Category Archives: Minerals

RFF#97 – There’s one time when you can guiltlessly add salt to your food…

Posted on by

…after you’ve exercised excessively and have consequently sweated excessively.

The story behind today’s post began two weeks ago when I played tennis for three hours…drank a lot of water…went to sleep…and woke up at 4:00am with one of the worst headaches of my life!!!!

You see, normally your blood has a balance of sodium [Na] and water [H2O] (in addition to many other things, but for the sake of today’s post we’ll just focus on the sodium)…

 

Balance of Sodium and Water

Note: Ratios are not to scale

 

But when you sweat, you lose both water and sodium…

 

Balance of sodium and water - after sweating

 

And if, like me, you exclusively drink water post-exercise, your blood steam will look like this…

 

Balance of sodium and water - after drinking water

 

This condition is called hyponatremia (hypo=low, natremia=blood sodium). The consequences of hyponatremia include dizziness, headache, nausea, and oh…did I mention death! For years I suffered from hyponatremia after playing sports. No one could tell me why, and I never figured out the problem until I took Physiology 302.

Sports drinks are the obvious solution. Me of course, having made a personal pledge to never drink caloric beverages, fell victim to my own good intentions.

However, while replacing electrolytes (such as sodium) is part of the solution, electrolytes alone won’t completely solve the problem. That’s part of the reason why sports drinks don’t exclusively contain electrolytes. And while they probably contain more sugar than you really need, sugar is nevertheless an essential ingredient.

That’s because on its own, sodium can’t pass through the cells of your intestine and enter your bloodstream. It needs to be transported. And one of the transporters that accomplishes this task is a sodium-glucose transporter, which means it needs both glucose and sodium to operate. Therefore, post-exercise, carbohydrate is needed to assist in the absorption of sodium.

Note: This diagram is highly simplified

Note: This diagram is highly simplified

 

While consuming a sports drink will get the job done, sports drinks are not your only option, anything that contains carbohydrate and sodium should do the trick (ex. crackers, juice, a pickle, etc.).

In conclusion, it’s kind of funny how so much of my work is dedicated to preventing people from suffering from having too much sodium, meanwhile I somehow manage to let myself suffer from having too little!! So as I sit here typing this story, after having just played tennis for three hours…rest assured, I’m snacking on a tiny bit of pasta and vegetables, to which I added a dash of salt!

Here’s some photos to lend cred to my story…

Since it's difficult to take a picture of yourself playing tennis, I opted for a shadow selfie.

Since it’s difficult to take a picture of yourself playing tennis, I opted for a shadow selfie.

 

I love those pink laces!

I love my pink laces!

 

–I learned about this fact from: Years of unpleasant experiences and my third year physiology professor Dr. French!

Advertisement

RFF#77 – While the WHO recommends 400-500 mg of Calcium per day, Health Canada and the FDA recommend 1000mg

Posted on by

The more I learn about nutrition, the more and more confused I get when it comes to the recommended daily nutrient intake levels. The fact of the matter is, no one really knows exactly how much calcium,  sodium, or iron we actually need on a daily basis. Part of this is due to the fact that we’re all different and the amount of Calcium that I need could be very different from the amount of Calcium that YOU need. Not to mention, the amount of Calcium that I require today may be different from the amount that I will need tomorrow. A large part of this is due to the fact that, beyond obvious factors like age and gender, there are many variables that can influence one’s calcium needs…

  • Consumption of foods/nutrients that aid Calcium absorption, such as Vitamin D…with that in mind, another factor influencing absorption is…
  • Exposure to sunlight. As you know, Vitamin D is produced when sunlight is absorbed through your skin, hence if you spend more time in the sun, you’ll probably absorb more Calcium.
  • Consumption of foods/nutrients that inhibit Calcium absorption. This includes chocolate, sugar, chocolate, alcohol and caffeine, giving you yet another reason to avoid these tempting, yet potentially harmful foods.
  • Genes! By now, it’s pretty obvious that genes affect everything. We’ve already discussed that Vitamin D aids Calcium absorption. However, even with adequate Vitamin D, your calcium absorption is dependent on which version of the vitamin D receptor gene you’ve inherited.

All things considered, you can imagine how hard it is to set Calcium recommendations for the entire population. In many ways,  it’s an impossible task, any recommendation will only be an estimated average that may or may not be ideally suited to you.

For me, the large difference between the WHO’s recommendation (400-500mg) and the Institute of Medicine’s (IOM) recommendation (1000mg [for adults]) is reassuring. Personally, I’m not a huge fan of dairy products. Though I don’t necessarily advocate for veganism, I definitely think that there are some serious issues with consuming large amounts of milk (largely due to the hormone content). So if you’re like me, you can now rest assured that according to the WHO, approximately a cup and a half of milk (which contains around 500 mg of Calcium) could be enough to prevent you from developing osteoporosis.

I learned about this fact from:

Click to access gsfao_osteo.pdf

http://www.ncbi.nlm.nih.gov/pubmed/15883634

http://www.ctvnews.ca/health/world-s-most-cited-nutritionist-debunks-dieting-myths-1.1657609