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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Milk myths and vegan propaganda

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You know that I’m no great lover of milk. I have written a number of times about chocolate milk (for my newer readers here are just a few of those posts: The chocolate milk and exercise myth, Is chocolate milk essential to good nutrition?, Don’t cry over chocolate milk). Chocolate milk is delicious because it is essentially a liquid candy bar. White milk is definitely a better choice from a nutrition stand-point. Personally, I loathe a glass of milk (my mum can vouch for my life-long efforts to avoid milk consumption) but I’m more than happy to put it on my cereal, add it to a smoothie, or use it in a recipe. Despite my distaste for milk as a beverage, and a food group, I still think that it has nutritional merits and that people who enjoy it should not be discouraged from drinking it. Putting my personal opinions about milk aside, I was frustrated to read the article 5 Ridiculous Myths About  Cows Milk this week.

Myth 1: You need cow’s milk to get calcium

It’s true, you don’t need milk to get calcium. There are plenty of other food sources of calcium. However, the statements that, “the calcium contained in cow’s milk is barely absorbable to the human body” and, “The most calcium-rich foods on the planet comes from plants, especially leafy greens such as kale, spinach, and broccoli” are not entirely true.

It seems that calcium absorption from milk products and kale is similar (1) – about 30-35%. Spinach is notorious for being loaded with calcium that is not bioavailable to us – about 5% (2).

Myth 2: Cow’s milk will give you strong bones

Contrary to the claim that cow’s milk will actually result in weakened bones, there is no reason to believe that it will hinder bone strength. Although, there’s also no reason to believe that milk consumption will strengthen bones either. The best way to ensure strong bones is to engage in regular exercise, especially strength training.

Myth 3: Cow’s milk isn’t cruel

Here’s where the article really goes off the rails. The discussion of veal is irrelevant to the discussion of milk. Dairy cows and cows raised for meat are not one and the same. Yes, we have all seen the recent mistreatment of dairy cows. I’m willing to bet that this was the exception and not the norm. Just like humans, cows need to be relaxed to produce milk. Most dairy farmers treat their cows with love and respect.

Myth 4: Cows need to be milked

I can’t argue with this one. Obviously this is a matter of supply and demand. If cows are regularly milked, they will continue to produce milk, even without calves to feed. If cows are not regularly milked, and do not have offspring to feed, they will cease milk production. I’m not sure how this factors in as an argument against milk consumption by humans.

Myth 5: Cow’s milk is for humans

The argument is that cow’s milk is intended to feed baby cows and that no other species consumes the milk of another. Honestly, there was a time when I was like, “yeah, this makes sense. It’s so unnatural for us to drink milk from another species.” Then I thought about it a little more. We do A LOT of things that no other species do. Just from a food standpoint alone: we cook our food in a variety of ways, we preserve food in a number of ways, we eat at restaurants, we combine ingredients to make a recipe… Just because no other species does these things doesn’t mean that we should cease doing them as well.


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Grocery store lessons: Greek yoghurt

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I’ve extolled the virtues of Greek yoghurt in the past. It’s a pretty great source of protein at up to 18 grams in 3/4 of a cup! Of course, once something gets popular you know that the knock-offs aren’t far behind. I think that nearly every brand of yoghurt now has their own line of Greeks on the market. Unfortunately, many of them aren’t actually Greek yoghurt.

True Greek yoghurt is made by straining regular yoghurt so that you’re left with a thick creamy yoghurt. This separation of the whey (that’s the watery stuff that’s strained out) leaves the Greek yoghurt rich in protein but also removes some of the calcium… It can’t all be good, right? While a serving of plain yoghurt has about 30% of your daily recommended calcium, a serving of Greek yoghurt only has about 15% of your daily recommended calcium. But I digress…

What’s wrong with the “knock-off” Greek yoghurts? Well, they’re not strained. Instead of just containing milk and bacterial culture they add thickeners like carrageenan, corn starch and pectin to achieve a thick Greek-style creaminess. They also add milk protein to bump up the protein content but from the ones I’ve seen that still only puts them at 8 grams of protein per serving. That’s actually less protein than you’ll find in many traditional plain yoghurts. Most of them also tend to be targeted at the “dieting” community so they’re sweetened with artificial sweeteners. And lest you think “at least I’m still getting the calcium I would from traditional yoghurt” you’re probably only getting about 10% of the Daily Value.

If protein and a thick creamy yoghurt are what you’re looking for make sure to check the ingredient panel as well as the Nutrition Facts Panel to ensure you’re getting exactly what you bargained for. When it comes to yoghurt ingredients, less is definitely more.

*The photo above shows the Nutrition Facts for a traditional Greek yoghurt and a “knock-off” Greek. Can you tell which is which?


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Don’t cry over chocolate milk

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I know that I just recently blogged about flavoured milk in schools but I can’t resist commenting on this Masters Thesis on Flavored Milk Consumption in School Systems and its Effect on the BodyThis topic really gets under my skin and it especially annoyed me to see a dietetic maters thesis supporting the dairy industry and their propaganda.

The thesis looked at milk consumption of students in one school who were obligated to have a carton of milk on their trays at lunchtime. On the first day students were offered both white and flavoured (chocolate and strawberry) milks, as was presumably the norm. On the second day they were offered only white milk. The third day was the same as the first. Milk consumption was measured by weighing the milk remaining in the cartons at the end of each meal. It was found that milk consumption was about 9% less on the second day than it was on the first. Thus, it was argued that students were missing out on consuming calcium, and other essential nutrients, as a result of only being offered white milk.

Firstly, we have no idea what the students were consuming throughout the rest of the day. All we have is milk consumption at lunchtime over three days. There is no way we can conclude from this information that students were consuming inadequate calcium when they were only offered white milk. We also can not conclude that they were consuming sufficient calcium when they were offered both flavoured and white milk.

Secondly, of course children are going to choose chocolate milk over white milk when it’s offered. Chocolate milk is far tastier than white milk.

Thirdly, a 9% decrease in milk consumption isn’t really that much. When you think about it, this was after one day. What might happen if children were only offered white milk over a longer period of time? Perhaps their consumption of white milk would increase.

Why is it always argued that children need to have flavoured milk for them to drink it? Should we be sweetening everything to make it more palatable to them? If we never offered them chocolate milk in the first place we wouldn’t have this problem.

 

The paper indicates that many people believe that chocolate milk is contributing to the obesity epidemic and this is why we must stop serving it in schools. Chocolate milk is not single-handedly making children obese. I think the problem is more that we are constantly feeding children products that are filled with added sweeteners, sodium, and flavouring to get them to eat them. This is setting them up for a lifetime of dependence on the food industry trifecta of sugar, salt, and fat. We need to break the cycle. We need to be grown-ups and start deciding what our children eat and drink rather than letting the food industry make that decision for us.


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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.