by Marina Komarovsky
“More potassium than two bananas (don’t tell the monkeys)!” reads a bottle of VitaCoco brand coconut water. Of all the super-drinks – fruit and vegetable smoothies, pomegranate juice, açai berry juice, you name it – coconut water is an especially trendy and popular addition to the grocery store beverage fridge. Marketed as the new sports drink, a close second to a tropical retreat, and a convenient way to connect with nature and nourish the body, the colorful juice box has broad appeal. Health claims for coconut products – both coconut water and coconut oil – abound. But let’s be honest, as nutrition students we know that no super-food is as extraordinary as marketers construe it to be, and that a balanced diet is your best bet for staying healthy. So why discuss it further? Because by delving into health claims, apart from satisfying our own nerdy nutrition curiosity, we as future nutrition professionals in all sectors of the field can help to elucidate these claims for a public that finds itself inundated with conflicting, flashy health messages.
So back to the coconut and the VitaCoco label. In what ways is it true, and in what ways is it misleading? A single-serving container of coconut water has 670mg of potassium, and VitaCoco claims that this is double the amount of potassium in a banana. Well, a “medium” banana has 422mg and an “extra small” banana has 290mg (according to fitday.com), so if we use the latter in our calculation, 290 x 2 = 580mg of potassium – fair, we can give it to them.
But what’s the big deal with potassium? Well, potassium is an electrolyte, essential for nerve and muscle action, and lost with perspiration during exercise. The Naked brand coconut water container proclaims that its contents are “nature’s perfect solution to help replenish the potassium and other electrolytes you need,” and the Zico brand brags about “beating traditional sports drinks for healthful rehydration and total body replenishment” after a workout. In a 2009 article addressing the then-emerging coconut hype, U.S. News health writer Katherine Hobson did an ounce-by-ounce comparison of Gatorade and Zico. She saw that while Zico contains more than fifteen times the potassium that Gatorade does, Gatorade contains more than twice the sodium. In the article she went on to explain that sodium is more important during vigorous exercise. Tufts President’s Marathon Challenge runner and MPH candidate Aileen Shen ’11 related an anecdote. “After a 20-mile course run,” she recounted, “my face was thickly outlined with salt, someone thought I put a white paste on my face to protect it from the sun … lo and behold it was salt. It’s amazing how much sodium one can lose.” This fact relegates coconut water to second place in the competition for restoring electrolyte balance.
Are electrolytes all you need during exercise? Of course not. The body also requires energy and water, and coconut water as well as sports drinks can supply both. A crossover study with ten male participants in Malaysia showed that ingesting a sports drink after a 90-minute run led participants to achieve 68% rehydration over the two hours following, while ingesting coconut water led to 65% rehydration, showing coconut water to be about as good. Meanwhile coconut water with added sodium even performed slightly better for 69% rehydration, and all three were better than plain water, at only 58% rehydration (Isamil et al. Southeast Asian J Trop Med Public Health 2007). Back in the nineties researchers in Ghana and Brazil had looked for a public health application. Could coconut water from young fresh coconuts be used as an oral rehydration solution for episodes of diarrhea in developing countries? However, they found that coconut water does not contain quite enough sodium or glucose to qualify for this purpose (Fagundes et al. Jam Coll Nutr. 1993; Yartey et al. J Trop Pediatr. 1993).
What else is there to a coconut fruit? While coconut water comes from the interior of a young coconut, the coconut meat that we are familiar with is harvested from a mature coconut. This part is used to make the thick white coconut milk, and also yields ground coconut for a variety of desserts and savory dishes. These are rich in coconut oil, another recent headliner.
And why the hype about the oil? Maybe because it represents a paradox. Coconut oil is composed of as much as 92% saturated fat, and for years we have heard that saturated fats can raise LDL and contribute to cardiovascular problems. The obvious conclusion would be that coconut oil is associated with these negative effects. But wait. Actually, coconut oil is composed mostly of medium chain fatty acids (6 to 12 carbon atoms in length), as opposed to saturated fat from animal products which consists primarily long chain fatty acids (14-22 carbons). Length can make all the difference because it changes the way fatty acids are metabolized. Coconut oil advocates are buzzing with news of exciting, though still questionable, benefits relating to immunity, metabolism, and cardiovascular health.
But among the most notable benefits is a positive effect on cognition, especially among those suffering from dementia. Like all cells, brain cells need energy, and they obtain it preferentially from glucose. But during dementia, these cells lose their ability to produce glucose energy, and cannot survive. However the brain can also use energy from ketones, and this is where the medium chain fatty acids found in coconut come in. Instead of being absorbed into the blood from the small intestine, these fatty acids travel directly to the liver, where they are converted to ketones. These ketones can then travel to the brain, allowing an alternate energy source for the cells that can no longer use glucose.
The idea that some fatty acids are beneficial for the brain isn’t new. For instance, you may have heard that omega-3 fatty acids have a positive effect. Dr. Ernst Schaefer, Director of the Lipid Metabolism Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging, has explored the association between omega-3 and dementia in the Framingham Heart Study data. He explains that the roles of omega-3 and medium chain fatty acids are different: while the latter exert a benefit by being incorporated into cell membranes, the latter are utilized inside the cells.
People are stopping to reconsider their beliefs about the effects of coconut oil when they see it on an ingredients label or a supermarket shelf. Meanwhile, the pharmaceutical industry has used the new findings about medium chain fatty acids to formulate a treatment for patients with dementia – medium chain fatty acids are the active ingredient in the new prescription supplement Axona. The ones in coconut and the ones in Axona are not identical: coconut oil contains mostly the 12-carbon long lauric acid, and Axona is made with the 8-carbon long
Food fads are quick to catch, and coconut, with numerous health claims and trendy image, can be pretty appealing. After the summer of 2009, which saw a spike in coconut sales, reporter Sarah Maslin wrote in the “Fashion & Style” section of the New York Times, “Like banh mi sandwiches and sriracha chili sauce, the young coconut and its juice is the latest formerly humble food to be discovered by New York City’s style set.” Indeed, a decade ago, you would have seen coconuts piled on a cart on the side of the road in South India or Ecuador. They are still being sold from those carts, but you will also find coconut products in most grocery stores in Boston and on photographs of Madonna, who invested over a million in Vita Coco last year. Coconut is in fashion, but for those hoping to boost their health or exercise performance, it’s important to figure out where the health claims are coming from.
Marina Komarovsky is a Friedman alumna (’11) with MS-Nutritional Epidemiology/MPH-Health Communication degrees from Tufts. Her goal in writing is to relate study findings from researchers who are into nutritional biochemistry and statistics to those who are not into those things at all. She currently works as a research coordinator at Northeastern University.