By
Bryan Walsh | January 26th, 2010
Throughout its long history, coffee has endured both accolades and opposition.
Over the ages, some of the world’s greatest composers, thinkers and
statesmen have extolled coffee’s virtues, while others have denounced it
as a poisonous, mind-corrupting drug. Coffee has been praised by
certain religions and prohibited by others.
Some governments have subsidized coffee crops; others have imposed
steep taxes and duties on them. Doctors validate coffee’s health
benefits yet worry about its contribution to cardiovascular disease,
diabetes, and even cancer.
Coffee is more popular than ever, which contributes to its
contradictory status. In moderation, coffee poses minimal health risks
for most people. In some cases, coffee even appears to be protective.
But many North Americans now consume coffee in large quantities, which
can significantly damage our neuroendocrineimmune system over the long
term.
Neuro-what?
The neuroendocrineimmune system consists of the processes and
structures that form our central nervous systems, our hormonal systems,
and our immune systems, all of which are linked in complex
relationships.
For example, many of us know that when we are stressed, we get sick
more easily. Emotional and mental demands, especially if prolonged,
cause our stress hormones to increase, which means our immune systems
don’t work as well.
The complicated interplay of our neuroendocrineimmune systems
suggests that there is no clear division between mind and body. What we
think and experience is as much “us” as what our body does.
How do we know what we know?
It’s hard to get a clear picture of coffee’s health effects.
Epidemiological studies, which try to find relationships between
multiple lifestyle factors, can be hard to interpret.
For one thing, coffee drinking is correlated with other dietary and
lifestyle behaviours such as alcohol and nicotine consumption and a
sedentary lifestyle. In other words, people who drink a lot of coffee
also tend to drink and smoke, and be out of shape.
On the other hand, people who avoid coffee often do so for
health-related reasons. They’re also more likely to be health-conscious
in other ways, making health-promoting lifestyle choices such as
exercise. Comparing coffee drinkers with non-coffee drinkers thus misses
a number of important variables.
Second, there are vast differences in coffee’s pharmacological
constituents depending on the type of bean used in the study, the
methods of roasting, and the varying ways of preparing coffee, not to
mention the differences between commercially available instant coffee
versus freshly roasted organic coffee.
There are also differences in individual sensitivity to caffeine,
likely due to the genetic traits related to caffeine metabolism (see
“Coded for Caffeine”, in the Spezzatino Coffee issue), as well as
lifestyle influences. For example, the half-life of caffeine is shorter
in smokers than non-smokers, while the half-life of caffeine is doubled
in women taking oral contraceptives.
Finally, most research studies observe and measure the effects of a
single dose of caffeine rather than the effects of chronic ingestion.
Yet most coffee drinkers drink coffee daily.
As a number of studies have shown, single-dose experiments don’t
necessarily reflect the effects of our regular routines. For example,
researchers have shown that we can build tolerance to the cardiovascular
effects of caffeine within two to three days. Therefore, research
studies that show a given effect on the body from an acute single dose
bear little relevance to the chronic ingestion of caffeine.
In my naturopathic practice, I use evidence from epidemiological and
experimental studies. But I also draw on experience and a systematic
understanding of how our nervous, endocrine, and immune systems interact
in order to make educated guesses about coffee’s potential effects on
my patients.
Caffeine and your brain
Caffeine is one of coffee’s primary constituents with psychoactive
activities. It’s part of a group of substances collectively referred to
as methylxanthines. These alkaloids are well known for their ability to
increase cognitive abilities, improve energy, enhance well-being, and
increase arousal and alertness.
As mentioned elsewhere in the Spezzatino Coffee issue (see “Lab to
Lunch”), these effects occur largely because of caffeine’s ability to
block adenosine receptor sites throughout the body. However, there are
other neurochemical effects that are worth noting.
Once again, studies demonstrating the effects of caffeine on
neurotransmitters (chemicals that allow the cells of our nervous system
to communicate) don’t always give us a realistic picture.
First, the dose used in neurochemical studies generally exceeds quantities ingested during normal everyday life.
When animals are used, they are non-coffee drinkers. (It’s hard to
make mugs that small, and without opposable thumbs… well, let’s just say
there’ve been some unfortunate spills of hot liquid. Luckily, no legal
cases against McDonalds are pending.) Therefore, researchers use a
single dose of caffeine, which may not reflect the neurochemical effects
of chronic consumption of caffeine.
Second, neurotransmitters are produced in different amounts in
different areas of the brain simultaneously, and have very different
effects on mood and personality depending on where in the brain they’re
used.
Quick overview: serotonin is involved in mood and appetite
regulation; gamma-aminobutyric acid (GABA) typically inhibits neuronal
activity to cause relaxation and sleep; and acetylcholine is involved in
muscle contraction.
Chronic caffeine intake has been shown to increase the receptors of
serotonin (26-30% increase), GABA (65% increase), and acetylcholine
(40-50%). This may contribute to the elevated mood and perceived
increase in energy we feel after a coffee (which makes espresso a handy
pre-workout drink). Despite increasing receptors, caffeine also inhibits
the release of GABA, which contributes to our feeling of alertness.
Chronic caffeine intake also increases the sensitivity of serotonin
receptors. In other words, receptors specific to serotonin are more
responsive to serotonin present in the synaptic cleft — it’s sort of
like installing a bigger satellite dish to catch more of an existing
signal. One study showed a decrease in serotonin release, but an
increase in serotonin reuptake, leading to an overall increase in
serotonin levels. (Think of it as the brain’s natural recycling.)
In the human body, when neurotransmitter receptors increase in
number, or if they increase their sensitivity, it generally suggests a
reduction in functional capacity and activity of neurons associated with
those receptors.
Either the brain needs more chemicals to do the job, or the neurons
involved aren’t working as hard. This might mean that a certain
neurotransmitter is in short supply, or that its activity needs to
increase. In the case of caffeine and serotonin, this can partly explain
the mood-enhancing effects of drinking coffee.
Caffeine has also been shown to increase serotonin levels in the
limbic system, a relatively primitive part of our brain involved in
regulating basic functions such as hormonal secretions, emotional
responses, mood regulation and pain/pleasure sensations. This has a
similar mode of action as some antidepressant medications.
The increase in serotonin levels, combined with the increase in
serotonin receptors, cause the characteristic withdrawal symptoms (such
as agitation and irritability) when coffee intake is stopped. The brain
has come to expect more action in its serotonin receptors, and when its
abundant supply of happy chemicals is abruptly cut off, it gets crabby.
Indirectly, chronic caffeine intake may impact neurochemistry by
reducing cofactors – chemical partners – necessary for neurotransmitter
synthesis.
For example, coffee inhibits the absorption of iron, a key mineral
involved with the synthesis of serotonin and dopamine. Additionally, we
need the activated form of vitamin B6, pyridoxal-5-phosphate, to
synthesize serotonin, dopamine and GABA. Coffee consumption can decrease
amounts of circulating B-vitamins, which could affect neurotransmitter
synthesis in another way.
Thus, caffeine impacts whether certain chemicals are available; how
receptive our brains are to them; and whether we’re even making those
chemicals in the first place.
Caffeine and your hormones
Both scientists and lay people know the effects of caffeine consumption on hormones relatively well.
For example, quickly perusing the internet brings up numerous sites
claiming that caffeine “wears out the adrenal glands”. But not
surprisingly, this may not be entirely accurate. While we know many
things about the impact caffeine has on human’s stress physiology,
certain mechanisms of how it occurs are still relatively mysterious.
Caffeine strongly affects the activity of the
hypothalamic-pituitary-adrenal (HPA) axis: the linked system of
hypothalamus and pituitary glands in the brain, and the adrenal glands
that sit atop the kidneys. The HPA axis influences the body’s ability to
manage and deal with stress, both at rest and during activity.
The adrenal glands secrete two key hormones: epinephrine and
cortisol. Epinephrine, or adrenaline, increases respiration rate, heart
rate and blood pressure; while cortisol frees up stored glucose, which
we need in greater amounts during times of perceived stress.
As you can imagine, for our early hominid ancestors, the ability to
quickly access and use stored energy was a helpful feature. However,
while this is an excellent acute response to an immediate stress (such
as being chased by a bear), it’s a damaging response when the stress is
chronic (such as the cumulative demands of our daily modern lives).
Studies in humans have shown that caffeine increases cortisol and
epinephrine at rest, and that levels of cortisol after caffeine
consumption are similar to those experienced during an acute stress.
Drinking coffee, in other words, re-creates stress conditions for the
body.
While scientists have some ideas about how caffeine increases HPA hormones, the exact mechanism still remains unclear.
Compounding the problem, people tend to consume more caffeine during
stressful periods (as nearly every student during exam season knows
well). They add stress to stress, potentially making things even worse.
Rat studies have shown that caffeine consumption during chronic
stress increased cortisol, blood pressure, and other negative hormonal
events. Chronically stressed rats who consumed caffeine ended up sicker,
and died sooner, than rats experiencing chronic stress without caffeine
consumption.
However, again, chronic caffeine consumption leads to a degree of
physiological tolerance and thus among people who drink coffee
regularly, blood pressure, heart rate, excessive urination, epinephrine
production, and even anxiety and stimulation may not be as strongly
affected.
Other hormonal effects of caffeine appear to be related to
competitive actions for metabolism in the liver. Like a gridlocked city,
the liver only has so many “roads”, or metabolic pathways, available.
More “cars” (i.e. chemicals) on the “roads” slow things down.
For instance, the liver detoxifies caffeine using the CYP1A2 enzyme
system, which is also responsible for initial metabolism of estrogen
during Phase I clearance by the liver. This is one reason caffeine is
likely metabolized more slowly in women taking oral contraceptives or
postmenopausal hormone replacement therapy.
While research showing the effects of chronic caffeine consumption on
circulating levels of estrogen isn’t yet available, researchers have
suggested that caffeine consumption may lower the risk of breast cancer
by upregulating the CYP1A2 isoenzyme and thus improving estrogen
metabolism.
Caffeine and your immune system
The immune system is a vast and complex system that communicates
extensively with itself and connects to every other system of the body.
For simplicity’s sake, we’ll separate the immune system into two
sections: the Th1 side (T-cell mediated system) and the Th2 side (B-cell
mediated antibody system). The Th1 side is our innate immune system –
the system that develops early in life – and is our first line of
defense against pathogens such as viruses and bacteria.
On the other hand, the Th2 system is acquired: as we are exposed to
pathogens throughout our lives, we produce antibodies to them.
Antibodies recognize foreign invaders if exposed to them repeatedly, and
will launch a stronger and swifter attack if a second invasion takes
place. Because of this system, someone will experience a reaction to
poison ivy only after their second exposure.
The two sides of this system act as a seesaw: when one side is dominant, the other side is suppressed.
Research suggests that chronic caffeine exposure shifts the immune
system to a Th2 dominance. This may help the treatment of Th1 dominant
autoimmune conditions, but in the average person, it may elevate the Th2
system excessively, creating an overzealous Th2 immune response. A
dominant Th2 system predisposes individuals to hypersensitivity
reactions such as asthma and allergies.
To date, there have not been any correlations between chronic
caffeine consumption and increased prevalence of Th2 associated
conditions, but based on existing knowledge of caffeine and the immune
system, the link seems plausible.
In my clinical naturopathic practice, we have seen certain autoimmune
conditions improve with caffeine consumption, while others get worse.
If someone with rheumatoid arthritis (an autoimmune condition that
causes joint pain and inflammation) says they get significantly more
joint pain when they drink coffee, one could hypothesize that their Th2
system is dominant, and the caffeine is promoting destruction of their
joints by further stimulating this already overzealous Th2 system.
Putting it all together
No known studies demonstrate statistically significant correlations
between coffee over-consumption and the unwinding of the
neuroendocrineimmune system. We just don’t know for sure yet how all the
puzzle pieces fit together.
However, certain theoretical pathways can be created, and have been
observed clinically. We can also make some informed speculation based on
what we already know of the neuroendocrineimmune system’s
interrelationships.
Effects on metabolism
Chronic coffee consumption increases insulin resistance, a situation
in which the body cannot effectively deliver glucose into the cells of
the body. In this situation, insulin, which helps transport glucose into
the cells, cannot do its job well because the body’s cells are less
receptive.
This typically occurs with a diet high in refined sugars and
starches. Thus, the body must release ever-larger amounts of insulin to
do the job. Like parents tuning out their screaming toddler, the body
becomes less and less sensitive to insulin’s effects, which means more
circulating glucose, which means more insulin release… and so on.
It’s a vicious cycle. And, unfortunately, it’s a cycle that currently
occurs in the majority of North Americans. Combine the standard Western
diet high in refined carbohydrates with stress and a high caffeine
intake, and you have a potential recipe for metabolic disaster.
Insulin stimulates the release of interleukin-6 (IL-6), which is a Th2 cytokine (a cell signaling molecule).
If IL-6 is chronically elevated (in this case, from high insulin
levels), it may lead to a Th2 dominance and potential hypersensitivity
from an overzealous antibody response. This can result in acquired
sensitivities to foods and chemicals.
Interleukin-6 also stimulates the release of cortisol, which, as a
glucocorticoid hormone, increases the body’s glucose level. This leads
to an increased demand for insulin, which is problematic because of the
insulin resistance that started the cascade in the first place.
Let’s recap: a diet high in refined sugars and starches leads to more circulating glucose.
- More glucose means more insulin needed to dispose of it.
- More insulin means cells tune out, which means even more insulin
dumped into the bloodstream (especially if people continue to eat this
high-carbohydrate diet).
- More insulin means insulin resistance — possibly aggravated by high caffeine consumption.
- More insulin means more IL-6 and more inflammation and hypersensitivity.
- More IL-6 means more cortisol, which means more glucose… and here we are, back at the beginning of a very nasty cycle.
Consider this as you cradle your extra-large coffee and glazed donut this morning during your white-knuckle commute to work.
Effects on brain function and mood
The elevated blood sugar and insulin don’t just stop at inflammation.
They can create imbalances in the neurotransmitters serotonin, dopamine
and GABA, which can lead to sub-clinical mood problems such as mild
depression (aka “the blues”), low motivation, irritability, and impaired
cognition.
People with chronically high glucose, insulin resistance, systemic
inflammation, and stress typically have “fuzzy brain”, memory loss,
lethargy, and/or a short fuse.
Coupled with the potential iron and B-vitamin deficiencies created by
coffee, which, again, cause impaired synthesis of key
neurotransmitters, this may result in mood states where people feel the
need for coffee to keep themselves functioning properly.
Have you ever felt that you desperately needed coffee for a
pick-me-up? Do you tell people, “I’m a grouch until I get my coffee?” If
so, you may be experiencing this situation.
Caffeine in moderation is likely not an issue for most people.
Indeed, it may actually have health benefits. (See the article on
traditional Chinese medicine and coffee, in the
Spezzatino
Coffee issue) Problems occur when we drink coffee all day long and
combine it with sedentary lifestyles, poor diets, and chronically
elevated stress.
We drink much more caffeine than our great-grandparents did. Not only
has our coffee consumption increased, but the market is saturated
(pardon the pun) with other sources of caffeine. There is much more
refined sugar available to us, and our lives move at a much faster pace.
The industry standard size for a cup of coffee is six ounces. If
you’re North American and under 40, I bet you don’t even own a six-ounce
glass of anything – never mind finding a cup that size at the local
coffee shop!
It’s the perfect storm: caffeine, stress, sugar, and sedentary
living. This combination and its complex relationships with your
neuroendocrineimmune system may be affecting you more than you realize.
Systems in our body are closely interconnected. Stimulation of one
area can have far-reaching effects, especially if the stimulation is
dramatic and/or prolonged.
Large amounts of caffeine likely have numerous negative impacts on
the body that research has not yet elucidated, but if we piece the
available studies together, such impacts appear to be very real
possibilities.
Follow the evidence that your body offers you. Pay attention to how you feel when you drink coffee.
Do you feel good for a short period, then shaky and irritable? Do you notice more pain or other kinds of physical distress?
If you’re experiencing any of the symptoms I’ve mentioned above,
ranging from anxiety to inflammation, consider bringing a little decaf
into your life.
Roast your own coffee
Brought to you by the creators of Precision Nutrition, Spezzatino
Magazine is an encyclopedia of food, with each issue focusing on a
single food such as: basil, grapes, wild game, tomatoes, fish, coffee,
chocolate, and more.
In volume 8, our biggest and best issue yet, we focus on coffee. (And this article comes directly from the magazine.)
Because you’re a PN reader, we’d like to share with you some
additional goodies, including another article on how to roast your own
coffee at home, which may be healthier than drinking the commercial
varieties. So click the link below, check out volume 8, and get your
free stuff.
Free Stuff – Roast Your Own Coffee Beans
Learn more
To learn more about making important improvements to your nutrition
and exercise program, check out the following 5-day video courses.
They’re probably better than 90% of the seminars we’ve ever attended
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Source:
http://www.precisionnutrition.com/coffee-and-hormones
Thus, the Swing Kids (German: Swingjugend)
arrived. Mostly concentrated in large cities like Berlin, the Swing
Kids used music as a political tool against the Nazi party. The name of
the movement itself poked fun at Nazis. "Swing Kids" or "Swing Youth"
was a parody on the numerous “youth groups” promoted by the Nazi
government. They also used their greeting “Swing Heil," as a parody of
“Sieg Heil,” the Nazi salute.
The
beginnings of the swing era can be traced to developments of larger bands
by Fletcher Henderson in New York, and Bennie Moten in Kansas City. Fletcher
Henderson along with his brother Horace and with Don Redman created the pattern
for swing arrangments. Henderson helped establish the independent use of trumpet,
trombone, saxophone, and rhythm sections with the use of soloists. A swing
score generally has specific notes for each instrument to play in every measure.
Then the music arranger decides which measures will be used for solo improvisation.
The score is then taken to a music copyist who extracts the individual parts
for the various instruments. 
Bands
of the swing era produced a much fuller sound than the sound produced by earlier
dixieland jazz bands. The resulted from the use of two to three times as many
players. Because there were more players, swing music was organized in a homophonic
construction. This resulted in the music sounding less complex and more organized
in its effect. Block chords used by swing bands are a prime example of homophonic
construction.
