25 October 2012

Digestion, or what happens when we eat?

Digestion is the mechanical and chemical breakdown of food into smaller components that are more easily absorbed by the body through the blood stream, for instance. Digestion is a breakdown of large food particles to smaller ones.

When food enters the mouth, its digestion starts by the action of chewing, a form of mechanical digestion, and the contact of saliva (spit). Saliva, which is secreted by the salivary glads, contains salivary amylase, an enzyme which starts the digestion of starch in the food. After undergoing chewing and starch digestion, the food will now be in the form of a small, round mass, called a bolus (It will then travel down the esophagus, a tube which leads from the mouth and into the stomach). Gastric juice, which is very acidic, in the stomach starts protein digestion. Gastric juice mainly contains hydrochloric acid and another enzyme called pepsin. As these two chemicals may damage the stomach wall, mucus is secreted by the stomach, providing a slimy layer that acts as a shield against the damaging effects of the chemicals. At the same time protein digestion is occurring, mechanical mixing occurs by waves of muscular contractions that move along the stomach wall. This allows the mass of food to further mix with the digestive enzymes. After some time (typically an hour or two in humans, 4–6 hours in dogs, somewhat shorter duration in house cats), the resulting thick liquid is called chyme. When the a valve in the bottom of the stomach opens, chyme enters the duodenum (the upper reaches of the small intestine) where it mixes with digestive enzymes from the pancreas, and then passes through the rest of the small intestine, in which digestion continues. When the chyme is fully digested, it is absorbed into the blood. 95% of absorption of nutrients occurs in the small intestine. Water and minerals are reabsorbed back into the blood in the colon (large intestine). Some vitamins, such as some B vitamins and vitamin K produced by bacteria in the colon are also absorbed into the blood in the colon. Waste material is eliminated during defecation.

When a proper diet and enough water is consumed, this process proceeds very naturally. If not enough water or fiber is consumed, problems may occur. That, however, is a topic for another day.

07 April 2011

To Your Health

Today, April 7, has been designated World Health Day in honor of the establishment of the World Health Organization (WHO) in 1948. It is seen as an opportunity to draw attention to major health concerns world wide at this time each year. International, national and local events are sponsored by WHO related to a particular theme. This year, the theme is Antimicrobial Resistance and it's global spread.

What does this mean to you? Most of us live longer and healthier lives today in part because of antimicrobials, those drugs that, as a last resort, are used to kill off infections that are causing infectious diseases. Until their discovery in the 1940's, people died from these diseases on an alarmingly frequent basis. Today, most of us cannot imagine living in a world without antimicrobials such as antibiotics.

We are now on the edge of losing this precious arsenal. The use and mis-use of these medicines over the past 70 years in both medicine and animal husbandry has caused the rise of antimicrobial resistant microorganisms. Perhaps the most well known of the resistant strains is MRSA (Methicillin-resistant Staphyloccocus Aureus). These microorganisms have caused death, suffering, disability and high health care costs.

Global travel allows these organisms to travel within hours. Unchecked, we could potentially lose our ultimate line of defense against our tiniest enemies.

How did this happen? Antimicrobial resistance – also knownas drug resistance – happens when microorganisms like bacteria, viruses, fungi and parasites change in ways that make the medications used to cure the infections they cause useless. When the microorganisms become resistant to most antimicrobials they are often referred to as “superbugs”. This is a major concern because a resistant infection may kill and can spread to others.

Antimicrobial resistance is often caused by the improper use of medicines, for example, when taking too low a dose or not finishing a prescribed course of treatment. Low-quality medicines, wrong prescriptions and poor infection control (not checking back with the doctor if you're still sick) also encourage the development and spread of drug resistance. Lack of government commitment to address
these issues, poor professional surveillance and a diminishing arsenal of tools to diagnose, treat and prevent microbial infections also contribute.

Drug companies hesitate to put large sums of money into researching new antimicrobial agents and no new class of drugs has been discovered in decades. So, what are we to do? 1) ALWAYS take ALL of the prescribed drug, as written; 2) follow up with your doctor to be sure your infection is gone, as directed; 3) do not encourage prophilactic (daily) use of antibiotics for frivilous reasons (e.g., farm animals); 4) stay informed, get involved, and remember... "no action today, no cure tomorrow" (WHO, 2011).

If you have any comments or questions, please feel free...


Dr. P.

02 April 2011

Cholesterol; a complicated chemical

Cholesterol is an often misunderstood nutrient. It is required by  your body for building cell membranes, nerve conduction, hormone and vitamin production and numerous other tasks. It is so important that your body makes it in various organs, primarily the liver (20 - 25%). It is generally considered to be in the fat family, because it has a fatty lipid tail hanging off one side, chemically speaking, and so we shall consider it a fat as well for simplicity's sake.

The amount of cholesterol in your body is balanced by the amount you take in through the foods you eat and how much your body produces. The more you eat, the less your body produces. Foods that contain cholesterol include all animal products, especially cheese, egg yolks, beef, poultry, pork and shrimp. How much you produce is mostly genetic.

The amount of cholesterol circulating in your body is a good indication of whether or not you have too much in your system. This is measured using LDL (low density lipoproteins) and HDL (high density lipoproteins). These have been nick-named "bad fat" and "good fat" respectively, not because of how much cholesterol is in them (they contain the same amount) but because of the size and quantity of each of the molecules. LDL is a small molecule that is easily caught in small nicks and tears in arteries, then sticks to itself building up dikes that eventually block those arteries and raise your blood pressure, or cause heart attacks and strokes. HDL is a much larger molecule. It doesn't fit into those little tears, but it also sticks to LDL particles and can scrape them off the sides of your arteries and actually reduce the build up of those dikes, even to the point of near elimination. That's why doctors like high HDL and low LDL numbers on your lab test results.

So, what if you wanted to lower your blood cholesterol with diet and exercise before trying medication? There are actually a few foods that are recognized as good tools for lowering cholesterol before medication is necessary.

First, you need to be Vitamin B sufficient to properly metabolize cholesterol. If you aren't getting enough of this group of vitamins, your cholesterol will tend to be high. Make sure you have plenty of Vitamin B Complex in your diet.

Second, Vitamin C is needed to utilize cholesterol. Vitamin C doesn't last very long in the body, nor in most of the products we buy. It's best to get things as fresh as possible since this vitamin starts breaking down from the moment the fruit or vegetable it produces is picked. Also, if your Vit. C supplement is old or has been exposed to air or moisture, it's probably not the potency you think it is; make sure to get plenty of this vitamin in your diet.

Other things recognized for their effectiveness in lowering cholesterol are garlic, soy, fiber, chromium, grape seed extract and pantothine. And, of course, lots of whole grains and fresh fruits and veg!

It's also really important to avoid "trans" fats. These fats do not occur in nature, but do occur in margarine and shortening, and in lots of snack foods. These products encourage LDL production in your system. It may seem counter-intuitive to use butter instead, but our family mixes one stick of butter with 1/2 cup of canola oil, making our own "spread" which is buttery and delightful and contains no trans fats, and also is much less expensive than "light" butter or buttery spreads from the market.

I hope this has helped you to better understand this truly complex chemical. As always, if you have any questions, please feel free to ask.


Dr. P

24 March 2011

The Keys that Unlock The Doors

Enzymes are specialized proteins that help with digestion of the foods that we eat. While we will not even try to address all of the types of proteins that our bodies use, this class of proteins help to lead us into the topic of digestion and diet that we will talk about later.

The first enzymes that your body produces are in your mouth. This enzyme, called amylase, helps in the digestion of carbohydrates. It is important to chew your food well so that the saliva and amylase in your mouth can mix well with the food that you eat to begin the digestion process. People who eat too quickly send incompletely digested food to other carbohydrate digesting enzymes lower in the digestive tract, leading to gas and discomfort after meals.

Enzymes tend to be specific for the type of food they are meant to digest (break down). They work much like a lock-and-key mechanism, where a certain type of food (protein, fat or carbohydrate) is shaped a certain way, and the enzyme has a complimentary shape on it. This catalyzes (speeds up) a chemical reaction in your body, allowing you to extract the energy from the food you eat and use the bits of the broken down food to build the body parts you need.

Different enzymes play different roles throughout your digestive tract. Some are in the stomach, where much of the protein is digested. Some are in the small intestine, where much of the fat is digested. In your large intestine, where water is re-absorbed, there are happy little friendly micro gardens who help to break down the complex carbohydrates that are not already digested, like those often found in beans and cabbage.

Most people have a complete compliment of all the enzymes they need to provide everything they require to be healthy (note the exception of essential fatty acids and essential amino acids). However, some people are missing certain enzymes, either by inheritance or by chance genetic mutation. These people must be put on special diets to avoid certain foods (or include certain foods) to be healthy. This shows how critical enzymes are to our every day health.

Another group of people who must be on special diets due to altered enzymes are those who have had surgery to some part of their digestive tract. Anyone who has had bariatric surgery knows that certain vitamins must be injected after surgery because they can no longer be extracted from their food through digestion.

Enzyme production increases in your body naturally when you are hungry, or when you smell something good, or around your normal eating time, or when something that normally stimulates you to eat happens (remember Pavlov's dogs?). Start eating, and enzyme production steps up as your body detects what sort of food you're eating. Drink too much while you're eating, and you will dilute the enzymes in your system and interfere with digestion; some people advise not to drink while you're eating. I say, drink in moderation and try to stay naturally hydrated (and don't eat bad cooking).

If you eat a balanced diet, and you have no genetic reason not to, your body will produce all the enzymes you need to stay healthy and give your body everything it needs.

As always, should you have any questions, please ask.


Dr. P.

21 March 2011

Affordable Health Care May be In Our Lifetime