidine may well be linked to longer life in people as well.

"They... surveyed 800 Italians about their diets, and those who reported a higher intake of spermidine were found to have lower blood pressure, a 40 percent lower risk of heart failure, and a reduced risk for other cardiovascular diseases," reports Metro.

The bottom line: dining on cheddar for breakfast, lunch, and dinner will never be healthy (sadly), but thanks to this study, you can now plausibly tell yourself you're promoting cardiac health and possibly longer life by indulging your lust for cheese now and again.

So go ahead, make yourself a grilled cheese to celebrate.