Britain in 2008 is a
society that is wrapped up in triple 'epidemics' of stress, obesity
and chronic disease. None of these issues were considered a problem
in society 100 years ago; unfortunately, whilst we are regularly
bombarded with the status quo recommendations – don't get
stressed,
don't get fat, with the threat of chronic disease as back up
– but
rarely are the links explored, let alone explained.
The physiology of stress
generally relate to two classes of hormones, catecholemines and
glucocorticoids. To keep things simple, I will refer to only to the
main catecholamine in question, adrenaline, and the major
glucocorticoid, cortisol. Whenever we activate our 'fight or flight'
stress response, this causes both hormones to be released. These
hormones are responsible for the familiar effects we might experience
in a challenging situation; increased heart rate, an increase in
energy, increased awareness/anxiety and a dry mouth to name a few.
Non-essential processes like digestion are shut down, whilst the
bloodstream is filled with glucose and fatty acids ready for fighting
or running.
It is through this
initial breakdown of fat and carbohydrate into smaller, usable
products (fatty acids and glucose) that both the adrenal hormones are
considered catabolic (breakdown) hormones. But if it were this
simple, surely the more stressed an individual becomes, the more fat
they will break down and the leaner they will become? Observation of
the stressed people around us and official health figures both show
this is definitely not the case.
Clearly, better
understanding of the stress response is required. In particular,
there seems to be little differentiation between the roles of
adrenaline and cortisol. There is a propensity in stress culture to
lump the effects of these two hormones together, when in reality they
work in unison with one another in contrasting roles. The stress
response actually comes in two waves; the first initiated by the
release of adrenaline, which plunders the body's resources to prepare
and prime the body for action. Adrenaline will normally stay in the
bloodstream in high concentrations for several minutes. The second,
cortisol-dominant phase is more of a compensation reaction to the
plundering of resources that just occured. Cortisol stays in the
bloodstream for hours. So when this stress response becomes
over-deployed, over-compensation occurs and this makes a stressed
individual an stressed, overweight individual.
Cortisol causes fat cells and liver cells to
activate more lipogenic (fat-producing) enzymes.
The more cortisol you release, the more fat you will store. Why?
Evolution has given us a perfect stress response to the dangers we
have faced for the majority of the last 40 million years. These would
have been threats to our physical safety, and running from a predator
would have left us with emptier fat cells, but the compensation
response (fuelled by cortisol) ensures that normality is resumed.
However, the first stage of this stress response will be activated
regardless of your activity levels and, as it was designed to provide
masses of glucose for working muscles quickly, this will cause an
excessive build-up of glucose in your bloodstream when you sit raging
in a traffic-jam, or sweat uncomfortably behind your desk. So what is
the end result of this? The cortisol release, that nature intended to
salvage something for the fat cells from what little remained in
circulation, now has the resources to hold a festival of fat storage.
There is more glucose left to shuttle into your fat cells to be
converted to triglycerides (stored fat). There are more
glucocorticoid receptors in the abdomen, hence the 'apple-shaped' fat
distribution so often seen in stressed individuals and those on high
doses of steroids.
It would be nice if your
muscles were refueled in the same way as your fat cells.
Unfortunately not the case. In order to help those muscles that have
just become empty outrunning a lion, cortisol activates enzymes that
cause produce insulin resistance. Thus, the non-working muscles are
marginalised to give priority access to those that need it most. A
clever system, but what happens when no muscles have been exercised?
Insulin resistance, and therefore increased insulin production.
Insulin resistance does not mean that insulin does not do it's job,
it simply means that it takes longer to do so and those cells with
unlimited storage (fat cells) end up taking more than they otherwise
would. More insulin means more fat storage. It also predisposes an
individual to Type II diabetes.
So far we have got a
system that spends a few minutes shuttling energy out of muscle and
fat cells in the face of an apparent emergency then, when it turns
out that this was simply an email that reminded you of another task
you will not have time to do, spends the next few hours shuttling
this excessive energy into fat cells, regardless of what you are
eating.
It doesn't stop there,
though. As mentioned above, stressful situations throughout the
course of evolution would inevitably have left an individual with
less energy stores, with those valuable fat stores depleted. The
2nd-wave of the stress response (the compensation phase) deals with
this very cleverly, inhibiting a hormone called leptin (an appetite
suppressant) in the brain, which signals for an individual to
replenish themselves with foods that the body can convert easily to
stored fat; sugar. Often my clients tell me they lack the willpower
to eat the foods they know they should – normally, this is
simply a
physiological response to uncontrolled blood sugar levels and
uncontrolled stress.
Beyond these direct
mechanisms that stress hormones cause increased fat storage, there
are many other effects that are likely to trouble the determined
dieter. Digestion is shut down from the moment you face a situation
you interpret as stressful (your dry mouth is caused by the salivary
glands shutting down). Compromised digestion is at the basis of
almost every health concern, but inefficient digestion means the
inefficient conversion of food to energy, which causes more fat
storage. It will also increase the likelihood of vitamin/mineral
deficiency to near certain; this will compromise the body from
cellular level up, with vitality and metabolic rate the likely
losers. For various complex mechanisms, primarily regarding the
disruption of healthy digestive and immune function, food allergies
are more likely to develop.
Cortisol also binds to
steroid receptors all over the body, resulting in less receptor sites
available for other steroid hormones such as estrogen and
testosterone. Testosterone, especially, is involved heavily with
muscle metabolism. Both have potent effects on mood, mental aptitude
and libido. Both adrenaline and cortisol will respectively stop you
from going to sleep and ensure you can never reach deeper levels of
sleep required for sufficient repair. Without reaching the deeper
levels of sleep, you will be unable to release optimal levels of
growth hormone, a powerful fat-burning hormone.
So clearly, the message
is simple: Don't Get Stressed. But are there any practical steps one
can take to making this more of a reality?
Although stress causes
bad sleep, one of the easiest way to spike your own release of
hormones is to compromise on the time you spend asleep. Breaking this
catch-22 situation is clearly of paramount importance. Areas to look
at here are what time you go to sleep, whether you keep a television
in your room (watching late at night easily disrupts the sleep/wake
cycles) or if you do work in your bedroom before going to bed.
Valerian Root, a herb is very useful if you have trouble going to
sleep, and hydroxytryptophan, an amino acid, is useful if you would
like to get into a deeper, more relaxed sleep. One of the best
investments you could ever make in establishing better sleeping
patterns is a black-out blind; this really does make a difference,
even to those who do not feel they have a problem sleeping.
Controlling your blood
sugar levels with regular meals is another very easy way to break the
cycle of overworked adrenal glands. This means smaller meals, 4-6
times per day, with good levels of quality protein and fat (mirroring
the type of diet we evolved upon). Avoiding alcohol, tobacco, sugar
and especially caffeine are also steps that can be achieved with more
ease than one might think. An individual that consumes 3 cups of
coffee at work at 2 cups of tea at home may be shocked to realise
that they are consuming a daily total of over 600mg of caffeine
(thats the equivalent of 10 cans of red bull!). Beyond these two
changes there is the more complex matter of altering the way you
respond to the world around you – analysing who/what pushes
your
buttons and whether you should allow this to happen, analysing if you
are trying to get too much done in too little time and whether your
work/life balance is as optimal as it could be. These matters are
often easily identified, but not as easily rectified.
The stress response is a
great example of a system that has evolved perfectly for the world in
which we evolved in. Unfortunately, this is a very different world
from the one that we are surrounded by today. Frequent activation of
our stress response, together with lack of physical exertion that our
bodies clearly expect in this situation, are doing untold damage.
This applies to our immune and cardiovascular systems as much as it
does to our figure.
Moreover, it serves as
yet another example of how diet and lifestyle habits have an enormous
impact on the hormonal conditions (and therefore body composition) in
an individual. It also demonstrates numerous factors that have an
impact on stress levels, and thus what impact stress levels has on
even basic processes such as the metabolism of food, mood and sleep.
Once more, getting back in sync with evolution on all fronts is your
best guarantee to achieve your goals.
