Consuming Canned Soup Linked to Greatly Elevated Levels of the Chemical BPA

Consuming Canned Soup Linked to Greatly Elevated Levels of the Chemical BPA

BPA, Found in Soup Can Lining, Associated with Adverse Health Effects in Humans

For immediate release: Tuesday, November 22, 2011

A new study from researchers at the Harvard School of Public Health (HSPH) has found that a group of volunteers who consumed a serving of canned soup each day for five days had a more than 1,000% increase in urinary bisphenol A (BPA) concentrations compared with when the same individuals consumed fresh soup daily for five days. The study is one of the first to quantify BPA levels in humans after ingestion of canned foods.

The findings were published online November 22, 2011, in the Journal of the American Medical Association (JAMA) and will appear in the November 23/30 print issue.

“Previous studies have linked elevated BPA levels with adverse health effects. The next step was to figure out how people are getting exposed to BPA. We’ve known for a while that drinking beverages that have been stored in certain hard plastics can increase the amount of BPA in your body. This study suggests that canned foods may be an even greater concern, especially given their wide use,” said Jenny Carwile, a doctoral student in the Department of Epidemiology at HSPH and lead author of the study.

Exposure to the endocrine-disrupting chemical BPA, used in the lining of metal food and beverage cans, has been shown to interfere with reproductive development in animals and has been linked with cardiovascular disease, diabetes, and obesity in humans. In addition to the lining of food and beverage cans, BPA is also found in polycarbonate bottles (identified by the recycling number 7) and dentistry composites and sealants.

The researchers, led by Carwile and Karin Michels, associate professor in the Department of Epidemiology, set out to quantify whether canned-soup consumption would increase urinary BPA concentrations relative to eating fresh soup.

They recruited student and staff volunteers from HSPH. One group consumed a 12-ounce serving of vegetarian canned soup each day for five days; another group consumed 12 ounces of vegetarian fresh soup (prepared without canned ingredients) daily for five days. After a two-day “washout” period, the groups reversed their assignments.

Urine samples of the 75 volunteers taken during the testing showed that consumption of a serving of canned soup daily was associated with a 1,221% increase in BPA compared to levels in urine collected after consumption of fresh soup.

The researchers note that the elevation in urinary BPA concentrations may be temporary and that further research is needed to quantify its duration.

“The magnitude of the rise in urinary BPA we observed after just one serving of soup was unexpected and may be of concern among individuals who regularly consume foods from cans or drink several canned beverages daily. It may be advisable for manufacturers to consider eliminating BPA from can linings,” said Michels, senior author of the study.

Support for this study was provided by an Allen Foundation grant and a Training Grant in Environmental Epidemiology from the National Institute of Environmental Health Sciences.

“Canned Soup Consumption and Urinary Bishphenol A: A Randomized Crossover Trial,” Jenny L. Carwile, Xiaoyun Ye, Xiaoliu Zhou, Anotonia M. Calafat, Karin B. Michels, JAMA, online Nov. 22, 2011; in Nov. 23/30 print issue.

For more information:

Todd Datz
617-432-8413
tdatz@hsph.harvard.edu

photo: iStockphoto.com

Thanks cpio, right after I finish eating a bowl of organic canned soup...

So would this apply to all canned foods along with canned soup? Should we ditch all canned foods?

I've read this before and I think it's pretty much all canned foods. The easiest switch people can make is to move from canned veggies like corn, peas, etc to frozen ones. Soup is tough, sardines too. (that's right, I'M the guy who eats sardines)

sdguy wrote:I've read this before and I think it's pretty much all canned foods. The easiest switch people can make is to move from canned veggies like corn, peas, etc to frozen ones. Soup is tough, sardines too. (that's right, I'M the guy who eats sardines)

I have no problem leaving canned veggies alone, I never eat them. Ditto canned soup. Canned fish, including sardines (yes, I eat them too), that's a toughie.
In fact, canned sardines are the mainstay of Dr. Benjamin Frank's No Aging Diet which he popularized in the '70's. He said canned sardines had even more RNA/DNA than fresh sardines. I have noted that when I follow that diet, I do look younger. So who
knows Maybe canned is OK in some cases.

Just FYI, here's a post about the diet from a couple of years ago at a life extension newsgroup:

Subject: Life extending effects of nucleic acid supplementation

Durk Pearson and Sandy Shaw’s 1982 bestselling book, Life Extension— A
Practical, Scientific Approach (more than 2.5 million copies sold), is
generally recognized as the spark that ignited the currently popular
field of anti-aging/life extension medicine. Pearson and Shaw’s
blockbuster extolled the free radical theory of aging and introduced
the terms free radicals and antioxidants to millions of non-scientist
health enthusiasts. However, Pearson and Shaw’s success was partially
due to another popular book that helped to pave the way, which
preceded their publication by six years.

In 1976, a pioneering New York medical doctor named Benjamin Frank
created a minor sensation with his book—Dr. Frank’s No-Aging Diet. Dr.
Frank was unique. He was not only an MD, but also had a PhD in
biochemistry. He was simultaneously a practicing physician and
researcher, performing anti-aging experiments with mice and rats in
addition to taking care of his patients.

Dr. Frank was ahead of his time. He was an early advocate of high-dose
vitamin therapy (especially Bs, C, & E), plus other nutrients not well
known or available in the early ’60s through the mid-’70s when he did
most of his research. For example, he recommended the use of
carnosine, CoQ10, lipoic acid, DMG (then known as “Vitamin B15”),
glycerol phosphate (magnesium glycerophosphate — he believed several
grams per day promoted cell membrane integrity, and also restored
receptors), vanadium, orotic acid, lecithin, choline, and inositol. A
further indication of his foresight was his recommendation of the use
of biguanide drugs like metformin, which is now becoming recognized as
one of the most effective anti-aging drugs currently available (see my
article, Metformin—An Effective and Underappreciated Life Extension
Drug, in the November 1998 issue of Vitamin Research News).

Dr. Frank’s Theory of Aging

Dr. Frank theorized that aging and degenerative diseases are caused by
the loss of cellular energy production (ATP) due to membrane damage
and decreased efficiency of the Kreb’s cycle and the associated
electron transport chain. He also believed that damage to cellular DNA
from free radicals and crosslinkages could not be repaired due to
inadequate cellular energy and availability of “raw materials” (i.e.,
nucleotides and nucleic acids [Fig.1.]) to repair the DNA. He believed
that this decay of DNA further led to improper formation of messenger
RNA and ribosomal RNA, which in turn led to abnormalities and
structural defects in the cell. Frank’s theory is clearly related to
the mitochondrial, free radical, crosslinkage, and membrane theories
of aging, all previously discussed in Vitamin Research News.

The key difference between Dr. Frank’s theory and the approach used by
advocates of the other related theories is the specific anti-aging
therapy that he recommended—high-dose nucleic acids, combined with
high potency multivitamins. Dr. Frank did not discount the approaches
recommended by other researchers—he believed, however, that their
methods (i.e., antioxidants, cross-linkage inhibitors) would not be
effective unless combined with adequate amounts of RNA.

Dr. Frank believed that one cause of inadequate concentrations of RNA
and nucleotides for repair and production of energy is an age-related
increase in enzymes that destroy nucleic acids (i.e., nucleases—
specifically, ribonuclease, which breaks down RNA). As people grow
older, ribonuclease enzyme activity has been reported to increase.
Consequently, just as the requirement to repair damaged cells
increases, the substances required for this repair (nucleic acids) are
being degraded by higher concentrations of destructive enzymes.
Consequently, Dr. Frank believed older people have an even higher
requirement for nucleic acids than younger people. Thus, the older we
get, the greater our need for nucleic acids, both for replacement and
for repair.

Nucleic Acids as Potential Life Extending, Disease-Preventing
Nutrients

Dr. Frank believed that exogenous RNA, especially when combined with
associated B vitamins, minerals, amino acids, and sugars (like D-
ribose) would enter the cell and aid in normal regeneration of the
damaged cellular elements. This would, in turn, bring about normal
enzyme synthesis and activation, and most importantly would increase
cellular energy production. For this reason, Frank believed that
providing RNA and associated compounds would aid in the repair of
damaged DNA. He knew that ribonucleic acid is important in the
initiation of DNA synthesis, acting in a coenzyme-like fashion. Dr.
Frank stated, “The importance of nucleic acids in protein synthesis
and in enzyme synthesis, as well as the importance of RNA in bringing
about DNA synthesis, and the actually observed anti-aging effects of
nucleic acids on whole man, support the claims regarding the value of
increased intake of nucleic acids in the prevention and treatment of
cellular degeneration.”

Dr. Frank claimed that not only do nucleic acids (1) decrease overall
oxygen utilization, but also (2) increase its inherent effectiveness,
lessening potential oxidative damage to the cell. He believed that the
“anti-anoxia effect” of nucleic acids (ability to do better work on
less oxygen) was due to the increased synthesis of CoQ10 and
enhancement of the efficiency of Kreb’s cycle and respiratory chain.
He believed nucleic acids might even lead to increased synthesis of
mitochondria.

Dr. Frank described the dramatic results of his use of oral and
injectable ribonucleic acid in the prevention and treatment of a wide
variety of age-related illnesses. He used a nucleic acid-rich diet and
nucleic acid extracts for a variety of ills including emphysema, heart
disease, diabetic complications, arthritis, fading eyesight, memory
loss, and other diseases of aging. He believed that nucleic acids
should be considered as essential nutrients, along with fats,
carbohydrates, proteins, vitamins and minerals.

Dr. Frank reported that a common finding of those on a high nucleic
acid diet was a normalization of blood lipid levels. This was
reflected by a drop in total cholesterol and triglycerides, and an
elevation of HDL. He believed that the cholesterol-lowering effect of
nucleic acid-rich diets was due to increased ATP formation, enhanced
electron transport chain activity, improved CoQ10 and cytochrome
oxidase synthesis, and increased NADH oxidation.

He also reported that some of the earliest noticeable effects of RNA
therapy were increased energy, followed by improved skin tone, with
increased elasticity and reduction in fine wrinkles. He frequently
referred to the skin-tightening effect, causing folds to diminish and
the skin to acquire a tighter and more youthful appearance.

Frank’s dietary recommendations included:
Four days per week—eat one can of small sardines.
Eat fish on the other three days.
Calve’s liver once/week
Lentils, peas, lima beans, or soybeans.
Asparagus, radishes, onions, scallions, mushrooms, spinach,
cauliflower, or celery.
Seven glasses of fluid per day—4 of water, 2 milk, and 1 vegetable.

While most modern nutritionists attribute the benefits of a high fish
diet to the concentration of omega 3 fatty acids, Dr. Frank was of the
opinion that it was primarily due to the high content of nucleic acids
in most fish, and especially in sardines. (He did not discount the
possible benefit of the omega 3 fatty acids, but believed that they
were merely a synergistic adjunct to the nucleic acids.) He reported
that sardines contain 1.5 percent nucleic acid, liver approximately
0.5 percent, and muscle meat 0.05 percent. Consequently, Dr. Frank had
many anti-aging activists in the mid-’70s eating sardines like crazy.
(Frankly, I got sick of eating sardine sandwiches!)

Dr. Frank recommended consuming a minimum of 1.5 gm daily of nucleic
acid for general health and well being. However, he recommended much
higher doses for those with specific health concerns. He cautioned,
however, that when taking higher therapeutic doses of RNA, that urine
pH be only slightly in the acid range. He found that highly acidic
urine with a high RNA diet (more than 2 gm daily) may result in
elevated levels of uric acid in the blood, which can cause kidney
stones. This can be easily prevented by drinking plenty of water.
Urine acid-base balance (pH) can be easily tested by using urine pH
test strips.

Clinically, Dr. Frank used dosages of RNA between 500 mg-20 gm. He
usually recommended the higher doses (over 5 grams) be used several
times per week. If dosages higher than 2 gm daily were taken, Dr.
Frank recommended doing so under the care of a physician, where BUN,
creatinine and uric acid levels could be monitored, and recommended
that the urine pH be maintained near 6 (i.e., between 5.0-7.0). Dr.
Frank stated that those with uric acid of 2-3 mg can take considerably
larger amounts of nucleic acid than those with levels closer to 5, 6,
or 7 mg. Higher amounts of uric acid can be better tolerated in near
alkaline urine than in very acid urine. It should be noted that he
never observed any problems in people with normal kidney function, who
drank adequate fluids and maintained urine pH in the desired range. He
recommended that additional protection could be gained by consuming
adequate amounts (500-1,000 mg) of magnesium each day.

Historical Basis of RNA as an Anti-Aging Supplement

Dr. Frank was not the first to experiment with nucleic acids. In 1908,
Dr. C.S. Minot first proposed that nucleic acids were vital for the
health of cells and were essential for the longevity of the organism.
However, the first evidence that nucleic acids might actually promote
longevity was demonstrated by a series of experiments conducted by Dr.
T. Brailsford Robertson in Australia in 1928. Dr. Robertson believed
that the lifespan of organisms was determined by the ratio of nuclear
(chromosomal) materials to the cytoplasm (protein) of the cells. He
referred to this ratio as the “nucleocytoplasmic ratio”—and proposed
that the way to optimize this ratio was to supply the nuclei of the
organism with nutrients in “excessive abundance.”

He tested his hypothesis in a series of experiments. He used 30-40
male and 30-40 female mice in each test group, with a similar group of
controls in each experiment. The test groups received 25 mg of yeast
nucleic acid each day throughout their lives. Robertson’s hypothesis
was apparently confirmed, as the results were strikingly and uniformly
positive. He reported an average lifespan extension of 12.5 percent
for males, and 17 percent for females (Fig. 3).

Despite these positive, provocative results, almost twenty years
elapsed before any further research was done in this area. In the
mid-1940s, Dr. Thomas Gardner, an organic chemist in the scientific
department of Hoffman-La Roche, picked up where Robertson had left
off. Gardner agreed with Robertson’s hypothesis that the
nucleocytoplasmic ratio decreased with aging, but was not convinced
that correcting this ratio was the mechanism of RNA’s life-prolonging
effects. He proposed several other possible mechanisms for these
benefits. He suggested that nucleic acids might slow down the
metabolism of the nucleus of the cell. He reasoned that if nucleic
acids were provided to the cell in high amounts, they could be
utilized in metabolism without destroying the nucleus or cytoplasm,
and thereby enable the cells to live longer at a higher energy level.
Alternatively, he theorized that the life-prolonging effect of yeast
nucleic acid might be due to its ability to stimulate the immune
system, since sodium yeast nucleinate was known to stimulate the
growth and proliferation of white blood cells (leukocytes). He equated
this to the proposed anti-aging effects of Anti-Reticulo Cytotoxic
Serum (ARCS) then being used in Russia (Bogomolets). ARCS was briefly
reviewed in the August, 2003 issue of Vitamin Research News.

Whatever the mechanism, Gardner attempted to replicate Robertson’s
work, with several modifications. First, he began his studies with
mice that were 600 days old (instead of beginning treatment after
weaning, as Robertson had done), because “mice are beginning to get
old at that age.” Also, he believed that Robertson’s dosages were
unrealistically high. He calculated that 25 mg per mouse per day would
translate into a human dose of 55 gm per day. Gardner was apparently
considering human use of RNA, and realized that few humans could
consume such high doses. Consequently, Gardner administered 1/10th of
the dosage used by Robertson, resulting in a daily RNA dosage of 2.5
mg per mouse per day. This corresponded to an equivalent human dosage
of 5.5 grams per day, which Gardner believed could be practically
consumed.

Gardner used 72 female and 31 male albino mice, divided into test and
control groups. Gardner reported that the treated mice retained
vitality and vigor longer than the controls, fewer went blind, and the
treated mice appeared healthier and exhibited greater activity than
the controls. Although the lifespan extension of the mice receiving
nucleic acids was not as great as reported by Robertson, there was an
overall trend toward increased longevity in the nucleic acid-treated
mice. Gardner attributed his less spectacular results to the fact that
he started the experiment when the mice were already advanced in age,
and that the dosage was so much less than that administered by
Robertson.

Interestingly, Gardner reported that Robertson and his staff had taken
15 gm yeast nucleic acid per day, and that Gardner himself (perhaps as
a result of observing his healthy mice) had been taking 5 gm of yeast
nucleic acid for weeks “without any ill effects.” He concluded that
“As Robertson tested with three times the amounts I have suggested for
[human] use, there is no reason known at the present time for fearing
to use yeast nucleic acid freely for veterinary experimental purposes…
and…for extending their life spans as well as for experimental therapy
on aging men and women for the same purpose.”

Nearly another twenty years were to elapse before further experiments
with RNA were conducted—this time with even more spectacular results.
Dr. Max Odens conducted a study with ten 750-day-old rats, of a
species that had a normal lifespan of 800-900 days. Five rats were
untreated controls. The other five received weekly injections of “DNA
solution in water…plus ordinary RNA.” Unfortunately, details of the
exact composition and dosage that was administered were not given.
After twelve weeks of injections, Odens reported that the treated rats
looked younger, were very lively, and had gained weight, in contrast
to the untreated rats which “looked old, moved slowly, did not eat
much, and had lost weight. The difference was remarkable.” Odens
further reported that all of the untreated rats died before 900 days,
while 4 of the treated rats survived between 1600 and 1900 days, and
one rat lived 2250 days! Odens concluded that “with weekly injections
of DNA and RNA, the life span of 4 rats was doubled on the average,
and the life span of the fifth rat was more than trebled.” These
results are frankly, hard to believe. But some credence must be given
this report, considering the journal in which it was published—the
prestigious Journal of the American Geriatrics Society.

Conclusion

The claims for the life-extending benefit of nucleic acid
administration are supported by a diverse series of experiments that
span nearly 50 years. Based on these findings and the reports by Dr.
Frank of its widespread clinical benefits with human use, I
consequently agree with Dr. Frank’s recommendation to add at least 1.5
grams per day of nucleic acids to an anti-aging nutritional supplement
regimen. This recommendation is buttressed by the facts that two of
the research teams admitted taking high dose nucleic acids themselves,
after seeing the effects they had on their experimental animals, and
that the third researcher also recommended consideration of nucleic
acid supplementation for human and veterinary use. It is surprising
that more researchers have not attempted to replicate these studies—
especially when considering the high degree of safety and minimal cost
of high quality yeast-derived nucleic acids that are available today.

Thanks for posting Delphine, that's interesting information. I've been meaning to add grass-fed calf liver into my diet but have been too lazy to find a good source. This is yet another reason to get going on it.

Sardines are a big loss. But maybe not all cans are plastic linned.

I too would like to find grass-fed beef/calf liver. I do take tablets of dessicated liver from Argentina, where the cattle are pastured. Dessicated liver is an old-time bodybuilding staple.

God Bless Google, I found a producer of canned fish that claims their cans are BPA-free:

http://www.wildplanetfoods.com/

Delphine- that is a great read. I'm interested in eating sardines now. That link might come in handy. Thanks for sharing.

Here is some more info on BPA free canned goods:

http://www.treehugger.com/green-food/7-companies-you-can-trust-to-use-bpa-free-cans.html

Glad you appreciated the post bh20. Yeah, sardines are serious nutrition! Thanks for the link from TreeHugger, good to know of safe canned sources.

Delphine

Also I think the biggest thing to watch for is acidic foods like tomatoes in cans.

Don't cans have a protective lining?

Shaftless yes cans have a plastic lining most contain BPA which tends to leach more into the food when they are acidic.