By Dr. Mercola
The fresh taste of in-season produce is arguably one of the purest pleasures in life there is. But the downside (and one of the key reasons why fresh produce is so widely appreciated) is that peak growing seasons are limited for many fruits and veggies to just a few months a year.
If you want a peach in December, and you live in the US, your options for finding a truly ripe peach are limited to imported varieties at the supermarket, which are often dry and tasteless, frozen or canned. But are canned peaches even remotely close to their fresh counterparts?
Are Canned Peaches Just as Nutritious as Fresh?
A new study published in the Journal of the Science of Food and Agriculture1 found that not only do canned peaches have similar levels of nutrients as fresh, in some cases they may actually have more.
How could this be? In some cases the canning process may make nutrients more readily available to your body (such as in the case with the lycopene in tomatoes, which increases when they are cooked).
In a comparison of canned peaches versus fresh, the canned were found to have significantly higher levels of vitamin C, folate and antioxidants, higher but not statistically different levels of vitamin A, and lower, but not statistically different, levels of vitamin E, total phenolics and total carotenoids. The researchers concluded:2
“The nutritional content of canned peaches has been shown in this study to be comparable to that of fresh peaches. There were no statistically significant decreases in those nutritional parameters measured in this study between fresh freestone peaches and canned cling peaches.
Vitamins A and E along with total carotenoids decrease immediately upon processing, but appear to stabilize after the processing step, showing minimal additional changes upon storage for 3 months.
This study shows that canned peaches can provide comparable nutrient levels to the consumer as fresh peaches, meaning that consumers can enjoy peaches year round without worrying about loss of nutrients in their diet.”
A 2007 study similarly found comparable levels of vitamin A, vitamin E, minerals, vitamins and carotenoids in canned foods and their fresh counterparts.3 For those without access or the resources to buy fresh produce, this makes it sound as though canned is a perfect alternative, and perhaps it would be if not for several other factors that were not taken into account in this research…
Most Can Linings Contain Bisphenol-A (BPA)
BPA is commonly associated with the plastic products that contain it, but it’s also widely used in the lining of canned goods. BPA is an endocrine disrupter, which means it mimics or interferes with your body's hormones and "disrupts" the normal functioning of your endocrine system.
The glands of your endocrine system and the hormones they release are instrumental in regulating mood, growth and development, tissue function, metabolism, as well as sexual function and reproductive processes.
Some of the greatest concern surrounds early-life, in utero exposure to BPA, which can lead to chromosomal errors in your developing fetus, causing spontaneous miscarriages and genetic damage. But evidence is also very strong showing these chemicals are influencing adults and children, too, and leading to decreased sperm quality, early puberty, stimulation of mammary gland development, disrupted reproductive cycles and ovarian dysfunction, cancer and heart disease, among numerous other health problems.
Eating canned goods could very well increase your BPA levels to alarming levels. According to one study, eating canned soup for five days increased study participants' urinary concentrations of BPA by more than 1,000% compared to eating freshly made soup.4
Those researchers believe canned goods may be an even more concerning source of exposure to BPA than plastics, which means eating canned goods could increase your risk of BPA-related health problems. In fact, avoiding canned goods as much as possible is one of my topmost recommendations for avoiding exposure to this ubiquitous chemical toxin.
The Canning Process is Detrimental to Antioxidants
The reason why canned food can be stored for years without spoiling is because of the canning process, which has been in use since the 1800s. When a food is canned, it is sealed into a container then heated at high temperatures to kill any organisms inside. This creates a sterile environment that will not go bad for an extremely long period of time.
The problem with this method is that the heating process doesn’t only kill pathogenic organisms; it’s also detrimental to other beneficial compounds in the food, including antioxidants. As the Journal of the Science of Food and Agriculture5 authors noted, “Vitamins A and E along with total carotenoids decrease immediately upon processing.”
This decrease means that your body is missing out on some of the healthiest aspects of produce if you choose to eat them canned as opposed to fresh. A raw, fresh peach, for example, has an ORAC score of 1,814 while a can of peaches in heavy syrup has an ORAC score of 436, meaning that more than 75 percent of the antioxidant activity is lost in the canning process.6
ORAC stands for Oxygen Radical Absorbance Capacity, and an ORAC unit or ORAC “score” is a standardized method of measuring the antioxidant capacity of different foods and supplements. The higher the ORAC score, the more effective a food will be at neutralizing free radicals. The fewer free radicals you have running amok within your body, the healthier you will generally be.
Canned Foods May Also Contain More Advanced Glycation End Products (AGEs)
When food is cooked at high temperatures (including when it is pasteurized or sterilized), it increases the formation of AGEs in your food. When you eat the food, it can transfer some of these AGEs into your body. AGEs build up in your body over time leading to oxidative stress, inflammation and an increased risk of heart disease, diabetes and kidney disease. While carbohydrates such as fruits and vegetables are relatively low in AGEs compared to other foods (such as meat products and fats), the canning process will generally increase the AGEs they contain compared to consuming the produce fresh.
Biophotons and Many Enzymes Are Missing in Canned Foods…
By and large, heating your food, especially at high temperatures, destroys naturally occurring enzymes. Enzymes are proteins -- catalysts to speed up and facilitate reactions in your body. Many biochemical reactions will not even occur without these enzymes (you have about 1,300 of them). So if all of your food is cooked, your body is going to be deficient in the specific enzymes it was designed over countless millennia to get from the diet in order to function properly. It will also be lacking biophotons.
Living raw foods contain the biophoton light energy your body’s depends on. Every living organism emits biophotons. It is thought that the higher the level of light energy a cell emits, the greater its vitality and the potential for the transfer of that energy to the individual who consumes it. The more light a food is able to store, the more nutritious it is. Naturally grown fresh raw vegetables, for example, and sun-ripened fresh fruits, are rich in light energy. The capacity to store biophotons is therefore a measure of the quality of your food.
The greater your store of light energy from healthy raw foods, the greater the power of your overall electromagnetic field, and consequently the more energy available for healing and maintenance of optimal health.
Salt, Syrup and Other Common Canned-Food Additives
Canning often changes the taste and texture of foods, which is why they often have copious amounts of processed salt, sugar and other additives, such as MSG, added to restore the lost flavor. Canned soup is notorious for its heavy salt content, but even seemingly simple items, like canned kidney beans, often contain large amounts of salt, high fructose corn syrup and other additives you’re better off avoiding. Consider that just one cup of canned peaches or pears can contain over 30 grams of sugar! So even if canned foods may be able to match the vitamin levels of fresh foods, there are many other considerations to keep in mind.
Fresh Is Virtually Always Preferable to Canned
Canned foods certainly have their place, especially in times when food would otherwise be scarce or impossible to preserve (such as for military personnel on the battle front). If you’re on a very tight budget, canned foods may also offer a way for you to inexpensively supplement your diet with fruits and veggies.
Ideally, however, understand that it is important to consume your food in the most natural form possible, which means fresh, not canned. The next best options are frozen or freeze dried, as this will reduce or eliminate the BPA and common additive concerns associated with canned foods. Finally, if you choose to consume canned goods the following tips will help you to find the healthiest canned goods available:
- Although it may not be practical, can your own. Understand that the term canning can also apply to glass Ball jars. This is especially beneficial if you ferment the food.
- Choose organic, as these canned goods will at least be free of pesticides and genetically modified ingredients.
- Avoid canned foods packed in syrup or sodium; look for canned goods that contain no additives, and if possible, find a local artisan who sources local seasonal fruits and vegetables using mason jars, as these will be free of the aforementioned problems and normally contain some probiotic cultures as well.