GMW: Soy diet worsens heart disease in mice

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GMW: Soy diet worsens heart disease in mice

" GM WATCH " <info

Thu, 5 Jan 2006 13:10:46 GMT

 

 

 

 

 

GM WATCH daily

http://www.gmwatch.org

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As this research was undertaken in the US, it seems highly probable

that the soya used was, in fact, GM.

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Soy diet worsens heart disease in mice

By University of Colorado at Boulder

Jan 4, 2006

http://www.foodconsumer.org/777/8/Soy_diet_worsens_heart_disease_in_mice_.shtml

 

Editor's note: We do not know what type of soy the researchers used for

their study. Conventional soy and genetically modified soy may lead to

different conclusions. Previous studies have found that GM soy

increases the death risk in mice.

 

A University of Colorado at Boulder study has shown the health of mice

carrying a genetic mutation for a disease that is the leading cause of

sudden cardiac death in people under 30 worsened considerably when the

animals were fed a soy-based diet.

 

Male mice carrying the mutation for hypertrophic cardiomyopathy, or

HCM, were severely affected by the soy diet, exhibiting progressively

enlarged heart muscles and eventual heart failure, said CU-Boulder

Professor Leslie Leinwand. When the mice in the study were switched to

a diet

of the milk protein, casein, the condition of the males improved

markedly, said Leinwand, chief author of the study.

 

Female mice carrying the mutation for HCM, which is characterized by

the thickening of heart muscle that can obstruct blood flow, were

relatively unaffected, she said. The research team hypothesized that

heart

deterioration in male mice was due at least in part to plant-based

estrogens in the soy food diet that triggered a cascade of biochemical

reactions and ultimately increased apoptosis, or programmed cell

death, in the

heart.

 

" We were shocked by the results, " said Leinwand, chair of the

molecular, cellular and developmental biology department and chief

study author.

" This study shows that at least in mice, diet can have a more profound

effect on heart disease than any drug that we could imagine. "

 

A paper on the subject by Leinwand, Dr. Brian Stauffer, a cardiologist

at Denver Health Medical Center and the University of Colorado Health

Sciences Center, CU-Boulder research associate John Konhilas and

doctoral student Elizabeth Luczak appears in the January issue of the

Journal

of Clinical Investigation, one of the nation's leading medical

journals.

 

" To our knowledge this is the first report of significant differences

in cardiac muscle adaptation due to dietary manipulation, " the

researchers wrote in JCI.

 

The CU research team speculated the soy diet affected male mice more

severely because the females already had large amounts of estrogen

naturally circulating through their bodies, making the proportional

increase

in estrogen compounds from the soy diet significantly less, said

Leinwand. In addition, male mammals, from mice to humans, are more

severely

affected by the symptoms of HCM than females, she said.

 

The study mice were bred over generations to carry HCM, a disease which

causes the heart's lower chambers, or ventricles, to thicken and

prevents the heart from fully relaxing between heartbeats, said

Leinwand. In

the latter stages of the disease, the heart's ventricle chamber

enlarges, the heart wall thins and the pumping contractions of the

heart are

impaired, leading to heart failure, she said.

 

HCM is the leading cause of death in young athletes and affects about

one in 500 people, although milder forms of the disease often go

undiagnosed, said Leinwand. To date, 18 genes associated with HCM have

been

identified and several more are being investigated, she said.

 

Soy foods and diet supplements are perceived to be a huge health

benefit to humans, as evidenced by the estimated $4.7 billion spent by

consumers on them in 2005, said Leinwand. " I don't think normal, healthy

people should be alarmed by the results of this study, " said Leinwand.

" But

we are seeing more cautionary reactions from the medical community in

recent years regarding the ingestion of huge quantities of dietary

supplements, including soy phytoestrogens. "

 

Leinwand said plant estrogens have been shown to have a potent effect

on living organisms. While they are sometimes suggested by doctors to

treat menopausal symptoms in women, studies have shown that common plant

estrogens like genistein and daidzein can contribute to reduced

fertility in farm animals.

 

" There are some very complex issues in this study that we don't yet

fully understand from a biochemical standpoint, " she said. " But the study

should help lead to a better understanding of how genes and diet

interact. "

 

Currently, the main treatment for end-stage HCM is a heart transplant,

she said.

 

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The CU-Boulder study was funded by a grant from the Heart, Lung and

Blood Institute of the National Institutes of Health and the American

Heart Association.

 

Contact: Leslie Leinwand

leslie.leinwand

303-492-7606

University of Colorado at Boulder

 

 

 

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