Exporting Keynote Presentation to PDF creates aliased artifacts

I am trying to save a Keynote as a PDF, but whenever I do so it results in aliasing. Specifically there is some Greek text in the Keynote like alpha, and in the PDF version it gets aliased (the left curve of the alpha letter gets cut off). How do I address this?

Should I change the font or increase it? I don't think either of these are options as I combined everything into a single figure in Keynote so I can't go back and edit each individual element.

I put a photo here for reference: you can see closely that the alphas get cut off somehow.