Dispelling nutrition myths, ranting, and occasionally, raving


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

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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.


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I don’t think you’re ready for this gelatin

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Apparently gelatin is the latest “superfood”. Yep, the stuff in jello. Of course, you have to take away the added sugar, colour, and flavour for it to ascend to “superfood” status. You all know how I feel about “superfoods”. They’re a super scam. Sure, many of them are nutritious (think avocados and blueberries) but there’s nothing about them that makes them superior to other fruits and vegetables.

Okay, even if gelatin isn’t a “superfood” is it exceptionally good for you? Should we all be eating plain jello or taking gelatin capsules? Let’s take a look at the specific claims in the article…

Improved digestion – According to pretty much every wellness blog and self-proclaimed nutritionist gelatin improves digestion. However, as far as I can tell there is no scientific basis for this claim. I can’t find any research on the topic. This isn’t to say that gelatin doesn’t help digestion, but we don’t currently have any reason to believe that it does. 

Reduced food intolerance and allergy – This is a frightening claim. It would be lovely if it were true; people with peanut allergies could eat some gelatin and then chow down on some peanuts. And what about those people who suffer from gelatin allergy?

Strong bones and flexible joints – Because gelatin is made from animal cartilage (unless it’s the vegetarian variety which is made from seaweed) it’s easy to see how people draw the connection between gelatin and joint and bone health. However, despite this widespread belief, there’s no evidence to support the use of gelatin for bone and joint health. The same applies for Thick hair, strong nails and healthy teeth. Just because a substance (e.g. collagen) acts to strengthen our hair doesn’t mean that it will do so if we consume it orally. Otherwise, we would be able to improve our eye sight by eating eyeballs. A bit of an exaggeration, but you get the point.

Ageless skin – See the last point above. I’d also like to add that skin ages! Sorry, no matter what supplements we take, and what lotions and potions we apply we are all going to get wrinkles. Want to retain your youthful complexion for as long as possible? Eat a healthy diet with a variety of fruits and vegetables and fluids, get enough sleep, exercise, avoid tanning and sunburns.

Improved sleep – I was able to find one study that suggested that 2 grams of glycine ingested at bedtime improved subjective sleep quality. There’s 1.3 g of glycine in one serving of gelatin so it’s possible that you might obtain some benefit from it. However, this quantity may not be present in capsules so before you go running out to buy them before bed you might want to make sure that you’re getting what you’re paying for.


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Strong bones

Last week a US government advisory group announced that there is no benefit for healthy “older” women to take low-dose calcium or vitamin D supplements. These conclusions were based on findings that these supplements do not appear to reduce the risk of broken bones.

There are a few important things to note about this pronouncement: 1. This message applies only to healthy older women. Women who are suffering from certain illnesses may require more of some nutrients and should consult with their doctor before stopping (or starting) any supplement regimen. 2. The advisory group did not look at higher supplement doses. There may be benefits (or risks) to consuming higher supplemental doses. 3. The announcement was based on risk of broken bones in comparison to risk of kidney stones. The advisory group did not look at any benefits of supplementation other than bone health. There may be additional benefits to vitamin D supplementation (again, or risks) we just don’t have sufficient research to advise on this basis yet.

I think that the most important lesson we can take away from this study is that many illnesses that befall us when we’re elderly are a result of exposures and lifestyle during our youth. As I remember learning in school: osteoporosis is a pediatric disease with geriatric consequences. We can’t mistreat or neglect our bodies when we’re young and then expect to make up for it when we’re elderly. To ensure strong healthy bones as seniors we need to ensure that children and young adults consume healthy balanced diets; including adequate vitamin D (which may require supplementation) and calcium. Children also need to engage in regular physical activity and we need to continue to exercise throughout our lives to maintain muscle mass and strong bones.

While it’s never too late to start leading a healthy life, it’s also never too early.