Guidelines and Precautions. The jury is still out on melatoninâs effects on blood pressure. If you have high or low blood pressure, or take medications to control your blood pressure, it is best to avoid the supplement unless advised otherwise by your doctor.uidelines and Precautions. The jury is still out on melatoninâs effects on blood pressure. If you have high or low blood pressure, or take medications to control your blood pressure, it is best to avoid the supplement unless advised otherwise by your doctor.
1 This can cause the can to bulge or rust.  Use canned tuna by the expiration date on the can. If the can doesn't have a best by date, mark it with the date of purchase and use the tuna within 12 to 24 months of purchase.
Most sources say that home-canned foods will store safely for at least one year. With other food items, the level of acid in the food is the critical element for determining how long it may store. Low-acid foods last longer on your shelves than foods with higher amounts of acid. Some sources say all commercially canned food should last at least two years. Surprising to some, canned meats can last the longest. Most sources say they will keep for 2 to 5 years. Some sources say they will last even longer. I found a shocking story about a can of meat that was 118 years old.