Caffeine and Women

According to the opinion of medical specialists and scientists, healthy people consume caffeine in moderation, without producing any backfire.

From reproduction to osteoporosis, scientists around the world have investigated the effects of caffeine on the health of women. In this booklet you will find background information on caffeine and summaries of recent research linking caffeine to women’s health.

History of Caffeine

Since antiquity, people have enjoyed caffeinated beverages. In 2700 BC the Chinese Emperor Shen Nung and drank hot tea. Coffee originated in Africa about 575 AD The beans were used as money and consumed as food.

Caffeine is a naturally occurring substance found in the leaves, seeds or fruits of more than 63 plants. The most commonly known sources of caffeine are coffee and cocoa, cola nuts and tea leaves. The amount of caffeine in foods varies depending on portion size, product type and method of preparation. When it comes to teas and coffees, the plant variety also affects caffeine content. The reason caffeine is added to some soft drinks is because of its flavor characteristics. The caffeine level is regulated and its presence clearly labeled and indicated.

There are many surveys that show that caffeine consumption patterns have not changed significantly over the last decade. A survey conducted in 1996 by Barone and Roberts concluded that the average consumption of caffeine is 200 mg per day, and that pregnant women tend to consume less caffeine than the general population. A moderate amount of caffeine is approximately 300 mg of caffeine per day (about 3 cups of coffee or 60 ounces of caffeinated cola drink).

Psychological Effects

Depending on the amount consumed, caffeine can be a mild stimulant of the central nervous system and cardiovascular system. Caffeine does not accumulate in the body over time because, in general, is metabolized and eliminated a few hours later. Therefore, the pharmacological effects of caffeine are short and dissipate within a few hours.

The sensitivity of individuals with regard to caffeine varies greatly and can even be modified with age. It develops a tolerance to many effects of caffeine with regular use. For example, a person who regularly consume caffeine, you can drink several cups of coffee in a few hours and not notice any effect, whereas a person who does not drink coffee regularly, may feel a stimulating effect after the first cup . Some people may feel nervous if they consume more caffeine than your body is used to tolerate. When it stops abruptly consumption of caffeine, some people experience symptoms such as headaches, fatigue or lethargy. Generally, these effects are temporary, lasting only a few days and can be avoided if the decline of caffeine is done gradually.

It is considered that moderate caffeine consumption is approximately 300 mg, equivalent to about 3 cups of coffee. In general, individuals tend to find their own acceptable levels of caffeine. Those who experience unwanted effects, such as insomnia and nervousness, try to cut back on caffeine. If the effects still continue, it should consult a health care provider. Although it has always been related to caffeine with insomnia, in practice, the person experiencing effects such as sleeplessness learn not to consume caffeine before bedtime.

Caffeine is a mild diuretic, but often are exaggerated urinary effects attributed to him.Recent research concluded that the minimal diuretic effects of caffeine does not compromise the general hydration status of healthy women’s bodies.

Some women experience urinary incontinence as they age. Although caffeine does not cause this condition, sufferers may experience a greater degree of “urgency” for a short time after consuming a caffeinated beverage. It is recommended that women discuss the consumption of soft drinks and caffeine with your doctor or health professional. Learn ways to manage symptoms of incontinence, such as exercises to strengthen pelvic muscles and bladder may help reduce the frequency of these episodes.

Caffeine and pregnancy-what are the risks?

Today, thanks to the increased attention paid to maternal nutrition, many women wonder if it is safe to consume food or beverages containing caffeine during pregnancy. Although some studies have shown mixed results, organizations of health professionals, such as the College of Obstetricians and Gynecologists in the United States, recommend that pregnant women should limit their consumption of caffeine equivalent of 1 or 2 cups coffee. The use of caffeine during pregnancy should be a topic to discuss with the physician.


Because today many women get pregnant later, research has focused on identifying factors that may affect fertility, such as caffeine. In 1988 a study suggesting that the amount of caffeine consumed in 1 to 2 cups of coffee a day may reduce female fertility.However, the researchers acknowledged that delayed conception could be due to other factors they did not take into account, such as physical activity, stress and other dietary habits. Since then, other major studios that are better planned and carried out failed to support the findings of 1988.

In 1990, researchers at the Centers for Disease Control and Prevention of Disease and Harvard University examined the association between the time it takes to conceive and consumption of caffeinated beverages. The study involved over 2800 women who had given birth recently as 1800 women who were diagnosed with primary infertility. He interviewed members of each group and asked specifically about caffeine, medical history and lifestyle habits. The researchers concluded that caffeine had little influence on the time it takes to conceive of women who actually had children. Caffeine consumption was not considered a risk factor for infertility.

In support of these findings in 1991 in Denmark conducted a study involving 11,000 women, which examined the relationship between the number of months to conceive, smoking and drinking coffee and tea. Although smokers who consumed more than eight cups of coffee in fact delayed conception, nonsmokers did not have that problem, although they consumed caffeine.

A study involving 210 women and published in the American Journal of Public Health in 1998 examined the differences in fertility associated with consumption of different caffeinated beverages. It was decided to conduct this study in particular the discrepancies that existed in previous findings. There was no significant association between total caffeine consumption and decreased fertility. In fact, researchers found that women who drank more than half a cup of tea per day had a significant increase in fertility. And this fact proved true with caffeine in the first attempts of a woman conceiving. The correlation between tea and fertility was supported by a 1994 study, however, these women had significantly higher levels of consumption.

Spontaneous abortions

The association between caffeine and spontaneous abortions is still under investigation.Recently, researchers from McGill University in Montreal published a study demonstrating the existence of a relationship between caffeine consumption and abortions. Although caffeine consumption before and during pregnancy appeared to be associated with increased fetal loss, the authors did not take into account a number of factors that could cause a false association, for example, the effects of morning sickness or nausea, the number of cigarettes smoked and the amount of alcohol consumed.

Before the McGill study, a research team from the National Institute of Child Health and Human Development conducted a study of 431 women. The researchers monitored the women and the amount of caffeine they consumed from conception until birth. They took into account morning sickness, smoking, alcohol consumption, maternal age, and found no association between consumption of 300 mg of caffeine per day and adverse pregnancy outcomes.

Some years earlier, in 1992, researchers analyzed the effect of cigarettes, alcohol and coffee consumption on the outcome of pregnancies of more than 40,000 women.Although alcohol consumption and smoking in general produce adverse effects on pregnancy outcome, moderate consumption of caffeine was not associated with spontaneous abortions or low weight of the fetus at birth. Moreover, the relationship between caffeine intake and spontaneous abortions was also investigated in a study involving pregnant women 5.342 in 1997. In it, the researchers concluded that there was an increased risk of spontaneous abortion if consumed a moderate amount of caffeine. In December 2000, another study in Uppsala, Sweden, concluded that reducing caffeine intake during the first months of pregnancy is a prudent measure.

Birth defects and low birth weight babies

In the 80 published studies that also supported the conclusion that moderate caffeine consumption during pregnancy may be associated with preterm delivery or low birth weight of babies at birth. Since 1980 we reviewed over 20 studies and concluded that there is no evidence to show that consumption of moderate levels of caffeine can have a discernible adverse effect on the outcome of pregnancies.

In 1991 he published a study that examined caffeine consumption during pregnancy and subsequent development of the children of a group of 1500 women for 7 years. Caffeine consumption was equivalent to approximately one-half cup to two cups of coffee per day had no effect on birth weight of babies, birth length or head circumference of the fetus.Follow-up examinations were performed for children at eight months, four years and seven years. Nor were found adverse effects of caffeine on motor development or intelligence of the child.

In the early 80′s, the Food and Drug Administration (FDA) conducted a study in rats that were fed with high doses of caffeine through a stomach tube. Although the results obtained necessitated the development of messages that advise pregnant women to avoid caffeine, the study was criticized because it did not represent the way humans consume caffeine. In 1986, FDA investigators performed another study in which rats consumed high doses of caffeine in their drinking water. The second study concluded that there were no adverse effects in the offspring of these rats, which completely contradicted the findings of the first study.

In 2001 he published another study that examined the effects of caffeine consumption on fetal growth, but there was no evidence to prove that caffeine consumption during pregnancy had adverse effects on fetal growth. Another study in 2002, “The effect of caffeine exposure during pregnancy on birth weight and age” gestational “and published in the American Journal of Epidemiology concluded that there was no relationship between Moderate caffeine consumption and reduced weight of the baby at birth, gestational age or fetal growth.

Virtually all studies that were conducted during the last decade showed no link between birth defects and caffeine consumption. FDA evaluated the scientific evidence and concluded that caffeine does not have an adverse effect on reproduction in humans.However, as with other dietary habits, the agency continues to advise pregnant women to moderate your intake of caffeine.

It is important to drink plenty of fluid during pregnancy. While consuming moderate amounts of caffeine is fine, the doctors also remind pregnant women who drink different types of soft drinks during the day.


It is important for women to watch your diet when breastfeeding their children to ensure a healthy milk supply. The Committee on Drugs of the American Academy of Pediatrics United States reviewed the effects of caffeine on lactation and reported that the minimum consumption of caffeine has no adverse effects. Although dietary caffeine can pass into breast milk, mothers who are breastfeeding can eat small amounts of caffeine without ever spending a significant amount to the baby. However, if caffeine is greater, the result could be a poorer and weaker food for the baby, so it is wise to limit caffeine intake.Professional organizations of health, such as the College of Obstetricians and Gynecologists in the United States, recommend that pregnant women should limit their consumption of caffeine equivalent of 1 to 3 cups of coffee.

Fibrocystic changes in breast

In the late 70′s began to discuss the relationship of the caffeine in some diseases of the breast. An informal survey suggested that stopping caffeine may relieve the symptoms of fibrocystic breast changes, a disease that causes benign fibrous lumps in the breast.Although caffeine is not directly related to the development of this disorder, some people reported that they noticed improvements and less swelling in their breasts when they eliminated caffeine from their diets. However, these findings were based on anecdotal case histories of a small number of women and not in clinical trials, so the results may not apply to all women suffering from fibrocystic breast changes. The National Cancer Institute (NCI) conducted a major study involving over 3000 women. This study was conducted in 1986 failed to demonstrate an association between caffeine intake and benign tumors, fibrocystic changes and swelling of the breasts.

Both the Council of Scientific Affairs, American Medical Association and the National Cancer Institute published reports that say there is no relationship between caffeine consumption and incidence of fibrocystic changes in breasts

The issue of cancer

The concerns raised the possible relationship between caffeine and fibrocystic breast disease led to the possible relationship between caffeine consumption and breast cancer. However, all the research conducted to date did not show any relationship between caffeine consumption and the development of any type of cancer.

Breast cancer

In 1990, researchers reviewed scientific data on the possible relationship between caffeine and breast malignancies. Of the 11 studies reviewed, none were able to establish a meaningful relationship between caffeine intake and the occurrence of breast cancer.

More specifically, three independent studies were conducted in Israel, the United States and France, which analyzed the relationship between coffee consumption and breast cancer development. Each of the studies analyzed the dietary intake, medical and reproductive history and frequency of coffee consumption. The results of each investigation could not establish a link between coffee consumption and breast cancer.

Moreover, the study by the NCI in 1986 on breast disease, also found no association between caffeine consumption and breast cancer. Interestingly, the NCI researchers warned that those who drank coffee had a slightly lower incidence of breast cancer.Patients are advised to clarify all your doubts and questions with medical professionals who serve them.

Ovarian cancer

A thorough review of research that have been made between the relationship between ovarian cancer and caffeine, found no evidence to suggest that caffeine is a risk factor for ovarian cancer when taking into account other known factors. In fact, the International Agency for Research on Cancer (IARC) found that there is no adequate evidence to suggest that coffee drinking causes ovarian cancer.

In general, no universal scientific research supports the existence of a relationship between caffeine and cancer. Consequently, both the Cancer Society of the United States and the National Research Council of the National Academy of Sciences reports that no convincing evidence linking caffeine to any type of cancer.

Osteoporosis: to enhance bone health

Based on the recent awareness of the incidence of osteoporosis in postmenopausal women, the relationship between caffeine and bone health is a relatively new area of research. It has been shown that caffeine causes a mild and temporary increase in the level of excretion of calcium, which led to speculation that the use of caffeine may compromise bone health. However, studies show that adequate calcium intake offsets the potential effect of caffeine on bone density.

This was illustrated by a recent study that examined consumption of caffeinated coffee in a group of 980 postmenopausal women. The researchers found no relationship between consumption of caffeinated coffee that had made these women throughout their life (equivalent to two cups a day) and reduced bone mineral density among women who drank at least one cup of milk for his adult life.

Other studies conducted in the Faculty of Medicine, Pennsylvania State University and the Mayo Clinic concluded that although caffeine intake slightly increases calcium excretion in the urine, caffeine was not a important risk factor for osteoporosis. A study on the effect of carbonated beverages in calcium excretion was performed at the Center for Osteoporosis Research at Creighton University, reached the same conclusion: “The net effect of carbonated beverage component ( even caffeine) in the calcium economy is minimal. “

Based on the evidence that exists at present, adequate calcium intake, especially during the teenage years is the best nutritional insurance for healthy bones and strong. Women of childbearing age should consume at least three servings of calcium rich foods per day, for example, skim milk or yogurt, as well as other food and beverages are included in your diet alone.


In some women, nausea, morning sickness is very common, during the first three months of pregnancy. Although this is an unpleasant phenomenon, researchers believe that it is a normal and common in the early months of pregnancy.

During a normal pregnancy, hormone levels are high, and increase the likelihood of feeling nausea. When you feel sick and nauseated, pregnant women may not feel hungry for certain foods and beverages, including those containing caffeine. Health professionals often advise pregnant women have morning sickness to eat crackers and drink water.

Many literature reports consider that 300 mg of caffeine is a moderate amount.Professional organizations of health, recommend that pregnant women should limit their consumption of caffeine equivalent of 1 or 2 cups of coffee. There are a variety of decaffeinated beverages available for those who wish to limit or avoid caffeine during pregnancy.

What products contain caffeine and how much?

The following table shows the approximate content of caffeine of various foods and drinks:

ARTICLE milligrams of caffeine typical range *

Coffee (8-ounce cup)
Drip Leaching or 85 65-120
75 filter 60-85
Decaffeinated March 2 to 4
Express (1-ounce cup) 40 30-50
Teas (8-ounce cup)
Preparation common 40 20-90
Instant 28 24 to 31
Ice Cream (8 oz) 25 9-50
Some soft drinks (8 ounces) 24 20-40
“Energy drinks” 80 0-80
cocoa-based beverages (8 ounces) 6 3-32
Milk Chocolate (8 ounces) May 2 to 7
Milk chocolate (1 ounce) June 1 to 15
black chocolate, semisweet (1 ounce) 20 5-35
coverage Chocolate (1 ounce) 26 26
chocolate-flavored syrup (1 ounce) 4 4

* In the coffee and tea products, the range varies depending on the method of preparation, variety of the plant, product brand, etc..
Source: Food and Drug Administration of the United States and National Association of Soft Drinks

Caffeine and cardiovascular disease: a matter of the heart

The relationship between caffeine and cardiovascular disease is another area that has been widely studied and has not yet found a causal relationship between caffeine and heart disease, high blood pressure or arrhythmia episodes.

Although most studies investigating cardiovascular diseases involve men, two studies that analyzed only for women. A study recently conducted in Scotland on heart health, included 10,359 men and women between 40 and 59. The analysis showed that there is no link between coffee consumption and cardiovascular disease.

In addition, the respected Framingham Study analyzed the relationship between coffee consumption and incidence of cardiovascular disease in a group of 2648 men and 3566 women. After examining all the possible relationship between coffee consumption and heart disease, researchers concluded that coffee consumption does not produce a harmful effect and there is no relationship between coffee consumption and recurrent episodes of heart attacks.

The effects of caffeine on blood pressure and arrhythmias has also been the subject of scientific research. The American Heart Association mentions caffeine, along with other substances as a factor likely to contribute to produce an irregular heartbeat. Women with these symptoms should consult their doctors.

The report of the Surgeon General of the United States, Nutrition and Health, says that there are a number of studies that show any rise in blood pressure resulting from consumption of caffeine is less than the increase produced by normal daily activities, such as climbing stairs, and is so fleeting as the latter. A recent study by the Faculty of Medicine, Johns Hopkins University published in Archives of Internal Medicine, found that coffee drinking is associated with small increases in blood pressure, but appears to play an insignificant role in the development of hypertension. The Guide to decrease high blood pressure from the National Heart, Lung and Blood Institute recommends the following, “the caffeine in coffee and other beverages such as tea and sodas, only raises blood pressure temporarily. For so you can continue to consume beverages that contain caffeine, unless the person has a particular sensitivity or other heart disease and your doctor considers it is not advisable to consume them. “ In certain circumstances, doctors may advise people with hypertension should limit their consumption of caffeine.


As long as there are questions and doubts about the safety of foods and their ingredients, researchers continue to seek the answers, and in fact, at this time many more studies are underway. However, it can be concluded that studies on the effects of caffeine on health are substantial. The abundant evidence on this ingredient shows that moderate consumption of caffeine (approximately 300 mg) is considered safe.Professional organizations of health, such as the College of Obstetricians and Gynecologists in the United States and the March of Dimes recommend that pregnant women limit their consumption of caffeine equivalent of 1 or 2 cups of coffee.


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