As far as High Blood Pressure is concerned, you don't have to avoid ALL canned foods, just watch the sodium content. For example there is a ton of no salt added vegetables, and reduced sodium canned products. So I wouldn't say avoid canned foods, just watch it, and use moderation. Personally, I don't eat many canned foods because I try to stay under 1200 mg of sodium per day, and not many canned selections support that.
As far as your husbands other symptoms..