Photo: Kristin Cooks

Thanks to our brilliant intern, Kristin Cook, for sharing this insightful piece from her blog:

Living in the Bay Area, it’s hard to ignore the popularity of juicing and juice cleanses. A new juice shop seems to open every week and the selections at my local grocery store keep expanding. A typical juice cleanse lasts three days and consists of drinking six different pressed juices a day. All solid foods, snacks and stimulants like coffee and alcohol are eliminated. Let me first say that an occasional fresh juice is a great way for some people to consume more fruits and vegetables. Drinking juice can help fill a void in your diet and supply your body with the naturally occurring vitamins and minerals found in plants. That being said, juice cleanses can be dangerous for your health and most of the claims are not supported by science. Juice cleanses promise benefits such as increased energy and stamina, mental clarity, weight loss and elimination of toxins. Let’s talk about the facts and health implications of juicing and find out what the hype is all about.

It is no surprise that fresh fruits and vegetables are good for you. Studies show that an increased consumption of whole fruits is linked to a lower incidence of type 2 diabetes. On the flip side, high consumption of fruit juice is associated with a higher risk of developing type 2 diabetes (1). When fruit juice is extracted from whole fruit, the juices contain extremely high levels of sugar. For example, the Pineapple, Apple & Mint juice from BluePrint contains 45 grams of sugar in one serving- the same as a medium soda! Taking in 45 grams of sugar in one sitting can spike your insulin levels and lead to a sugar crash later. In addition, the rapid absorption of sugar sets off a domino effect of hormonal and metabolic changes that promote excessive food intake (2). The absence of fiber in juice is the main cause for the difference in your body’s reaction to fruit juice versus whole fruit. The fiber in whole fruit has an impact on your energy intake and fullness level. Multiple studies found that consuming whole fruit increases satiety and delays the return of appetite as opposed to drinking the sugar-equivalent of meals of juice (3). Juice cleanses claim to boost energy and mental clarity. I don’t know about you, but I don’t feel energetic or productive when I’m hungry!

The promise of weight loss attracts a lot of people to juice cleanses. Although you are likely to see the number on the scale decrease, it’s not what you think. A three day juice cleanse is very low in protein. When your body doesn’t have enough protein, it will start breaking down muscle mass as an energy source. You will likely lose weight during a juice cleanse, but chances are you are losing water weight and some muscle tissue. When you return to your normal diet, you will likely gain back all of the weight and then some. If weight loss is the goal of a juice cleanse, it can create a very unhealthy pattern of yo-yo dieting and restrictive eating.

Lastly, cleanses claim to detoxify the body and provide a break for your digestive system. The truth is, your body was created to detoxify itself! That’s what the liver and kidneys are for. No controlled studies have found the effectiveness of detox diets in humans (4).

If you are looking to make a healthy change or reset your eating habits, I recommend eating fresh fruits and vegetables, drinking plenty of water and cutting out alcohol and junk food. If you like to drink your produce, try smoothies which keep the fiber from fruit and vegetables. If you still want to drink juice, that’s okay too! Make sure to listen to your body and read labels to understand the nutritional content, especially sugars.

I would love to hear your questions and comments about juicing and juice cleanses! Have you ever tried a juice cleanse?


1. Muraki, Isao, et al. “Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies.” Bmj 347 (2013): f5001.

2. Ludwig, David S., et al. “High glycemic index foods, overeating, and obesity.” Pediatrics 103.3 (1999): e26-e26.

3. Bolton, Robin P., Kenneth W. Heaton, and Lennard F. Burroughs. “The role of dietary fiber in satiety, glucose, and insulin: studies with fruit and fruit juice.” The American journal of clinical nutrition 34.2 (1981): 211-217.

4. Klein, A. V., and H. Kiat. “Detox diets for toxin elimination and weight management: a critical review of the evidence.” Journal of Human Nutrition and Dietetics (2014).

What To Eat Before & After Your Workouts

What To Eat Before & After Your Workouts

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