History of Caffeine

People have enjoyed caffeinated beverages since ancient times. As long ago as 2,700 B.C. the Chinese Emperor Shen Nung sipped hot brewed tea. Coffee’s origins date back to 575 A.D. when in Africa beans were used as money and consumed as food.

Caffeine is naturally occurring in the leaves, seeds or fruits of more than 63 plant species

worldwide. The most commonly known sources of caffeine are coffee and cocoa beans, cola nuts and tea leaves. The amount of caffeine in food products varies depending on the serving size, the type of product and preparation method. With teas and coffees, the plant variety also affects caffeine content. The reason caffeine is added to some soft drinks is for its flavor characteristics. The level of caffeine is regulated and its presence clearly labeled when added.

Various food consumption surveys show caffeine consumption patterns have not changed significantly over the last decade. A 1996 survey by Barone and Roberts found that caffeine consumption averages around 200 mg per day, and pregnant women tend to consume less caffeine than the general population. A moderate amount of caffeine is about 300 mg of caffeine per day (about 3 cups of coffee or around 60 ounces of caffeinated cola)

Woman | Caffeine | Physiological Effects

Depending on the amount consumed, caffeine can be a mild central nervous and cardiovascular system stimulant. Caffeine does not accumulate in the body over the course of time since it is usually and normally metabolized and eliminated within several hours of consumption. Thus, the pharmacological effects of caffeine are usually brief, passing within hours.

People differ greatly in their sensitivity to caffeine and this may change with advancing age. With regular use, tolerance develops to many of the effects of caffeine. For example, a person who consumes caffeine on a regular basis may drink several cups of coffee in a few hours and notice little effect, whereas a person who isn’t a regular coffee drinker may feel some stimulant effect after just one serving. Some people may experience feelings of nervousness if they consume more caffeine than they are accustomed to. When regular caffeine consumption is abruptly stopped, some people experience symptoms, such as headaches, fatigue or drowsiness. These effects are typically temporary, lasting for a few days, and may be avoided if caffeine cessation is gradual.

Moderate caffeine consumption is considered to be about 300 mg., which is equal to around 3 cups of coffee. Overall, individuals tend to find their own acceptable level of caffeine. Those who feel unwanted effects, such as insomnia and jitteriness, tend to ease off their caffeine consumption. If the effects remain, a healthcare provider may be consulted. Although significant attention has been paid to caffeine and insomnia, in practice, the person who experiences effects such as sleeplessness learns not to consume

caffeine before bedtime. Caffeine is a mild diuretic, but the urinary output effects attributed to caffeine have frequently been exaggerated.

Recent research has found that the minimal diuretic effects of caffeine do not compromise overall body hydration status in healthy women. Some women experience urinary incontinence as they age. Although caffeine does not cause this condition, women with this condition may experience a greater degree of “urgency” for a short time after consuming a caffeinated beverage. Women may benefit from discussing their beverage consumption and caffeine intake with their health care provider. Learning methods of managing their symptoms such as performing pelvic and bladder muscle training exercises may also reduce incontinent episodes.

What Products Contain Caffeine And How Much

MILLIGRAMS ITEM TYPICAL RANGE*

          OF CAFFEINE 

Coffee (8 fl. oz. cup)

Brewed, drip method ..........................85  65 - 120

Brewed, percolator ...........................75  60 - 85

Decaffeinated, brewed.........................3   2 - 4

Espresso (1 fl. oz. serving) .................40  30 - 50

Teas (8 fl. oz. cup)

Brewed .......................................40  20 - 90

Instant ......................................28  24 - 31

Iced (8 fl. oz. glass) .......................25  9 - 50

Some soft drinks (8 fl. oz.)..................24  20 - 40

“Energy drinks” ..............................80  0 - 80

Cocoa beverage (8 fl. oz.) .................. 6   3 - 32

Chocolate milk beverage (8 fl. oz.) ......... 5   2 - 7

Milk chocolate (1 oz.) .......................6   1 - 15

Dark chocolate, semi-sweet (1 oz.) .......... 20  5 - 35

Baker’s chocolate (1 oz.) ................... 26  26

Chocolate-flavored syrup (1 fl. oz.)........  4   4

*For the coffee and tea products, the range varies due to brewing method, plant variety, brand of product, etc.

Woman | Caffeine | Cancer

The concern raised about caffeine and fibrocystic breast disease led to a concern about possible association between caffeine consumption and breast cancer. However, extensive research conducted to date has shown no association between caffeine consumption and the development of any cancer.

Breast Cancer

In 1990 researchers reviewed scientific data investigating caffeine and malignant breast tumors. Out of 11 studies reviewed, none established a significant link between caffeine intake and breast cancer incidence.

Specifically, three separate studies performed in Israel, the United States and France, analyzed the relationship of coffee consumption to breast cancer development. Each study respectively accounted for dietary intake, medical and reproductive history and frequency of coffee intake. The results of each investigation established no association between coffee consumption and breast cancer.

Furthermore, the 1986 NCI study on breast disease found no association between caffeine consumption and breast cancer. Interestingly, the NCI researchers noted that coffee drinkers had a slightly lower incidence of breast cancer. Patients with questions are advised to consult their health care provider.

Ovarian Cancer

In a thorough review of the research on caffeine’s relationship to ovarian cancer, no evidence indicated that caffeine consumption is a risk factor for ovarian cancer when known factors are taken into account. In fact, the International Agency for Research on Cancer (IARC) found there is inadequate evidence to suggest coffee drinking causes ovarian cancer.

Overall, the universal scientific research does not support a relationship between caffeine consumption and cancer. As a result, both the American Cancer Society and the National Academy of Sciences’ National Research Council report there is no convincing evidence relating caffeine to any type of cancer.

Woman | Caffeine | Osteoporosis — Boning up on Health

Given the recent awareness about the incidence of osteoporosis in post-menopausal women, the relationship between caffeine and bone health is a relatively new area of investigation. It has been shown that caffeine consumption causes a slight and temporary rise in the level of calcium excretion leading to speculation that the use of caffeine could compromise bone health. Yet studies show that adequate calcium consumption offsets the potential effect of caffeine on bone density.

This is illustrated in a recent study that examined the lifetime intake of caffeinated coffee in 980 postmenopausal women. The researchers found no association between lifetime caffeinated coffee intake (equivalent to two cups per day) and reduced bone mineral density among women who drank at least one cup of milk a day during their adult lives.

Other studies conducted at The Pennsylvania State University’s College of Medicine and the Mayo Clinic have found that while caffeine intake slightly increases urinary calcium excretion, caffeine was not an important risk factor for osteoporosis.

A study on the effect of carbonated soft drinks on calcium excretion, done at Creighton University Osteoporosis Research Center, came to the same conclusion: “The net effect of carbonated beverage constituents (including caffeine) in calcium economy is negligible.” Given the current evidence, an adequate calcium intake — especially during adolescent years — is the best nutritional insurance for healthy and strong bones. Women of childbearing age should consume at least three servings a day of calcium-rich foods, such as low-fat milk or yogurt in addition to the other foods and beverages in their diet.

Woman, Caffeine and Heart Disease – Matters of the Heart

Caffeine and heart disease is another area that has been extensively examined, and no causal relationship between caffeine consumption and heart disease, high blood pressure or irregular heartbeat has been shown.

While most studies investigating heart disease in large populations involve men, two studies have included women. Researchers of the recent Scottish Heart Health Study conducted a study of 10,359 men and women aged 40-59. Their analysis showed no relationship between coffee consumption and heart disease. Additionally, the well-respected Framingham Study analyzed the relationship between coffee consumption and incidence of heart disease in 2,648 men and 3,566 women. After examining all possible links between coffee intake and heart disease, the researchers reported that no harmful effect of coffee consumption was found and that there was no association between coffee intake and recurring heart attack episodes.

The effects of caffeine on blood pressure and irregular heartbeat have also been topics of scientific investigation. The American Heart Association lists caffeine, along with other substances, as a possible contributor to an irregular heart beat. Women with such symptoms should check with their health care providers.

The U.S. Surgeon General’s report, Nutrition and Health, states that a number of studies have shown that any rise in blood pressure due to caffeine consumption is less than the elevation produced by normal, daily activities, such as climbing stairs, and is just as fleeting. A recent Johns Hopkins University School of Medicine study published in the Archives of Internal Medicine found that coffee drinking is associated with small increases in blood pressure, but appears to play a small role in the development of hypertension. The National Heart, Lung, and Blood Institute’s Guide to Lowering High Blood Pressure advises, “Caffeine in coffee as well as in other drinks, such as tea and sodas, only raises blood pressure temporarily. So you should be able to continue to

have drinks that contain caffeine, unless you are sensitive to it or have heart disease and your doctor tells you not to have any.” Under some circumstances, health care providers

may advise people with hypertension to limit caffeine.