This is exactly why I have certain sites that have no ads on them at all, no AdSense or any other type of ad. Don't want to sacrifice ad revenue for SEO.
If you have so many ads to your site and if your visitors can not find anything meaningful to your site then they will not come to your site again. So try more to provide quality and useful content to your site and make interaction with people and display ads but in less amount and be sure that ads are also relevant to your field & visitor demanding for that particular product for which you display ads and this way you will get better results.
Google will now penalize all the websites which are flooded with ads, but too much, it's too much.