The
information in this column is intended for informational
purposes only, and does not constitute medical advice or
recommendations by the author. Please consult with your
physician before making any lifestyle or medication changes, or if you
have any other concerns regarding your health.
STRESS
& YOUR RISK OF
HEART ATTACK
There
is a great deal of
anecdotal observation linking prolonged levels of increased stress with
cardiovascular events such as angina (chest pain due to narrowed
coronary
arteries), heart attack, stroke, and death due to these conditions. The precise mechanisms
whereby chronic
psychological stress increase cardiovascular-related disease and death
are not
completely understood at this time.
During this prolonged period of pervasive stress and
distress, as our
nation confronts the worst economic crisis since the Great Depression,
a timely
research study on the topic of psychological stress and cardiovascular
disease
risk has just been published in the Journal
of the American College of Cardiology.
In
this prospectively
conducted study, 6,576 clinically healthy men and women, with an
average age of
50 years, were followed for an average of 7.2 years.
At the onset of this clinical research study,
extensive psychological and physiological and laboratory profiles were
obtained
on each patient volunteer. These
profiles
included previously validated psychological, behavioral and physical
health
questionnaires, as well as laboratory testing for C-reactive protein,
cholesterol
levels, and other cardiovascular disease risk factors.
All patient volunteers were also evaluated
for evidence of obesity and high blood pressure.
After completing this comprehensive
assessment of potential cardiovascular disease risk factors, these
6,576 men
and women were carefully observed, for an average of 7 years, for the
new onset
of acute cardiovascular disease events, including heart attack
(myocardial
infarction) or the urgent need for angioplasty or coronary artery
bypass
surgery; as well as for the new onset of heart failure, stroke, or
death due to
an acute cardiovascular event.
During
the course of this
study, this cohort of middle-aged men and women experienced 223 acute
cardiovascular events, 63 of which were fatal.
The results of this clinical study, after analyzing the
large amount of
data collected, were both intriguing and instructive.
First of all, high levels of psychological
distress were closely linked with the following behavioral and
physiological
factors: an increased likelihood of smoking cigarettes, reduced levels
of
physical activity and exercise, elevated levels of serum C-reactive
protein,
and high blood pressure. A
closer
analysis of these same stress-associated factors revealed an even more
important finding. The
majority of the
observed stress-associated risk for acute cardiovascular events was
directly
related to behavioral activities,
while only a minority of the overall stress-related risk was linked to
non-behavioral physiological causes.
Altogether,
approximately 65
percent of the stress-associated risk for cardiovascular disease events
in this
large group of patient volunteers was linked to behavioral choices on
the part
of individuals, including an increase incidence of cigarette smoking
and a
decreased level of physical activity and exercise.
Stress-related hypertension was judged to
contribute about 13 percent of the overall risk of acute cardiovascular
events
observed in this study, while increased levels of the inflammatory
C-reactive
protein appeared to contribute to approximately 6 percent of the risk
(both
blood pressure and C-reactive protein levels have long been known to
rise in
response to stress, as well as in response to smoking).
This
study is important, and
for several reasons. In
this study, the
development of cardiovascular events, including death, were carefully
followed
in a thoroughly evaluated cohort of initially health middle-aged men and women, and this large group of
patient volunteers were followed for, on average, the better part of a
decade. All patient
volunteers were
carefully and comprehensively evaluated for both psychological and
physiological
abnormalities at the onset of the study.
These research methods, therefore, provided a very rich
and powerful set
of data upon which this study’s conclusions are based.
We
have long known that
prolonged levels of psychological stress directly affect circulating
levels of
hormones and other stress-response proteins that can accelerate the
development
of cardiovascular diseases. However,
importantly, this study reveals that engaging in risky health-related
behaviors
appears to underlie the overwhelming majority of the increased risk for
cardiovascular disease that is associated with psychological stress,
rather
than non-behavioral stress-related physiological changes.
The
results of this study
suggest that the majority of stress-related cardiovascular disease
risks can
probably still be prevented simply by maintaining a healthy lifestyle
and, most
importantly, by refraining from unhealthy behaviors that tempt us when
times
are tough, and when we are feeling stressed.
Even when you are feeling stressed, as much of nation is
currently
experiencing during the ongoing economic crisis, please abstain from
tobacco,
minimize red meat and other fatty foods in your diet, and avail
yourself to
whatever forms of moderate and frequent exercise are available to you
(at least
4 to 5 times per week). If
you have high
blood pressure, or elevated serum levels of C-reactive protein or
cholesterol,
then ask your doctor to develop a treatment plan for you, and stick
with this
plan! If you are
one of the estimated 48
million people in this country who, shamefully, do not have health
insurance
(or one of the many millions more who have completely inadequate
healthcare
insurance), you can still improve your blood pressure, and serum
cholesterol
and C-reactive protein levels, by cutting the fat and excess calories
from your
diet, and by exercising regularly and frequently, and by avoiding
tobacco and
excessive alcohol. As
an added benefit,
engaging in these relatively modest healthy lifestyle behaviors, you
will also
increase your ability to psychologically and emotionally cope with the
high
levels of stress that many of us are feeling these days.
VITAMIN
D & THE PREVENTION OF COLON &
RECTAL POLYPS
As
most readers of this
column already know, I have a very strong interest in disease
prevention
through dietary and other and holistic lifestyle strategies. As an oncology physician,
I have especially
been interested in lifestyle and dietary approaches to cancer
prevention (my
new book, “A Cancer Prevention Guide for the Human Race,” should be
available
in the fall or winter of 2009).
Recently,
several very large
prospective, randomized, placebo-controlled cancer prevention trials
have
published their results regarding antioxidant vitamins and related
dietary
supplements, and the news from these large trials has been, uniformly,
disappointing. However,
while the
putative cancer prevention properties of Vitamin E, Vitamin C, Vitamin
A,
beta-carotene and selenium are now in serious doubt, Vitamin D, which
actually
functions more like a hormone than a vitamin, continues to merit
serious study
as a potential cancer prevention aid (I should note, however, that a
recent
prospective randomized clinical trial has called into question a role
for
Vitamin D as a breast cancer prevention agent).
The
two most important areas
where Vitamin D continues to show some ongoing promise, in addition to
its
vital role in preserving skeletal health, are in the prevention of
colorectal
cancer and cardiovascular diseases.
While the research data in this area remains somewhat
contradictory,
there are still several high-quality clinical research studies
available that
suggest a potential role for Vitamin D in reducing the risk of cancers
of the
colon and rectum (unfortunately, however, most of these studies rely
upon
relatively low-powered research methods).
Now,
a newly published
summary in the journal Cancer Epidemiology Biomarkers
& Prevention
provides important additional information regarding Vitamin D’s
potential role
in preventing the colon and rectal polyps that give rise to the vast
majority
of colorectal cancers.
In
this meta-analysis study
from Harvard
University,
17 previously published
epidemiological studies were reviewed and statistically evaluated. In particular, these 17
clinical studies
evaluated the serum levels of Vitamin D, dietary intake of Vitamin D,
and the
incidence of precancerous adenomatous colorectal polyps in healthy
patient
volunteers.
Based
upon the results of
this meta-analysis, on average, patients with the highest levels of
Vitamin in
their blood were 30 percent less likely to be diagnosed with colorectal
adenomas. When
considering more advanced
adenomas, which are much more likely to progress to colorectal cancer,
patients
with the highest levels of Vitamin D in the blood were 36 percent less
likely
to be diagnosed with this more aggressive type of polyp.
Increased
dietary Vitamin D
intake was also associated with a decrease in the risk of developing
new or
recurrent adenomatous polyps of the colon and rectum.
However, the protective effect of increased
dietary Vitamin D intake was not as robust as was observed in patients
with
measured high levels of this vitamin in their blood, and only a
marginal
decrease in colorectal polyp incidence was identified among patients
who
consumed higher levels of Vitamin D in their diet.
While
the 17 previous
research studies that were analyzed in this new report tended to rely
upon
lower-powered research methods, the findings of this analysis are in
agreement
with multiple other epidemiological studies that have identified a
modest-to-moderate
potential protective role against colorectal cancer for Vitamin D. However, I must caution
readers that Vitamin
D, like almost everything else in our diet, can be toxic in large
quantities
(or even in smaller quantities if you have kidney disease, parathyroid
gland
abnormalities, or other preexisting health conditions involving
abnormal
calcium or Vitamin D metabolism).
Excessive intake of Vitamin D can result in serious health
problems, and
so I recommend that you only consider taking Vitamin D supplements
above the
current recommended range following consultation with your primary
physician or
an endocrinologist.
Disclaimer:
As always, my advice to readers is to seek the advice of your physician
before making any significant changes
in
medications, diet, or level of physical activity.
