What is a good attention grabber for a research paper on alternative medicine?

It's hard to know exactly what type of attention grabber or "hook" would be best without knowing exactly what the focus of your thesis is. However, there are some general approaches to keep in mind when writing one.
A common approach is to start with an anecdotal story involving your topic. If in your research you came across an interesting story or case example involving alternative medicine, you can open with this. You want this story illustrates the main point of your thesis statement. Don't get caught up in the details of the story, at least not yet. Start right in the middle of the action to hook your reader in from the beginning. For example: "Mr. Smith had no idea how the nickel ended up in his ear canal, and the doctor was at a loss of how to extract it." By starting in the middle of the action, your reader will have a lot of unanswered questions and will want to read on to learn more.
Another popular approach is to open with a surprising fact. This approach lets the reader know that if they read on they will learn something new and unexpected. You can open with a statistic or surprising piece of information that is related to your topic. For example, you could begin with a statement like "___ percent of patients suffering from ____ ask their doctors for alternative treatments."
You can also open with an interesting quote from an expert in the field. This, like using an anecdote or statistic, brings the reader right into the middle of the conversation and piques their interest. Using quotations also adds to your credibility since it shows that you have done research and gathered information from experts. Just make sure that the quotation is related directly to your thesis statement.