@Mridula
Canned vegetables are not necessarily bad for health but they are not as nutritious as fresh. Canned veggies are usually just veggies, water, salt. They are often less expensive and will last much longer than fresh ones. Canning does not affect the nutritional values of food very much. But while there are many advantages to choosing canned foods, there's also a downside.
*Sodium amount is generally higher.
*According to popular site, WebMD, a new study shows that eating canned vegetables could expose you to chemical compound, bisphenol A, more commonly known as BPA. It is a chemical building block that is used to make polycarbonate plastics and epoxy resins. According to a study published in the December 2009 issue of Consumer Reports, "Latest tests of canned foods, including soups, juice, tuna, and green beans, have found that almost all of the 19 name-brand foods tested contain some BPA". The study also discovered BPA in products that were labeled "BPA-free".
Remember that what is canned is more important than the canning process itself. Read the labels on your cans and look for ingredients that you consider unhealthy or that have a bad effect on you.