Thursday, May 23, 2013

Sour News Concerning your Body's pH. Taste, pt 4

As we’ve seen over the course of this adventure into taste, these sensations can often have different meanings to the body. Have you ever craved something sour? Does the thought of your favorite oil-and-vinegar dressing on a sandwich make your mouth water? Ever wondered why?
As it happens, acids have a particularly sour taste. (If you are wondering, bases are rather bitter). This includes citrus juices such as lemon, lime or orange. Vinegar is primarily acetic acid and water. Acids (and bases) also happen to be pretty important to the body. This is a popular topic for nutrition blogs. You don’t have to go far to find yet another article or post about the importance of acid/base balance and eating an “alkaline diet” vs an “acidic diet”.
But what does this mean, really? And why do people get so excited about it?
Let’s start at the beginning. pH balance is important. Your body has an optimum pH range, and it’s pretty small – 7.35-7.45. It’s slightly alkaline (or basic). This is not only the optimum range for your body to operate, but if you leave this range by much (or for very long), your body will enter either acidosis (if it drops) or alkalosis (if it rises). Either of these conditions is fatal. It makes sense, then, that the body would have any number of ways to help maintain this pH, even if your diet isn’t perfectly pH balanced.
Please, take a moment to thank your lungs and kidneys.
The lungs use oxygen and carbon dioxide (breathe in, breathe out) to maintain blood pH. If this pH begins to move in either one direction or the other, the lungs will help bring it back in check by regulating your breathing to optimize the CO2/O2 exchange (think about hyperventilation here). The kidneys use a slightly different mechanism to do the same thing – they will balance hydrogen ions (H+) by either pulling them from the blood to excrete them (in urine), or by releasing the back into the bloodstream.
Remember, our understanding of these systems is relatively new. After all, humans have been eating both acid (meat, flour) and alkaline (fruits, vegetables) foods for a very long time. And somehow we managed to survive thousands of years without epidemics of alkalosis or acidosis.
Many of these articles will tout the importance of an alkaline diet because an acidic diet will deplete calcium from the bones. There’s a certain degree of logic to this, and it has to do with using phosphorus to help balance the acidity of the foods in your diet. Long story short, calcium and phosphorus are pretty closely related, and this can cause a change in the mineral composition of your bones… over time. But fear not, there’s an easy way to keep this from happening. And I’ll give you my secret, because I’m feeling particularly generous today.
Balance your diet.
It makes sense if you spend your time consuming acidic foods – such as soda – health problems will follow. It also makes sense that if you eat a balance of foods (acidic included) you’ll be healthier overall. Fruits and vegetables are considered to have an “alkaline effect” in the body, but this principle alone doesn’t dictate why we should eat these foods. Plant based foods also have vitamins and minerals that are harder to come by in acidic foods, such as meat. They also have fiber, which can have some very positive effects not only on digestion, but cholesterol and blood sugar. Meats also have vitamins and minerals that aren’t as easy to find in plants. The protein in these foods is also more readily available to the body.
Besides, acids, which are sour, have been shown to have some pretty interesting effects in the body. As it happens, studies have shown that sour foods and beverages, such as lemonade, shorten pharyngeal transit time (the time it takes you to swallow). If you have dysphagia – trouble swallowing, which is seen primarily in older adults and people with certain medical conditions – this is a pretty big deal, since sour foods have been shown to improve the ability to swallow safely (1, 2, 3).
Sour tastes also stimulate the salivary glands. For people with persistent dry mouth (which can be caused by a number of diseases and medications), a few drops of lemon in a glass of water can help get the salivary glands going. After all, without your daily 3 pints of saliva, swallowing, talking and chewing can become a chore.
Who ever said being a sourpuss was a bad thing?
For more information:

-- Les, MS RD LD

Thursday, May 16, 2013

Microwave, Friend or Foe?

Cooking is a pretty big deal. The rest of Kingdom Animalia doesn't do it. We stand alone. In fact, there’s even some speculation that the ability to cook food gave us a pretty phenomenal advantage as humans – cooking gets us better access to the nutrients of food, so we spend less time chewing through all the fibrous goodness of nuts, fruits, veggies and whatever else we can find, and more time thinking of things to do with our (now larger) brains. (1, 2, 3)
Of course, now we are using our brains an awful lot, for work, school and the ever-important daily errands, and less for cooking. So we find ourselves with frozen veggies that we can zap (or nuke, if you prefer) in the microwave rather than letting simmer over the stove or bake in the oven for hours on end. A hot meal is ready to go in just a few quick minutes, sending us whatever delicious nutrients it carries.
But there seems to be some debate (on the internet at least) about the safety of the microwave. Is it really safe? Does the magic zapping of your dinner damage nutritious goodness of the food? Does that food cause cancer if you eat it? Does the radiation leak out, causing problems for people nearby?
In a word – No. The microwaves are pretty tiny, and aren’t capable of travelling all that far. Plus, there’s that nifty screen on the inside of the microwave door that prevents them from leaking out. Microwaves work by shaking the molecules of water in the food around a bit, which causes friction, which releases energy as heat and then you have warm food. And as much as microwaves do for us, they are pretty weak. Too weak to penetrate (and damage) DNA, and surely weaker than UV rays, X-rays and gamma rays. There is no published, reliable data to support the idea that microwaving your food can cause cancer. Further, grilling or frying meats can cause the formation of some pretty nasty amines, but microwaving the meats first (like when you are defrosting) can cause the precursors to these amines to drain off with the juice. So in this case, microwaving is probably a better idea than not microwaving.
So it’s faster, it doesn’t cause cancer, and the nutrition value… just as good, maybe better. This is especially true for veggies, which have a load of water that is often lost in cooking. This water carries away water soluble vitamins, and can reduce the nutrient content of the food. Microwaving doesn’t do that! No water leeching means you can hang on to those vitamins, which is definitely a plus. One word of caution, however – Vitamin C is prone to destruction at high temperatures (around 25% loss), so be sure to include a balance of foods high in vitamin C that are not exposed to higher temperatures.
There is one big thing to watch out for with the microwave, however: your container. Be sure to always use a microwave-safe container when cooking your foods. The microwaves themselves don’t cause any damage, but many containers are not heat-safe and the materials may breakdown and leech into your food. So scrap the leftover to-go containers, plastic butter tubs and one-time-use frozen dinner trays, and heat your foods in a microwave-approved container instead.
Nutrients galore.
Everything I could ask for.
Lovely Microwave.
For more information:
For more information and to learn about the origins of these myths:
-- Les, MS RD LD