Consuming canned vegetables may harm your digestion and, in the long run, negatively impact your overall health.
Written by Susan Parker | Updated on May 28, 2025
Reviewed by Susan Parker
11 sources cited
Overview
We’d like to think all fruits and vegetables are good for us, but researchers have discovered that certain ones can sabotage your health, not improve it. I’m talking about the ones that you get out of a can.
The results of eating these fruits and vegetables can devastate your digestion.
That’s why scientists are raising alarms about this unique health danger. Read on to get the facts.
Problems With Tiny Particles
According to researchers at Binghamton University, canned items can be contaminated with tiny particles (called nanoparticles) that interfere with the body’s use of nutrients.1 By the way, this goes for canned meat and fish as well as fruits and vegetables.
Studying health issues has given me great respect for the effect some substances can have in extremely small doses. The tiny particles in canned food fall into that category. They can exert an outsized negative effect on your digestive tract’s ability to break down and absorb the food you eat.
The particles are a form of zinc – zinc oxide. And while zinc is a necessary mineral for the proper function of your immune system, the zinc in canned food can disrupt your immune function.
"We found that zinc oxide (ZnO) nanoparticles at doses that are relevant to what you might normally eat in a meal or a day [from canned food] can change the way that your intestine absorbs nutrients or your intestinal cell gene and protein expression," warns researcher Gretchen Mahler, an associate professor of biomedical engineering.
Prof. Mahler reports that food companies put zinc oxide nanoparticles into the linings of cans because they are antimicrobials. They kill bacteria and other potential pathogens that might be lurking in the food.
But when the scientists analyzed the canned asparagus, chicken, tuna and corn they found the food contained an astonishing megadose of zinc – An eye-popping 100 times the daily dietary allowance. The RDA is 11 milligrams for men and 8 for women (11 if pregnant). I would agree that a hundred times that amount is alarming by any standard. Without doubt it’s a huge dose.
Wreaks Havoc on The Intestinal Lining
Now, it’s already well-known that super doses of zinc interfere with the absorption of other vitamins and minerals. But Prof. Mahler took a close look at what these particles can do to the human digestive tract.
She says the nanoparticles “tend to settle onto the cells representing the gastrointestinal tract and cause remodeling or loss of the microvilli, which are tiny projections on the surface of the intestinal absorptive cells that help to increase the surface area available for absorption."
The destruction of this tissue not only hurts nutrient absorption but also sets off inflammation that can lead to leaky gut – the increase in permeability of the intestinal walls. These holes or lesions in the walls allow toxins and harmful microorganisms to enter the bloodstream. They should be kept out.
Prof. Mahler says she can’t predict what the long-term health effect of eating canned foods containing these nanoparticles will be.
But I think it’s pretty obvious that no good can come of it.
Enjoy The Benefits of Unprocessed Produce
If you need more convincing that fresh fruits and vegetables are a lot better for you, a study at the University of Otago shows the fresh stuff is better for mental health than processed, cooked, or canned.2
In this research, the scientists looked at the eating habits of 400 people in New Zealand and the United States.
They found that the people who ate the most raw fruits and vegetables suffered less depression, had more positive moods, were more satisfied with their lives, and were just plain happier overall. The scientists did not find the same benefits linked to consuming canned items.
The top ten raw foods that were linked to better mood and mental health were carrots, bananas, apples, dark leafy greens such as spinach, grapefruit, other citrus fruits, lettuce, fresh berries, cucumber, and kiwifruit.
I’d add that fresh fruits and vegetables also just taste a lot better than the overcooked mush – often over-sugared or over-salted – that you get out of a can.
Oh, and one last note. When you eat your fresh fruits and vegetables, try to get at least eight servings a day. A study in Norway shows you need that much to optimally lower your risk of heart disease, stroke, and premature death.3
