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[SANET-MG] organic strawberriesa cancer treatment
ISIS Press Release 07/09/06
Organic Strawberries Stop Cancer Cells
Latest evidence on why organic foods are good for health. Prof. Joe
Cummins and Dr. Mae-Wan Ho
A fully referenced version of this article is posted on ISIS members’
website. Details here
Organic foods a cornucopia of health-promoting compounds
Scientific evidence has been accumulating on the health benefits of
organic foods (Are Organic Foods More Healthy? Organics for Health;
Organic Agriculture Helps Fight Cancer; Food Quality? What's That? / Do
Animals Like Good Food?) (see Box).
Box 1
Why organic foods are healthy
Richer in essential minerals such as calcium, magnesium and ion, and
trace minerals such as copper [1-3]
Contain more vitamins and micronutrients [3]
Rich in antioxidants and other compounds that fight cancer and heart
disease (see main text)
Low in nitrates [4, 5]
Contain little or no harmful pesticide residues (see main text)
Grown without polluting pesticides and fertilizers and hence provide a
cleaner environment for health
Contain little or no antibiotics that harm beneficial natural gut
bacteria [6]
Contain no harmful artificial food additives such as hydrogenated fats,
phosphoric acid aspartame and monosodium glutamate [7]
One important thing about organically grown foods is that they are a
cornucopia of health-promoting chemical compounds. A new landmark study
shows that organic strawberry extracts inhibited the proliferation of
cancer cells more effectively than conventional strawberry extracts.
What is it about organically grown plants that make them rich in
secondary metabolites off the main track, which are great for fighting
diseases like cancer? Many of these compounds are actually part and
parcel of the plant’s own defence against pests and disease.
Bengt Lundegardh and Anna Martensson [8] at the University of
Agricultural Sciences Uppsala Sweden believe that the benefits of
organically grown foods have a lot to with activating the plant’s
defence mechanisms to synthesize its own protective agents because
synthetic pesticides are excluded. An active soil where plants and
microbes interact also facilitates the exchange of metabolic compounds
such as vitamins and cofactors. In addition, organically grown foods
have a richer mineral content, on account of a more balanced nutrient
uptake in the absence of artificial fertilizers, which would have
provided excesses of easily available nutrients such as nitrates.
Bioactive compounds in foods, especially the plant phenolic
antioxidants, are well known to prevent cancer and cardiovascular
disease [9]. Phenolics are present in many crops, particularly fruits,
and it has become clear that organic foods are richer in cancer fighting
antioxidants [10, 11].
Organic strawberry extracts stop cancer cells
Strawberries have been studied extensively for their cancer fighting
ability and that is where the benefits of organic fruit cultivation
shine through. Swedish researchers at Swedish University of Agricultural
Sciences, Alnarp, and Lund University compared extracts of five organic
and conventional cultivars for their ability to inhibit the
proliferation of human colon and breast cancer cells. They found that
extracts from organically grown strawberries inhibited cell
proliferation more effectively than extracts from the conventionally
grown ones, and in both types of cancer cells [12].
The strawberry extracts decreased cell proliferation in a dose-dependent
manner between 0.025 to 0.5 percent dry weight of extract to volume of
cell culture. At the highest concentration, the organic extracts
inhibited proliferation of colon cancer (HT29) cells by 60 percent and
breast cancer (MCF-7) cells by 53.1 percent; the corresponding values
for conventional strawberry extracts were 49.7 percent and 37.9 percent
respectively. The differences between conventional and organic were
statistically highly significant.
The most effective extracts at inhibiting cell proliferation contained
48 percent more ascorbate and 5 times more dehydroascorbate. (Vitamin C
is ascorbate plus dehydroascorbate.) The organic strawberries also had
more antioxidants and a higher ratio of ascorbate to dehydroascorbate.
Compost as a soil supplement increased the level of antioxidant
compounds in strawberries [13]. The strawberry extracts, rich in vitamin
C and antioxidants, were found to interfere with the mitogen-activated
protein kinase (MAPK) signaling cascade that leads to cell division, and
to suppress cancer cell proliferation and transformation [14].
These latest findings on organic strawberries are in line with those on
other organic fruits. Organic yellow plums were found to be richer in
phenolic acids when grown in natural meadow or with a ground cover of
clover than conventionally grown plums [15]. Plum and clover extracts
induced apoptosis (cell death) and reduced the viability of human liver
cancer cells [16].
Absence of pesticides another tangible health benefit
Apart from providing secondary metabolites that fight diseases, the
absence of pesticide residues in food and feed is another tangible
health benefit of organic food. The “green revolution” has boosted food
production in developing countries through high inputs of pesticide and
fertilizers. Investigators at the Centre for Rural Development and
Technology Dehli India studied residues of organochlorine,
organophosphorous, carbamate and pyrethroid pesticides in conventionally
grown wheat and rice and found that organic wheat and rice had little or
no detectable pesticide. Production of wheat and rice under conventional
system was higher than organic but this higher production is at the cost
of health risk and also poses other hazards to flora and fauna [17].
The National Research Council in the United States concluded in their
1993 report [18] that dietary intake is the major source of pesticide
exposure for infants and children in the United States, and this
exposure may account for increased pesticide related health risks in
children compared to adults (see Box 2).
Box 2
What the US EPA says about pesticides in infants
The US Environmental Protection Agency states [19]: “Laboratory studies
show that pesticides can cause health problems, such as birth defects,
nerve damage, cancer, and other effects that might occur over a long
period of time. However these effects depend on how toxic the pesticide
is and how much of it is consumed. Some pesticides also pose unique
health risks to children.”
That is because [20], “their internal organs are still developing and
maturing”, and “in relation to their body weight, infants and children
eat and drink more than adults, possibly increasing their exposure to
pesticides in food and water.” Furthermore, “certain behaviors – such as
playing on floors or lawns or putting objects in their mouths – increase
a child’s exposure to pesticides used in homes and yards.”
Pesticides may harm the developing child by blocking the absorption of
important food nutrients necessary for healthy growth. Furthermore, if
the child’s excretory system is not fully developed, the body may not
fully remove pesticides. There may also be crucial periods in human
development when exposure to toxin can permanently change th way an
individual’s system works.
Researchers at the Rollins School of Public Health, Emory University,
Atlanta, and Department of Environmental and Occupational Health
Sciences, University of Washington, Seattle, Washington in the United
States measured dietary exposure in the urine of infants and children
before and after they switched from consuming conventional to organic
produce and then again back to conventional. They showed that the
metabolites of the organophosphates malathion and chlorpyrifos declined
to undetectable levels immediately after switching to organic diets, and
remained undetectable until they switched back to conventional diets
[19]. This supported the earlier conclusion that the children were
mostly likely exposed to organophosphate pesticides exclusively through
their diets.
Children are not the only ones affected by pesticides. In Denmark, a
1999 study on human sperm and semen quality in relation to organic or
conventional diet found that the group consuming mainly organic food had
a reduced pesticide intake based on the pesticide levels measured in
their food. The researchers concluded that pesticide exposure in the
diet did not entail a risk of impaired semen quality [20] even though
the group of men not consuming organic food had a significantly lower
proportion of morphologically normal sperm, which is generally
considered predictive of pregnancy outcome, as abnormal sperms are
indicative of DNA damage [21, 22]. It is not clear why the investigators
thought that increase in abnormal sperms did not impair semen quality.
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