Thursday, August 20, 2009

Hypovolemia Day


Carrots and tomatoes and lettuce, oh my. As I mentioned briefly yesterday, between furosemide day and hypvolemia day, the scientists designed a specific diet of particular foods: bananas, oranges, grapes, oatmeal, water, decaf tea and salads with vinegar (you wouldn’t believe how much sodium is in bottled salad dressings!).

Note the lack of protein and almost complete lack of salt; a significant change from taking salt tablets every day the first week!

Knowing this would be part of the protocol, I started to pay attention to the salt content in various foods. Actually watching and lowering salt intake has been something of a learning curve, since sodium is not something I generally track. I do read food labels, but often only for protein, vitamin, and overall calorie content.

Table Salt
While originally preparing for the second stage, I started noting the milligrams of sodium in all foods I keep in my pantry and refrigerator. Then, while grocery shopping this week, I examinied various foods in the store out of curiosity.

And may I just say... HOLY <Word Not Allowed On My Blog>. I’m in awe of anyone who has the challenge of "restricting sodium" due to heart conditions – because eating any kind of processed foodstuffs or going to a restaurant must be nearly impossible! Even things you wouldn’t think had much salt can in fact possess shocking amounts – canned veggies, juices, and particularly “low fat” or “low sugar” foods.

I’m seeing a “Law Of The Jungle” of sorts among food manufacturers. If they remove sugar, they compensate with artificial sweeteners, salt or fat. If they remove fat, they compensate with caffeine, salt or other spices. If they remove salt, they compensate with… you get the idea. They have to work some flavor in there somehow, or I guess people won’t buy [or get addicted to] the goods.

Even products such as soups or veggie bowls merely marked “low sodium” – well, the few I auditioned just seemed greasy and sour. However, I calculated the amounts I usually eat and was surprised to find that I am almost always in the “normal” range. (Though that also accounts for a high water intake… and the average Lean Cuisine entrĂ©e can still blow a whole day.)

Sodium Intake
At any rate, and getting back to the point of the study, the previous weeks’ diets result in mild hypovolemia, or a physiological state in which the volume of blood plasma decreases – just like what happens in space during weightlessness. (It’s often confused with “dehydration,” which is loss of bodily water… though that happens too… or is the cause.)

Unsurprisingly, the first test “repeat” at this point is a measurement of blood plasma volume. Then another tilt test, then you change into workout clothes for another exercise-to-exhaustion episode on the cycle ergometer. In short, all procedures performed on Normovolemia Day are repeated on Hypovolemia Day, and the data is compared.