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1. How much coffee is safe to drink?
Generally medical experts say that 300 milligrams or 2 to 3 cups of a
day is a safe level for coffee drinkers. 4 to 5 cups and above are
considered by some as already excessive and may pose risks.
?Like most diet-related recommendations, if one is going to consume
foods/beverages with caffeine, it is suggested that intake be kept at
a moderate level. ?Moderate? can be a difficult term to define because
the word has many meanings. Typically, nutrition and health experts
recommend keeping caffeine consumption at levels that are equivalent
to 300 milligrams, which is equal to about 3 cups of coffee. Note:
Caffeine recommendations are often given in terms of ?number of cups
of coffee? since that is the caffeine-containing beverage most often
consumed by Americans. This recommendation sounds easy, right? If you,
family members, or co-workers are coffee drinkers, what is the size of
your coffee cup? A ?cup? of coffee is generally 5-6 ounces and
supplies about 100 milligrams of coffee. If one consumes coffee out of
a mug, then that ?cup? of coffee is giving you more caffeine. Also,
the amount of caffeine in coffee or tea can depend on how it is
brewed, which adds another level of difficulty in making caffeine
recommendations based on the number of cups of coffee. Note: Older
adults and women who are either thinking about becoming pregnant, are
currently pregnant, or are currently lactating probably want to keep
caffeine intake at levels less than 200 milligrams or 2 cups of coffee
(see the sections below on caffeine?s effect on the elderly, and
during pregnancy and lactation).Can one consume too much caffeine?
Almost any substance can be consumed in excess - including caffeine.
Excessive intakes of caffeine is often defined as more than 500
milligrams of caffeine per day, which is roughly similar to 5+ cups of
coffee(remember, a cup of coffee is 5-6 ounces).?
?Nuri-Facts?
http://216.239.53.104/search?q=cache:v8Fxe3CKoe8J:fcs.tamu.edu/food_and_nutrition/nutrifacts/issue10.PDF+coffee+safe+%22number+of+cups%22+site:.edu&hl=en&ie=UTF-8
?The relationship between reported coffee consumption and specific
causes of death was examined in 9484 males enrolled in the Adventist
Mortality Study in 1960 and followed through 1985. Coffee consumption
was divided into three levels: less than 1 cup per day, 1-2 cups per
day, and greater than or equal to 3 cups per day. Approximately one
third of the subjects did not drink coffee. Cause-specific mortality
rates were compared using survival analysis including Cox's
proportional hazard model, and controlling for potential confounders
such as body mass index, heart disease and hypertension at baseline,
race, physical activity, marital status, educational level, smoking
history, and dietary pattern. Inclusion of interaction terms between
coffee consumption and attained age as time-dependent covariates
allowed the hazard ratio to vary with age. Univariate analyses showed
a statistically significant association (p less than 0.05) for coffee
consumption and mortality for most endpoints. Multivariate analyses
showed a small but statistically significant association between
coffee consumption and mortality from ischemic heart disease, other
cardiovascular diseases, all cardiovascular diseases, and all causes
of death. For the major causes of death, the hazard ratios decreased
from about 2.5 at 30 years of age to 1.0 around 95 years of age. These
results indicate that abstinence from coffee leads to compression of
mortality rather than an increase in lifespan.?
?Coffee and Tea?
http://www.ithyroid.com/coffee_and_tea.htm
?Both studies showed an association between the number of cups of
coffee drunk daily and the risk of producing rheumatoid factor. In
fact, one of the studies showed those who drank four or more cups of
coffee each day were twice is likely to have the marker for rheumatoid
arthritis. They found the same results even when they adjusted for
other risk factors such as age, obesity, alcohol consumption, and
smoking.?
?Coffee Drinking May Cause Rheumatoid Arthritis?
http://www.edocamerica.com/medical_news/default.asp?page=16
?The American Heart Association reports that studies investigating a
direct link between caffeine, coffee drinking and coronary heart
disease ?have produced conflicting results." However, according to the
association, "moderate coffee drinking (one to two cups per day)
doesn't seem harmful.?"
?How safe is drinking coffee, really??
http://www.mlive.com/news/kzgazette/index.ssf?/base/features-1/1074707401186040.xml
?Moderate coffee drinking, up to three cups, improves intellectual
performance--but only if you are fatigued. Studies also suggest
caffeine or coffee could help prevent the neurodegenerative
Parkinson's Disease, inhibit alcoholics' craving to drink, help
migraine sufferers, relieve depression and make depressed people less
likely to commit suicide. But caffeine also interferes with sleep and
withdrawl can spark headaches. Research also suggests caffeine can
trigger panic attacks in people who are susceptible to them.?
?Coffee from the ground up?
http://www.mindfully.org/Food/Coffee.htm
------------------------------------
2. Does coffee affect the thyroid?
According to most medical studies, coffee has a positive effect on the thyroid.
?In a case-control, serially matched study, 70 patients with thyroid
cancer, 55 with benign thyroid disease and 71 controls were
interviewed in regard to a variety of socioeconomic, social and
dietary characteristics. Statistical analysis revealed a strikingly
negative (p less than 0.05) association between benign and malignant
thyroid disease and consumption of coffee. After adjustment for
possible confounding variables, the association remained statistically
significant. The mechanism by which coffee consumption may play a
protective role against development of benign or malignant thyroid
neoplasms may be the stimulatory effect of caffeine on the
intracellular cyclic AMP production, which is known to inhibit cell
growth.?
?Coffee and Tea?
http://www.ithyroid.com/coffee_and_tea.htm
?Thyroid cancer risk was not associated with consumption of coffee or
tea. These findings were consistent in both gender-specific and
histology-specific (papillary and follicular) analyses.?
?A pooled analysis of case-control studies of thyroid cancer:
cigarette smoking and consumption of alcohol, coffee, and tea.?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14674742&dopt=Abstract
?Other dietary variables, including milk, beer and hard liquor, and
coffee were not related to thyroid cancer risk. Among the papillary
sample, risk increased with longer use of multivitamins (OR = 2.9, 95%
CI = 1.2-7.4 for > 10 years of use).?
?Lifestyle and other risk factors for thyroid cancer in Los Angeles County females?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12160598&dopt=Abstract
?Risk factors for thyroid carcinomas and adenomas were investigated
using a standard questionnaire in a case-control study in Southwestern
Germany, a known iodine deficiency area?The protective role of coffee
drinking and the consumption of cruciferous vegetables, such as
broccoli, were confirmed for both genders. A high consumption of
tomatoes (> 200/year) was associated with an elevated risk of > 2.5
for malignant tumors but not for benign tumors in both genders.?
?Association between malignant tumors of the thyroid gland and
exposure to environmental protective and risk factors?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11048335&dopt=Abstract
?To analyze the risk factors of thyroid cancer among Japanese women
who generally consume much more iodine than Europeans, we conducted a
hospital-based case-referent study at Aichi Cancer Center Hospital
(ACCH) in Nagoya, Japan? Thyroid cancer cases consumed coffee less
frequently (OR = 0.5) and had had more experience of delivery than
referents (> or = 3 times; OR = 2.5)? For the multivariate analysis,
past history of thyroid diseases (OR = 4.3) was positively associated
with the risk of thyroid cancer and everyday coffee consumption (OR =
0.6) tended to decrease the risk.?
?Risk factors of thyroid cancer among women in Tokai, Japan?
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8952218&dopt=Abstract
--------------------------------------
3. How does it affect estrogen levels?
Unlike its effects for thyroid, it seems that coffee isn?t good for
estrogen levels.
?Scientists from Brigham and Women?s Hospital believe that consuming
more than 2 cups of coffee each day could boost estrogen levels in
women that could worsen conditions like endometriosis and breast pain.
According to their study, women who drank the most coffee had higher
levels of estradiol during the follicular phase of their menstrual
cycle, regardless of their age, body mass index, caloric intake,
smoking status, or intake of alcohol and cholesterol. Those who
consumed at least 500 mg of caffeine each day (4-5 cups of coffee) had
close to 70% more estrogen during the follicular phase than woman who
had no more than 100 mg of caffeine.?
?Womens Health in the News?
http://www.womenshealthinthenews.net/issue11_26_2001.html
?Drinking more than two cups of coffee daily may boost estrogen levels
in women and could exacerbate conditions such as endometriosis and
breast pain, study findings suggest.?
?According to the researchers, women who drank the most coffee had
higher levels of estradiol, a naturally occurring form of estrogen,
during the early follicular phase, or days 1 to 5 of the menstrual
cycle.?
?Coffee May Boost Estrogen Levels in Women?
http://66.102.7.104/search?q=cache:kgflo7QiZywJ:www.fibroid101.com/coffee.htm+coffee+%22estrogen+levels%22+study&hl=en&ie=UTF-8
?In a study done at the Brigham and Women's Hospital in Boston,
researchers evaluated for the effect of coffee on the hormone levels
of nearly 500 women, aged 36 to 45, who were in the first five days of
their menstrual cycle. They found that the more coffee a woman
consumed, the higher her level of estrogen was likely to be. In fact,
women who consumed four to five cups of coffee per day?the equivalent
of at least 500 milligrams of caffeine?during the early part of their
menstrual cycle produced nearly 70 percent more estrogen than women
who consumed less than one cup of coffee a day?or 100 milligrams of
caffeine. In fact, caffeine intake from all sources, including black
tea, cola drinks, cocoa, chocolate, and over-the-counter medications
such as Drisdan, Midol, and Excedrin, was linked with higher estrogen
levels. Based on these results, researchers cautioned women against
drinking more than two cups of coffee per day, because high levels of
estrogen can exacerbate PMS symptoms.?
?Coffee and PMS?
http://www.drlark.com/nc/pms_coffee.asp
?Coffee and Women?
http://www.drlam.com/opinion/coffee_and_women.cfm
?Coffee Increases Estrogen in Women?
http://www.mercola.com/2001/dec/8/coffee_estrogen.htm
---------------------------------
4. Other health issues of drinking coffee.
Due to some new research, there are conflicting views on the effects
of coffee for example on heart disease and Parkinson?s disease.
------------------------------------------
Cancer and Diseases:
?Caffeine is one of the most thoroughly investigated ingredients in
the food supply, including its effects on women's health. Health
concerns associated with caffeine include ulcers, fibrocystic breast
disease, cardiovascular disease, heartburn, cancer and birth defects.?
?Health concerns specific to women and caffeine include breast cancer,
fibrocystic breast disease and osteoporosis. After careful review,
there is not adequate evidence to link breast cancer with caffeine
consumption.?
?An even more discussed concern over caffeine intake by women is the
incidence of fibrocystic breast disease. Also known as benign breast
disease, it is characterized by benign fibrous lumps and breast
tenderness. It was once thought to be the result of caffeine in the
diet. Some women report decreased tenderness with elimination of
caffeine, but this is not universal. The largest study to date
concluded that there is no evidence of a connection between
fibrocystic breast disease and caffeine.?
?The case of caffeine and osteoporosis is more convincing. Caffeine is
a diuretic, meaning it increases urine output. Therefore, with
increased intake, we can lose more minerals like calcium in the urine.
For women at risk for osteoporosis and postmenopausal women, this can
pose a problem.?
?Women's Health Issues?
http://www.ext.colostate.edu/pubs/foodnut/09360.html
?THE USE OF CAFFEINE?
http://www.andrews.edu/NUFS/caffeine.html
?Coffee and Health?
http://lrs.ed.uiuc.edu/students/tchen3/health.html
?Caffeine?
http://216.239.53.104/search?q=cache:7_awIoxyTyAJ:www.brown.edu/Student_Services/Health_Services/Health_Education/Nutrition/caffeine.htm+coffee+health+site:.edu&hl=en&ie=UTF-8
?For coffee lovers, the good news is that scientists found no evidence
that coffee drinking was connected to heart disease. In fact, deaths
from heart disease were highest in those who did not drink coffee.
Those who abstained or drank less than one cup a day were more likely
to report symptoms like back problems, constipation, nausea,
gallstones, and congestion. Unfortunately, consistent with other
studies showing that coffee drinkers may have poorer health habits
than those who abstain, the people who drank coffee in this study were
more likely to smoke and have higher cholesterol levels. The women who
drank coffee also had greater amounts of body fat.?
?Study Shows Coffee Not Hazardous to Heart Health?
http://www.healthandage.com/Home/gid2=1078
In a contrasting study it shows that coffee is a major contributor to
heart disease.
?In numerous studies, caffeine has also been shown to raise blood
pressure levels. A recent study conducted by Dr. James Lane and
researchers at Duke University Medical Center found blood pressure
levels elevated from caffeine ingested during the day and lasting
throughout the evening. This sustained increase in blood pressure
raises concern, even presenting a clear correlation between even minor
elevations in blood pressure and increased risk for coronary heart
disease.?
?Over time, daily blood pressure elevations and increased stress
hormones caused by caffeine consumption could contribute to an
increased risk of coronary heart disease among adults.?
?Caffeine: Friend or Foe for Heart Health??
http://www.healthyroads.com/mylibrary/data/ash_ref/htm/art_caffeinefriendorfoeforhearthealth.asp?
-------------------------------------------
Sleep Deprivation:
?Besides the slight increased risk of heart disease, there are other
problems. First, caffeine is a stimulant whose consumption allows you
to get by with less sleep and reduces the depth of sleep. Such sleep
deprivation results in higher levels of the stress hormone cortisol
and it interferes with glucose metabolism, leading to insulin
resistance. This insulin resistance (and subsequent higher baseline
glucose levels) further promotes aging, blood vessel disease and other
problems. In other words, caffeine consumption promotes inadequate
sleep and less sleep promotes disease and premature aging.?
?Discovery Channel :: Second Opinion: Ask The Doctor?
http://dsc.discovery.com/anthology/secondopinion/ask/ask_archive4.html
---------------------------------------
Rheumatoid Arthritis:
?A new report suggests heavy coffee drinking may raise your risk of
developing rheumatoid arthritis. The findings are based on two studies
of more than 25,000 people in Finland.?
?Both studies showed an association between the number of cups of
coffee drunk daily and the risk of producing rheumatoid factor. In
fact, one of the studies showed those who drank four or more cups of
coffee each day were twice is likely to have the marker for rheumatoid
arthritis. They found the same results even when they adjusted for
other risk factors such as age, obesity, alcohol consumption, and
smoking.?
?The authors concluded that drinking coffee plays some role in the
development of rheumatoid arthritis. They suggest that some ingredient
in coffee triggers the production of rheumatoid factor, which may
later lead to the disease.?
?Coffee Drinking May Cause Rheumatoid Arthritis?
http://www.edocamerica.com/medical_news/default.asp?page=16
?Study Links Coffee Consumption to Arthritis Risk?
http://thyroid.about.com/library/news/blcoffe.htm
----------------------------------
Pregnancy Risks:
?Pregnant women are advised against drinking beverages with caffeine
since this cause central nervous system stimulation effects in the
baby in the womb and also tends to affect the birth weight of the
baby. In some cases birth defects have been reported. There are many
medications which should not be taken during pregnancy and during
breast-feeding as they adversely affect the health of the baby. They
include, among many others, nicotine (tobacco), alcohol, insulin,
caffeine, cocaine, theophylline (asthma drug), and a long list of
prescription drugs. All pregnant women are well-advised to have
regular prenatal checkups.?
?Caffiene: Any Health Risks??
http://www.cdc-cdh.edu/hospital/cardio/art44.html
?In the first of the latest studies to be published, in the journal
Paediatric and Perinatal Epidemiology, Dr Massimo Giannelli and
colleagues from the London School of Hygiene and Tropical Medicine
examined caffeine and the risk of miscarriage.?
?They studied 160 women from Reading, Berkshire, who had just had a
miscarriage along with 314 women who were still pregnant.?
?They found that, compared to those who consumed low levels of
caffeine one cup of coffee, four cups of tea or three cans of cola
women who consumed 300mg of caffeine, or four cups of coffee, were
around twice as likely to miscarry.?
?The Risk to Pregnant Women in a Cup of Coffee?
http://www.healthy.net/asp/templates/news.asp?Id=7780
----------------------------------
Coffee Reduces Risk to Diabetes
?More than 125,000 study participants who were free of diabetes,
cancer, and cardiovascular disease at the start of the study were
selected from the on-going Health Professionals Follow-up Study and
the Brigham and Women?s Hospital-based Nurses Health Study. Some
41,934 men were tracked from 1986 to 1998 and 84,276 women from1980 to
1998 via food frequency questionnaires every two to four years to
assess their intake of both regular and decaffeinated coffee.?
?During the span of the study, 1,333 new cases of type 2 diabetes were
diagnosed in men and 4,085 among the women participants. The
researchers also found that for men, those who drank more than six
cups of caffeinated coffee per day reduced their risk for type 2
diabetes by more than 50 percent compared to men in the study who
didn?t drink coffee. Among the women, those who drank six or more cups
per day reduced the risk of type 2 diabetes by nearly 30 percent.
These effects were not accounted for by lifestyle factors such as
smoking, exercise, or obesity. Decaffeinated coffee was also
beneficial, but its effects were weaker than regular coffee.?
?Long-Term Coffee Consumption Linked to Reduced Risk for Type 2 Diabetes?
http://www.hsph.harvard.edu/press/releases/press01052004.html
---------------------------
Beneficial for Parkinson?s Disease and other ailments:
?Want a drug that could lower your risk of diabetes, Parkinson's
disease, and colon cancer? That could lift your mood and treat
headaches? That could lower your risk of cavities??
?Consider this: At least six studies indicate that people who drink
coffee on a regular basis are up to 80% less likely to develop
Parkinson's, with three showing the more they drink, the lower the
risk. Other research shows that compared to not drinking coffee, at
least two cups daily can translate to a 25% reduced risk of colon
cancer, an 80% drop in liver cirrhosis risk, and nearly half the risk
of gallstones.?
?Coffee: The New Health Food??
http://my.webmd.com/content/Article/80/96454.htm?z=1728_00000_1000_nb_04
But in another study it seems that it increases the risk on women but not on men.
?Women who drink more than six cups of coffee each day and are also
receiving hormone replacement therapy have an increased risk of
developing Parkinson's disease, Harvard researchers reported.?
?Numerous studies have demonstrated that intake of caffeine among men
is associated with a reduced risk of Parkinson's disease, Dr. Ascherio
noted, but the evidence in women of a protective effect of drinking
coffee and other caffeine-laden drinks has not been established.?
?Using data accumulated through the Nurses Health Study, which
collected prospective dietary and health information on 77,713 women
and followed them for 18 years, researchers were able to find 154
cases in which these women developed neurologist-diagnosed Parkinson?s
Disease.?
?ANA: High Coffee Intake, Hormone Therapy Increases Risk of Parkinson?s Disease?
http://www.pslgroup.com/dg/220272.htm
-----------------------------
Alertness and Mood:
?Caffeine can increase the speed of rapid information processing by
10%, and a cup of regular (caffeine containing) coffee after lunch
helps to counteract the normal 'post-lunch dip' in ability to sustain
concentration, aiding alertness. Research has also shown that a couple
of cups of coffee help to improve alertness and concentration during
night shift hours. These findings have been further endorsed by Smith
et al, who conducted a study in 1993 to examine the effects of coffee
on daytime and night-time performance and alertness.?
?Alterness and Mood?
http://woz.commtechlab.msu.edu/courses/446su02/GROUPS/group6/final/health3.html
-----------------------------
Coffee and Suicide
?Women who drink two, three, or more cups of coffee a day are less
likely to commit suicide than non-coffee drinkers, according to a
Medical School study of 86,626 nurses. That rather startling
conclusion comes less than a month after another study of the same
women excluded coffee as a cause of heart disease.?
?These results apply equally to men, other research has found. For
example, a check of 120,000 people in northern California showed
substantially the same lowering of suicide risk for two, three, even
six or more daily cups of coffee for both sexes.?
?Coffee Won't Grind You Down: May Reduce Risk of Suicide, Study Concludes?
http://www.news.harvard.edu/gazette/1996/03.14/CoffeeWontGrind.html
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