{"id":111844,"date":"2009-12-29T12:10:13","date_gmt":"2009-12-29T17:10:13","guid":{"rendered":"http:\/\/www.marksdailyapple.com\/?p=9895"},"modified":"2009-12-29T12:10:13","modified_gmt":"2009-12-29T17:10:13","slug":"is-canned-food-safe-to-eat","status":"publish","type":"post","link":"https:\/\/mereja.media\/index\/111844","title":{"rendered":"Is Canned Food Safe to Eat?"},"content":{"rendered":"

\"tincanIdeally, The Primal Blueprint<\/a> is a living, breathing document. Whether it\u2019s emails from insightful readers or random articles from my RSS feed casting a subject in a completely different light, or even personal N=1 revelations spurring a meticulous re-examination of previously-held stances, I\u2019ll often find myself rethinking certain aspects of the PB. They usually hold up pretty well, mind you, but it\u2019s always good to take stock of the evidence. It keeps us in the Primal community on our toes. Take yesterday\u2019s post, for example. The discovery of grain residue<\/a> from a 100,000 year old dig site was undoubtedly intriguing, because it suggested that a major tenet of the Primal lifestyle \u2013 that grains have no place in the human diet \u2013 might need some refining. In the end, our position remained the same (the intense labor inherent in the sourcing, gathering, hulling, processing, and cooking of grass seeds would have been too great for Grok<\/a> to make it a staple food \u2013 especially when nutritionally-superior and far more nutrient-dense alternatives existed in abundance), but it was tested and therefore strengthened.<\/p>\n

Sometimes, though, new evidence forces me to completely rethink things. Even something so seemingly innocuous as a random comment from a reader can set me off on a researching bender. Last week, someone mentioned the Bisphenol A (BPA) leaching tendencies of canned tomatoes. That was all it took to send me on a tear.<\/p>\n

<\/span><\/p>\n

First, I looked deeper into the BPA issue. I\u2019ve mentioned it before<\/a>, and the battles over BPA content in plastics have gotten a lot of publicity, but after looking at the preponderance of evidence derived from recent animal trials, I\u2019m not sure I can recommend using canned food at all <\/em>anymore. Industry leaders say BPA is crucial for preventing direct contact between food and metal; they also say ditching the stuff would lead to far more botulism cases. That may be. But it\u2019s undeniable that BPA has an effect on animals.<\/strong> Various dosages have different effects, and it\u2019s unclear whether the animal models are relevant to human models, but the stuff does leach and it does impact the mammals that have been tested. A quick rundown (these are rodent studies unless otherwise noted) of dosages in \u00b5g\/kg\/day and the reported effects:<\/p>\n

0.025<\/strong> \u2013 Permanent changes to genital tracts in adult females with in utero exposure to BPA<\/a> that only show up during adulthood. This may be attributed to \u201cincreased expression of estrogen receptor-alpha and progesterone receptors.\u201d Another study found that BPA exposure \u201cincreased terminal end bud density at puberty as well as\u2026 terminal ends\u2026 in adult animals\u201d in the mammary glands. In both rodents and humans, the end and terminal buds are where cancer arises<\/a>.<\/p>\n

1.0<\/strong> \u2013 Ovarian cysts were seen in adult mice with prenatal exposure to BPA, but not in the corn oil group (don\u2019t go chugging corn oil, though!). BPA-treated mice also exclusively displayed<\/a> other adverse reproductive and carcinogenic effects, including sarcoma of the uterine cervix (a fairly rare cancer) and mammary adenocarcinoma (breast tumor).<\/p>\n

2.0<\/strong> \u2013 Pregnant mice fed normal levels of (read: in doses similar to the range \u201ccurrently being consumed by people\u201d) BPA, but not octylphenol (another xenoestrogen used in commercial products), bore males that developed enlarged prostates by adulthood<\/a>.<\/p>\n

2.4<\/strong> \u2013 BPA exposures of pregnant rats (from gestation day 12 onward) and nursing rats (up until postnatal day 21) resulted in decreased testosterone levels in the testicles by nearly half<\/a>.<\/p>\n

2.5<\/strong> \u2013 Given no further \u201ctreatment aimed at increasing tumor development\u201d beyond fetal BPA administration, mice mammary glands were induced to develop carcinoma<\/a>. Mice with prenatal exposure, then, were predisposed to breast cancer in adulthood.<\/p>\n

10.0<\/strong> \u2013 In male rats, low levels of BPA exposure affected the prostate epigenome (\u201cgenetic code\u201d of the prostate), enough to render it especially susceptible to disease later in life<\/a>. In female mice, exposure to BPA resulted in altered maternal behavior: BPA mothers expressed less interest in nursing and more time away from their pups<\/a> when compared to the control corn oil group.<\/p>\n

30.0<\/strong> \u2013 A BPA dosage far below the human \u201ctolerable daily intake\u201d was apparently not tolerated especially well<\/a> by rats; BPA \u201cabolished and inverted\u201d sexual differentiation of the brain and behavior.<\/p>\n

50.0<\/strong> (the official U.S. human exposure limit, as ordained by the EPA) \u2013 In nonhuman primates, continuous administration of BPA interfered in the formation of spine synapses<\/a> in the hippocampus and prefrontal cortex. Spine synapse formation is especially critical in the regulation of mood and general cognition; government-approved levels of BPA were enough to \u201cabolish\u201d synapse formation in some of our closest primate relatives.<\/p>\n

There are plenty more, too.<\/p>\n

(You might be wondering whether injecting rats with BPA is relevant to the kind of environmental exposure we humans get. Scientists found that the route of BPA administration in these studies \u2013 whether BPA was injected or given orally \u2013 did not impact plasma levels of the xenoestrogen. No matter how small the dose, oral exposure and injection resulted in identical blood plasma levels<\/a> \u2013 so don\u2019t think that just because we\u2019re not shooting up with syringes of BPA we\u2019re necessarily avoiding enhanced blood plasma levels.)<\/p>\n

What makes these intriguing (and somewhat worrisome) is that dosages were kept well within the official daily limit supposedly tolerated by humans. In fact, most of the dosages fell far below the daily limit set by the EPA: 50 \u00b5g\/kg\/day.<\/p>\n

Then I got to wondering just how much BPA we\u2019re exposed to on a regular basis. While this PDF table<\/a>, courtesy of Consumer Reports, may not apply to most of our readers, it gives a good idea of the amount of daily BPA regular folks who eat processed, canned food on a regular basis are taking in. If, for example, you eat a serving of Progresso Vegetable Soup, you\u2019re eating (on average) 22 \u00b5g of BPA. A serving from a can of Del Monte Fresh Cut Green Beans contains 14.9 \u00b5g. A serving from a can of Campbell Chicken Noodle Soup contains 10.2 \u00b5g. These are just servings, mind you, and how many people just eat a third of a can of soup or green beans?<\/p>\n

But wait \u2013 22 \u00b5g, 14.9 \u00b5g, 10.2 \u00b5g? That doesn\u2019t sound like much. Besides, the EPA and FDA say 50 \u00b5g\/kg\/day is totally safe. What\u2019s to worry about?<\/strong><\/p>\n

Well, Consumer Reports also employs its own food safety experts<\/a>. The same ones who ran the test on the BPA levels of popular packaged items arrived at a slightly different safe daily dosage, believe it or not. Citing the fact that exposures of 2.4 micrograms of BPA per kilogram of body weight resulted in reproductive and sex hormone issues in rats (see above), the Consumer Reports food safety scientists \u201crecommend 0.0024 micrograms per kilogram of body weight.\u201d<\/strong> That means just a single serving of Del Monte green beans would put a 165-lb adult about 80 times past the Consumer Reports daily limit. Is that too much? Whom should we listen to \u2013 the FDA or Consumer Reports?<\/p>\n

According to BPA researcher Frederik vom Saal, professor of developmental biology at the University of Missouri at Columbia, most regulatory standards regarding industrial chemicals are based on tests of abnormally high doses, but the evidence clearly shows that seemingly minute doses can have \u201ccompletely different and potentially more harmful effects.\u201d<\/strong> The FDA\u2019s dosage limits, then, seem based on faulty or incomplete evidence. Even a special FDA scientific advisory panel was critical of the official company line<\/a>, expressing disagreement with the FDA\u2019s dismissal of a \u201clarge number\u201d of studies on BPA. Congressmen Henry Waxman and Bart Stupak echoed the calls for further review of the official stance on BPA in a recent letter to the FDA commissioner, suggesting<\/a> that \u201can industry meeting last week to discuss ways to block restrictions on BPA\u201d indicated a willingness \u201cto mislead the American people on this public health issue.\u201d The two congressmen were of the opinion that the FDA shouldn\u2019t exclude non-industry funded studies from consideration.<\/p>\n

I\u2019m not a fan of politicians, but I\u2019m going to have to agree with these two. The evidence that BPA is damaging across a whole range of dosage levels in animal models is pretty compelling and deserves further consideration. It isn\u2019t conclusive, but when we\u2019re talking about the widespread, near-daily ingestion of manmade chemicals that exhibit some classically xenoestrogenic effects, it\u2019s better to err on the side of caution and take a good hard look.<\/strong><\/p>\n

Some have tried. There are some limited human studies on BPA, but they haven\u2019t established anything beyond correlation. In 2008, results on the first major study of health effects on humans were published. Higher serum BPA levels were strongly associated with various disorders<\/a>, including heart disease and diabetes. Was it the BPA causing the problem, or was BPA merely a marker for processed junk (canned\/in plastic) food consumption? Causality cannot be confirmed. Other studies have associated recurrent miscarriage<\/a>, oxidative stress and inflammation<\/a> with urinary concentrations of BPA, and another study<\/a> (PDF) found an association between prenatal exposure to BPA and externalizing behaviors in children, including aggression, delinquency, and hyperactivity. “Altered hormone levels in men\u201d have also been linked<\/a> to urinary BPA concentrations.<\/p>\n

Based on the animal models in which serum BPA had measurable effects, especially on developing fetuses, I think there might be something more than pure correlation going on here. We already know that BPA has been found in umbilical cord blood<\/a> (PDF), so the possible delivery system is there. We already know that various amounts of BPA show up in canned and processed food, so there\u2019s a possible source that people are tapping into. What we don\u2019t know for sure is whether the dosages are safe or not. Do we trust the FDA or CR?<\/p>\n

If a government agency explicitly tasked with regulating the safety of all the various things consumers put into their bodies can\u2019t be bothered to look at the actual studies attempting to establish whether something is safe or not, I\u2019m not sure I want to listen to its daily dosage recommendations. Consumer Reports is generally well-regarded, and they don\u2019t exclude a study simply because its findings were inconvenient. While their donors may have agendas, at least those agendas, as far as I’m aware, don\u2019t revolve around removing restrictions on potentially harmful chemicals.<\/p>\n

From now on, I think I\u2019ll be avoiding canned goods as much as possible (I already basically do this), and I\u2019d advise most everyone else \u2013 especially expectant mothers<\/strong> \u2013 to do the same. Just don\u2019t lose your minds over this. Can your own vegetables<\/a> or buy vegetables stored in glass jars<\/a>. Or, maybe, just eat fresh, whole food. This won\u2019t be an issue if you\u2019re already following the PB<\/a> and avoiding processed food and sodas in cans, but it might be worth it to pass it on to friends, family, co-workers, vegans, vegetarians, and anyone else with whom you normally clash on nutritional matters.<\/p>\n

So, what about the tomatoes \u2013 will I be tossing all my cans of organic tomato paste and organic crushed plum tomatoes? Probably not, to be honest.<\/strong> I don\u2019t plan on giving birth anytime soon, and I don\u2019t see myself prematurely entering puberty. I\u2019m also a big fan of chili, which simply isn\u2019t the same made with fresh tomatoes. I am going to look for alternatives, though; I plan on trying canning again, and I might give those glass jar tomatoes from Tropical Traditions a shot. A quick Googling reveals a number of other glass jarred tomato vendors if those don\u2019t work out. I think Whole Foods might even carry a brand, but I can\u2019t be sure. Eden Foods uses BPA-free cans, if you can find them.<\/p>\n

Okay, maybe the new \u201cstance\u201d on canned food isn\u2019t so new or revolutionary. We already avoided the stuff simply because it usually meant you weren’t eating fresh, whole food; now we\u2019ve just got another reason to avoid it. Let\u2019s hope more consumers come to the same conclusion, though, because I somehow can\u2019t see the FDA or the industry having a change of heart anytime soon.<\/p>\n

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Related posts:<\/p>\n

    \n
  1. Are Microwave Ovens Safe?<\/a><\/li>\n
  2. Dear Mark: Your Brain on Junk Food<\/a><\/li>\n
  3. Are Plastics Safe?<\/a><\/li>\n<\/ol>\n

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    Ideally, The Primal Blueprint is a living, breathing document. Whether it\u2019s emails from insightful readers or random articles from my RSS feed casting a subject in a completely different light, or even personal N=1 revelations spurring a meticulous re-examination of previously-held stances, I\u2019ll often find myself rethinking certain aspects of the PB. They usually hold […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[],"class_list":["post-111844","post","type-post","status-publish","format-standard","hentry","category-news"],"_links":{"self":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts\/111844","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/comments?post=111844"}],"version-history":[{"count":0,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/posts\/111844\/revisions"}],"wp:attachment":[{"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/media?parent=111844"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/categories?post=111844"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mereja.media\/index\/wp-json\/wp\/v2\/tags?post=111844"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}