Dr. Becky Maes - Is It Bad For You? Approved by Dr. Becky Maes

Are Canned Foods Bad For You?



Short answer

Canned foods can have altered nutrient profiles due to canning; they may lose heat-sensitive vitamins like C and B, yet retain or increase bioavailability of minerals, fiber, and some antioxidants. Choosing BPA-free and low-sodium options, and with few additives, makes canned foods part of a balanced diet.



Long answer

Nutritional Content, Losses, and Gains in Canned Foods

Navigating the aisles of the grocery store, you might wonder if the convenience of canned foods comes at a nutritional cost. It's crucial to distinguish between the myths and realities regarding the nutrient content of these shelf-stable staples. Scientific research indicates that the canning process, which includes packing, sealing, and heat sterilization, can indeed affect the nutritional profile of the food inside the cans. However, this influence can manifest as both losses and gains, and understanding these can help guide healthier food choices.

When foods are canned, some nutrients are particularly susceptible to degradation. Water-soluble vitamins, such as vitamin C and certain B vitamins, are more vulnerable to heat and can diminish during the canning process. A study in the Journal of the Science of Food and Agriculture notes that thermal processing can result in a loss of up to 90% of vitamin C content in fruits and vegetables.

  • Vitamin B1 (thiamine) may be reduced as it is heat-sensitive.
  • Vitamin C losses are most significant in fruit and vegetables, due to the high heat required for canning.

Despite these losses, the story isn't all negative. The canning process can also help preserve nutrients or even make some more available for absorption. Certain nutrients are more stable and less likely to degrade when exposed to heat. For example:

  • Fat-soluble vitamins such as A, D, E, and K are generally well-preserved during canning.
  • Minerals and fiber do not undergo significant changes during the canning process, maintaining their levels.
  • Some antioxidants, like lycopene in tomatoes and beta-carotene in carrots, become more bioavailable after the canning process. A study in the Journal of Agriculture and Food Chemistry found that the body might absorb lycopene better from canned tomatoes than fresh ones.

In addition, canned foods are often stored for extended periods, and the nutrient content can remain relatively stable post-canning, as compared to fresh produce which may lose nutrients more rapidly through continuous exposure to air, light, and variable temperatures. This suggests that canned foods can be a good source of certain nutrients, particularly when fresh produce is off-season, expensive, or unavailable.

It's also vital to note that not all canned foods are created equal. The quality of the raw ingredients and the canning process itself can vary among brands and types of foods, potentially affecting the nutritional outcome. Consumers should look for canned products with no added sugars or salts and in some cases, those that are canned in water or natural juices rather than syrups or brines might be preferable for maintaining optimum nutritional value.

To sum up, while the canning process can lead to the loss of some vitamins, it can also preserve or even enhance the availability of other nutrients. The convenience and potential nutrition of canned foods can be a valuable part of a balanced diet, especially when informed choices are made. The decision of whether to include canned goods in one's diet should be balanced with the consideration of these nutritional changes.

BPA in Canning and Its Potential Health Effects

Bisphenol A, commonly known as BPA, is a chemical compound frequently used in manufacturing a variety of consumer products, including the epoxy resins lining some food cans. It's important to understand how BPA can enter your diet and what research suggests about its potential health effects.

BPA is used to prevent corrosion and contamination in canned goods, providing a protective barrier between the metal of the can and the food. However, BPA can leach into the food, especially when cans are exposed to high temperatures or the food itself is acidic or fatty.

Research Findings on BPA:

  • Several animal studies have raised concerns about BPA's effects on reproductive and developmental health, potentially acting as an endocrine disruptor. (National Center for Biotechnology Information)
  • Human studies have associated high levels of BPA exposure with cardiovascular problems, diabetes, and obesity. A cross-sectional study associates higher BPA levels with a greater risk of type 2 diabetes. (Environmental Health Perspectives)
  • Concern has also been raised over BPA's potential impact on brain health, with some research suggesting it could affect neurodevelopment in children. (JAMA)

Agencies like the Food and Drug Administration (FDA) regulate BPA levels and maintain that the amounts found in canned goods are generally below the threshold considered harmful. It's worth noting, though, that some manufacturers have voluntarily phased out the use of BPA in response to consumer demand for BPA-free products.

Minimizing BPA Exposure from Canned Foods:

  • Choose fresh or frozen foods over canned goods when possible.
  • Look for cans labeled “BPA-free.” Many companies now use BPA-free linings made from alternative materials like acrylic and polyester resins.
  • Avoiding the heating of canned goods within the can, as this could increase the rate of BPA leaching.
  • Consider alternative storage options after opening a canned good, as BPA can continue to leach into the remaining food if stored in the original can.
  • Rinse canned vegetables and beans, as this may help reduce BPA levels along with sodium.

While consumer awareness and regulatory measures have spurred changes in manufacturing processes, it's crucial for individuals to stay informed and make conscious choices to mitigate potential risks. By combining cautious consumer choices with a varied diet, the potential health impacts of BPA intake can be minimized.

Sodium Content in Canned Foods and Health Implications

Canned foods have long been a staple for their convenience and long shelf life, but they often come with a hidden cost – high sodium content. Sodium is used in canning to preserve the food and prevent the growth of bacteria, thereby enhancing flavor and prolonging shelf life. The implications of this added sodium on health can be significant.

According to the Centers for Disease Control and Prevention (CDC), the recommended limit for sodium intake is less than 2,300 milligrams a day, with an ideal limit of no more than 1,500 milligrams per day for most adults. Yet, some canned products can contain a substantial portion of this limit in just a single serving.

Health Implications of High Sodium Intake:

  • Hypertension: Excessive sodium intake is strongly linked with high blood pressure, which is a leading risk factor for heart disease and stroke.
  • Heart Disease: According to a study published in the British Medical Journal, high sodium diets are associated with an increased risk of cardiovascular events.
  • Osteoporosis: Sodium can affect the skeletal system by causing the body to lose calcium, leading to a decrease in bone density over time.
  • Kidney Function: Excess sodium can also put a strain on the kidneys, which may lead to kidney disease.

The American Heart Association (AHA) warns that more than 70% of the sodium Americans consume comes from packaged, prepared, and restaurant foods, not the saltshaker. When it comes to canned foods, some of the most popular items like soups, beans, and vegetables can sometimes have more than 500 milligrams of sodium per serving. This can accumulate quickly throughout the day, leading individuals to exceed recommended sodium limits unknowingly.

Reading Labels Carefully:

It's essential to read nutrition labels on canned foods to assess their sodium content. For those wishing to reduce sodium intake, look for canned products labeled as "no salt added" or "low sodium." Additionally, rinsing canned foods, like beans and vegetables, can reduce their sodium content by up to 40%.

Healthier Alternatives:

Considering the potential health implications of high sodium content in canned foods, opting for fresh, frozen, or dried counterparts when possible can be a healthier choice. These alternatives are usually lower in sodium and retain most of their nutritional value.

Understanding the sodium content and health implications of canned foods necessitates careful consideration and moderation in consumption. By evaluating labels, seeking out low-sodium options, and making informed decisions, individuals can enjoy the convenience of canned goods without the unwanted side effects of excessive sodium intake.

Preservatives and Additives Common in Canned Goods

When perusing the canned goods aisle, you may notice that many products have lengthy ingredient lists, many of which include preservatives and additives. It's essential to understand what these are and how they may impact your health.

Bisphenol A (BPA): BPA is a chemical often found in the epoxy resins used to line the inside of cans. It can leach into food and has been linked to health issues such as reproductive disorders, heart disease, and diabetes. The FDA has stated that BPA is safe at the very low levels that occur in some foods. However, due to consumer concern, many manufacturers now offer BPA-free cans.

Sodium: Canned foods are notorious for their high sodium content, used to preserve the food and enhance flavor. Excessive sodium intake can lead to hypertension and cardiovascular diseases. The American Heart Association recommends no more than 2,300 milligrams per day, moving toward an ideal limit of 1,500 mg per day for most adults.

  • Expert opinion: The American Heart Association on sodium intake

Nitrates and Nitrites: Often added to canned meats, these preservatives can form nitrosamines in the body, which are potential carcinogens. While some studies suggest a link between nitrate/nitrite intake and cancer, especially stomach cancer, evidence is still being debated in the scientific community.

Calcium Chloride and Citric Acid: These are commonly added to canned fruits and vegetables to help preserve texture and firmness. Considered generally safe, these additives are found naturally in various foods. However, they can sometimes cause digestive issues for those with sensitivities.

Artificial Food Colorings: Some manufacturers use artificial colors to make the canned food appear more appealing. These colorings have been scrutinized for potential health effects, including behavioral issues in children and possible links to cancer, though research findings are inconsistent.

Understanding the range of preservatives and additives in canned goods can help consumers make informed decisions. Checking labels for these substances and seeking out options with minimal additives, or those labeled as "BPA-free," can mitigate potential health concerns associated with canned foods.

Impact of Canned Food on Long-Term Health

When discussing the long-term health implications of consuming canned foods, it's crucial to recognize the complexity of the subject. Canned foods can play a beneficial role in a balanced diet due to their convenience and often extended shelf life, but there are also potential health considerations to bear in mind.

Nutritional Content: The canning process involves high heat to ensure food safety and longevity, but this can lead to nutrient loss, particularly in vitamins sensitive to heat, such as vitamin C and some B vitamins. However, canned foods often retain most of their minerals and fat-soluble vitamins like vitamins A, D, E, and K. Researchers have found that canned fruits and vegetables can be just as nutritious as their fresh counterparts, especially when produce is out of season or overripe, which may further reduce nutrient levels.

  • Study Reference: Rickman, Barrett & Bruhn (2007). "Review: Nutritional comparison of fresh, frozen and canned fruits and vegetables. Part 1. Vitamins C and B and phenolic compounds." Journal of the Science of Food and Agriculture.

Bisphenol A (BPA) Exposure: Some cans are lined with BPA, a chemical that can leach into food and has been linked to health issues like hormone disruption, heart disease, and other chronic conditions. The impact of BPA on long-term health is ongoing, and while some studies have raised concerns, regulatory agencies maintain that the levels in canned goods are safe for most people.

  • Expert Opinion: According to the Food and Drug Administration (FDA), current dietary exposure to BPA from food contact materials is not dangerous to the general population, including children.

Sodium and Sugar Content: Canning can involve added salt or sugar to enhance taste and preservation, contributing to increased intake of these substances. High consumption of sodium is linked to hypertension and increased risk of heart disease, while excessive sugar intake may lead to weight gain and increase the risk of type 2 diabetes over the long term. Wise selection of "no salt added" or "low sodium" options, as well as fruits canned in their own juice or light syrup, can help manage this issue.

Contaminants: Contamination during the canning process can also occur, posing health risks. For instance, Clostridium botulinum is a bacterium that can thrive in improperly canned goods leading to botulism, a rare but potentially fatal illness. Adherence to food safety guidelines and choosing reputable brands can mitigate such risks.

Environmental Considerations: Over-reliance on canned foods can contribute to increased packaging waste, which has indirect health implications. The production and disposal of cans may contribute to wider environmental problems, which in turn have long-term health impacts on communities, such as pollution and its associated diseases.

To navigate the potential long-term health impacts of canned food, consider the following practical tips:

  • Opt for canned foods with as few added ingredients as possible.
  • Choose brands that use BPA-free lining.
  • Rinse canned vegetables to reduce sodium content before use.
  • Check the expiration dates to ensure you consume them while they're still safe and at their best quality.
  • Recycle cans to mitigate environmental impact.

By maintaining an informed perspective on your dietary choices, especially concerning canned foods, you can enjoy the benefits of convenience without compromising your long-term health.

Choosing Healthier Canned Food Options and Reading Labels

Navigating the aisles of canned goods can be a daunting task when trying to choose healthier options. Being mindful of what's inside the can is just as important as the convenience it offers. Here's how you can select better quality canned foods and decipher the labels:

Analyze the Ingredient List

Start by scrutinizing the ingredient list, which is usually a telltale sign of the product's nutritional value:

  • Look for a short list of ingredients you recognize; the fewer, the better.
  • Ensure the main ingredient of interest, such as beans or tomatoes, is listed first, indicating it's in the highest quantity.
  • Avoid canned foods with added sugars or syrups, such as 'high fructose corn syrup,' which can contribute to excess calorie consumption.
  • Steer clear of foods with artificial additives, colorings, or preservatives like 'sodium benzoate'.

Check the Sodium Content

Sodium can be a significant concern in canned products. The American Heart Association recommends no more than 2,300 milligrams a day and an ideal limit of no more than 1,500 mg per day for most adults:

  • Opt for 'low-sodium' or 'no salt added' versions of canned foods.
  • Read the 'Nutrition Facts' label to check the amount of sodium per serving.
  • Rinsing canned foods such as beans can reduce sodium content by up to 40 percent, according to a study published in the Journal of the Science of Food and Agriculture.

Be Aware of the Packaging Material

The material of the can itself is something to consider:

  • Select cans labeled 'BPA-free'. BPA (Bisphenol A) is a chemical that can leach into food and has been linked to health issues.
  • Be cautious of dented or damaged cans, which can harbor bacteria and lead to foodborne illnesses.

Understand food labeling lingo

Terms used on canned food labels can sometimes be misleading. Here's a guide to understanding what they mean in terms of health:

Label Term Meaning
'Lightly Salted' 50% less sodium than the regular version
'No Added Sugars' No sugars were added during processing, but the product still may contain natural sugars
'Organic' The contents are certified organic, possibly containing fewer pesticides and GMOs
'Natural' The FDA does not define it strictly, so it could still contain additives or preservatives

Consider Nutrient Retention

Canning preserves the food's nutrients, with certain exceptions:

  • Water-soluble vitamins like vitamin C and B-vitamins may decrease during the canning process. It's essential to supplement these through other dietary sources.
  • However, some nutrients may actually increase; for instance, canned tomatoes have higher levels of lycopene, an antioxidant that's been linked to reduced risk of chronic diseases.

By being vigilant about food labels and opting for healthier canned food options, it's possible to include these convenient items in a nutritious diet. Remember to balance your meals with fresh produce and other whole foods for a well-rounded intake of vitamins and minerals.

Frequently asked questions

The fiber content in canned fruits and vegetables is comparable to that of their fresh or frozen counterparts. The canning process does not break down dietary fiber, so canned produce can be a good source of fiber in the diet.

Certain canned foods, such as tomatoes, can actually have increased bioavailability of nutrients like lycopene due to the high heat used in the canning process. Generally, foods with a low acid content retain most of their minerals, and since fiber and protein are stable during canning, foods high in these nutrients like beans and fish maintain their nutritional value well.

Yes, rinsing canned foods such as vegetables and beans under water can help reduce the levels of certain additives like sodium and preservatives. This simple step can improve the healthfulness of canned foods, especially for those on sodium-restricted diets.

Canning does not significantly affect the protein content in foods. Proteins are complex molecules that generally retain their structure during the heat processing of canning. Thus, canned meats, legumes, and fish remain good sources of protein.

Acidic foods, like tomatoes, can cause leaching of compounds like BPA from the can lining into the food. Choosing BPA-free cans and limiting consumption of canned acidic foods can help reduce exposure concerns. Acid content doesn't affect the safety or nutrition of the food itself, provided the cans are properly processed and intact.

Possible long-term side effects

  • hormone disruption
  • heart disease
  • type 2 diabetes
  • high blood pressure
  • cardiovascular events
  • osteoporosis
  • kidney disease
  • cancer risk
  • weight gain
  • botulism
  • neurodevelopmental issues

Ingredients to be aware of


  • nutrient retention
  • convenience
  • longer shelf life
  • more bioavailable nutrients
  • stable mineral and fiber levels

Healthier alternatives

  • fresh produce
  • frozen foods
  • dried counterparts
  • low sodium options
  • bpa-free cans

Thank you for your feedback!

Written by Diane Saleem
Published on: 12-05-2023

Thank you for your feedback!

Written by Diane Saleem
Published on: 12-05-2023

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