To green juice or not to green juice?

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While juicing has been around for eons, the latest craze has now gravitated towards the even ‘healthier’ pressed, whole juice. The concept makes some sense – stop extracting the pure sugar from your favourite plant foods (forsaking fibre and flooding your system with sugar) and opt for a pureed version of the whole food … complete with all the ‘goodies’.
Pressed (whole) juice is now the beverage of the moment. Celebrities drink it. So do fitness fanatics, yoga disciples and vegans. They’re guzzling raw vegetable drinks to “cleanse” their bodies, consume more veggies and shed unwanted kilos. On the surface, it seems that firing up your Nutribullet is the easiest way to consume copious amounts of fresh vegetables and fruit. It makes for a fast breakfast, lunch on-the-run or snack, and it’s healthy. Right?

Well, maybe not. Let’s take a look at the facts…

Problem #1

One of the major issues with any form of juicing (whole or otherwise), is that you are condensing the volume of fibrous plant foods, allowing consumption in quantities beyond your natural capacity. If you piled the hefty contents of your Nutribullet onto a plate prior to blending, it’s unlikely you’d manage to consume it all in its whole state before your stomach sent a signal to your brain that you’ve had your fill. With the absence of chewing your food and the consequent gradual release of saliva and associated enzymes, much of the digestive process, which nature has perfected, is lost.

Digestion of carbohydrates (including all veggies & fruit) begins in your mouth when mixed with saliva. If you do not chew your food, saliva doesn’t have an opportunity to do its job. Saliva contains special enzymes and antibacterial properties. Saliva contains the enzyme amylase, which breaks down starch into simpler, digestible sugars such as maltose and dextrin.  About 30 percent of starch digestion takes place in your mouth and these enzymes also play a role in protecting teeth from decay. Saliva also contains a potent form of the enzyme lipase which is essential for fat digestion.

Problem #2
The high vitamin K content in a spinach/kale smoothie, for example, can be life-threatening if you take blood-thinning medications, such as warfarin. Such anticoagulants often are prescribed after a stroke, deep vein thrombosis or other circulatory conditions. Kale, spinach, turnip greens, collards, Swiss chard and parsley contain enough vitamin K per cup to lower the drugs’ anti-clotting activity.

If you’re one of the many millions of people taking cholesterol-lowering statins, stay away from grapefruit. The citrus fruit blocks an intestinal enzyme that controls absorption of some statin drugs. You’ll also face a higher risk of muscle and joint pain, muscle breakdown, liver damage and kidney failure if you drink grapefruit juice, or eat the fruit, while taking statins. Grapefruit also can interfere with drugs for high blood pressure, anxiety, allergies and other ailments.
If you have kidney problems, beware of fruit and vegetable juices with high amounts of potassium, such as bananas and kale. Four cups of chopped kale can be lethal if your kidneys are weak due to high blood pressure, severe infection, an enlarged prostate, certain drugs or pregnancy complications.

Green juice & thyroid function:
Kale, bok choy, cauliflower, collards and spinach are rich in the substance thiocyanate, which in very high concentrations, can interfere with adequate iodine nutrition. The thyroid needs iodine to produce thyroid hormone, and thus exposure to very high amounts of thiocyanate can potentially result in hypothyroidism (an underactive thyroid) and compensatory growth of the thyroid (goiter). Your thyroid function is responsible for your metabolism, so a reduced production can result in numerous health issues, including excess fat gain. The risks may be exacerbated in individuals who are already iodine deficient, and these may include those with restricted diets, such as vegetarians and vegans.

Australia is known to have very low levels of iodine in our soil, hence the reason much of our salt is now ‘iodised’ and ‘iodised salt’ is now compulsory in commercial bread production.  Adequate iodine nutrition is particularly important in women of child-bearing age and their children, given the importance of iodine and normal thyroid function on the developing brain in young infants.

Eating whole greens in their usual amounts will not be a significant contributor toward thyroid disorders.
Problem #3

Juice cleanses don’t work!
We clean out our houses, our lint filters and cars. So why not our insides? That’s the reasoning behind juice cleanses, which are intended to rid your body of ‘toxins’. I’ve said it before and I’ll say it again – FORGET IT! The practice is a waste of your time and money, not to mention potentially detrimental to your health. Your body is not like the filter in your clothes dryer. It doesn’t need ‘cleansing.’ Our bodies have their own elaborate, complex and very efficient detoxification system, known as the liver, intestines and kidneys.  It’s physiologically incorrect to think the body can’t detox on its own … or that an elaborate regime of starvation plus juice will do the job for you!

In the process of ‘detoxing’, you’re actually starving your body of essential nutrients, potentially causing loss of bone, tooth decay from the sugary juices and loss of valuable lean muscle tissue, not to mention the additional stress of being hungry and the headaches (often touted as the effect of rampant toxins!) caused by the blood sugar rollercoaster. Which, by the way, stimulates further fat storage!

Problem #4
Juices can be calorie bombs!
If you’re downing up to 2 litres of juice a day to lose weight – which many fasts recommend – stop! Juicing for days to lose weight can be potentially harmful. That’s because you’re losing out on important nutrients.  And don’t expect to get slimmer. In fact, you might gain weight, because you’re consuming more calories than you realise – mostly from naturally occurring sugar in the fruits and vegetables. Some juices and smoothies are more caloric than a meal. Consume too many, and you can end up with a few thousand calories of juice a day and still be unsatisfied.
Problem #5

You’re depriving yourself of protein.
Juice (pressed or otherwise) is not a meal replacement. A 70kg person needs a minimum of 70 grams of protein daily to repair cells and create new ones. Protein also preserves and builds lean body mass, stabilises blood sugar and create satiety, which supports health and even burns calories. Fruits and vegetables [alone] are not a great source.

Donna Aston - Author

Nutritionist Certified Fitness Trainer Author of five best-selling health & fitness books Emotional Intelligence Certified Practitioner (Genos) Managing Director: Aston & Co. Pty. Ltd. Fitness advisor: Prevention Australia Magazine & SEN radio CIRQ acrobatic master trainer

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