diseases found commonly at lower altitudes occur less at
high altitude. The Indian Army recorded the incidence of
18 different diseases in 130,700 soldiers stationed at
altitudes from 3692 to 5538 metres over a period of seven
years. When the rates of disease were compared to those
found in soldiers on the plains, almost all diseases had a
lower incidence at altitude. The occurrence of bacterial,
viral or protozoan infections was significantly lower
(except for amoebic hepatitis and lobar pneumonia).
Diabetes, hypertension, ischemic heart disease, asthma,
rheumatoid arthritis, several types of gastric disorders, skin
diseases, psychiatric ailments (including neurosis and
psychosis) and anaemia all occurred with much lower
frequency when the soldiers were living at altitude.
Living continuously at altitude for a period of months or
years is not an option for most people. Russian doctors, in
trying to find a solution to acclimatising pilots, athletes,
mountaineers and cosmonauts to low-oxygen environments,
discovered that adaptation to low-oxygen environments
could occur rapidly in a clinical setting and without the side
effects of altitude sickness. The oxygen levels found at
altitude were administered in a controlled manner and given
in measured intermittent doses. The technique became
know as Intermittent Hypoxic Training (IHT), whereby
oxygen levels of between 10 and 15 per cent (equivalent to
an altitude range of 2500-6000 metres) are administered by
a machine known as a Hypoxicator, which separates air
through a semi-permeable membrane. The person is asked
to breathe the high-altitude air for just a few minutes at a
time while their blood oxygen levels are continuously
monitored. They then breathe ambient or normal air for a
few minutes, giving their body time to adjust back to
normal conditions. The time spent alternating between low-
oxygen air and normal air is 60 to 90 minutes at a time. The
procedure is generally carried out once or twice a day for a
total of 16 to 30 sessions. Researchers found that this
technique allowed adaptation to altitude to occur with less
stress to the body than continuous exposure to low oxygen.
Because the dose and the blood oxygen levels are totally
controlled, there is no danger of altitude sickness. The
intermittent nature of the hypoxic exposure means the
adaptation to lowland is not lost, as is the case in normal
acclimatisation to altitude. Adaptation to intermittent
hypoxia has the unique attribute of activating the body's
own internal production of antioxidants in the brain, liver
and heart as a result of the frequently repeated re-
oxygenation that occurs on breathing room air. This differs
from continuous hypoxia, which actually reduces
Since the beginning of time, living things, from simple
viruses and bacteria to humans, have shown the seemingly
miraculous ability to adapt to changes in their environment.
In humans the process of adaptation is more efficient and
more fascinating than in any other species. Our genetic
characteristics and potentials are not fully expressed until
something challenges us to adapt. In this way, challenges
and stresses help us to develop strengths and abilities we
might not otherwise have developed. As we adapt to one
level of any environmental or even emotional stress, we
become capable of handling even larger doses in the future.
This ability is what enables, for example,
weightlifters to lift unimaginable loads well beyond their
own bodyweights. This is why our species (and all other
currently living species) has survived and even thrived
despite environment changes and times of extreme difficulty
and social upheaval. IHT forms an important branch of an
emerging new discipline called Adaptive Medicine. The
Russian Academy of Medical Sciences has a Department of
Adaptive Medicine, one of its aims being to look at the
therapeutic potential of IHT. An International Academy of
Adaptive Medicine was formed in 1990 by an
interdisciplinary group of scientists and clinicians from
many countries including Japan, Australia, Germany and the
USA. Its aim is to develop further understanding and share
information about the ways in which the adaptive process
enables the body to respond to different stress stimuli, with a
view to treating and preventing different diseases. The
scientific definition of stress as given by Dr Hans Selye, one
of the first researchers to really study stress in the laboratory,
is: "A stressor is anything that challenges an organism to
adapt." In this context, heat, cold, physical exercise,
electrical stress, lack of food, hypoxia of altitude and even
emotional or psychological turmoil are stress factors that can
be used to strengthen us if we experience them in amounts
we can tolerate and to which we scan adapt. Almost all of
these factors have been used as means to help people restore
health. On the other hand, too much of any of these stress
factors, carried on for too long without sufficient recovery
time, can exhaust the adaptive mechanism and contribute to
disease rather than health. If you fast, use saunas or cold
baths, begin an exercise program to get fit or undertake IHT,
you are engaging the principles of adaptation for the
restoration of health. One of the amazing things about
adaptation is what's known as 'cross adaptation'. Adaptation
to one type of stress or load will, to some extent, increase
the body's ability to cope with
stresses of another type. It is well know that a regular
exercise program is associated with an increased tolerance to
stress. Stress-related diseases such as hypertension, heart
disease, ulceration of the stomach or duodenum, diabetes,
dermatological diseases and disordered immunity have all
been shown to have improved outcome with both exercise
and IHT. Protection comes because the body becomes more
tolerant and resistant to stress. Dr F Z Meerson, one of the
most prolific writers and researchers in the field of Adaptive
Medicine, describes in his book Essentials of Adaptive
- Fade away of the stress reaction
- Increased activity of the central and peripheral stress
limiting systems
Desensitisation of target organs
-
Oxygen deficiency is associated with many diseases. It has
been postulated to play a role in many metabolic diseases,
including