bite my words

Dispelling nutrition myths, ranting, and occasionally, raving


Leave a comment

Follow Friday: @EWG’s Food Scores

user-guide

Interested in finding out how your food stacks up? Now you can check its “score” with a quick search on the Environmental Working Group’s Food Score page. Foods are rated based on three criteria: nutrition concerns, ingredient concerns, and processing concerns. They also have an iphone app available in the app store, an android app is coming soon. It’s an easy way to find out more information about your food.


6 Comments

Is your “green monster” a nutritional nightmare?

unnamed

I recently came across a blog post decreeing green smoothies to be a nutritional no-no. Great, so people finally find a way that works for them to get a bunch of veg and fruit in one go and now we tell them that these drinks might be the death of them.

Green smoothies seem like a no-brainer. If you’re making them at home you can easily control what goes into them and ensure that they’re packed with nutritious foods and not calories from things like frozen yoghurt. I know a lot of people who find it difficult to eat breakfast in the morning; smoothies can be a great way to get breakfast in as liquids may be more readily tolerated than solid foods first thing in the morning.

Now that people are hooked on green smoothies the fearmongering begins. Why should you fear your green smoothie? Well, raw cruciferous vegetables, such as kale, a staple in many green smoothies, contain goitrogens. These are substances that interfere with thyroid gland metabolism by inhibiting the absorption of iodide. When consumed in large quantities, they may cause goiters. Goitrogens are also found in turnips, cabbage, brussels sprouts, cauliflower, broccoli, and water.

Iodide (not to be confused with the toxic iodine, despite “iodine” being used interchangeably with iodide) deficiency hasn’t been a significant health concern in developed countries in many years because we generally cook cruciferous vegetables before eating them. In Canada, fortification of table salt with iodide is also mandatory. However, with the diminished use of the salt shaker and the popularization of sea salt (which is not fortified and loses iodide during processing) it’s likely that iodide will become a nutrient of greater concern in countries such as Canada.

Before you start reaching for the iodide supplements (which, by the way, you’ll find as kelp or bladderwrack, not as iodide/iodine) you should be aware that at very high amounts (more than 1.1 mg per day), iodide consumption can inhibit thyroid hormone synthesis. Even without consuming fortified table salt, most North Americans consume more than enough iodide per day as iodide is used as a sterilizing agent in dairies and restaurants, a conditioner for dough in bakeries, and in food colourings. Iodide is also found in saltwater fish (both fin and shell), molasses, seaweed, plain yoghurt, milk, and eggs. Some protein bars and multivitamins also contain iodide.

Back to your green smoothie. Should you be concerned about the effect your daily smoothie might have on your thyroid gland? Probably not. Unless you’re guzzling green smoothies for breakfast lunch and dinner, are consuming a cruciferious vegetable-heavy raw-diet, and have an existing thyroid condition it’s unlikely that a green smoothie once a day, or less, is going to have anything but a positive impact on your health. The most important feature of a healthy diet is variety. Consuming too much of anything be it green smoothies, potato chips, bread, or bananas, is unhealthy. Eating a balanced diet containing a variety of foods helps to ensure that you’re getting all of the nutrients you need. And yes, a green smoothies can be a part of a balanced diet.


Leave a comment

Are mushrooms the new meat?

4015323685_a22f9caa1f_z

How could I resist the headline: 7 simple weight-loss foods? Of course, we all know that there are no magical weight loss foods. Weight loss and management is all about the overall pattern of eating. Eating half a grapefruit before every meal, eating eggs, or blueberries is not necessarily going to mean that you’ll lose weight.

The suggestion that bothered me the most was to swap out meat for mushrooms. I’ve got nothing against mushrooms (cooked, obviously). Nothing against meat either. Certainly, if you’re a frequent meat eater and you start replacing meat with mushrooms, you’re probably going to lose weight. However, mushrooms, despite their meaty texture are not nutritionally comparable to meat and the suggestion that they’re interchangeable concerns me. Go ahead and have a portabello burger or a mushroom lasagne, but bear in mind that those mushrooms aren’t providing you with the protein, iron, vitamin B12, etc that meat does. Ensure that you include other sources of these nutrients in your diet as well as the mushrooms.


2 Comments

Can yoghurt prevent diabetes?

8747186157_5cfe842ba2_z

A friend of mine recently shared the news of a new study reporting an association between yoghurt consumption and decreased risk of type 2 diabetes.

The study was actually a meta-analysis of three large studies. Meta-analyses always make me a little nervous due to the ease of cherry picking and interpreting the results to yield the desired effect. The results of a meta-analysis can only be as good as the results of the original studies on which they’re based. I’m not saying this was the case here, just that it’s something to bear in mind when reading about meta-analyses. The researchers do have on their side the fact that all three studies had large sample sizes. After examining the results of these three studies, they added an additional 11 prospective-cohort studies for their meta-analysis.

The researchers controlled for a number of potential confounders. However, there’s always a remaining risk that an unaccounted for confounding variable might be the true reason for any observed effect. While the researchers reported a significant decreased risk of type 2 diabetes in regular yoghurt consumers they were also quick to acknowledge that this does not indicate causation. Yes, people who consume yoghurt appear to be less likely to develop type 2 diabetes than people who don’t. However, the studies all relied upon self-reported food frequency questionnaires and they were observational. It is possible that there is some unaccounted for variable that’s reducing the risk of type 2 diabetes in yoghurt consumers other than the yoghurt.

The researchers do make an interesting suggestion that the probiotics in yoghurt may be responsible for the decreased risk of type 2 diabetes. I do wonder about the validity of this as many yoghurts contain limited live bacteria due to their processing. In addition, it’s unlikely that many probiotics in yoghurt survive the acidic stomach environment to make their way to the intestines. Perhaps it’s the by-products of the bacteria in the yoghurt (e.g. vitamins, lactic acid) that are responsible for decreased risk of type 2 diabetes. Just postulating here. I would love to see a study in which participants are prescribed diets containing either yoghurt with live bacteria, yoghurt without live bacteria, and no yoghurt. Yes, it would take a long time to determine if the yoghurt reduced the risk of type 2 diabetes but other effects could be examined as well and it would be interesting to see what the true effects of  regular yoghurt consumption are on health.


Leave a comment

A bit more about food combining

PB&B sandwich photo by Kevin Reese. Used under a Creative Commons Licence.

PB&B sandwich photo by Kevin Reese. Used under a Creative Commons Licence.

After I wrote about the utter nonsense of food combining last week I had a reader contact me to suggest that perhaps I could elaborate on the positive side of food combining. To be clear, this is not what is traditionally meant by “food combining” which is a complicated way of eating which erroneously is believed to aid digestion and is more based on not eating certain foods in conjunction with others than with eating a variety of foods together.

I mentioned in my previous post that combining some foods can be beneficial in terms of absorption. Fat soluble vitamins (ADEK) need to be consumed with fat in order to be absorbed. This is one of the many reasons that a low-fat diet has been decried by dietitians. Skimmed milk with added vitamin D? No sense to it unless you’re washing down a croissant (or an avocado, nuts, or other fat-containing food of your choice).

In addition to aiding absorption of fat-soluble vitamins, certain foods can help with the absorption of other nutrients. Foods containing vitamin C can help with the absorption of iron, particularly from plant foods in which the iron is less bioavailable than in meats. For example, eating peppers with your spinach salad can help you to absorb more iron. Or having an orange with your oatmeal, tomatoes and beans, etc. Of course, there are also instances where nutrients can hinder the absorption of other nutrients. Tannins and fibre may decrease the absorption of some minerals and medications. Oxalate (found in spinach and some other fruits and vegetables) can impede the absorption of calcium.

As my astute reader pointed out, there’s also the benefit of glycemic control imparted by eating certain foods together. As any reader of Wheat Belly can (and likely will) point out to you, whole wheat bread has a higher glycemic index than white sugar. The thing that’s not taken into consideration when latching onto that fact is that we rarely eat whole wheat bread in isolation. Turn your bread into a peanut butter and banana sandwich or chicken salad sandwich and you’ve altered the glycemic load of the meal because you’ve added other macronutrients. Consuming fat, protein, or fibre can all help to mitigate the effect of carbohydrates on blood sugar. This is why, if someone with diabetes is experiencing low blood sugar it’s much better to give them candy or juice than a chocolate bar. On the flip-side, this is why most dietitians will recommend that you consume two food groups at snacks. Having a piece of fruit and a few nuts or cheese and crackers, berries and yoghurt, veggies and hummus… will help to prevent a spike in your blood sugar and keep you feeling full for longer that if you were to just have a piece of fruit. It also helps you to meet your nutrient needs if you include a vegetable or fruit as part of your snack.