Juicing Is Not As Healthy As Eating Whole Fruit and Vegetables
Juicing has become a popular health trend in the last few years with words like “smoothies”, “juicing” and “juice cleanse” entering our vocabulary as healthy options for weight loss and a convenient way to get your vitamins and minerals for the day. In my practice as a personal trainer in New York City, I am often asked about how healthy juicing actually is as it has become ubiquitous in just about all fitness establishments. Gyms and just about any store or restaurant claiming to sell “healthy food” have machines set up to get you your juice. A natural drink made with nothing but wholesome fruit and vegetables. It goes without saying that you can drink more fruit and (especially) vegetables than you can eat, and the idea is with juicing you can easily get all the nutrition from fruits and vegetables quickly and efficiently. The perfect guilt-free health food for people on the go, a marketing mantra that makes juices especially popular in urban environments, add an air of upscale trendiness to it and you have a nearly universally accepted food. The health claims supporting the practice of juicing are numerous and juices are purported to help you do everything from lose weight, increase energy, and detoxify the body by flushing toxins out of the system. Some even claim that it can cure cancer and reverse metabolic disease. As appealing this all sounds, like so many health food claims, the science validating them is non-existent and thus far no additional benefit has been seen from the consumption of juices over eating whole fruits and vegetables. It might sell more juicers and specialized juice based diet books and programs but the seldom mentioned fact is that consuming juices over whole fruits and vegetables might actually be harmful as a landmark study found that greater consumption of specific whole fruits, particularly blueberries, grapes, and apples, was associated with a lower risk of developing type 2 diabetes, whereas greater consumption of fruit juice is associated with a higher risk. Juicing may also make weight loss harder and there is evidence as well that consumption of juice only diets can severely stress the kidneys.
You might ask how could something so seemingly “natural” as juicing not be the answer to our desire for a healthy and wholesome vitamin boost? The answer is one that has plagued us since even before the advent of the Industrial Revolution, where we remove ourselves from situations where we take foods that we have been eating for hundreds of thousands of years in a naturally occurring, unprocessed form, process them and make the claim that this more convenient and easier to consume version is somehow equal to or superior to its unrefined counterpart. It’s a story that places the blame for our astronomically higher rates of obesity and diet related metabolic disease when compared to populations consuming foods in their more naturally occurring states. Convenience is one thing, but like all compromises, it comes with a price and as such it is crucial to also look at the complex relationships developed between our species and the fruits and vegetables we consume. Our ancestors didn’t just evolve eating fruit and plants but the fruit and plants evolved with us over time. One of the theories as to why primates like humans and apes see in color while other carnivorous mammals do not is that it allows us to spot and identify ripened fruit.[3,4] The point in time where fruit is not only safest to consume in terms of digestion, but also when the fruit will yield the most amount of micronutrients and macronutrients. A mango, for example as it ripens and changes color from green to yellow, undergoes significant changes in amylase activity which serves to break down the indigestible starch content and converts it into sugars that humans can easily digest. Our sense of smell also tells us when fruit is best to consume and while today we take these abilities somewhat for granted, they point a finger back into the past at the links between us and our truly natural food sources.
For Most Of Our Time On The Planet Humans Ate Fruit & Vegetables & Did Not Drink Them In the Quantities We Do Today
That said, changes in the way we eat, or in this case, drink a naturally occurring food source represents a stark contrast to how we ate as a species for a very long time. For the better part of our time on the planet, we ate fruit in its whole form, and while some fruits are high in sugar, the combination of high fiber content, pulp and makeup of the fruit itself makes for a slow absorption of its naturally occurring saccharides into our bodies. Now putting fruits and vegetables into a juicer, or buying pre-packaged juice might make it easier to consume, but in so doing we bypass the rather straightforward way in which our bodies have been designed to consume produce. One of the fundamental lessons of evolutionary biology is that processed foods, regardless of how natural the source, are entities that are physically different from their unrefined forms. Differences that mean our ability to use them as a healthy source of nutrition changes as well. A discord that in many cases leads to reduction in the overall wholesomeness of the food and may have a negative impact on our health. Which might very well explain the relationship between eating whole fruits and reduced incidences of type 2 diabetes while consuming juices saw higher rates of diabetes onset.
Now some would argue that juicing has been around for centuries and man has consumed juices with little in the way of adverse outcomes since the beginning of the Neolithic period. To which we must remember that the steady supply of fruits and vegetables was nowhere near as abundant as it is today, and at no time would the average human several hundred years ago have access to daily helpings of juices blended from a wide variety of fruits and vegetables in the quantities we have nowadays. One of the most poignant tenets of modern medicine is that it is the dose that makes the poison and by juicing our fruits and vegetables, we not only consume more than we probably should, but at a rate that our bodies are not simply not accustomed to dealing with. For example, while they may be chock full of vitamins and nutrients, those benefits don’t cancel out the negative aspects. A typical “healthy” smoothie, for example is often far more than your body can naturally accept without some negative consequences. A common juice recipe of a cucumber, some celery sticks, an apple and three beets might not sound like much, but when was the last time you ate all of those things at the same time? You probably could, with some effort, over the course of a few hours, because of the fiber content, so imagine the shock it presents to your body when consumed in seconds.
The Sugar Content of Some Juices Are Just As High As A Can Of Soda
The speed at which it is consumed and the concentration of sugars all serve to drastically raise the glycemic index of what would ordinarily be perfectly acceptable additions to diet in their whole forms. (See my article here on Glycemic Index) However, combined in a juice form that same recipe would have about 40 grams of sugar, the same amount as a 12 ounce can of soda. If the fiber and pulp is reduced through the juicing process, as it always is with commercial juices, the carbohydrates present in the fruits and vegetables will be more rapidly converted into glucose and will thus cause a greater spike in insulin levels. And even if some pulp is retained, the rate of consumption and concentration of sugars will still lead to an inevitable insulin spike. Developing diabetes isn’t as simple as just eating or drinking sugary foods, but spikes in insulin do increase the storage of fat in fat cells in addition to preventing fat cells from releasing fat for energy. Which is not at all desirable to those of us trying to lose weight or maintain a healthy weight. Insulin spikes also lead to increased hunger and fatigue, which in turn has been shown to increase the likelihood of overeating and weight gain.
Juicing Does Not Detoxify Your Body
The other argument for the consumption of juices is that by concentrating fruits and vegetables in juice form it can increase the concentration of healthy phytochemicals and antioxidants, making it the perfect concoction to “flush out” and detoxify toxins built up in the body. As common a belief as this may be, it fails to take into consideration the fact that fruits and vegetables are not without harmful components and that just because something is natural does not mean it is not without potentially harmful components. Most of the history of human agriculture has been about reducing the levels of toxins and poisons in fruits, vegetables and plants to levels where regular consumption does not pose a problem. Oxalates, for example, which are commonly found in certain fruits, vegetables and nuts are nephrotoxins, which are a group of toxic agents that inhibit, damage or destroys the cells and tissues of the kidneys. Cases of oxalate poisoning have occurred due to juice diets, and in one case where beets, collard greens, kiwi, parsley, spinach, and soy products were consumed in juice form for a period of 6 weeks renal failure occurred as a result.
Other cases of oxalate poisonings have been attributed to juicing by researchers resulting in renal failure, however for those with normal kidney function and who do not consume high oxalate juice, the risk of juicing nephropathy is likely low. Nevertheless, because juice consumption enhances oxalate absorption, researchers maintain that it is still prudent to calculate daily oxalate consumption , and of course this is not an issue at all when whole fruits are consumed. Going on a juice cleanse where all you consume are juices has thus far been disproven as having any health benefits, and the human body does not need periods of fasting or juice diets to protect itself from the rigors that poor eating habits inflict upon it. If you want to “detoxify” your body, simply don’t put anything toxic in it by eating a balanced and moderate diet of minimally processed foods, adequate fluid intake, regular exercise and proper sleep. None of which have any ill effects, and leave juicing as a last resort for the infirmed and those who are unable to eat fruits and vegetable in their raw form due to health reasons.
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Featured everywhere from the Wall Street Journal to network TV, Kevin Richardson is the international fitness consultant for UNICEF, a natural bodybuilding champion, creator of Naturally Intense High Intensity Training and one of the most sought after and best reviewed personal trainers in New York City. Learn more about his award winning personal training services here!
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