No, you can't get a murmur from aluminum.

And although in this forum it is hotly debated whether or not aluminum gives your Alzheimers and Parkinsons, it's not true in trace amounts. The only reason medical professionals are claiming caution with aluminum is not specifically that it can cause these diseases, rather, people who have these diseases have more aluminum in their brains, which may even be a byproduct of the disease. So we don't know.

I think you'll be okay. Everything in moderation, and a few exposures to aluminum foil won't cause any detrimental effects.