Healthy Beverages: Back To The Basics

Several commercials depict physically fit athletes, actors, and hip-hop artists chugging brightly hued sports drinks and vitamin-fortified waters, but rarely does any commercial show a marathon runner or a basketball player slamming a glass of chocolate milk after a workout. And certainly no ad or commercial would deign to show sweaty, bulky football players dunking tea bags into teacups as a way to replenish themselves after a rigorous game. The implication is that only sports drinks and enhanced waters impart benefits that promote a healthy lifestyle. Yet a growing body of evidence points to old-school beverages—tea, coffee, and low-fat or chocolate milk—as the best elixirs for nutrition, health, and workout recovery.

Science Gets Nutrition Down to a Tea
As the second most consumed beverage in the world, tea has a history of human consumption dating back thousands of years. All varieties of nonherbal tea—including green, black, and oolong—originate from the leaves of the tea plant Camellia sinensis, and the variation in color and type of tea is the result of different processing techniques. Dried, unoxidized tea leaves produce green tea; wilted, oxidized tea leaves yield black and oolong teas. Regardless of type, tea is an antioxidant-rich beverage, containing more polyphenols than many fruits and vegetables. Besides being rich in compounds that combat cell-damaging oxidative stress, tea has a chemical makeup that includes enzymes, carbohydrates, protein, and lipids. The impressive chemical profile of tea—particularly its high antioxidant content—serves as the basis for the surge in research on the health benefits of tea.

For hundreds of years, ancient cultures have relied on tea for medicinal purposes, and modern science is now verifying why Oxidative stress is a molecular imbalance that interferes with the body’s ability to detoxify harmful compounds leading to cellular damage and is associated with chronic health problems such as atherosclerosis, diabetes, dementia, and even cancer. Packed with compounds that protect cells from oxidative stress, tea has emerged as a natural dietary aid to lower the risk of these ailments. Research indicates that tea strengthens the body’s immune system, reduces the buildup of plaque on arterial walls, and aids in the control and prevention of diabetes (Chen et al., 2009). Other studies have found that regular tea consumption may lower the risk of developing Parkinson’s disease and reduce the incidence of cognitive problems associated with Alzheimer’s disease (Ehrnhoefer et al., 2008).

For consumers who exercise regularly, a mug of tea can be particularly beneficial: Research suggests that physically active individuals who regularly consume tea experience accelerated body-fat reduction (Nagao et al., 2005) and increased endurance and recovery (Panza et al., 2008; Arent et al., 2010). And several other studies show that tea consumption lowers total cholesterol while increasing high-density lipoprotein (HDL, the good cholesterol), reduces inflammation associated with inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis, and may have an anti-inflammatory effect on arthritis.

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Although there is some debate as to whether green tea or black tea is more nourishing, studies show that both have a positive effect on health. Perhaps this is due to the fact that regardless of its color, tea contains an abundance of polyphenols, which are plant-derived antioxidants. In fact, the most abundant compound in green tea is catechin, a polyphenol that encompasses up to 30% of the weight of tea leaves. Catechins are converted to theaflavins during the oxidation process that turns green tea leaves into black tea (see figure on p. 36). Consequently, the most abundant polyphenol in black tea is theaflavin, and research shows that theaflavins may possess as much antioxidant potency as catechins (Leung et al., 2001). Whether black, green, or oolong, tea is clearly one of nature’s oldest health beverages.

The Java Health Plan
Another natural beverage that has been around for centuries—perhaps as long as tea—is coffee. And while tea may be the most consumed beverage in the world, residents of many Westernized countries seem to prefer coffee. Thanks to the daily coffee-drinking habit of many Americans, the primary source of antioxidants in the U.S. diet is coffee, according to researchers at the University of Scranton in Pennsylvania (Carey, 2005). Like tea, coffee is packed with polyphenols, and it actually has a higher content of antioxidants than green or black tea and other beverages such as fruit and vegetable juices (Fukushima, 2009). However, in the past coffee did not receive such glowing praise. Studies conducted before the 1980s linked coffee to a myriad of health issues such as high blood pressure, heart disease, and liver problems. Most of that research was based on unfiltered coffee, which was more commonly consumed before the introduction and widespread use of automatic drip-coffee makers and filters. Coffee filters remove diterpenes, which are the chemicals in coffee that elicit unhealthy changes in the body. Researchers now believe that filtered coffee may provide numerous health benefits.

Frank Hu, Professor of Nutrition and Epidemiology at Harvard University School of Public Health, discussed Frank Hu, Professor of Nutrition and Epidemiology at Harvard University School of Public Health, discussed the emerging health benefits of coffee at the 2010 IFT Annual Meeting & Food Expo. He explained that large studies conducted since the introduction of coffee filters have found no association between coffee consumption and high blood pressure, cardiovascular disease, or liver disease. In fact, the studies indicate a strong correlation between high coffee consumption and lower cardiovascular-related deaths. “Coffee contains not only caffeine but numerous other bioactive compounds. … So when we think about coffee, we have to think beyond caffeine because those other bioactive compounds may have a very important role in the [prevention] of metabolic disease and [adverse] cardiovascular outcomes,” Hu said.

Hu and his colleagues at Harvard School of Public Health published research which indicates that coffee consumption appears to lower the risk of developing type 2 diabetes by up to 50% (Salazar-Martinez et al., 2004; van Dam et al., 2006). “Coffee is the primary source of chlorogenic acid and other antioxidants. It is also a major contributor of several minerals, including magnesium, potassium, and chromium. Those minerals have a very important role in insulin sensitivity and insulin action,” Hu said. Moreover, coffee’s effect on diabetes has little to do with caffeine—which has only a short-term effect on metabolism—and more to do with its other constituents, including chlorogenic acid and other polyphenolic antioxidants such as caffeic acid, quinic acid, and lignans. Chlorogenic acid “may reduce glucose uptake and stimulate beneficial gut hormone secretion in humans,” Hu said. However, he cautioned that because coffee contains so many bioactive compounds, “it is very difficult to attribute the benefits of this beverage to a single compound or nutrient.”

Other epidemiological evidence suggests that coffee may mitigate the risk of certain types of cancer. An analysis of cancer research data has determined that consumers who drink at least four cups of coffee a day are 39% less likely to develop head and neck cancers (Galeone et al., 2010). Another study points out that coffee consumption is inversely linked to the risk of liver cancer: As coffee intake increases, the risk of developing the disease decreases dramatically (Hu et al., 2008). And an inverse relationship exists between coffee consumption and another type of cancer: The European Prospective Investigation into Cancer and Nutrition (EPIC) study indicates that people who daily consume more than 100 ml of coffee (or tea) have a significantly reduced risk of developing glioblastoma, a type of malignant brain tumor.

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Coffee also appears to have a positive effect on neurological diseases and diabetes. Researchers have concluded that coffee consumption may reduce the risk of both Parkinson’s disease and Alzheimer’s disease (Eskelinen et al., 2009; Sääksjärvi et al., 2007). Of particular note in the study on coffee consumption and Alzheimer’s disease, study participants who drank more than three cups of coffee per day exhibited a 65% decreased risk of developing the disease. Evidently, coffee benefits human health beyond simply increasing alertness.

The Milky Way to Health and Nutrition
It is no secret that milk is an excellent source of protein, calcium, and vitamin D, and it helps build teeth and bone mass during childhood and adolescence. But as consumers progress into their late teens and beyond, most opt for beverages other than milk to accompany meals or replenish energy after physical activity, and society encourages this trend. The majority of restaurants catering to crowds older than age 18 offer soda, coffee, tea, beer, wine, and liquor. On the occasions when milk is an option, it is usually relegated to the kids-only section of the menu. Yet recent research findings not only detail the benefits that milk imparts to the skeletal system but also highlight the value of whole, low-fat, and chocolate milk when it comes to overall nutrition, bone density, weight loss, muscle-building, and more.

Milk contains nine essential nutrients and vitamins, including protein, vitamins A and D, niacin, riboflavin, and calcium, and according to the American Academy of Pediatrics (AAP), consumers from two years of age through adolescence need these nutrients—particularly calcium and vitamin D—for peak bone mass development. Specifically, consuming calcium and nutrients via milk during adolescence helps reduce the risk of bone fractures and osteoporosis later in life (Greer et al., 2006). Moreover, because saturated fat is essential for the 80% of brain development that takes place during the first two years of life, the AAP recommends whole milk for children up to age two (applicable to toddlers who are neither overweight nor obese) and reduced-fat milk beyond age two, when limiting the intake of saturated fat takes precedence to avoid cardiovascular and weight issues.

The ways in which milk helps the human body don’t end after adolescence. Milk consumption continues to benefit consumers well into their golden years. Milk aids in weight management and weight loss, accelerating the loss of body fat around the waistline (Zemel et al, 2005; Shahar et al., 2010). Scientists are still investigating this phenomenon, but evidence thus far indicates that milk provides two nutrients that play roles in fat loss: calcium and vitamin D. A low calcium intake causes the body to emit a hormonal response that increases fat storage, thereby decreasing the breakdown of fat for energy. Furthermore, because it contains other nutrients that may have a collaborative effect, milk is a far better source of calcium than calcium supplements when it comes to fat loss, and the vitamin D in milk increases calcium absorption.

Individuals who exercise regularly may want to drink milk before, during, and after their workouts. For endurance-based exercise such as long-distance cycling, preliminary studies suggest that consuming low-fat or fat-free milk before and during such activity generates physiological responses similar to those from carbohydrate-based sports drinks. In addition, endurance athletes who drink reduced-fat milk instead of sports beverages before or during exercise experience less protein breakdown even though the onset of fatigue is the same for both (Roy, 2008). Other research indicates that when consumed after resistance training, both unflavored and chocolate-flavored versions of reduced-fat milk improve muscle development, enhance strength, and increase fat loss (Hartman et al., 2007; Josse, 2010). It appears that the combination of carbohydrates and high-quality protein in milk make it highly effective in helping consumers prepare for and recover from both endurance exercise and strength training. “Low-fat milk is a nutritional powerhouse,” according to Henry Lukaski (2008) of the U.S. Dept. of Agriculture’s Grand Forks Human Nutrition Research Center. “It consists of 90% water, so it is a good source to replace fluid lost in sweat. Low-fat milk also is an important source of the key proteins whey and casein. … Low-fat chocolate milk offers additional benefits because it has a greater carbohydrate or sugar content than low-fat milk.”

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Health and nutrition benefits are not limited to only reduced-fat and chocolate milk. According to a study by researchers at the Harvard School of Public Health, women experiencing infertility due to impaired ovulation should drink whole milk (Chavarro et al., 2007). The findings reveal that women who consume whole milk or whole-milk products reduce their risk of ovulation-related infertility by 27%. The researchers believe that the high estrogen content of whole milk may play a role in reducing the incidence of infertility. Thus, for women who are trying to conceive, drinking whole milk may remove at least one barrier on the path to procreation.

The Not-So-Obvious Beverage Choices
Science has proven that the intrinsic mixture of antioxidants, vitamins, and minerals in tea, coffee, and milk make them three of the healthiest beverages on the market. And even though beverage manufacturers are using coffee, tea, and—to a lesser extent—milk to develop functional and ready-to-drink beverages, the bottled formulations are not nearly as potent. At the National Meeting of the American Chemical Society in August 2010, scientists disclosed that many of the popular coffee- or tea-based beverages on the market contain far fewer antioxidants than the amount in one cup of home-brewed tea or coffee (ACS, 2010). In some instances, health-conscious consumers would need to drink 20 bottles of the manufactured beverages to get the amount of polyphenols contained in a single cup of tea. The findings also indicate that besides the low concentration of bioactive nutrients, most bottled functional beverages contain sizeable amounts of sugar and calories, which don’t make for a healthy diet.

Another study determined that sedentary adolescents perceive sports drinks as healthy to consume even though such beverages are formulated specifically for engaging in athletic activities (Ranjit et al., 2010). While sports and energy drinks may offer some aid for athletic endurance and alertness, there is no scientific evidence proving their ability to address other health concerns. And the reality is that most consumers simply do not engage in enough exhaustive physical activity every day to justify their intake of sports and energy drinks. As a result, inactive or minimally active consumers who drink sports drinks are ingesting nonnutritive calories that contribute to weight gain.

It thus seems that in the healthy beverage category, man-made concoctions have not been able to surpass or even match what nature already provides. For this reason, consumers may want to remain loyal to whole-some beverages that have stood the test of time instead of chasing the latest health-drink trends. Tea, coffee, and low-fat milk may not have eye-catching hues and impulse-inducing commercials, but their antioxidant and protein-rich contents are far more nutritious and beneficial to the human body. And isn’t that worth more than a celebrity endorsement?

Toni Tarver is Senior Writer/Editor for Food Technology magazine
([email protected]).

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