Author’s note: This is the first of three columns on vegetables and fruits. In the first column, I tackle the popular “juicing” fad. The second tackles the perennial question — what is the best way to consume produce — raw or cooked?The third column reviews what you should know about buying fresh produce and top tips to avoid pesticide contamination.
Juicing — what you should know (and claims to ignore!)
Juicing. It seems like an ideal way to lose weight and get healthy, right? After all, you’ve seen that sexy babe with her fingers wrapped around a glistening glass of juice, a tape measure conspicuously draped around her impossibly tiny waist. The caption guaranteeing ‘easy’ or ‘amazing’, or even ‘miraculous’ weight loss tempts you to ‘click here now’.
Wouldn’t it be great if you could juice your way to a size six, without hunger, without dieting? Wouldn’t it be great to drink your recommended nine servings of fruit and veggies in just one glass, not worry about the calories, and drink yourself thin?
There is a difference between juicing and blenderizing fruits and vegetables. With juicing, the juice is extracted and important health benefits are tossed in the garbage, namely the pulp and fiber. By liquefying or ‘blenderizing’ the machine purees everything and the liquid outcome still contains the fiber.
There are two types of fiber, soluble and insoluble. Most plant foods contain both types and both have health benefits, ranging from better digestion and lower risk for heart disease to lower risk of certain cancers and inflammation.
Studies show that soluble fiber is especially important for gut health and weight management, and passes through your digestive tract to nourish your friendly bacteria, known as a prebiotic effect.
Fiber fills you up and is helpful in weight management, whereas drinking juice has no impact at all on your appetite. A glass of juice contains the equivalent calories to a glass of regular sugar-sweetened soda.
And although juice and blenderized produce contain vitamins and minerals, there are important health benefits lost — more about that later.
Digestion starts in your mouth.
Consider how many oranges it takes to make just one 6-ounce glass of juice? Depending on the size and juiciness of that orange, you might need four, five…or more. Would you peel and eat that many at one sitting? You’re probably satisfied with one. You’re ingesting all of the calories of those excess oranges, without the fruit having an impact on your appetite.
We underestimate the impact that chewing has on digestion. Starting in your mouth, mechanically breaking down larger particles of food into smaller particles helps your stomach absorb nutrients, and chewing stimulates the release of digestive enzymes in the mouth. The act of chewing triggers the stomach’s hydrochloric acid production to speed up the digestive process.
Blending vs. Juicing
But you may have invested in one of those “turbo blenders” like a Vitamix or Ninja that quickly pulverize whole fruits and vegetables. Since blending does not destroy fiber, it’s better than a juicer, where you throw the pulp away.
But consider how much raw produce you use to create one glass of blended juice? If a cup of raw kale is one serving, how much do you use in your smoothie? Two, three, four cups…or more? Daily?
All vegetables are rich in different types of micronutrients, and in portions typically consumed they are healthful. However, more is not always better.
All greens contain minute amounts of naturally occurring substances that protect the plant. Spinach is rich in oxalic acid and too much could exacerbate kidney stones in susceptible people. Kale and other brassicas contain goitrogens, micronutrients that eaten in excess can interfere with thyroid hormones. Too much is not recommended. [These potentially harmful substances are largely deactivated when cooked, a good reason to lightly steam or sauté in olive oil, instead of drinking mass quantities of raw greens daily.]
And beware; some fruit seeds and skin are not meant to be eaten, so take care not to throw everything into the turbo blender.
For example, apple seeds contain amygdalin molecules, which produces cyanide — ingesting too many seeds can cause stomach ache or even worse. The skin of the cherimoya fruit and its seeds are toxic — the seeds have been used for insecticides and eating the skin can induce paralysis for 4-5 hours.
Variety is the spice of life — in all things. Since kale and bok choy are in the same brassica family, rotate your choices to include arugula, or Swiss chard, or beet greens. Check out the vegetables with the highest amount of fiber here.
Juice-fasting & ‘detox’ fallacies
Juice “fasts”, “detoxes”, or other pseudo-medical abstractions are designed to lighten your wallet. We’ve all seen the advertisements for “retreats” or juicing regimens promising “rejuvenation” and “healing” from consuming only “pure” raw juices and water.
Although I’m not a religious person, I am constantly amazed at how the human body can perform daily miracles… of chemical and biological processes. It sometimes blows my mind that a human can abuse their body so unmercifully — for example, driving through a McDonald’s and consuming a Big Mac, fries, and milkshake — and the body somehow comes up with the right amount of enzymes to digest and absorb and excrete.
But it’s not possible to undo a lifetime of poor eating in seven days — your body needs the right balance of nutrients and nutrition to perform … every single day. And going on a “juice fast” doesn’t cut it.
Consider this: what’s your dream car? An old 4-cylinder clunker or a high-performance sports car? Fuel your own ‘engine’ as if it were a Ferrari. We’re designed to chew and swallow, not merely sip. Your engine can’t run properly by excluding whole groups of nutrients, namely protein and fat. And it’s absolutely not necessary.
Fuel up with whole, fresh foods, avoid processed foods and drink water — your body will detoxify itself. That’s why we have a liver, kidneys, lungs, and intestines — to naturally digest, absorb, and detox daily.
Try this simple “detox” plan for a week and see if you don’t feel great. Eat fruits, vegetables, whole grains, legumes, nuts and healthy fats from plant and/or lean animal sources. Chew slowly, giving your digestive system from your mouth to your stomach time to work thoroughly. Drink water, or herbal or black tea, all shown to help your engine run optimally.
Don’t get me wrong. I’m not saying 100% juice is an unhealthy food; what I’m saying is that juice is processed food, and most importantly, juice won’t deliver as advertised. Eat your fruits and vegetables — whole foods are much greater than the sum of its parts.
Wash all produce (even pre-washed) before you eat it, including fruits and vegetables that you will peel (bananas, pineapple, carrots). In the upcoming Part 2 of this 3-part series, I’ll examine the recommendations for sourcing healthy produce.
Finally, people with diabetes and those taking medication for diabetes should never juice fast…ever. And fasting is never recommended for pregnant women or for children.
AuthorityNutrition.com. Fiber can help you lose weight, but only a specific type.
MayoClinic.org. Dietary Fiber: Essential for a Healthy Diet.
PopSugar.com. High-Fiber Vegetables.
WholeFoods.com. An Up-to-Date Look at Goitrogenic Substances in Food.