Have you noticed the plethora of energy drinks in vending machines, grocery stores, gas stations, and even hospital cafeterias? I work at a university associated with a large medical center, and wherever I go on campus, I see people -- young and old, patients and employees alike -- guzzling these drinks down. Even fatigued cancer patients ask whether they should be drinking them to boost their energy.
Marketed to boost physical or mental health, energy drinks usually have a similar composition to sports drinks (calories from sugar, electrolytes, sodium, and potassium), along with additional vitamins (B vitamins, vitamin C) and minerals (zinc, chromium), as well as additives such as caffeine and herbal supplements (ginseng, milk thistle, and ginkgo, to name a few).
Rockstar energy drink claims to provide an "incredible energy boost for those who lead active and exhausting lifestyles -- from athletes to rockstars," while Red Bull energy drink was "developed for people who want to have a clear and focused mind, perform physically, are dynamic and performance-oriented whilst also balancing this with a fun and active lifestyle."
Sounds great, right? Who doesn't want an energy boost or to be clear and focused? But are there any concerns about their use? Yes.
Energy drinks are considered a form of dietary supplement, not food, and therefore no limits are placed on the amounts of ingredients in these products by the Food and Drug Administration.
Caffeine is the main active ingredient in most energy drinks, so let's compare the amount in an energy drink versus a cola-type beverage. Soft drinks are considered foods by the FDA, and thus the caffeine content is generally recognized as safe when used up to a level of 0.02 percent. This translates to about 71mg per 12-ounce beverage.
In looking at a 16-ounce bottle of a popular cola beverage, I see it contains 65mg caffeine for the whole bottle. A popular energy drink of the same size contains 160mg caffeine! To be fair, there is a statement on the energy drink: "Not recommended for children, pregnant or nursing women or those sensitive to caffeine." But we all know that many people don't pay much attention to the fine print.
The potential impact on cancer patients
For cancer patients, the diuretic effect of a high caffeine intake is concerning. Most patients I counsel aren't taking in enough fluids; a high caffeine intake would just exacerbate their dehydration.
One of the biggest issues I have with these products are the vitamins, minerals, and herbal ingredients included to allegedly "boost energy," "increase metabolism," and "calm the mind." Many contain at least 100 percent of the daily value of certain vitamins (particularly B vitamins). While these are water-soluble vitamins, people can still ingest too much, especially if they're also taking a vitamin/mineral supplement.
The herbal ingredients concern me the most. Just as with over-the-counter supplements, there is no regulation on the purity and safety of these substances, and many commonly seen in energy drinks can have potential drug-nutrient interactions and side effects (for example, ginkgo and increased risk of bleeding).
Another concern of many registered dietitians is that energy drinks can contain significant calories from sugar. Most people, especially cancer patients, don't need the simple sugar intake, not to mention the additional artificial colorings and flavorings. I am always a big advocate for myself and my patients of getting calories and nutrients from food, not supplements. Food first is my motto!