Yes apple cider vinegar does become Alkaline inside your body which means it Alkalizes your body when you consume apple cider vinegar.
When your body is more Alkaline instead of acidic then your body can fight off diseases much easier so you may prevent yourself from getting some diseases including cancer if you consume a tablespoon of apple cider vinegar per day.
Apple Cider Vinegar doesn't cure diseases once you get them but it can prevent diseases before they start since your body will be Alkalized.