Fresh, frozen, or canned vegetables and fruit - which is more nutritious? The answer is all of them! The nutrient content of vegetables and fruit (e.g. vitamins, minerals, and antioxidants) begins to drop after they are harvested. Typically, vegetables and fruit are frozen or canned immediately after harvest when the nutritional content is at its peak. Fresh produce that has been sitting on the shelf long past its harvest may actually be lower in nutrients than food that is frozen.

When compared, studies have shown that fresh, frozen, or canned foods have very few differences in total nutrient content (Cancer Care Ontario, 2004). However, to reduce the sodium and caloric content, buy low-sodium or sodium-free canned vegetables, fruit canned in juice rather than syrup, and frozen vegetables without added high-fat or sugar sauces. You may prefer the convenience and lower prices of canned or frozen produce, or choose to buy local fresh vegetables and fruit for the taste, colour, and texture.

Regardless, any way to increase your intake of vegetables and fruit is the best way. 

While fresh, frozen, or canned vegetables and fruit have similar nutrient content, overcooking can drain these foods of important nutrients. To preserve nutrients, limit the cooking time and temperature. Also, use cooking methods that re-use the cooking water, such as soups or sauces, or methods that use very little water, such as steaming or microwaving.