October 2003

Vol. 2     No. 10  

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Update for 2003 � 2004

I wish a healthy vegetarian diet would protect you from every known ailment and tragedy � but sad to say it won�t.  You are still subject to catching the common cold and the flu, which cause fatigue, fever, runny nose and cough.  These acute upper respiratory viral infections are among the most common of all human diseases.  In the United States, the incidence is 3 to 6 episodes per person per year on average.  Children under 6 have the highest rates because of their frequent exposure to many viruses at school, and their lack of immunity (immunity which they would have acquired from previous infections).  More than 200 different viruses are known to cause these infections.  While rhinovirus is most common, coronavirus, respiratory syncytial virus, adenovirus, parainfluenza, and influenza virus all play important roles.  Influenza-like illnesses begin to increase in mid-January and peak during early February.

Treat these viral infections with the most advanced medications known to modern medical science and they will last 2 weeks, but if you do nothing, you will be better in 14 days.  In other words, there is no cure for the common cold or flu.  However, there are treatments that may shorten the duration of illness and will definitely lessen the symptoms associated with an upper respiratory infection.  Most importantly, you can prevent some of these diseases with immunizations � and, I believe, a healthy diet and lifestyle.  I can�t prove it true, but I have heard a thousand times, �Now that I eat a healthy vegan diet (based only on whole plant-foods) I get colds and flu much less often, I�m never as sick, and I recover faster.�  There is much indirect evidence that substantiates this common observation.

Better Diet and Lifestyle = Immune Power

Wouldn�t you expect unhealthy people to become ill more often and more severely?  Obesity has been shown to diminish the immune response.1  This is not simply the result of carrying around extra body fat, but more important, because individually the components of the diet that cause obesity harm your immune function.  Dietary fats, animal protein, and cholesterol are known to suppress the immune system � in contrast, antioxidants found in plant foods enhance the disease-fighting capabilities of our bodies.2   All fats,3 and especially the �good� fats, suppress the immune system.   This means the so-called �healthy oils� like olive oil,4 corn oil,5 flaxseed oil,6 and fish oil,6-8 suppress immune function and increase your risk of viral infections.  Even eating the whole fish diminishes your defenses.9 Therefore, the best diet to follow in order to prevent colds and flu is a low-fat, plant-food-based diet; in other words, starches, vegetables, and fruits.

Be careful how you lose that extra body fat.  Low-carbohydrate, high-protein liquid diets seriously impair immune function,10 whereas a low-fat, high-carbohydrate diet enhances the viral-killing machinery of the immune system.11  Too much coffee, alcohol, sunshine, sleep, and exercise can suppress your immune system, too.12-23  (See the June 2003 Newsletter (SARS) for more details.)


     Is it a cold or flu?

A common cold is a virus infection involving the upper respiratory system and characterized by congestion of the mucosa, watery nasal discharge, and generalized fatigue lasting 4 to 9 days.  Influenza (the flu) is similar, but with more intense symptoms including headaches, muscle aches, fevers, chills, and cough, lasting 2 to 6 weeks.

  Hand Washing is Simple and Effective

These viral infections are spread by passing the virus between people.  The most common intimate contact people have is with their hands � touching other people and objects, contaminated with viruses, they have touched.  From the hands, the viruses are transferred to the mucous membranes of your mouth, nose and eyes, where they infect these tissues.  You almost don�t stand a chance of avoiding contact because these viruses can survive on surfaces for several hours.

In medical school I was taught �the solution to pollution is dilution.� In other words, you can wash these villains away, and handwashing is a very effective means of preventing the spread of the virus.  This benefit has been documented in seniors and young children.24,25  The key to effectiveness is, of course, compliance.26










My Favorite Vitamin-Herbal Potion

Walk into my kitchen and you will find a bottle of concentrated Echinacea extract pills and a bottle of Vitamin C wafers up on an easy-to-reach shelf.  There is nothing more I would rather believe than that my potion prevents me from becoming very ill when I start with a few sniffles or a cough � even if the evidence is weak.  In 1970 Linus Pauling claimed that Vitamin C prevents and alleviates the episodes of the common cold.  Over the past three decades numerous studies have been done to assess the benefits of Vitamin C.  One recent analysis of the published literature found a decrease in the duration of illness and severity of disease by 23%.27  However, a review by the Cochrane Committee (a very respected impartial body of scientists) could only substantiate a modest reduction in the duration of cold symptoms.28  The most recent study shows no benefits for either duration or severity of cold symptoms in healthy adult volunteers with doses of Vitamin C in excess of 1 g daily taken shortly after onset of a cold.29  When considering the benefits of Vitamin C, remember fruits and vegetables might be the best source, and realize there is no Vitamin C in meat, poultry, dairy or any other animal product, and refined foods have had much of the Vitamin C removed. 

Echinacea purpurea, a plant originally used by Native Americans to treat respiratory infections, has been found to stimulate the production of antiviral factors by human white blood cells.30  Even very small doses (0.012 microgram/ml) had this effect.  These results are consistent with the proposed preventive effects of Echinacea on colds and flu.  Well-done studies have reported a 10 to 30% reduction in duration and severity of symptoms using concentrated extracts (rather than whole-plant products) of Echinacea.31-33   A recent study using whole plants parts showed no benefits.34 My personal approach is that I take my Echinacea and my Vitamin C with the first hint that I might have come into contact with a virus, or the first symptom of a cold or flu.  I figure I have done no harm � and maybe some good.

Flu Shots Are Worthwhile for Me

Longer life expectancy seen with modernization has been attributed to better nutrition, improved sanitation, immunization, and to a much smaller extent, medical advances in pharmaceuticals and surgery.   Approximately 2500 years ago the first observation was recorded that persons previously exposed to the plague had reduced susceptibility to future disease.  Two hundred years ago (1796) the first successful immunization method was developed by infecting humans with cowpox to prevent a similar infection, smallpox (by Edward Jenner).  Because of this event we have the word vaccination � derived from vacca, the Latin word for cow. The foundation principle of vaccination (commonly called immunization) is: once exposed to a potential enemy, like a virus, the body learns and remembers from that first encounter, and then makes a quicker and more effective future response to a similar exposure.  �Memory cells� (white blood cells) are produced by the first encounter, but this memory is not perfect and does not guarantee successful defense against future invaders.  Over time, memory cells diminish.

My experience with influenza vaccines was tainted during my early years in practice.  Two of my patients became paraplegic (paralyzed from the waist down) as a result of immunization for the swine flu in 1976 (a flu which never appeared).  However, since then flu vaccines have not caused such serious adverse reactions.  I have also been influenced by a severe bout with the flu I suffered several years ago and I will do anything reasonable to avoid this experience again.  I now get an influenza immunization injection annually.

Influenza Vaccines Work and Are Safe

The major public health measure to prevent influenza has been the use of inactivated vaccines.  These vaccines are derived from previous influenza A and B viruses which circulated during the previous flu season.  Each year's vaccine should contain three virus strains representing the influenza viruses that are likely to circulate in the upcoming winter.  This year�s vaccine (2003) contains the same A and B strains as last year (2002).35-37  About 2 weeks are required to produce adequate immunity after vaccination and the response persists for 6 months or longer.  If the correct strain of virus is present in this year�s vaccine, then the live vaccine will prevent 85% of infections and the inactivated will prevent 71%.  Influenza vaccination has been shown to reduce mortality by 41% for all subjects, and by 75% for those who had also been vaccinated several times over previous years � the benefits seem to accumulate with repeated annual vaccinations.38   Overall, there is a reduction in upper respiratory illnesses, lost work days, and antibiotic use for those who have received their �flu shots.� 

Currently available vaccines have been highly purified, and therefore, cause few adverse reactions.  Up to 5% of people experience fever and mild symptoms.  Up to one-third receiving the killed vaccine by injection may have tenderness at the site of vaccination.  Since the vaccine (live and killed) is produced in eggs, people who are egg allergic should avoid vaccination or be desensitized.  Vaccination is particularly important for those people who have other serious diseases, such as asthma or heart disease, and for the elderly.  The vaccine should be taken in early autumn, before flu season.

There are two types of vaccines available, �live� and �killed� (inactivated) vaccines.  Live vaccines (FluMist) are given by inhalation through the nose, rather than an injection, but are expensive ($50 vs. $10 for �killed� vaccine).36  Live vaccines should not be used in: people younger than 5 or older than 49, people with serious illnesses or immunodeficiency problems, pregnant women, children receiving aspirin, or people with a history of Guillain-Barr� syndrome.


 Drugs for Flu Prevention 

Your doctor can prescribe four different kinds of drugs to people who are at high risk of complications from influenza when an influenza outbreak occurs before vaccination or less than 2 weeks afterwards.37  Oral amantadine (Symmetrel, and others) or rimantadine (Flumadine, and others) started before exposure and continued throughout the period of exposure (up to 6 to 8 weeks) can prevent illness due to influenza A in 70-90% of adults.  Oseltamivir (Tamiflu) and zanamivir (Relenza) are about 60-70% effective for prevention of both influenza A and B in adolescents and adults; only oseltamivir is FDA-approved for this indication.  All four have side effects and cost between $31 and $266 for a course of therapy depending upon the kind of medication chosen.


Raising Body Temperature

One of the body�s natural responses to infection is a raise in body temperature, commonly known as a fever.  Beyond drawing attention to an illness, fever plays a role in killing infectious organisms, such as cold and flu viruses.  In the past, fever therapy has been used to treat neurosyphilis and forms of chronic arthritis.  This therapy may even be an effective treatment for Lyme disease.39  Many other factors, in addition to a raised body temperature, play a role in fighting an infection; however, simply raising the body�s core temperature may augment the immune response.  Research centers worldwide are using artificially raised body temperature, called �whole body hyperthermia� to treat cancers,40,41 and it has been tried as a treatment for AIDS.42

A warm bath, and dry and steam saunas, have been recommended for centuries to benefit cold and flu sufferers.  Therefore, one of the treatments I recommend is to soak in a bath or better yet a hot tub at 108 degrees Fahrenheit in order to raise your core body temperature--possibly as high as 102 degrees F (normal temperature being 98.6 degrees F).  How long should you bathe at this temperature?  An hour would be ideal.  However, for most people this treatment is too uncomfortable for that lenght of treatment.  People with heart or other debilitating diseases should not raise their body temperatures.

Symptomatic Treatments for Colds and Flu

Zinc for the Common Cold

Evidence supports use of zinc gluconate lozenges for reducing the symptoms and duration of the common cold, but the side effects, mouth irritation, bad taste, and nausea, might prevent people from using them.43  Zinc may act by preventing the virus from binding to the cells of the respiratory tract, thus preventing the viruses from entering the cells. The benefit appears to be maximal if the lozenges are started immediately after the onset of symptoms.

Nasal Congestion

Pseudoephedrine (Sudafed)

Pseudoephedrine is a decongestant for relief of stuffy nose and head due to colds and allergies.  Side effects include nervousness, dizziness, and sleepiness.


The nasal symptoms of a cold, such as runny nose, sneezing, and itchy nose, are effectively reduced by antihistamines.  A common side effect is sleepiness, which can be a drawback impairing driving and work-related activities, but can also help you sleep when taken at bedtime.  Common over the counter antihistamine products include Actifed, Comtrex, Contact, Dimetapp, and Tavist.  Many other products are sold with antihistamines as one ingredient in a cold preparation.

Sodium cromoglycate (Nasalcrom)

Nasalcrom is inhaled through the nose and relieves stuffy and runny nose by stabilizing cells that line the respiratory tract, preventing the release of secretions.  This medication can be very effective and is well-worth a try.

Cough Suppressants

Dextromethorphan, often labeled as DM on the bottle or box, is similar to codeine, a powerful doctor-prescribed cough suppressant.  The drug acts on the brain to elevate the threshold for coughing.  It is almost as effective as codeine for cough, but does not produce the drowsiness or constipation commonly seen with codeine.\

Pain and Fever Relief

Tylenol, aspirin, and nonsteroidal anti-inflammatory drugs (NSAID), like Advil and Motrin, can be taken to relieve some of the head and body aches and to reduce an uncomfortable fever.  Although aspirin and NSAID are usually more effective than Tylenol, they have more side effects, especially irritation of the stomach.  If a patient can take plain aspirin, then I recommend it over all other medications. Two to four adult aspirins dissolved in a glass of water and gargled, then swallowed, provide excellent relief from a sore throat.  Aspirin should not be taken by children with febrile illness because of the risk of Reye�s syndrome.

Your Doctor and Prescription Drugs

There is very little more your doctor can do for you when you get a cold or flu than what you can do for yourself with the above recommendations.  If your illness progresses with complications, such as pneumonia, your doctor can be of great help to you by administering antibiotics. 

However, with an uncomplicated upper respiratory infection antibiotics should not be used.   But that�s not the way medicine is practiced.  In a recent survey, 21% of all antibiotic prescriptions given to adults were for colds and flu.45  Another study found 60% of patients seen in primary care for the common cold received antibiotics.46  Every doctor and patient should know antibiotics are completely ineffective against viruses. 

A proper indication for the use of an antibiotic might be treatment of a superimposed bacterial infection.  An indication for this kind of bacterial infection may be the presence of green and/or yellow mucus from the nasal passages or in the sputum from a cough.  Clear drainage would suggest no such bacterial infection has occurred and therefore antibiotics would be useless at best.  The side effects of antibiotics are many, including adding the unpleasantness of a vaginal yeast infection to a woman�s suffering.


         So What Does
        Dr. McDougall Do? 

I wash my hands frequently throughout the year, but even more vigorously when there is an outbreak of colds or flu, or if I touch someone who is sick.  I get an annual flu shot.  I take my Vitamin C and Echinacea during cold and flu season, and especially any time I feel like I�m starting to come down with something.  After I have passed the point of prevention and am sick, I use my hot tub every evening to raise my body temperature.  I treat my cough with a syrup containing dextromethorphan, I gargle with aspirin dissolved in water for a sore throat, and occasionally I take aspirin for body aches.  Do any of my efforts prevent a cold or flu or help me get over it faster?  I don�t know, but I feel better; and I feel like I have at least taken some action to help myself � for whatever that is worth.



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