You'll want to leave it out. if it isn't conducive to the content of your paper, it's more like a distraction from what you're trying to say. parentheses might be a "safe" way to signify a side topic, but it weakens the paper as a general statement because the reader has to pause and take a moment to absorb a new topic before going back to what you were saying
Information that does not go with the main idea of the essay distract the reader and take away from the essay's purpose. Depending on the information, it may also reduce your credibility on the essay's topic. An unreliable or untrustworthy essay can negate even the best reasons and thoughtful thinking. Leaving it out reduces the risk of the essay being considered incorrect. Also, including unnecessary information, like jokes, can change the tone of your essay.
