Koslo's Nutrition Solutions

Monday, June 28, 2010

Coconut water: Is it really "natures sports drink"?

Coconut water is not something new. The liquid inside young, green coconuts has long been enjoyed in tropical countries due to its availability, cultural traditions and beliefs regarding its health benefits. But now it has gone main stream in the US and can be found in colorful juice-box style packages in a variety of flavors in most supermarkets. Sales of coconut water in the US have jumped in the last five years from near zero to $40 to $60 million dollars annually. Part of this increase can be attributed to celebrity endorsers like Madonna, Matthew McConaughy and Demi Moore who have recently invested in Vita Coco, and to the investment of Pepsi in O.N.E.. But is this drink really “nature’s sports drink” and what are the facts behind the hype? I for one am a skeptic of almost every new food or beverage that has the makings of a fad so I thought I would do some research and decide for myself.
Just the nutrition facts ma’am
Coconut water is not to be confused with coconut milk which is squeezed from the inside pulp and used as a common ingredient in many Thai recipes. Coconut water is from young green coconuts and is low in calories and a natural source of electrolytes including sodium and potassium. Eight ounces of coconut water has 46 calories, 9 grams of carbohydrates, 250 mg of sodium, 600 mg of potassium, 60 mg of magnesium, 45 mg of phosphorus, and 2 grams of protein (USDA, Nutrient Database). The electrolyte content is more than double that of traditional sports drinks with about half of the carbohydrates. So if you go buy a young, green coconut and crack it open and wash that bagel down with it after your workout then yes, it can contribute to optimal hydration and recovery. In addition to electrolytes and carbohydrates, coconut water contains other beneficial components including vitamins, minerals, antioxidants, and amino acids.
Not so fast!
There is always a rub. The commercial brands sold in the US (I looked at the nutrient data for 5 brands including Vita and Naked Juice) have a potassium content that is similar to the water fresh from the fruit however, the sodium content is much lower with an average of 35-60 mg per eight ounces. Compare this to Gatorade which contains 70 calories, 19 grams carbs, 154 mg sodium, and 42 mg potassium per serving and you will see that as a sports drink the sodium level is far too low for adequate electrolyte replacement.
Coconut Juices versus traditional sports drink
Product (per 8 ounces Calories Carbs (g) Sodium (mg) Potassium (mg)
Popular coconut waters:
Harvest Bay Original Coconut Water 47 12 25 480
Naked Juice Coconut Water 44 10 14 473
O.N.E.100% Coconut Water 44 10 44 487
Vita Coco 100% Pure Coconut Water 44 10 29 494
Traditional sports drink:
Gatorade Thirst Quencher 50 14 110 30

I also did a search for research on the use of coconut water as a fluid replacement drink for physical activity and found two studies completed recently. The first study compared rehydration after exercise with young coconut water, a carbohydrate electrolyte beverage, and plain water (Saat, et. Al, 2002). The results indicated that recovery was similar when either the coconut water or the carbohydrate beverage was ingested. However, as stated previously water straight from the nut has a higher sodium content then the commercial varieties sold in stores. The second study used a sodium enriched coconut water for testing rehydration compared to a sports drink and fresh coconut water from the nut (Ismail, et.al,2007). The results indicated that the sodium enriched coconut water was as effective as the sports drink in whole body rehydration.
Bottom line
If you are looking for a low calorie refreshing beverage with lots of potassium, then this is your drink. But in terms of recovery from exercise, I recommend sticking with traditional sports drinks. Sports drinks are specifically formulated for athletes with the amount of electrolytes and carbohydrates at the levels found through years of research to promote optimal hydration. Drinks like Gatorade contain 4-8% carbohydrate concentration (10-18 grams per 8-ounce serving), around 100 mg of sodium and 30 mg of potassium. This formula has been shown to promote fluid absorption from the intestines and encourage fluid retention in order to prevent dehydration and prolong exercise.
If you are curious go ahead and give it a try but test it during training not competition. As for this sports dietitian, I am going to wait for the results of those research studies conducted with the commercial varieties before I put it on my recommendations list.

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Thursday, June 24, 2010

Wow is it hot!

It sure is a hot one today in Phoenix with a high of 112! This means that you need to either get outside very early or very late to do your exercise. You also want to make sure that you are hydrating adequately.

Physiologically speaking exercising in the heat puts the most stress on your body. You are dealing with the heat gained from physical exertion as well as the hot environment. Dehydration results if you don’t take in enough fluids to keep up with your sweat losses. An average person that weighs 110 to 165 pounds can lose 2 to 4% of his body weight per hour and losses of just 2% result in decreased performance. Exercising in the heat decreases your efficiency and as you become more dehydrated you rely more heavily on stored glycogen. This means you will tire faster due to the build up of lactic acid and that is why your usual run or ride may seem so much harder this time of year.

So what do you need to do to stay hydrated? First, are you a salty sweater? I know I am! Have a look at your clothes and see if you have white stains on them after you exercise. If you do then yes you are a salty sweater. This is a good piece of information. The other thing you want to know is how much fluid you lost during your exercise. Best way to do this is to weigh yourself before and after your workout. Then for every pound lost you want to replace that with 2 cups of fluid and preferably fluid that has electrolytes.

Check the label of your sports drink. You want to have at least 100 mg of sodium, 30 mg of potassium, and 14 g of carbohydrate per 8 ounce serving. If you prefer electrolyte chews, they generally have more carbohydrates and less sodium but are still a good choice. Wash them down with at least 8-12 ounces of water. Plain water is not sufficient in the extreme heat so make sure you have a plan and hydrate early and often. More on electrolytes and the array of hydration choices out there later...

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Tuesday, June 1, 2010

KNS adds a blog!

Ok if you haven't noticed from my previous blogs I am new to blogging. I took some downtime yesterday and tried to tackle a giant stack of journals and magazines and came across an article titled "Ten Rules for Better Blogging" in my American Dietetic Association journal. After reading it I came to the conclusion that so far with my posts I have broken all ten rules! So let's try this again. Koslo's Nutrition Solutions now has a blog and I want to use this forum to have a conversation with you, the athlete, the casual exerciser, the health conscious about how our food choices affect our health. I like to keep abreast of the research so I will focus on the latest findings on food and supplements and their effects on health and performance. But I want this to be a conversation so please comment on my posts and I promise to be a better blogger in the future.

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