Matt Freeman DNP, MPH
I used to live down the street from a juice stand named “Tamara.” The juice was mouth-watering: whatever combination you could imagine. The passion fruit had a perfect tang, the grapefruit was sour, the oranges were ripe and sweet. Situated at the corner of Dizengof Street and Ben Gurion Boulevard, “Tamara” was the ideal location in Tel Aviv. It was easily accessible en route to the beach, on the way back from the beach, or while out for a stroll.
“Don’t you wish we invented, Tamara?” asked my friend, Ariel. “They just have a shack, some fruit, and they hire good-looking students to serve up the juice for the equivalent of US $6.
Ariel and I would chuckle at the juice bar across the street, which was staffed by a schlubby guy. He ne never had any customers. The Tamara brand exuded refreshing youthfulness.
Tamara never claimed to be anything but a juice bar. They served juice that tasted good; just a refreshing treat. They offered no illusion that they were serving some sort of magical elixir. To my knowledge, Tamara does not serve wheat grass.
An acquaintance, Nadav, made an odd claim about Tamara. “It’s a good place for smokers,” he explained. “They need the anti-oxidants so they do not get cancer.” Although not a smoker himself, quitting smoking did not seem to be on Nadav’s radar as a disease prevention strategy. And that’s when I started to think more about juice.
“I’ve gone back to juicing.”
I greeted one of my patients recently, and I asked how he had been feeling. “I’m in much better shape. I’ve gone back to juicing.” Paging Nadav.
In fact, many have embraced versions of Nadav’s scientific misconceptions. Oprah Winfrey, Mehmet Oz, Gwynneth Paltrow, and others have extolled the virtues of “juicing” as the key to a healthy weight and a healthy life. Forget flu vaccine, hand washing, seatbelts, or other self-explanatory measures to protect one’s health. The answer lies in juice.
Where does this appeal come from? Why has it been so sustainable?
Juice and Cleansing
Juicing—retail or homemade juice consumption—is frequently associated with the notion of “cleansing.” There are pervasive references for the need to cleanse the liver and colon.
Amid other functions, the liver converts fat-soluble toxins into water-soluble versions, which can be tossed into the colon via bile or into the kidney for excretion in urine.
The colon removes water and absorbs some nutrients, particularly vitamin K, B12, thiamine, and ribovlavin.
The liver and colon do this regardless of what one eats or drinks. In fact, the concept of “detoxifying” the liver is not a possibility. The liver itself detoxifies, so it cannot be detoxified by an external source.
Catherine Collins, a National Health Service dietitian at St George’s Hospital in London put it best. “It’ll probably give you a chance to reassess your drinking habits if you’re drinking too much. But the idea that your liver somehow needs to be ‘cleansed’ is ridiculous.”
The liver would actually be dysfunctional if it were to be detoxified.
Cleansing advocates argue that toxins accumulate and line the interior of the colon. Moreover, these invisible toxins are weight-bearing and cleansing therefore leads to weight loss.
This is false. The colon is actually full of perhaps trillions of microbes: bacteria, fungi, and protozoa. In fact, the bacteria in the colon serve to produce a small but significant proportion of vitamins.
Bowel obstructions can form from a variety of sources, but this is really just a version of constipation: not an accumulation of “heavy toxins.” A total detoxification of the colon would be disastrous in terms of eliminating beneficial bacteria (so called “normal flora.”) Microbes, by definition, are “microscopic,” and so they just cannot be large enough to contribute to body weight.
The Origins of Fruit- and Juice-Based Diets
According to restaurant analyst Andrew Freeman, the most significant introduction of juicing in popular culture was the Beverly Hills Juice Club in 1975. (I know Andy Freeman. He is a great guy. But we are not related—at least as far as we know.) Coincident with a resurgence of American “vitamania” in the late 1970s, juice became allied with the notion that it is a gateway to missing nutrients, and thus a ticket to better health.
The Beverly Hills Juice Club also shortly predated the “Scarsdale Medical Diet,” introduced in 1978. A bestseller, the Complete Scarsdale Medical Diet was the first “ultra low calorie diet.” Although not juice-specific, the Scarsdale Medical Diet permitted “sliced fruit: as much as desired.”
The Complete Scardsale Medical Diet
The Complete Scardsale Medical Diet was the invention of Herman Tarnower MD, a cardiologist. Whether deliberate or not, Tarnower’s low-carbohydrate, low-calorie, but fruit-permissive diet was remarkably reinforcing. Diet followers enjoyed significant weight loss at the beginning of their adoption of the diet plan. It is, in fact, the same technique used by pretty much any popular diet: caloric restriction. By swapping half a grapefruit for a meal, Scarsdale dieters were limiting themselves to fewer than 1,000 kilocalories per day.
The body responds with as one might expect in a state of starvation: it digs into energy stored as glycogen. Glycogen itself is connected to water, so there is a substantial fluid loss during the first week or two. The grapefruit or unlimited sliced fruit are not magic: it is just fluid loss.
One of Tarnower’s diet followers was his girlfriend, Jean Harris. Headmistress of the Madeira School in McLean, Virginia, Harris was losing extra pounds on the Complete Scarsdale Diet.
There was one additional element that “completed” the diet: amphetamines. Tarnower was prescribing speed for Harris, which undoubtedly led to further weight loss. The drugs also contributed to her shooting Tarnower to death in 1980. (Not to name drop again, but Jean Harris and I grew up on the same street.)
Over the coming decades, various reincarnations of The Complete Scarsdale Medical Diet surfaced. All of them followed the same caloric restriction model.
Fruit and juice, however, came to the forefront with The Beverly Hills Diet.
The Beverly Hills Diet
Introduced in 1996, the Beverly Hills Diet was another bestseller. The diet was the invention of Judy Mazel, who had no formal education or credentials in nutrition or the health sciences.
The first ten days of the Beverly Hills Diet are limited to fruit. The diet actually encourages diarrhea, claiming that it is a sign that the diet is working. Just like the others, the fluid loss from diarrhea provides an immediate—but not sustainable—weight loss. The starvation-based approach of The Complete Scarsdale Medical Diet seems benign in comparison with a diarrhea-based diet. According to the World Health Organization, diarrhea is the seventh leading cause of death worldwide (1.5 million deaths per year.)
I cannot help but recall my friend Kristen’s stories from med school. She had gone on some sort of educational program to Ecuador. She referred to a particular item at the breakfast table as “diarrhea juice.”
The Beverly Hills Diet later gave way to the Atkins, South Beach, and Paleo diets, all of which are variations on the caloric restriction theme.
Juice as a Nutritional Superpower
The combination of fruit-based diets and the Beverly Hills Juice Club evolved into the idea of “juicing.” This became an accessible option as household juicers became more affordable and retailers began selling wider varieties of juice combinations. Pomegranate/açai/blueberry smoothies are available at convenience stores. A countertop juicer sells for under $50.
No longer the domain of the Beverly Hills Juice Club, “juicing” became an option for everyone.
Authors of diet books were quick to capitalize on the availability of juice. One name emerged above all others: Joseph Mercola DO.
Dr. Mercola and the Juice Miracle
On his web site, http://www.mercola.com, Joseph Mercola extols may benefits of juice, particularly how it is preferable in comparison with whole fruits and vegetables. Mercola claims that juice is preferable because, “most people have impaired digestion as a result of making less-than-optimal food choices over many years.” Mercola does not explain the pathophysiology behind his claim: would French fry consumption in the past lead to an inability to digest a banana?
Mercola’s argument is that juice permits one to “pre-digest” nutrients thereby facilitating their absorption. The notion of “pre-digestion” plays upon the same idea that previous dietary indiscretions are irreparable, and that one must consume nutrients in liquid form only.
Mercola has some particularly bizarre claims about juice. He states that it increases energy by “optimizing” the body’s pH. The acid/base balance in the body is complex and constantly adaptive system. The stomach’s buffering mechanisms allow juice to remain acidic in the stomach, but this does go beyond the stomach. If the stomach could not buffer juice, our bodies would be in miserable acidic states. Optimal pH is maintained by the body regardless of what one eats or drinks.
Mercola’s acid/base claim connects with his even more curious assertion that juice provides the body with “structured water,” and “living water.” In an insult to those who have studied the most basic chemistry class, Mercola explains that juice comes as H2O2 not H2O.
H2O2 is hydrogen peroxide. If one were to drink it, it just turns to foam, and eventually just to water. Water does not come in living or structured forms; water is always one oxygen atom and two hydrogen atoms.
Juice and Immunity
Mercola argues that juice “supercharges” the immune system, implying that a hyper-responsive immune system is favorable.
Immunity actually only comes two ways: deficient and adequate. There is no “supercharge” to the immune system. In fact, an inappropriately responsive immune response occurs in autoimmune diseases, in which the body attacks itself. These include systemic lupus erythematosis, scleroderma, Hashimoto’s thyroiditis, and others. The “supercharge” is to one’s detriment. Allergies, for example, a result of a “supercharged immune system.”
Commercial juice retailers are a bit more subdued. Jamba Juice argues that its Zinc and Antioxidant Boost “helps support your immune system” with a footnote, “These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease.” Tropicana omits the disclaimer, stating that an eight-ounce glass of its orange juice, “helps to support a healthy immune system.”
The only plausible way to argue “immune system support” from orange juice is that one might be spared from getting scurvy.
Mercola has a strange an futuristic explanation: “…juice supercharges your immune system” with “phytochemicals and biophotonic light energy.” I do not even know how to respond to that other than by asking, “what?”
An antioxidant “boost” is not just dubious, it is dangerous. Nadav’s “smokers need juice” theory is problematic because antioxidants can actually exacerbate lung cancer and increase the risk of death from cardiovascular disease. Antioxidants were long believed to reduce certain activity on the surface of cancerous cells. It seemed like a good idea until the Carotene and Retinol Efficacy Trial (CARET), in which people who were at high risk for lung cancer (smokers, those with a history of asbestos exposure) were given beta-carotene supplements. The CARET trial stopped before its planned end date because those participants who received antioxidant supplements had more cases of lung cancer. (Sorry to break the news to Nadav.)
Juice and Alzheimer Disease
Mercola states on his web site, that juice can “Support your brain health. People who drank juices (fruit and vegetable) more than three times per week, compared to less than once a week, were 76 percent less likely to develop Alzheimer’s disease, according to the Kame Project
On the surface, the Kame project looks like a powerful endorsement for juice. In a study of 1,836 Japanese Americans in King County, Washington, who were followed for nine years. Those participants who drank juice once or twice per week had a hazard ratio of developing probable Alzheimer disease of 0.26. Those who did not report juice consumption had a hazard ratio of 0.84.
But a hazard ratio isn’t a measure of relative risk. Relative risk is the probability of an event occurring in an exposed group (juice drinkers) compared with an unexposed group (those who did not drink juice twice a week). For example, smokers have a relative risk of 20 of developing lung cancer: their risk twenty times that of nonsmokers.
Hazard ratios express the rate of an event occurring in one population (juice drinkers) versus a control population (non juice drinkers.) A test subject in a group with the higher hazard ratio has greater odds of reaching a specific endpoint first. In other words, the juice drinkers in the study had lower odds of developing Alzheimer Disease before those in the non-juice drinking group. A hazard ratio does not explain the extent of treatment benefit, so the dose of juice was not explained.
Furthermore, the Kame study only controlled for tobacco and alcohol use and a particular genotype found in Alzheimer Disease (ApoE). It did not control for significant predictors of dementia like family history or head trauma.
As an epidemiologist, one looks for certain key elements in research, such as a dose-response relationship and biologic plausibility. Mercola and the Kame study do not offer either of these core components of robust research.
Mercola’s claim that juice prevents Alzheimer Disease is not supported by the Kame study. The only possible claim is that there is evidence in one trial that drinking juice twice per week might forestall Alzheimer Disease in a specific population.
Joseph Mercola, the Questionable Advocate for Juicing
Perhaps Mercola is not the best advocate for juicing. Mercola was censured by the US Food and Drug Administration (FDA) in 2005 for making illegal claims about supplements. He then received a warning one year later, and the FDA warned him again in 2011. One would think that a single action form the FDA would lead one to back off, but Mercola’s supplement and book sales must be so lucrative that he is willing to look beyond censure.
Although his license remains active without sanctions, Mercola reputedly had a three-year battle with the Illinois Department of Financial and Professional Regulation, and he stopped practicing in 2012. In addition to his juice claims, Mercola opposes fluoridation, screening mammography, dental amalgams (fillings), and vitamin K administration to newborns. Although there are some debates about the appropriate ages and intervals for mammograms, these are not controversial subjects in public health.
Mercola’s allies are similarly problematic. His endorsements from a Dr. Andrew Saul are worrisome. Saul claims to have a “nontraditional PhD in ethology.” His other colleague, a Dr. Abram Hoffer, supported the use of niacin to treat schizophrenia. The research was later discredited because the diagnostic test to establish a diagnosis of schizophrenia was called into question.
Perhaps the juice industry would benefit from solid research rather than “expert” opinion from supplement profiteers like Joseph Mercola.
Is Juice Healthy?
Juice is not exactly a low-calorie, low-carbohydrate choice compared with soft drinks.
250 mL Serving Size
One could argue that juice contains vitamins, which are not found in soft drinks. But a serving of apple juice, for example, contains only four percent of the recommended daily allowance (RDA) of vitamin C. It really is just sugar and water. It is true that other juices fair better in terms of vitamin C content, but vitamin C is found in a wide range of other foods contained in the typical Western diet.
Fresh-squeezed juice, however delicious, is also troublesome from a food safety standpoint. In fact, one of the first cases I was assigned as an epidemiology student was an outbreak of salmonella at a Florida resort. The CDC referred to outbreak location as “Theme Park A” (no prizes for guessing: it is in Orlando and has a mouse mascot.) The acid in juice was deemed to be protective, but the sweeter nature of fresh-squeezed orange juice meant that it was less acidic and thus less likely to contain salmonella. Outbreaks of Escherichia coli 0157:H7 and cryptosporidia have struck apple juice and apple cider. So much for “detoxification.”
Make no mistake, juice is delicious. I love fresh-squeezed juice from Tamara, I take the risk and buy unpasteurized orange juice—enjoying a small glass with my coffee in the morning. But it is not a detoxifying superfood. It is a nice dose of sugar when I wake up. But I am under no illusions. I could just as easily have Coca-Cola, it is not going to lead to weight loss, and it certainly is not going to detoxify anything.
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