Is Canned Food Safe to Eat?

Marksdailyapple.com ^ | 12-29-09 | Mark Sisson

[woollyone]

Last week, someone mentioned the Bisphenol A (BPA) leaching tendencies of canned tomatoes. That was all it took to send me on a tear.

First, I looked deeper into the BPA issue. I’ve mentioned it before, 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’m not sure I can recommend using canned food at all 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’s undeniable that BPA has an effect on animals. Various dosages have different effects, and it’s 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 µg/kg/day and the reported effects:

0.025 – Permanent changes to genital tracts in adult females with in utero exposure to BPA that only show up during adulthood.

1.0 – Ovarian cysts were seen in adult mice with prenatal exposure to BPA

2.0 – Pregnant mice fed normal levels of (read: in doses similar to the range “currently being consumed by people”) BPA, but not octylphenol (another xenoestrogen used in commercial products), bore males that developed enlarged prostates by adulthood.

2.4 – 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.

2.5 – Given no further “treatment aimed at increasing tumor development” beyond fetal BPA administration, mice mammary glands were induced to develop carcinoma. Mice with prenatal exposure, then, were predisposed to breast cancer in adulthood.

10.0 – In male rats, low levels of BPA exposure affected the prostate epigenome (“genetic code” of the prostate), enough to render it especially susceptible to disease later in life. 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 when compared to the control corn oil group.

30.0 – A BPA dosage far below the human “tolerable daily intake” was apparently not tolerated especially well by rats; BPA “abolished and inverted” sexual differentiation of the brain and behavior.

50.0 (the official U.S. human exposure limit, as ordained by the EPA) – In nonhuman primates, continuous administration of BPA interfered in the formation of spine synapses 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 “abolish” synapse formation in some of our closest primate relatives.

~snip~

[NewJerseyJoe]

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