In the latest Webmaster Help video from Google, Matt Cutts responds to a question about Penguin's effect on internal links that use the same anchor text. The exact question is:
Do internal website links with exact match keyword anchor text hurt a website? These link help our users navigate our website properly. Are too many internal links with the same anchor text likely to result in a ranking downgrade because of Penguin?
"My answer is typically not," says Cutts. "Typically, internal website links will not cause you any sort of trouble. Now, the reason why I say 'typically not' rather than a hard 'no' is just because as soon as I say a hard 'no' there will be someone who has like five thousand links - all with the exact same anchor text on one page. But if you have a normal site, you know...a catalog site or whatever.... you've got breadcrumbs...you've got a normal template there...that's just the way that people find their way around the site, and navigate, you should be totally fine."
He continues. "You might end up, because of breadcrumbs or the internal structured navigation, with a bunch of links that all say the same thing, that point to one page, but as long as that's all within the same domain, just on-site links, you know, that's the sort of thing where, because of the nature of you having a template, and you have many pages, it's kind of expected that you'll have a lot of links that all have that same anchor text that point to a given page."
Long story short, this isn't an issue you should have to worry about. Like with everything else, just don't abuse it and make it an issue.