Soya's possible downside?

Soya's possible downside?

WASHINGTON: If you are completely sold on the idea of soy as a health food, here's something to make you rethink.

Lab experiments showed that a soy diet worsened a specific cardiac condition among male mice that carried a genetic mutation for heart disease. Hypertrophic cardiomyopathy or HCM is a heart condition affecting about one in 500 people. People with this condition are found to have thicker heart muscles. It is also found to be the leading cause of death among young athletes.

Milder forms may go undiagnosed and there is possibility of more people having this condition. Its symptoms include discomfort in the chest area, shortness of breath and palpitations.

The study was conducted by researchers from the University of Colorado, Boulder who published the results in the Journal of Clinical Investigation. The experiments helped the researchers identify 18 genes associated with the disease.

In their experiment, mice with HCM were subjected to a diet of soy. The scientists found the condition worsening among male mice. When the affected mice were taken off the soy diet and put on a diet of milk protein, they regained their health remarkably.

The fact that male mice were more affected led the researchers to believe that the phytoestrogen in soy was responsible for the response by making their heart muscles thicker. Female mice were less affected because they already had the estrogen naturally circulating in their bodies, the researchers speculated.

Prof Leslie Linwand of the CU said there was no need for people who take soy in their diet to get alarmed by the results.

Soy food and diet supplement makers have been promoting their products as a great health benefit. According to the industry's data, sales of soy products amounted to $4.7 billion in 2005.

Linwand also said the experiment was perhaps the first time researchers studied how dietary manipulation caused “significant differences in cardiac muscle adaptation”.