Tuesday, June 21, 2005

Human Nutrition


Essential Nutrients

Nutrients are classified into five major groups: proteins, carbohydrates, fats, vitamins, and minerals. These groups comprise between 45 and 50 substances that scientists have established, mostly through experiments with animals, as essential for maintaining normal growth and health. Besides water and oxygen, they include about eight amino acids from proteins, four fat-soluble and ten water-soluble vitamins, about ten minerals, and three electrolytes.
Although carbohydrates are needed for the body's energy, they are not considered absolutely essential, because protein can be converted for this purpose.


Energy

The body uses energy to carry on vital activities and to maintain itself at a constant temperature. By using a calorimeter, scientists have been able to establish the energy amounts of the body's fuels—carbohydrates, fats, and protein. About 4 calories each are yielded by 1 g (0.035 oz) of pure carbohydrate and 1 gram of pure protein; 1 gram of pure fat yields about 9 calories.
Carbohydrates are the most abundant foods in the world, and fats are the most concentrated and easily stored fuel. If the body exhausts its available carbohydrates and fats, it can use proteins directly from the diet or break down its own protein tissue to make fuel. Alcohol is also a source of energy and yields 7 calories per gram.
Alcohol cannot be oxidized by the body cells but must be processed by the liver into fat, which is then stored by the liver or in the adipose tissue.

Functions of Nutrients

Proteins
The primary function of protein is to build body tissue and to synthesize enzymes, some hormones such as insulin that regulate communication among organs and cells, and other complex substances that govern body processes. Animal and plant proteins are not used in the form in which they are ingested but are broken down by digestive enzymes (proteases) into nitrogen-containing amino acids. Proteases disrupt the peptide bonds by which the ingested amino acids are linked, so that they can be absorbed through the intestine into the blood and recombined into the particular tissue needed.
Proteins are usually readily available from both animal and plant sources. Of the 20 amino acids that make up protein, eight are considered essential—that is, because the body cannot synthesize them, they must be supplied ready-made in foods. If these essential amino acids are not all present at the same time and in specific proportions, the other amino acids, in whole or in part, cannot be used for metabolizing human protein. Therefore, a diet containing these essential amino acids is very important for sustaining growth and health. When any of the essential amino acids is lacking, the remaining ones are converted into energy-yielding compounds, and their nitrogen is excreted. When an excess of protein is eaten, which is often the case in countries with heavy meat diets, the extra protein is similarly broken down into energy-yielding compounds.
Many illnesses and infections lead to an increased loss of nitrogen from the body. This needs to be replaced by a higher consumption of dietary protein. Infants and young children also require more protein per kilogram of body weight.


Carbohydrates

Carbohydrates provide a great part of the energy in most human diets. Foods rich in carbohydrates are usually the most abundant and cheapest, when compared with foods high in protein and fat content. Carbohydrates are burned during metabolism to produce energy, liberating carbon dioxide and water. Humans also get energy less efficiently from fats and proteins in the diet.
The two kinds of carbohydrates are starches, which are found mainly in grains, legumes, and tubers, and sugars, which are found in plants and fruits. Carbohydrates are used by the cells in the form of glucose, the body's main fuel. After absorption from the small intestine, glucose is processed in the liver, which stores some as glycogen, a starchlike substance, and passes the rest into the bloodstream. In combination with fatty acids, glucose forms triglycerides, fat compounds that can easily be broken down into combustible ketones. Glucose and triglycerides are carried by the bloodstream to the muscles and organs to be oxidized, and excess quantities are stored as fat in the adipose and other tissues, to be retrieved and burned at times of low carbohydrate intake.
The carbohydrates containing the most nutrients are the complex carbohydrates, such as unrefined grains, tubers, vegetables, and fruit, which also provide protein, vitamins, minerals, and fats. A less beneficial source is foods made from refined sugar, such as confectionery and soft drinks, which are high in calories but low in nutrients and fill the body with what nutritionists call empty calories and it will be stored as fat!

Fats

Although scarcer than carbohydrates, fats produce more than twice as much energy. Being a compact fuel, fat is efficiently stored in the body for later use when carbohydrates are in short supply. Animals obviously need stored fat to tide them over dry or cold seasons, as do humans during times of scarce food supply.

In industrial nations, however, with food always available and with machines replacing human labour, the accumulation of body fat has become a serious health concern.


Dietary fats are broken down into fatty acids that pass into the blood to form the body's own triglycerides. The fatty acids that contain as many hydrogen atoms as possible on the carbon chain are called saturated fatty acids and are derived mostly from animal sources. Unsaturated fatty acids are those that have some of the hydrogen atoms missing; this group includes monounsaturated fatty acids, which have a single pair of hydrogens missing, and polyunsaturated fatty acids, which have more than one pair missing. Polyunsaturated fats are found mostly in seed oils. Saturated fats in the bloodstream have been found to raise the level of cholesterol, and polyunsaturated fat tends to lower it. Saturated fats are generally solid at room temperature; polyunsaturated fats are liquid. 1

1 ."Nutrition, Human," Microsoft® Encarta® 99 Encyclopedia. © 1993-1998 Microsoft Corporation.

Tour Durban Cycle Tour

And so it came to pass that the Tour Durban was done in (almost) perfect weather. We were charged up and ready. And the results speak out . . . read more below.
Also read about my son Christiaan's first ever cycle race . . .
Results for: Pieter Naude in Mr Price Tour Durban (24/04/2005)
Gender: Male
Club: Amanzimtoti Cycling Club
Age: 47
Start Time (Official): 6:08:39
Distance: 96 Km
Category: Vets 45-49
Batch: SACF Licenced Men 40+
Finish Information:
Finish Time (Net): 2:48:27
Avg. Speed (min/km): 1:45
Avg. Speed (km/h): 34.20
Race Positions:
Category (Gross): 64 out of 280
Gender (Gross): 618 out of 2027
Over All (Gross): 641 out of 2413
Category (Net): 65 out of 280
Gender (Net): 623 out of 2027
Over All (Net): 646 out of 2413

. . . and my son Christiaan did his first race. Started training about 3 weeks ago, no prior experience, still shaky and unsure on the bike, many training hours short for such a distance, and he did . . . ta-da . . . wait for it . . . 3 hours 55 minutes!!!

Well done my son. You will keep me in training because otherwise I will get my behind kicked by junior!!

Sunday, April 03, 2005

Been there done that . .

We are back in town, in cyberspace and in your face. Done the Argus, got the T-shirt and spent 10 lovely days in the Cape.

Didn't fall, didn't get blown away, didn't get mechanical trouble or punctures,didn't spare myself and did a respectable 3 hours 23 minutes in winds of up to 40km/h! We had to actually pedal HARD DOWN Chapman's Peak into Houtbay! Unheard of! One should be screaming down there at over 70, not push like hell to get 30!?!

Nevertheless; good race, excellent organization, always an honour to particpate and finish, always a pleasure doing business with the S'Easter!

Spent time in Cape Town, spent some money in Cape Town. Some days wonder if the emphasis on international tourism is not killing the local holiday-maker's (financial) fun. Maybe it's just me? Maybe I lost track of prices . . .

Went to Stormsriver Mouth - SA National Parks Board - Tsitsikamma National Park. Fantastic. One word: Fantastic. Been there before but I was amazed and totally overwhelmed by the quality of the service, the friendliness, the neatness, the hospitality. Then we went to the on-site restaurant and that totally bowled me over; world-class cuisine at affordable prices - with a setting like that one can easily expect to pay through your neck but not here! Congratulations SANparks. You've done us proud. I am NOT getting paid to say this but every reader of this log should make a plan to go there. At least once. It is worth every penny and is food for the soul.

We will be back next year to do it all again. For the love of the sport, the love of the Cape province, for no reason other than just to be there.

Tuesday, March 08, 2005

Argus Cycle Tour

As we will be traveling from Southern KZN to Cape Town for the annual Argus Cycle Tour there will be little if any postings here as I only have room for my beloved bicycle and not for my PC.
We are doing a little extended tour after Race Sunday and I cannot wait to show Renette what the Garden Route is all about. (Going to visit my brother Philip in Knysna).

Surely I also cannot wait to do some cycling in those lovely mountains!

All in all we will be back arround the 24th of March and I might just have a couple of things to report back on (I hope).


Wish me luck and if you are a fellow cyclist, "no chain!"

Greetings from the saddle,

Pieter

Sunday, February 27, 2005

Runners / Cyclists / Walkers : Pay Attention!

The risks of severe renal damage caused by endurance events

Although today’s ultra marathon runners and endurance cycling event participants are very well informed on issues such as training methodology, dietary requirements, hydration, footwear and all the vital do’s and don’ts that a variety of experts have experienced or researched, there are sports people who risk their very lives during endurance events such as the Comrades Ultra Marathon, the Argus cycling tour.
One can have all this information at hand and still end up with serious medical problems after the race.
Why?
Mainly because there are so many variables on race-day that might affect a healthy and well trained athlete such as temperature, humidity, the rate of wind movement across the body, the electrolyte balance in the body, individual susceptibility to various conditions etc.


The main problems related to kidney function during and after a race of this magnitude are:

Bloody urine (haematuria) after excercise

Acute Kidney Failure

Kidney stones

1. Bloody urine is quite common and is often due to repeated impact of the walls of the bladder against each other with subsequent bruising and bleeding. This causes bleeding in the bladder which is evident as the athlete passes urine after the race. This condition should clear within 72 hours as the wall of the bladder is repaired. This can effectively be prevented by trying not to empty the bladder completely just before and also during the race. The half-filled bladder is less likely to get as traumatised as a completely empty one. Although this is a self limiting condition, care must be taken and medical help should be obtained to exclude other, more serious reasons for haematuria. Bleeding in the bladder for periods longer than 48 to 72 hours must be considered as potentially serious and action must be taken.

2. Acute kidney failure is a serious condition and should be treated as such. Although not an uncommon complication of Heatstroke and Dehydration, in a lot of cases endurance athletes developed kidney failure without these predisposing conditions.
Reasons are unclear but seem to indicate that certain individuals might have a specific musculoskeletal defect that causes excessive breakdown of muscle tissues during prolonged exercise, with a resulting leakage of a substance called myoglobin into the blood circulation. This substance ultimately arrives in the kidneys and is filtered but acts as a toxin or poison to the kidneys, causing failure.
This is a variable that is unknown until it happens.
Other reasons for kidney failure on this basis of toxins being filtered are the use of anti-inflammatory drugs or pain killers before and during the race. Popular items are Indomethacin, Ibuprofen, Diclofenac, Aspirin, Naproxen. Athletes take these to prevent pain and reduce inflammation, thus shortening the recovery period. These agents are best left in the medicine cupboard and should not be taken as there is little evidence that they are effective for this application and the risks far outweigh the advantage.

What are the symptoms of acute kidney failure? The first and most obvious one is the inability to pass any significant urine during the first 24 hours after the race. This should immediately trigger the alarm bells and the athlete should seek immediate medical help – preferably a hospital with a renal care unit where dialysis can be, and probably will be performed. Missing this important first sign will cause the person to feel really ill after 36 to 48 hours with severe headaches and nausea. The headache is due to a steep rise in blood pressure as well as the increase in metabolic end-products not being removed from the system. At this stage the failure is well established and will need repeated renal dialysis until the kidneys recover.

Prevention:

Avoid heat stroke

Drink 100 -125ml fluid every 10 to 15 minutes as well as 400 to 500ml before the race.

Sponge frequently and adequately

Do not overestimate your ability, especially near the end of the race (60km and more)

Do not ignore warning signs (weakness, stumbling, headache, nausea, dizziness, apathy)

Abstain from taking anti-inflammatory drugs

Have a test done to determine the general condition of the kidneys well before the race.

Common urine dip tests can exclude kidney infection, certain metabolic disorders.

GFR test (Glomerular Filtration Rate) can determine the rate at which the kidneys filtrate and secrete metabolic waste. This test is available at some pharmacies and also at most pathology labs.

3. There is an abnormally high incidence, about five times normal, of kidney stones among male runners. It must be added that runners most likely to develop stones are those that have been running for the longest time, running the longest distances during training and who are the fastest runners.
Here the message is quite clear:
Always avoid dehydration.
Repeated dehydration can lead to the formation of kidney stones.
Drink optimal volumes of fluid during, but also immediately after the race, especially in hot and humid climates.

Brought to you by Uvongo Pharmacy where we are "Hooked on Health" and where fitness is a way of life.

We accept that sometimes, failing is inevitable.
Failing to try is not an option!

Friday, February 25, 2005

Prostate trouble

Between us men: Prostate trouble?

If you can answer yes to one or more of the following questions, chances are that you are suffering from BPH (Benign Prostate Hypertrophy) or enlargement of the prostate in the absence of malignancy.

1. Abnormally low volume of urine voided each time?
2. Feeling that bladder is not completely empty after urination?
3. Dribbling after urination?
4. Have to get up often during the night to urinate?
5. Do you feel the urge to urinate within two hours after previous urination?
6. Any discomfort and / or urgency when you feel the need to pass water?
7. Is voiding done in “stages”?

Some “comforting” news: About 70% of men will suffer from these symptoms during the average lifetime. It is quite common in men over 45 years and sometimes even much earlier.

Prostate? What/why/where/how?

It is a gland within the male urogenital system with the function of secretion. It is controlled and developed by the male hormones, especially Testosterone. It secretes a substance that contributes to the formation of seminal fluid which enhances the mobility and fertility of spermatozoa. It also prevents this fluid from running into the bladder and redirects it towards the penis. Starting at (normally) the age 40, due to a decrease in Testosterone and a shift in the normal hormonal balance, (all part of the natural phenomenon associated with aging), the prostate becomes enlarged causing a narrowing of the urethra (tube which carries urine from the bladder to the outside). This is what causes difficult urination.

Prostate hypertrophy (enlargement) almost always starts off as a benign condition. It may unfortunately be a much more serious condition than anticipated. It is not something to ignore. The sooner you recognize and talk about this “natural” problem, the sooner you can get a proper diagnosis done by your doctor, hopefully eliminating the more serious forms and consequences of prostate hypertrophy. BPH presents itself in stages:
Early detection during phase I can still be treated and controlled without expensive medicine or surgery.
During phase II proper diagnosis is essential and prescription medicine might be prescribed.
Phase III is much more serious and ultimately might need surgical intervention by a specialist.

How do we avoid stage III?
Early detection and treatment is the answer.
Regular check-ups from the age of 40.
Never ignore the symptoms.
Accept the fact that it is a very real and common problem which can be diagnosed, treated and sometimes prevented.

Advice for a healthier prostate:
A healthy lifestyle, exercise, cutting back on alcohol & tobacco & coffee, low-fat high fibre diet, adequate intake of minerals and vitamins and yearly examinations all form a good base.
The Natural Remedies department at Uvongo Pharmacy strongly suggests the intake of a natural substance called Saw Palmetto, a herbal extract derived from the Serenoa repens plant. This herb, taken regularly can relieve the symptoms and halt the progress of prostate conditions during phase I. This in itself can prevent or delay treatment with harsh chemicals and/or surgical intervention.

Still scared or shy or ignorant? Then you did not read this with complete honesty and it is suggested that you read it again or phone us at 0393150040 to discuss your health and your safety.