Archive for July 21st, 2005
Gluten intolerance also goes by the name of coeliac disease. There are various definitions of what gluten intolerance is, but the average definition describes it as a malabsorption syndrome precipitated by the ingestion of the gluten protein found in wheat products, known as “gliadin”.
There are two peak incidences of the disease - one in infants between six months and two years of age, and the other in adults between the ages of 30-50 years. Also, women tend to be more prone.
It is characterised by the flattening of the villi (thread-like projections responsible for absorption of fluids and nutrients) in the small intestine, which severely reduces the area available for nutrient absorption, resulting in potential or actual malabsorption of virtually all nutrients. The cells of the villi become deficient in digestive enzymes which leads to maldigestion. The mechanism by which gliadin damages the small bowel is not known, but it has been found to have genetic, immune and environmental components. The amount of small intestine that is affected can vary from person to person, but usually the upper bowel is most affected.
There are many symptoms of gluten intolerance and therefore no one symptom can be regarded as characteristic of the disease. Lack of energy, malaise or weakness are the most common symptoms, while others include diarrhoea, fat malabsorption (steatorrhoea), growth failure in children, bloated abdomen and vomiting.
Dietary Management
Since it has been shown that the gliadin fraction of gluten causes the problems, its complete withdrawal from the diet is needed, which normally results in prompt improvement. In fact, 50-60% of sufferers have few or no symptoms following a strict dietary regimen. Initially, the afflicted person may have malabsorption, therefore vitamin and mineral supplements and possibly even extra protein may be required.
Lactose intolerance sometimes appears secondary to gluten intolerance, however, once the bowel begins to heal after gliadin is omitted, lactase (enzyme that breaks down lactose) usually returns to normal levels and the lactose intolerance disappears.
The gluten-free diet excludes wheat, rye, barley, and oats, with wheat having the highest gluten content and oats the lowest. Thus oats may be tolerated in moderate amounts by some people, since it contains very little gliadin. Suitable substitutes for these foods include rice, potato, corn, tapioca, chickpea, soya, arrowroot and gluten-free flour. If these are not available at local supermarkets, then inquire at your local health shop.
Menu Adaptations
* A guarantee of a gliadin-free diet requires careful inspection of the labels of all bakery products and packaged foods. Gliadin-containing grains are used not only as a basic ingredient, but may also be added during processing or preparation. It is important to read food labels carefully since often gluten-containing products are used but are labelled with alternative names, such as:
o “Hydrolysed vegetable protein” can be made from wheat, soy, corn or a mixture of all three.
o “Flour” or “cereal products” and “vegetable products” may be made from wheat, rye, oats or barley.
o “Malt” or “malt flavouring” can be made from barley.
o “Modified food starch” may be made from wheat.
o “Vegetable gum” is made from oat gum.
o “Soy sauce” may contain wheat.
Other words to look out for are: emulsifiers, stabilisers, thickeners and hydrolysed starch.
* Additional hidden sources include beer; cereal beverages (e.g. Ovaltine, Milo); commercially prepared cakes and biscuits; ice-cream; processed soups; frozen foods with sauces; some cereals; crackers; most crisps; processed cheese; canned and processed meats and candy bars (unless pure chocolate)
* If you are wondering about good thickening flours for gravies and sauces, then arrowroot, tapioca and corn starch are suitable options. Furthermore, the best agents for combination with eggs and milk in a baked product are corn, potato, rice or soya flour.
* Some gluten-free foods and beverages include tea; coffee; rum; wine; jelly babies; chocolate; fresh fruit and vegetables; fresh fish, meat or poultry; eggs; rice; potatoes; rice cakes; peanut butter; popcorn; jam; honey and sugar.
* If gliadin is reintroduced into the diet, symptoms may occur within a few hours or even up to eight weeks later. People who go off and on the diet may become tolerant to it, with the result that it no longer has any effect. Note that gliadin must be avoided for life!
July 21st, 2005
If you are breast-feeding, you should be applauded since breast milk is the best form of nutrition for your baby, being superior to any alternative. It is always fresh and contains a variety of anti-infectious factors and immune cells. Also, it is the least allergenic of any infant food and automatically encourages close mother-child contact. But what must you eat and what kind of diet should you be following while trying to provide optimal nutrition for your child?
What should you eat? The process of lactation is nutritionally demanding and therefore a nutritious diet is very important. The recommended calorie increase is for an extra 500kcal per day above the levels for non-pregnant women. Maternal fat stores accumulated during pregnancy provide about 100 to 150 kcal per day during the early months of lactation — that is good news — you probably also want to shed those extra kilos.
The more often you breast-feed, the more milk your body will produce and the more energy you will expend — and the quicker you will lose the weight. But, be careful; this is not the time for strict weight-loss diets or crash diets during lactation — this can lead to decreased production of milk each day. Once lactation is well established, a moderate reduction in calorie intake (to increase the rate of fat utilisation) can usually be initiated without any detrimental effects.
A healthy, sensible eating and exercise programme should be your primary focus. The trick is to eat everything in moderation. Try to eat three or six meals a day. In other words, either three larger, fully satisfying meals, or six smaller meals throughout the day. Skipping a meal can result in low blood sugar level, which can cause you to overeat later or at the following meal. If this happens, often you get desperate and eat whatever you can lay your hands on — fatty foods like pastries, biscuits and chocolate which is not going to do much for the waistline.
Breads, cereals and grain products It is best to follow a high-carbohydrate, low-fat diet — as recommended by the Food Guide Pyramid. Breads, cereals and grain products like pasta and rice contain mostly carbohydrate and provide the body with energy and are easily burned up by the body. Luckily, carbohydrate foods also make wonderful comfort foods and lead to a calming effect on the brain, as the sleep-inducing hormone serotonin is released after eating carbohydrates that transmits calmness and mood stability to your brain cells.
Unfortunately, carbohydrates — especially bread — have been labelled fattening. Remember, it is not the carbohydrates that are fattening, but what you choose to put on it such as the butter, avocado, full fat cheeses, peanut butter, cold meats, cream sauce etc. In addition, the high fibre content of unrefined carbohydrates means that they help promote satiety, regulate our digestive process and help control our blood sugar levels — all useful in weight control.
Fruits and VegetablesEat lots of fruit and vegetables — the goal is to eat at least five servings of fruit and vegetables a day. They are a rich source of vitamins and minerals and are therefore termed our “protective” foods as they help the body fight off sickness and disease.
An added benefit is that they are relatively low in calories and also contribute to our daily fibre intake. Fruits are quick and easy to eat as snacks during the day, as are vegetables at meal times or as snacks. Just be cautious of “windy” foods such as dried fruit, green leafy vegetables like lettuce and spinach, onions, peas, cabbage, cauliflower and Brussels sprouts, which could upset your baby’s tummy and cause colic-like symptoms.
Milk and Dairy Products It’s recommended that pregnant and lactating women have a calcium intake of 1 200mg per day. Do this by including at least four to five portions of the following foods in you daily diet:
* 1 glass skim or 2% milk
* 1 fat-free or low-fat yoghurt (175ml)
* 30g reduced fat cheese
* ½ cup ricotta cheese
* 80g sardines
* ½ cup low-fat custard
As you can see, “low-fat” or %E
July 21st, 2005
Question:
Could you please send me some information about iron deficiency in pregnancy and how it can be treated and prevented?
Answer:
Possible causes of iron deficiency anaemia are:
# Inadequate iron intake due to a poor diet.
# Inadequate absorption of iron due to diarrhoea, intestinal disease, or interference by drugs such as antacids, cholestryramine, Tagamet, Zantac and tetracycline.
# Inadequate iron utilisation due to chronic gastro-intestinal disturbances.
# Increased iron requirements, which occur during infancy, adolescence, pregnancy and lactation.
# Increased excretion of iron because of excessive menstrual blood in females, haemorrhage from injury, chronic blood loss from a bleeding ulcer, bleeding haemorrhoids, oesophageal varices, ulcerative colitis, parasites and malignancy.
A marked increase in the maternal blood supply during pregnancy greatly increases the demand for iron. In total, the pregnant woman must have between 700 and 800mg of extra iron, most of which is needed during the last half of pregnancy, when the heaviest maternal and foetal demands occur.
Averaged over the entire pregnancy, this amounts to a daily increment of 15mg of iron. Adding this amount to the 15mg per day recommendation for non-pregnant women, brings the 1989 RDA for iron during pregnancy to a total of 30mg per day. Liver, kidney, beef, egg yolk, dried fruits, dried peas and beans, nuts, peanut butter, green leafy vegetables, molasses, wholegrain breads and fortified cereals are the best sources of iron. In most cases, women need to be supplemented, since it is difficult to meet the RDA through diet alone.
In fact, it has been recommended that all pregnant women with a well-balanced diet should take 30mg of ferrous iron supplement daily during the second and third trimesters. Further, for optimal absorption, the iron supplement should ideally be taken between meals and not with milk, tea or coffee.
Treatment Medication — the main treatment for iron-deficiency anaemia consists of oral administration of inorganic iron. Iron is best absorbed when the stomach is empty, however under these conditions it tends to cause gastric irritation.
Gastro-intestinal side effects of nausea, epigastric discomfort and distension, heartburn, diarrhoea and constipation can be minimised by increasing the dose slowly over a few days until the required amount is reached. In addition, iron should be given in at least three doses per day. Since side effects are dose-related, smaller dosages with a longer therapeutic programme have been suggested.
Diet Therapy — In addition to medication, attention should be given to the amount of absorbable iron in food. Liver, kidney, beef, egg yolk, dried fruits, dried peas and beans, nuts, peanut butter, green leafy vegetables, molasses, wholegrain breads and fortified cereals are the best sources of iron.
The bioavailability of iron in the diet is more important than the total dietary iron in correcting or preventing iron deficiency.
Nutritional factors enhancing iron absorption:
# The lower the iron stores in our bodies, the greater will be the rate of iron absorption.
# Heam-iron present in meat, fish and poultry (MFP) is much better absorbed than is non-heam iron, which is mainly present in eggs, grains, vegetables and fruits.
# MFP factors which are products of digestion of meat, fish and poultry increase the absorption of iron.
# Vitamin C and acidic foods (namely fruit) increase iron absorption.
Nutritional factors that decrease iron absorption:
# Carbonates, oxalates, phosphates and phytates (found in unleavened bread, unrefined cereals and soya beans) bind iron rendering it inabsorbable.
# Vegetable fibre inhibits non-heam iron absorption.
# Taken with meals, tea can reduce iron absorption by 50% through the formation of insoluble compounds with tannins found in the tea.
# EDTA (ethylenediaminetetra-acetic acid), a food preservative, causes a 50% reduction in non-heam iron absorption.
# Iron in egg yolk is poorly absorbed because of the presence of phosvitin. Also milk proteins and albumin reduce iron absorption.
Summary:
# Improve food choices to increase total dietary iron.
# Include meat, fish or poultry at every meal if possible.
# Include a source of Vitamin C at every meal. Examples include tomatoes, broccoli, Brussels sprouts, guavas, paw paw, pineapple and citrus fruits.
# Avoid drinking large amounts of tea with meals.
# Avoid high quantities of the preservative EDTA by checking food labels.
July 21st, 2005
Whether you are currently healthy and want to remain so, or are not-so-healthy and want to be, here are some guidelines to help get you there.
Ensure Adequate Energy (or Calorie) Intake
Energy requirements depend on sex, age and energy expenditure. Enough energy should be provided from a variety of foods to ensure the maintenance of a desirable body weight. In children and adolescents enough energy should be provided for growth and development.
Limit Fat and Cholesterol Intake
Whether from plants or animals, fat is a very concentrated source of calories. It is common for South Africans to consume 40-50% of their total energy intake in the form of fat, with usually more than 50% of these fats being saturated (animal fats).
To be healthy, this need to be less than 30% of total daily energy intake. You should also divide this 30% equally between the three different types of fats i.e. around 10% for saturated, monounsaturated and polyunsaturated fats each.
Saturated fats are generally animal fats and are found in meat, full cream dairy products, shortening, coconut and palm kernel oil.
Mono-unsaturated fats are found in olive oil, canola oil, avocado pears and nuts such as almonds, pecans, hazelnuts and peanuts and soft-type tub margarines, e.g. olive oil- or canola oil-based margarines.
Polyunsaturated fats are found in some vegetable oils like sunflower and corn oil, soft margarines, oily fish and flaxseed oil.
There is a fourth type of fat known as trans fatty acids. These are regarded as saturated fats and should be restricted. Foods typically high in trans fatty acids are hydrogenated vegetable fats, e.g. some brick margarines, and foods prepared with these hydrogenated vegetable oils.
Reduce your daily intake of dietary cholesterol to less than 300 mg. All animal foods contain dietary cholesterol and contribute to the cholesterol intake. Eggs, organ meats and shellfish are the richest sources.
Increase Intake of Complex Carbohydrates and Fibre
You should take in 55-60% of total energy per day as carbohydrates from a variety of sources, e.g. grains, cereals, fruit and vegetables. Sugar forms part of total carbohydrate intake and should be restricted to 10% of total energy - use in moderation!
Dietary fibre passes almost intact through your digestive system. It may help you to avoid constipation, stay healthy and prevent certain lifestyle diseases.
There are two types of fibre: water soluble and water insoluble fibre. Water soluble fibre is found in oats, barley, seeds, legumes and some fruit. Water insoluble fibre is found in roughage foods, such as wholewheat products, brown rice, and in the outer parts of seeds and fruit skins, husks and peels.
Most Western people eat only 10 to 15 grams of fibre per day, but a healthy diet should contain a daily intake of between 25 and 35g fibre per day. When fibre is added to the diet its intake should be increased gradually and accompanied by adequate fluid intake.
Moderate Protein Intake
A protein intake of approximately 15% - 20% of energy is recommended. This should come from animal as well as vegetable sources. The daily requirement for protein is relatively low and easily met by a varied and mixed diet.
Beef, mutton and pork contain a fair amount of saturated fat and cholesterol and should therefore be eaten in moderation. Chicken without the skin contain less fat and can be eaten more frequently - the same goes for fish.
Dry legumes, for example dried beans, peas, lentils and soya are also good protein sources. Furthermore legumes are high in fibre and low in fat. Nuts, although a good protein source should be used in moderation because of their high fat content.
Limit Sodium
In the body, sodium regulates fluid balance and affects blood pressure. High salt intake is associated with higher blood pressure in some people. A sodium intake of 3g sodium (5g salt) per day is recommended. Foods high in salt and those containing flavouring salts should be limited in the diet. Remember - most processed foods contain sodium.
Eat a Variety of Foods
No single food can provide all the nutrients you need. A varied diet increases the likelihood you’ll get all of the required nutrients. Variety also allows you to balance a few higher-fat, higher-calorie items with more lower-fat, lower-calorie ones. As a result, you are more likely to eat less fat and fewer calories.
Grains, vegetables and fruits should form the foundation for your diet because they provide excellent sources of vitamins, minerals, antioxidant, dietary fibre and other substances that are important for lowering the risks of many chronic diseases.
Use Alcohol in Moderation
You don’t have to drink! These guidelines are for those who do - not to encourage you to start!
One to two alcoholic drinks per day are allowed - don’t accumulate this for the weekend. This constitutes binge drinking which is harmful in itself.
Pregnant and lactating women should not drink alcohol at all. It is also not a good idea for people with a family history of alcoholism, high triglycerides, pancreatitis, liver disease, heart failure or uncontrolled hypertension, and for those on medication that interacts with alcohol. Also, since alcohol is high in calories, people with a weight problem should restrict alcohol intake.
One alcoholic drink is defined as the equivalent of one beer (340 ml); 120ml wine; 25 ml of brandy, whisky, other spirits and liqueur. The current guidelines define moderate consumption as no more than one drink per day for non-pregnant women and no more than two drinks per day for men.
So how can we interpret this into actual eating?
Easy, following the Food Guide Pyramid and Nutrition Facts Labels on food packages, show you how to turn the guidelines of 50% carbohydrate, 20% protein and 30% fat into healthy food choices. So go ahead and start eating healthily, the benefits are enormous. And don’t forget to exercise as well!
July 21st, 2005
Coffee, tea, coke, energy drinks and chocolate — all contain caffeine, a naturally occurring alkaloid found in something like a hundred plants that stimulates the nervous system.
Caffeine acts to increase the level of circulating fatty acids and can even be an effective mood moderator, says dietician Cindy Chin. And it’s effective in heightening alertness and mental performance.
Sportsmen looking to boost their performance may also benefit, says Chin — although large doses are banned in some competitive sports.
However, the negative effects far outweigh the benefits. “Caffeine increases restlessness, anxiety and heart rate, and you become more on edge.”
Nicus (Nutritional Information Centre) dietician and manager Irene Labuschagne says caffeine is addictive. “Too much caffeine may cause tremors, sweating, palpitations, rapid breathing and sleeplessness and may also induce migraine attacks in some people. Sudden withdrawal should be avoided, since this can cause severe headaches, irritability and lethargy.”
Professor Karen Charlton, Head of Nutrition and Dietetics at the University of Cape Town, suggests a simple way to check if you are a caffeine addict or not.
“One way to tell if someone ‘needs’ that cup of coffee or bottle of Coke is to take it away from them for a day or two and then see if any of the unpleasant side-effects occur,” she says.
But despite this, it has never been linked to the onset of heart attacks or cancer, although it would still be an idea to limit your intake of caffeine should you experience heart irregularities.
Death from coffee is practically impossible as the lethal dose hangs in the region of 10g. “This is the same as drinking 80 to 100 cups of coffee in rapid succession — not an easy thing to do,” says Charlton. The onset of vomiting, however, is likely to detract anyone from actually dying from coffee.
Still need the boost — what do you try?
# Cut down
“All things considered it seems most sensible to limit caffeine consumption to the equivalent of one cup of brewed or two cups of instant coffee per day,” recommends Labuschagne.
# Switch to decaffeinated
Struggle going to sleep? Try cutting out coffee or switching to decaf, which contains around 35 times less caffeine than ordinary filter coffee.
# DMAE (dimethylaminoethanol) a naturally occurring so-called smart drug produced in tablet and liquid form and commonly found in fish may be your answer. Those who have taken it have reported that they’ve felt more alert, productive and energetic and are even able to reduce their hours of sleep. Though not a registered drug, DMAE can be found in health shops.
# Ginseng
According to Gerard Kerschbaumer of herbal remedy suppliers Flora Force, Siberian Ginseng, which dates back 2000 years, helps combat stress and revitalises you without the letdown that comes with caffeinated products. However, he says Ginseng is not recommended for those with high blood pressure.
Chin on the other hand is sceptical when it comes to herbal alternatives for caffeine. “From a down the line medical perspective there is still no clarity due to lack of adequate monitoring for safety and efficacy. Each could have very different concentrations, even undeclared ingredients, and because one is more expensive than the other doesn’t make them necessarily better.”
What about Guarana?
Professor Charlton expresses caution against its use. “Guarana is marketed as a natural and safe herbal product, but there are worries among medical professionals of its potential dangers, if taken in high doses. It is not to be confused with a vitamin supplement.”
Charlton says guarana affects the body in a similar way to caffeine when taken in large amounts, and that people with heart problems and high blood pressure should avoid guarana.
# Eat right
Chin says low energy levels are usually caused by poor diet and stress. “The best way to improve you energy levels is to eat regular meals, especially breakfast.”
# Detox programme
Florrie Kershbaumer, a registered Cape Town homeopath, recommends a two-week detox rebalancing programme if you are continually exhausted even after taking coffee as an upper.
July 21st, 2005
The fact that more than 20% of the United States adult population is obese presents a major public health concern. However, the failure to follow through and maintain weight loss on their own, after termination of counselling, makes the long-term success of weight loss programs difficult to achieve.
Health professionals often assume that patients will dutifully comply with recommendations simply because they are urged to do so. The magnitude of noncompliance has been well documented. Adherence to dietary programs is thought to be poorer than to medication regimens. [Glanz, K.: Dietitians’ effectiveness and patient compliance with dietary regimens. JADA 84:444, 1984.] Dietary regimens are often restrictive, require changes in life-style and behaviours, interfere with family habits and customs, and are of long duration.
Weight control methods are considered a success if weight loss is maintained without expense to overall health. A goal of any successful weight reduction program is to promote permanent life-style changes. The physical and psychological consequences of repeated weight fluctuations may be more harmful than maintaining some degree of overweight. [Rock, C.L., & Coulston, A.M.: Weight control approaches: A review by the California Dietetic Association. JADA 86:44, 1988] The ultimate goal of all weight loss programs is to reduce nutritional risk factors associated with chronic diseases by increasing consumer awareness of healthy food choices.
In 1992 over 49 million people were dieting. The National Council Against Fraud estimates that quackery costs consumers between $25 billion and $50 billion a year - and nutrition fraud is the most common type. [Legislative Highlights, Journal of the American Dietetic Association. Page 648 - 650. May 1990]
Therefore to identify a quality weight loss program, and not to be misled by a “fad diet”, the following indicators must be considered:
* A variety of foods. Weight control programs should be individualized to fit people’s life-styles and food preferences. Individualization diminishes feelings of deprivation, which lead to discouragement, bingeing, and rebound weight gain - all hallmarks of the yo-yo diet syndrome.
*Enough calories to maintain good health. Consuming less than 1200 kcal a day may result in loss of muscle instead of fat and may compromise nutritional status as a result of deficient nutrient intakes.
*Realistic weight loss goals. To lose body fat and not just water, a maximum weight loss of 2 pounds per week is advised.
*Regular exercise. Especially as we age, exercise can be the key to weight loss and maintenance of a desirable weight.
*Behaviour modification. Registered dietitians counsel people to keep lost weight off by helping them alter their eating behavior and responses to foods for the rest of their lives.
Unfortunately, a current trend toward the view that a single food is either a panacea or a poison is being gradually adopted by major health associations. This “good food/bad food” dichotomy ignores the consensus among nutritionists that all foods can be compatible with health when used in moderation as part of a balanced, varied diet.
Over the past decade people have become obsessed with the nutritional value of the food they eat. Time and again, nutrition ranks high among consumer concerns, along with food safety, convenience, quality, and value. In the United States sales in the “healthy foods” category accounted for $65 billion in 1985, but are expected to reach $98 billion by 1995.
Consumers are asking for specific information about which foods and, in particular, which brands of packaged foods to choose from when they eat or purchase foods. For example the broad guideline to avoid to much fat, saturated fat and cholesterol require specific behaviour implementations that include:
* Eat more fresh fruits and vegetables, whole grain breads and cereals, potatoes, rice noodles, dried beans, peas, and lentils.
* Choose low fat dairy products, including skim, 1%, and 2% milk, low-fat cheeses, and low-fat yogurt.
* Choose lean meats, fish, chicken and turkey.
Very Low Calorie Weight Loss Diets (VLCD)
It is the position of the American Dietetic Association that while VLCD’s promote rapid weight loss and may be beneficial for certain individuals, such diets have health risks and should be undertaken only with the supervision of a multidisciplinary health team with monitoring by a physician and nutrition counselling by a registered dietitian.
Side effects that have been associated with VLCD’s are cold intolerance, fatigue, light-headedness, nervousness, euphoria, constipation or diarrhoea, dry skin, thinning of hair, anaemia, and menstrual irregularities.
Low body weight and Weight Loss
Excessive concern about weight may cause or lead to such unhealthy behaviors as excessive exercise, self-induced vomiting, and the abuse of laxatives or other medications. These practices may only worsen the concern about weight. Excessive exercise may also affect hormone production, increase the loss of calcium from the bones, and increase the risk of fractures.
Low body weight and rapid unintentional weight loss are highly predictive of mortality, especially in the elderly population. Weight loss is frequently reported in elderly patients.
Acute and chronic diseases are leading causes of involuntary weight loss. Whereas physical disease probably accounts for a majority of cases of involuntary weight loss, psychiatric disorders such as dementia and depression also may result in severe nutritional deficiencies.
Energy requirements decrease because of the lower basal metabolic rate and reduced physical activity. These low energy requirements make it more difficult for the elderly to obtain adequate amounts of required nutrients. Health care professionals must monitor body weight in elderly persons and carefully evaluate any cases of rapid, unintentional weight loss to prevent further deterioration of health status. [Low body weight and weight loss in the aged. JADA 90:1697-1706, 1990]
Weight loss generally consists of both lean body mass and body fat. Contributions of lean body mass and fat to total weight loss is a function of body fat content. Excessive loss of lean body mass will result in skeletal and cardiac muscle wasting and loss of visceral protein. Because lean body mass declines with age, elderly individuals who are at average or slightly above average weight may be better able to tolerate weight loss that occurs with aging or disease than underweight individuals.
It has been well documented that physical disease can lead to weight loss. Disease may limit dietary intake or may alter physiological processes, resulting in decreased nutrient digestion or absorption, increased nutrient excretion, or increased nutrient requirements.
Cancer is the most frequently cited cause of involuntary weight loss, and weight loss may occur during early stages of tumour growth before other symptoms emerge. The anorexia of malignancy has been related to taste alterations; changes in gastrointestinal tract contraction and secretion; metabolic disturbances resulting in changes of circulating glucose, amino acid, fatty acid, or lactic acid levels; changes in hypothalamic function; and weakness leading to decreased motor activity.
In addition to cancer, gastrointestinal disease, uncontrolled diabetes, and cardiovascular disorders such as congestive heart failure, alcohol abuse, pulmonary disease, and infection are major causes of involuntary weight loss. Less common, but still a cause of notable weight loss, is hyperthyroidism.
Specific nutrient deficiencies and low nutrient intakes, which may contribute to weight loss, have been documented in patients with dementia. Deficiencies of folate, thiamin, niacin, riboflavin, and vitamin B12 and electrolyte imbalance may impair cognitive function and mimic dementia.
Some nutrient deficiencies that alter mental status may be present in the elderly population. Altered mental states attributable to nutrient deficiencies and weight loss can be corrected. Several studies have shown that folate deficiency leads to confusion and signs of dementia in elderly individuals, but can be reversed with appropriate supplementation. If confusion and dementia caused by nutrient deficiencies are not diagnosed and corrected, they may lead to even lower nutrient intakes and more severe alterations in mental status.
July 21st, 2005
How Important is Protein?
Protein is necessary for the growth, maintenance, and repair of every cell in the body. It is present in countless forms throughout the body—as part of enzymes, hormones, antibodies, oxygen carriers, bones, muscle, hair, and skin, to name a few. Unlike the fuelproviding carbohydrates, proteins are the building blocks that provide structure and perform vital functions. However, when needed, proteins can break down to provide energy—4 calories per gram.
Small units called amino acids unite to form the structure of proteins. Altogether there are 20 common amino acids. They mix and match in thousands of different combinations to make up specific proteins. Since your body cannot manufacture nine of these amino acids, you must get them from your diet. Proteins in your food provide them, with the most concentrated sources coming from animal products—meat, chicken, fish, dairy products, and eggs. However, it is also possible to get protein from plants such as beans, nuts, and grains. In fact, most of the people in the world get their protein from vegetable sources for either cultural or economic reasons.
Animal versus Plant Proteins
Proteins from meat, poultry, fish, and dairy foods are called complete proteins because they furnish all the amino acids needed for growth. Most plant proteins, on the other hand, are incomplete: Except for the soy bean, no single plant provides all nine essential amino acids. (Soy, though complete, is still considered inferior to animal proteins.) You can, however, meet your daily requirements by consuming a variety of plant proteins over the course of each day. For example, the amino acids from beans taken at one meal can complement the amino acids from rice eaten at another meal that day. Other examples are peanut butter and wheat bread, or macaroni and cheese. (In the latter case, the essential amino acids from the animal product, cheese, allow the body to better use the amino acids in the macaroni.)
Dietary protein deficiencies in this country are relatively rare. When they do occur, they are usually the result of a disease that causes loss of appetite or loss of large amounts of protein from the body.
Excess dietary protein is a much more common problem. Government surveys estimate that the average American consumes about 100 grams of protein per day—almost twice the recommended daily allowance (RDA) of 50 grams for women and 63 grams for men. Excess protein taxes the body physiologically. Once it’s digested and absorbed, end products of protein metabolism are excreted in the urine; so any excess places extra burden on the kidneys. Nor does excess protein build muscles. It is either burned as energy or stored—not as muscle, but as fat. Many athletes, particularly those involved in strength training, believe that to build muscle you need more protein. In fact, Americans already get more than enough; and exercise, not extra protein, is the only way to increase muscle size and strength.
July 21st, 2005
The best rule to follow with cholesterol is the less of it, the better. Like fat, some cholesterol is necessary for good health, for it is a vital component of cell membranes, nerves, and hormones. But, unlike fat, our liver produces all we require; we don’t need any cholesterol at all in our diet.
Nevertheless, we get plenty. Many common foods contain cholesterol, some much more than others. Remember this: Because cholesterol is made by the liver, only animal products contain cholesterol. It is not a problem in peanut butter, margarine, or vegetable oil. Cholesterol is most abundant in eggs and organ meats (after all, cholesterol is made in the liver), but some cholesterol is found in all animal products. Even seafood, particularly shrimp, contains some cholesterol, though with its low saturated fat content, shrimp is no longer considered as “forbidden” as it was in the past.
Some people seem more sensitive to high intakes of dietary cholesterol than others. For everyone, however, experts recommend an intake of no more than 300 milligrams of cholesterol per day. Current daily intakes average about 370 milligrams, with women averaging a bit less.
As for recommended levels of blood cholesterol, the National Cholesterol Education Program (NCEP) has established guidelines to help identify those at risk of cardiovascular disease based on their blood levels of total and LDL cholesterol. Total blood cholesterol is actually made up of two components: lowdensity lipoprotein (LDL) and highdensity lipoprotein (HDL). The more abundant form is LDL cholesterol. Excessive levels of LDL are associated with increased risk of cardiovascular disease.
High levels of HDL, on the other hand, tend to prevent the disease. So, the lower your total and LDL cholesterol and the higher your HDL cholesterol, the better. According to NCEP guidelines, a desirable total blood cholesterol level is less than 200 milligrams per deciliter of blood; a desirable LDL level, less than 130 milligrams per deciliter. Your HDL cholesterol level should exceed 35 milligrams per deciliter. If your HDL is greater than 60, you’re lucky—you have a negative risk factor for cardiovascular disease.
July 21st, 2005
Of all the things we ingest, water is probably the most important—and the most neglected. You can live without nutrients for weeks or even months, but without water, you can survive for only days. Water accounts for 60 percent of the body’s weight. Water shuttles nutrients and oxygen to cells, where it participates in the chemical reactions that produce energy. It also transports waste products out of the cells and eventually out of the body. Water cushions joints, acts as a lubricant, and keeps food moving through the digestive tract.
Water regulates body temperature. It brings heat to the skin surface in the form of perspiration, thus cooling the body and preventing heat stroke or other temperaturerelated illnesses.
We get some of our water from foods, which are generally 85 percent to 96 percent water, but most of it comes from fluids such as juice, milk, soup, tap water, or anything else normally liquid at room temperature. (Don’t forget gelatin desserts, ice, and frozen juice bars.) Ideally, you should drink 6 to 8 glasses a day. Beverages that contain caffeine or alcohol are poor choices; they act as dehydrators by causing increased urine production.
Avoid the dehydrating effects of exercise. Load up with 16 ounces of cool water 10 to 15 minutes before an activity. During exercise, 4 to 6 ounces of cool water every 10 to 15 minutes will help keep sweat production up and body temperature down. Be sure to drink even more in hot weather.
July 21st, 2005