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[Livingontheland] Is Conventional Produce Declining in Nutritional Value?
- From: "TradingPostPaul" <tradingpost@riseup.net>
- To: livingontheland@lists.ibiblio.org
- Subject: [Livingontheland] Is Conventional Produce Declining in Nutritional Value?
- Date: Sat, 16 Dec 2006 13:49:46 -0700
Is Conventional Produce Declining in Nutritional Value?
Source: LE Magazine March 2001
http://www.organicconsumers.org/ofgu/vegies121205.cfm
Vegetables Without Vitamins
Imagine the surprise of going online and discovering that the vitamin and
mineral content of vegetables has drastically dropped.
Thats what happened to nutritionist, Alex Jack, when he went to check
out the latest US Department of Agriculture food tables. The stunning
revelation came after Jack compared recently published nutrient values with
an old USDA handbook he had lying around. Some of the differences in
vitamin and mineral content were enormous-a 50% drop in the amount of
calcium in broccoli, for example. Watercress down 88% in iron content;
cauliflower down 40% in vitamin C content-all since 1975.
Jack took his findings to the USDA, hoping for a reasonable explanation.
That was two years ago. Hes still waiting. So is Organic Gardening
magazine, which published an open letter, seeking an explanation from Dan
Glickman, Secretary of Agriculture. Glickman didnt respond, but USDA
employee, Phyllis E. Johnson did. Johnson (who is head of the Beltsville
area office), suggested to Organic Gardening that the nutrient drain should
be put in context. According to her, the 78% decrease in calcium content of
corn is not significant because no one eats corn for calcium. She further
explains that the problem may not even exist at all; that the apparent
nutrient dips could be due to the testing procedures. For example,
changes in the publics perception of what the edible portion is may
determine what parts have been analyzed over time. In other words, back
when the old food tables were made up, people may have been eating the cobb
too, so they got more nutrients.
The Vitamin Drain
We decided to look into this further. Jack had used a 1975 version of the
food tables for his research. We dredged up a 1963 version. After comparing
the nutrient values for over a dozen fruits and vegetables, it was clear
that the nutrient value of many foods has dropped, in some cases
drastically. For example, the amount of vitamin C in sweet peppers has
plummeted from 128 mg to 89 mg.= The vitamin A in apples has dropped from
90 mg to 53 mg. The fall-offs seem to be limited mostly to vegetables, and
some fruits.
Some vegetables appear to be gaining vitamins-at least vitamin A. Carrots,
for example, have more of the vitamin now than they did in 1963. Why is a
mystery. But the phenomenon has apparently occurred just in the nick of
time. The National Academy of Sciences has issued an alert that it takes
twice as many vegetables to get the daily requirement of vitamin A as
previously thought. Carrots and pumpkin are exempt from the caveat.
Despite the apparent increase of vitamin A in carrots, most vegetables are
losing their vitamins and minerals. Nearly half the calcium and vitamin A
in broccoli, for example, have disappeared. Collards are not the greens
they used to be. If you're eating them for minerals and vitamin A, be aware
that the vitamin A content has fallen from 6500 IUs to 3800 IUs. Their
potassium has dropped from from 400 mg to 170 mg. Magnesium has fallen
sharply-57 mg to 9. Cauliflower has lost almost half its vitamin C, along
with its thiamin and riboflavin. Most of the calcium in pineapple is
gone-from 17 mg (per 100 grams raw) to 7. And the list goes on and on.
The USDA refuses to act
Whats the deal on this nutrient drain? We decided to ask USDA ourselves,
so we contacted the head of the USDA Agricultural Research Service, whose
job it is to track the vitamins in food, among other things. Mr. Edward B.
Knipling responded to our inquiry with a restatement of Ms. Johnsons
letter to Organic Gardening magazine. So we pressed for a better answer.
Isnt the agency concerned that Americans may not be getting the vitamins
they think they are? What about the food pyramid? Wont a nutrient drain
upset the pyramid? Already the National Academy of Sciences is telling us
our vegetables don't have as many vitamins as they're supposed to. Will the
USDA double the required servings of vegetables to make up for the vitamin
loss? So far, no answer from the agency.
The question is, what is the nature and extent of the problem? Vegetables
are a major source of nutrition. Without them, humans miss out on important
vitamins, minerals and phytonutrients. Many nutrients (such as folate)
werent measured in the past. If they are also disappearing, the extent
is unknown. What about more exotic nutrients such as flavonoids, or
compounds like I3C? These arent tracked by the USDA. Are they
disappearing also?
Whats for dinner
The USDA advises that we should be eating 3 to 5 servings of vegetables
plus 2 to 4 servings of fruit a day to maintain health. (A serving is one
cup of something raw and leafy or one-half a cup of something either not
leafy or cooked-or 3/4 cup of vegetable juice). That is potentially 9 cups
of vegetables and fruit a day. Thats a lot of lettuce. Are people doing
this?
Harry Balzer is vice president of NPD Group, a firm that gathers
information on the eating habits of Americans. His data says no way.
According to him, the preferred American meal is one-dish, already
prepared. Unless a vegetable can be squirted out of a bottle, its a
nonentity. Why? Were in a hurry. Vegetables are considered side dishes,
and Americans dont have time for such frivolity. The decline is
relentless. Within the last 15 years, the percentage of all dinners
including a vegetable (other than salad or potatoes) dropped 10%. Its
now 41%.
This raises a big question. If people are not eating their vegetables, how
are they getting their vitamins? The answer is theyre not.
Study-after-study show that Americans dont meet the RDAs for many
nutrients. Thats not good considering that RDAs are probably too low to
keep most people in optimal health to begin with.
Americans know what they should be eating. Theyre just not doing it. And
theyre not likely to. According to Balzer, for example, pizza is one of
Americas favorite meals. It fulfills, he says, the American ideal of
being easy and fast, liked by old and young, and easy to clean up. If you
blot it with a paper towel, throw on some pineapple, and use your
imagination, it even seems to fit with the food pyramid. What else are
people eating? Bread, doughnuts, pasta, cheese, beef and milk. Without
fortified cereal, Americans would not come close to meeting RDAs.
Yes, but what about the produce section? Isnt it filled with resealable
bags full of wholesome, scrubbed little carrots, prewashed salad greens and
spinach? Somebody must be buying them, or they wouldnt be there, right?
According to Balzer, those puppies are highly successful, raking in a
billion dollars in sales ($100M is considered successful for a new food
product). But the fact that people are buying them doesnt mean theyre
eating them. The reality is that onions are most-often served vegetable in
America. Tomatoes (including ketchup) are second.
According to one study, less than one-third of Americans get the minimum
five servings of fruits and vegetables a day, let alone the recommended
nine. According to Balzers data, the percentage of Americans who buy
healthy groceries is about 10%. The other 90% relies on ketchup, onions,
fat-free snacks, ice cream, cheese and Sweet Tarts as their source of
nutrition. Now we find out that even if a person accidentally eats a
vegetable, it may not contain the nutrients its supposed to. What can a
person do?
Vitamin supplements work
Supplements have proven their worth in scientific studies. Cancer, heart
attacks, bone loss, stroke and macular degeneration-most any degenerative
disease you can think of can either be prevented by, or ameliorated by, the
right nutrients given in supplement form. Over the long term, the benefits
can really add up. For example, nurses who took multi-vitamins containing
folic acid for fifteen years slashed their risk of colon cancer by 75%.
Folate from food didnt work as well. No one knows why, although
bioavailability problems may be to blame. Its estimated that about 90%
of the population gets less folate per day than necessary for health (400
micrograms).
In the same study, nurses who took multi-vitamins containing vitamin B6
reduced their risk of heart disease by 30%. The more B6 they took, the
lower the risk. Could a high potency, high quality supplement reduce risk
even more? We dont know, but a study from Norway shows that a
combination of vitamin B6 and folate reduces homocysteine 32% within five
weeks in healthy individuals. This has the potential to significantly lower
the risk of heart attack and stroke. Other studies show that for every
decade of life, plasma concentrations of B6 decrease, and that people who
take supplements have a much greater chance of meeting RDAs than those who
dont.
There are good reasons to take supplements. The bioavailability of the
nutrients in supplements (assuming you buy high-quality) is 100% compared
to food which is very unpredictible when it comes to bioavailability.
Nutrient content also appears unpredictible. If the vitamin drain is
confirmed, it will mean that people cannot count on vegetables and fruit to
be the packages of concentrated nutrients theyre supposed to be. In a
time when most people arent coming close to getting five, let alone
nine, servings of fruits and vegetables, it seems pointless to ask them to
eat more to get the same nutrients.
The USDA is apparently unconcerned and not interested in the vitamin drain,
despite its mandate to ensure high quality safe foods. In her letter to
Organic Gardening, Ms. Johnson said that the nutritional content of produce
is not as important as things like appearance and big yield. In other
words, Ms. Johnson espouses the view of commercial growers that food is a
product in the same way that running shoes are a product. Looks are more
important than substance. That view of vegetables and fruits reduces your
spinach salad to pretty roughage, and your chances of meeting RDAs to slim.
The USDA can be accessed at http://www.usda.gov. The food tables are
available online.
The folks who do the food testing are in the Agricultural Research Service
which can be accessed at http://www.ars.usda.gov.
*1963 values have been set at 100%
References
Cleveland LE, et al. 2000. Dietary intake of whole grains. J Am Coll Nutr
19 (3 Suppl):331S-38S.
Composition of Foods (Raw, Processed, Prepared): Agriculture Handbook No.
8. USDA Agricultural Research Service. 1963.
Cuskelly GJ, et al. 1996. Effect of increasing dietary folate on red-cell
folate: implications for prevention of neural tube defects. Lancet
347:657-9.
Giovannucci E, et al. 1998. Multivitamin use, folate and colon cancer in
women in the nurses health study. Ann Intern Med 129:517-24.
Manore MM, et al. 1989. Plasma pyridoxal 5-phosphate concentration and
dietary vitamin B-6 intake in free-living, low-income elderly people. Am J
Clin Nutr 50:339-45.
Mansoor MA, et al. 1999. Plasma total homocysteine response to oral doses
of folic acid and pyridoxine hydrochloride (vitamin B6) in healthy
individuals. Oral doses of vitamin B6 reduce concentrations of serum
folate. Scand J Clin Lab Invest 59:139-46.
NPD Group, Inc. has a website at www.npd.com. Highlights from the 15th
Annual Report on Eating Patterns in America are available online.
Organic Gardenings letter to Dan Glickman, and the response of Phyllis
E. Johnson of the USDA - see www.organicgardening.com.
Rimm EB, et al. 1998. Folate and Vitamin B6 from diet and supplements in
relation to risk of coronary heart disease among women. JAMA 279:359-64.
Rose CS, et al. 1976. Age differences in vitamin B6 status of 617 men. Am J
Clin Nutr 29:847-53.
Subar AF, et al. 1998. Dietary sources of nutrients among US adults, 1989
to 1991. J Am Diet Assoc 98:537-47.
Subar AF, et al. 1989. Folate intake and food sources in the US population.
Am J Clin Nutr 50:508-16.
90% of women and 71% of men get less than the RDA for vitamin B6.
Dietary vitamin B-6 intake and food sources in the US population: NHANES
II, 1976-1980. Kant AK, et al. 1990.
Men with the lowest amount of vitamin C have a 62% increased risk of
cancer and a 57% increased risk of dying from any cause. Vitamin C
status and mortality in US adults. Loria CM, et al. Am J Clin Nutr
72:139-45, 2000.
Lutein and zeaxanthin reduce the incidence of cataract by 22%. A
prospective study of carotenoid and vitamin A intakes and risk of cataract
extraction in US women. Chasan-Taber L, et al. Am J Clin Nutr 70:509-16,
1999.
People with low levels of retinol, beta-carotene, vitamin E and selenium
are more likely to get cancer. Serum retinol, beta-carotene, vitamin E
and selenium as related to subsequent cancer of specific sites. Comstock
GW, et al. Am J Epidemiol 135:115-21, 1992.
Supplemental vitamin D reduces the risk of colon cancer by half compared
to dietary vitamin D which reduces it 12%. Calcium, vitamin D, and dairy
foods and the occurrence of colon cancer in men. Kearney J, et al. Am J
Epidemiol 143:907-17, 1996.
The area of China with the lowest micronutrient intake has the highest
rate of cancer. Supplementation with vitamin E, selenium and beta-carotene
lowers the rate. Vitamin/mineral supplementation and cancer risk:
internationaal chemoprevention trials. Blot WJ. Proc Soc Exp Biol Med
216:291-6, 1997.
American children have inadequate levels of vitamin E. Vitamin E
status of US children. Bendich A. J Am Coll Nutr 11:441-4, 1992.
Flavonoids protect against stroke. Dietary flavnoids, antioxidant
vitamins, and incidence of stroke: the Zutphen study. Keli SO, et al. Arch
Intern Med 156:637-42, 1996.
- [Livingontheland] Is Conventional Produce Declining in Nutritional Value?, TradingPostPaul, 12/16/2006
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