Canned and fresh vegetables are about the same.

healthlibrary.epnet.com

True or False: Fresh Food Is Better Than Frozen or Canned Food - HealthLibrary

Statements issued by the US Food and Drug Administration (FDA) and the International Food Information Council (IFIC) report that nutrients in fruits and vegetables are generally not lost during canning or freezing, and that fresh, frozen, or canned versions of the same food have relatively equivalent nutrient profiles.

truittbros.com

Fresh/Frozen/Canned

Recent studies (source) have shown that nutritionally, there's not much difference between fresh, frozen and canned.

Canned vegetables are healthier.

About.com

Is fresh food better than canned food?

Studies show that canned foods are just as nutritional, if not moreso, than fresh foods

divinecaroline.com

Is Canned and Frozen Produce as Healthy as Fresh? - Page 3 - DivineCaroline

It might be worth taking that extra step to obtain the benefits of eating certain canned vegetables—tomatoes, corn, and carrots in cans tend to have higher antioxidant contents than fresh ones.

Is Canned and Frozen Produce as Healthy as Fresh? - Page 2 - DivineCaroline

For example, a 1997 study conducted by the University of Illinois Department of Food Science and Human Nutrition found that beneficial ingredients like fiber and vitamins are retained mostly during canning.

Fresh vegetables are healthier.