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.
Practically âBest beforeâ dates are often simply suggestions for consumers, but they donât indicated when the food will turn inedible. This means that canned meat, for example, may have an average shelf life of 7 years, but have a âBest beforeâ date of 1 year after canning. Itâs still perfectly edible on the 7th year. And as we already mentioned, its life is much longer if stored properly.