Dispelling nutrition myths, ranting, and occasionally, raving

Will soy give you strong bones? Spoiler: maybe, if you’re a rat

Leave a comment

ZomboMeme 01102018175844

Recently there was a lot of criticism of a NYT article about what’s making us fat that was really about what diets might make mice fat. Along the same lines is this research from the University of Missouri that found soy diets might increase women’s bone strength.

The study was not on actual human women though, of course. No, this study’s participants were rats. These rats are apparently a good proxy for human women because they are selectively bred to have low fitness levels and, “average American women are relatively inactive both before, and especially after, menopause”. Essentially, both American women (particularly older women) and these rats are lazy so they’re totally interchangeable when it comes to research. As it’s much harder to get women to adhere to specific diets, and there are far more variable to control for and ethical considerations when it comes to human experiments, it just makes sense to use rats.

So, these rats were divided into two groups: one group was fed a corn-based diet (you know, just like the average post-menopausal American woman eats) and the other was fed a soy-based diet. The results showed that: “the tibia bones of the rats that were fed soy were stronger compared to the rats who were fed the corn-based diet, regardless of ovarian hormone status”. Leading to the conclusion that: “Bottom line, this study showed that women might improve bone strength by adding some soy-based whole foods to their diet”.

To recap: rats were fed either corn-based rat food or soy-based rat food. The rats fed the soy-based rat food were found to have stronger leg bones. Therefore, human women can increase their bone strength by eating more soy.

This is ridiculous. We are not rats. We do not live the same lives as laboratory rats. We are not all sedentary. We do not eat the same food as laboratory rats. It is a huge leap to say that this study in rats shows that consumption of soy by women can lead to stronger bones. We are not eating a homogenous diet of corn-based rat food. The forms of soy we consume as humans are very different from that in rat food (e.g. tofu, soy beverage, tempeh, edamame, TVP).

Perhaps soy-based foods can increase bone strength in humans but this study doesn’t tell us that. This study tells us that this breed of rat has stronger bones when fed a soy-based diet than when fed a corn-based diet.

Author: Diana

I'm a registered dietitian from Nova Scotia, living and working in Ontario, Canada. My goal is to help people relearn how to have a healthy relationship with food.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s