SURVIVING THE COLD AND FLU SEASON
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
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
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
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-Barré 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
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
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.
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
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.
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
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 hand 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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