Beyond removing items you dislike from your interests, you may also be able to reduce the number of advertisements your adult YouTube account is shown for products categorised as Alcohol or Gambling, regardless of whether your have personalised ads enabled or disabled. Scroll to the very bottom of the Google Ad Settings page and look for a section marked Ad categories on YouTube (BETA). Here, click the “See fewer” button next to the Alcohol or Gambling entries – the only two for which this feature is currently available. Click Continue on the pop-up the comes up to apply the restriction.