You Are What You Drink

By Paul E. Lemanski, MD, MS, FACP

Editor’s Note: This is the 105th in a series on optimal diet and lifestyle to help prevent and treat disease. Any planned change in diet, exercise or treatment should be discussed with and approved by your personal physician before implementation. The help of a registered dietitian in the implementation of dietary changes is strongly recommended.

Medicines are a mainstay of American life and the healthcare system not only because they are perceived to work by the individuals taking them, but also because their benefit may be shown by the objective assessment of scientific study. Clinical research trials have shown that some of the medicines of Western science may reduce the risk of heart attacks, strokes and cardiovascular death.

In the first 104 installments of the Non-Medicated Life, certain dietary practices and a healthy lifestyle have been shown to accomplish naturally for the majority of individuals most of the benefits of medications in the prevention and treatment of chronic medical conditions such as hypertension, high cholesterol, pre-diabetes, diabetes and heart disease. The dietary practices for the most part focus on foods. However, there is evidence for health benefit and risk also in your choice of beverage. This article will focus on water, tea and coffee.

Between 55 and 60% of the human body is water. Therefore, it seems self-evident that water and its daily repletion is critical to health. Indeed, there is evidence for a lower rate of heart disease death and cancer in those drinking more water as compared to those drinking less. In a heath study of Seventh Day Adventists, individuals drinking five or more glasses a day had about half the risk of dying of heart disease as compared to those drinking two or fewer. The mechanism is unclear, but may be related to the thickness of blood, with those drinking less having thicker blood that potentially increases the risk for blood clots. With respect to cancer, a study of 48,000 men found that bladder cancer risk decreased by 7% for each cup of water consumed, ostensibly by diluting carcinogens in the bladder as well as decreasing exposure by increasing elimination.

Of course, with water consumption, as in all things biological, the amount matters. Too little may increase risk, but too much of a good thing can also be bad. Excessive or too rapid consumption of water can lower the sodium concentration in the blood and lead to seizure and even, rarely, death. Most individuals who do not have kidney issues or heart failure will get benefit from drinking about 5-6 glasses of water a day.

Increasingly, Americans have choices in the water they consume that have health implications that need to be considered. In most American communities, public water system supplied “tap water” is tested for over 90 possible contaminants and must adhere to standards set by the EPA. Public water systems are routinely tested for chemical contaminants including heavy metals, such lead, as well as microbial contaminants. Private well water is not regulated by EPA and must be independently tested to assure purity. 

Moreover, bottled water may also have unrecognized risks associated: a 2018 study of 11 globally sourced brands of bottled water found 93% with microplastic contamination. Of course, this says nothing of the risk to the environment of millions of plastic bottles finding their way to the ocean or landfills. For those wishing the lowest possible risk, tap water may be filtered by a commercially available reverse osmosis membrane and stored in reusable borosilicate glass bottles or culinary grade stainless steel in place of plastic.

While water is the most widely consumed beverage worldwide, it is closely followed by tea. Beverage tea is made from steeping in water leaves of the tea plant, Camellia Sinensis. Herbal “teas” are something of a misnomer, as they involve steeping parts of other plants. Green tea is made by drying and crushing the fresh leaves of the tea plant swiftly before fermentation can occur. Black tea is made by drying and crushing in a way to allow fermentation prior to final processing. Oolong tea is midway in the fermentation process from green to black tea. 

Polyphenols in tea account for most of the health benefits with green tea containing distinctive polyphenols called catechins. Epigallocatechin-3-gallate (EGCG) accounts for 50-70% of the catechins in green tea and may protect against cancers of the breast, endometrium, ovary, and skin in women, and skin and prostate cancer in men. Indeed, although more research is needed, in a study of men with high grade intraepithelial neoplasia on prostate biopsy (a pre-malignant condition that proceeds onto prostate cancer 30% of the time within one year) green tea catechins reduced the incidence to 3%.

Coffee is the third most widely consumed beverage in the world. With regard to the benefit of coffee consumption to health, the NIH-AARP Diet and Health study found that those over 65 who drank six or more cups of coffee a day had a 10-15% lower mortality risk from all causes. However, in a study of those under 55, six or more cups a day increased the risk of death slightly. More recently in a study published in Annals of Internal Medicine, those who drank 1.5-3.5 cups of coffee per day (with up to a teaspoon of sugar) were up to 30% less likely to die than those who did not drink coffee.  

Moreover, those who drank unsweetened coffee were 16-21% less likely to die with those drinking three cups having the lowest risk compared to those who did not drink coffee. Despite these impressive findings, the limitation of these studies is that they are observational and thus identify an association, but cannot prove causality. Nevertheless, the degree of benefit observed should allay concerns about increased risk from coffee drinking, and reassure that in moderation coffee consumption may be of benefit to health.

Coffee consumption also appears to be associated with about a 30% reduction in the risk of developing Parkinson’s disease. The likely mechanism is the caffeine in coffee, as decaffeinated coffee did not seem to provide the benefit. Moreover, in those with Parkinson’s disease the caffeine found in two cups a day of coffee, appeared to improve movement fluidity within three weeks.

Coffee also appears in several studies to decrease suicide risk when consumed in amounts between two and six cups a day, but increased risk when exceeding eight cups a day. And although coffee consumption has not been associated with an increased risk of atrial fibrillation, it may increase the risk for premature ventricular contractions, and probably should be avoided in those with palpitations. It should also probably be avoided in those with glaucoma, seizure disorder and GERD. If there is any question, a discussion with your primary care physician is prudent.

In summary, water is the most widely consumed beverage in the world, followed by tea and coffee. Water consumption in the proper amount is associated with lower risk of cardiovascular death and cancer of the bladder. Tap water is tested by local municipalities and must meet EPA standards as safe. Well water must be independently tested. Water bottled in plastic bottles may not be safe. Tap water filtered through a reverse osmosis membrane and stored in borosilicate glass or culinary grade stainless steel is safest. Tea especially green tea is associated with lower cancer risk for breast, endometrial, ovarian, skin, and prostate cancer. Coffee, overall, consumed in modest amounts appears to decrease mortality risk and may also reduce the risk of Parkinson’s disease and suicide. Nevertheless, it probably should be avoided in those with glaucoma, seizure disorder, and GERD. 

Thus, while the old adage that you are what you eat may be true, what you drink may also contribute to health and aid in successfully living the Non-Medicated Life.

Paul E. Lemanski, MD, MS, FACP (plemanski3@gmail.com) is a board-certified internist practicing internal medicine and lifestyle medicine in Albany. Paul has a master’s degree in human nutrition, he’s an assistant clinical professor of medicine at Albany Medical College, and a fellow of the American College of Physicians.