glasses of fresh vegetable juices on wooden background

To the verb “to juice” means to extract the juice of fruits and vegetables. Juicing, as a meal replacement or mere refreshment, has become a 5 billion dollar business, and is projected to grow by 4% to 8% a year according to Barron’s.  There are more than 6,200 juice bars across the county. Devotees the likes of Bill Clinton, Jennifer Aniston, Gwenth Paltrow, and other celebrities and models have popularized the habit. As Barron’s points out, “The habit doesn’t come cheap: A 17-ounce bottle of cucumber, celery, parsley, kale, dandelion, Swiss chard, lemon, and ginger juice will set you back $13.07 at Juice Press, a raw-juice bar with four outposts in New York and a busy mail-order business.”

Some report a feeling of elation and find their symptoms such as rashes, bloating, constipation, gas, and acne are alleviated when they start juicing. Caitlyn Weeks, The Grass Fed Girl, explains in her article 9 Problems With Juicing, “I believe this is because when people go on a juice fast they eliminate all the possible food allergens that they were previously consuming. Most people are sensitive to dairy, wheat/gluten, soy, corn and other grains. People are also very often poisoning themselves with new substances like soybean, canola, and corn oil found in processed foods and at most restaurants. The removal of these food toxins will dramatically improve someone’s health, which is the same thing that happens on a juice fast along with some other unintended consequences.  [A] juicing diet is just a temporary fix and long term juicing can lead to other problems.”

We would consider the notion that juicing is healthy to be a dietary myth. Here is a list of our concerns about juicing:

1. Juice is not a whole food.

One of our main goals, as is outlined in the book Nourishing Traditions, is to eat whole foods in their most natural state. When we drink juiced vegetables and/or fruits, we are not eating the whole food. Juice doesn’t include the pulp, or the fiber. Caitlyn Weeks explains, “Fruits and vegetables come in whole forms for a reason and they have evolved certain nutritional profiles that we have barely begun to understand. Why mess with perfection when we have no idea what we are doing? I just think when a vegetable is pulverized and the pulp is removed from the water there may be certain phytonutrients or natural co-factors that we will be missing. This is similar to the way we now understand that isolated and/or synthetic vitamins are not replacements for healthy foods.”

2. Where is the fiber?

The primary effect of juicing is to remove most of the fiber from a vegetable or fruit. Unfortunately, that fiber is very important.

Fiber from vegetables and fruits helps to keep you full, which you probably already know. What you might not know is that the fibrous part of the vegetable also contains polyphenols, which act as anti-oxidants. Juicing typically removes both the fiber and the polyphenols. As Caitlyn Weeks points out, “The fiber from green vegetables can feed the beneficial bacteria which helps motility. Some people keep the fiber when making green drinks [in a blender] but that can cause problems too [which will be discussed later in this article].” Many people with health conditions such as Irritable Bowel Syndrome are better able to digest well cooked vegetables in broth and soups.

Orange juice in glass with mint, fresh fruits on wooden background

3. Fructose

You consume more fruit in juice than if you simply ate a piece or two of fruit. For example, few of us would eat four oranges at one time, yet that’s how many 8 fluid ounces of juice could contain. That is a staggering 22 grams, or 1.5 tablespoons of sugar. Apples contain even more sugar: 26 grams, or 1.8 tablespoons in a single 8 ounce glass. One orange, considered to be one serving of fruit, contains 9 grams, or under 2 teaspoons of sugar.

Dr. Thomas Cowan, MD, considers fruit to be an overrated food, and advises that we consume local, organic, seasonal fruit in small quantities. He advises avoidance of any dietary regimen emphasizing an increase of fruit or fruit products, including homemade juices which are a source of concentrated fructose. Instead of juice, he recommends homemade lacto-fermented beverages which aid in healing the gut and also with digestive function such as kombucha, beet kvass, and rejuvelac. Instead of beet juice, we would recommend fermented beet kvass.

Similarly, Dr. William Davis, M.D. advises us to  include whole vegetables in our diet, but claims that excess fruit can lead to diabetes. “Fruit has many healthy components, of course, such as fiber, flavonoids, and vitamin C. But it also comes with plenty of sugar. This is especially true of modern cultivated fruit, the sort that has been fertilized, hybridized, gas-treated, etc. for size and sugar content. When you hear conventional advice like “eat plenty of fruits and vegetables,” you should hear instead: “Eat plenty of vegetables. Eat a small quantity of fruit.”

Dr. Joseph Mercola, D.O., concurs that modern fruit is sweeter than what our ancestors would have consumed. “The wild fruits consumed by our ancestors were smaller and resembled most closely what a blueberry is today. Modern cultivated fruits are much larger, which means they have a lot more sweet pulp inside and less skin. The sweet ‘pulp’ or ‘flesh’ of the fruit is where most of the fructose is, whereas the skin holds the antioxidants.”

What about fruit smoothies?

While blenders like the Nutribullet, which can be used to make healthier vegetable smoothies, use less fruit than conventional juicers to produce a glassful, they still create problems. “By crushing your apple rather than simply biting into it, you are effectively making a sugary juice as you release the fructose — a type of sugar which is naturally found in fruit,” says Scott Laidler. Usually fructose is contained within the cells of the apple and broken down slowly as part of the digestive process. While you aren’t creating more sugar by crushing the apple, you are making it much easier for your body to absorb.

Keep in mind that some vegetables, such as carrots and beets, also have high sugar content.
Dark green leafy fresh vegetables in metal colander

4. Oxalates in Raw Vegetables

Some people either add vegetables to their juicing, or juice vegetables exclusively. Either way, we have concerns about them being consumed raw. Dr. Cowan cautions, on page 19 in his book The Fourfold Path to Healing: “Many vegetables are difficult to digest in their raw state, often because they contain toxins that block thyroid function, interfere with mineral absorption or irritate the digestive tract. Green leafy vegetables and cruciferous vegetables like broccoli and cabbage belong in this category. Cooking neutralizes these anti-nutrients and makes these vegetables easy to eat. Fermentation also neutralizes these substances, as in cabbage made into sauerkraut.  Raw salads can be very beneficial, but if your digestive apparatus is compromised, even these should be avoided.”

Sarah Pope, of The Healthy Home Economist, similarly recommends that we avoid juicing high-oxalate content vegetables such as broccoli, spinach, and green leafy plants. What are oxalates in foods and how can they harm our health? Sarah Pope explains:

Frequent consumption of large quantities of raw, leafy green vegetables as occurs when a person drinks green smoothies can be deceiving at first as a person will probably initially feel great after adopting this habit particularly if he or she is coming off a highly processed, nutrient poor diet. The vegetables used in green smoothies are almost without exception high-oxalate foods.  Over time, a high-oxalate diet can contribute to some very serious health problems particularly if you are one of the 20% of people (1 in 5) that have a genetic tendency to produce oxalates or if you suffer from candida or other fungal challenges. In those cases, a high-oxalate diet can deal a devastating blow to your health.

Humans have suffered the effects of oxalate toxicity since ancient times. A 2000 year old mummy from Chile was discovered through x-ray analysis to have an oxalate kidney stone about the size of a golf ball! Oxalates can be deposited almost anywhere in the body and wherever they land, pain or worse is the result. 75-90% of kidney stones are oxalate related with 10-15% of Americans afflicted at some point during their lives. As the star shaped crystalline stones pass from the kidney, they cause pressure and pain in the bladder and urethra and can actually tear up the walls of the urinary tract.

5. Goitrogens in Raw Vegetables

As Chris Kresser L.Ac., a teacher and practitioner of functional medicine explains: “Juicing a lot of raw green vegetables can be problematic for people with thyroid issues because a lot of those green vegetables have goitrogens.”

A goitrogen is a substance that suppresses the function of the thyroid gland by inhibiting iodine uptake, and these things are called goitrogens because they tend to cause goiter, which is a swelling of the thyroid gland. Some foods have been shown to be goitrogenic when they’re eaten in excess or if the person’s background intake of iodine is low. These are things like cassava, which is otherwise known as yuca, that’s how I usually talk about it; soy products; millet; sweet potatoes; cruciferous vegetables like cabbage, broccoli, Brussels sprouts, cauliflower, bok choy; and then most of the dark leafy greens like kale and collard greens.

At relatively low concentrations, if you eat these foods a few times a week, I don’t think it’s a problem, but if you start eating them more regularly and you eat them raw, which we’re going to come back to in a second, goitrogens can actually decrease the uptake of iodine in the thyroid gland from other foods that we eat that contain iodine. Now, this can typically be offset by supplementing with iodine or just eating more iodine-rich foods like sea vegetables or certain species of fish or fish head soup, things like that that are naturally high in iodine, but at higher concentrations, goitrogens interfere with the incorporation of iodine into thyroid hormone itself, and that means that even if there’s enough iodine going into the thyroid gland, it can’t be properly utilized and no amount of supplemental iodine either through food or supplements will be able to overcome that large intake of goitrogens.

Let’s imagine a scenario here where you have someone with hypothyroidism and they’re doing a green smoothie every day, and in that green smoothie they’re putting raw kale or collard greens and a fairly significant amount of those, and they’re doing that because maybe initially they feel good after they drink that, and they’re trying to get the nutrients from kale, and they’ve heard all about the power of green smoothies. What can happen to that person over time is that the goitrogens in the raw kale and collard greens will, as I said, inhibit uptake of iodine and start to make their hypothyroid condition worse, so raw kale green smoothies every day is a really bad idea for somebody with hypothyroidism. I feel like that message has gotten out a little bit recently but not to the extent that it needs to because I have a lot of patients who come and see me who are doing just that and they’re not aware of the potential effects on their thyroid gland.

We don’t anticipate that having broccoli once or twice a week would pose a concern for anyone! We just recommend that you don’t eat it raw; cooking reduces the goitrogenic substances by up to a third, with the except of soy and millet. We don’t recommend modern soy products. It is considered a best practice to avoiding eat several foods off the list below in one day; they have a cumulative effect. The following lists are provided by Paleo Hacks:

Top 11 Goitrogenic Foods

  • Bok Choy
  • Broccoli
  • Brussel sprouts
  • Cabbage
  • Cauliflower
  • Kale
  • Kohlrabi
  • Mustard and Mustard greens
  • Radishes
  • Rutabagas
  • Soy anything [which we don’t recommend]
  • Turnips

Foods with Smaller Amounts of Goitrogens

  • Bamboo shoots
  • Millet
  • Peaches
  • Peanuts
  • Pears
  • Pine Nuts
  • Radishes
  • Spinach
  • Strawberries
  • Sweet Potatoes
  • Wheat and other gluten-containing grains

6. We need fat to digest vegetables.

A Swedish study published in the International Journal of Environmental Research and Public Health found that eating fruits and vegetables didn’t lower the risk of coronary heart disease unless said fruits and vegetables were consumed with high-fat dairy products! Many of the vitamins and micronutrients in food are fat-soluble, which means they cannot be absorbed without the presence of adequate fat. That means that if you eat fruits or vegetables without fat, you’ll absorb only a fraction of the nutrients you would absorb if you ate them with fat. Read more about how fat is necessary to absorb nutrients in fruits and vegetables from Nourished Kitchen. Also, read Want Fat With That? A Surprising Way To Make Vegetables More Nutritious by Tara Parker-Pope.

7. Chewing is part of digestion.

Caitlyn Weeks points out that: “Digestion begins in the mouth when food is mixed with saliva, and some say it starts just from smelling/seeing food. Chewing cues stomach acid production and peristalsis. When someone is only having liquid food they may not send the right signals downstream to start digestion off right. If stomach acid is not released in sufficient amounts food will not get broken down and nutrients won’t be absorbed.”

8. Where is the scientific evidence that drinking fruits and vegetables is healthier than chewing them?

Jasmine Garnsworthy explains that: “Some juice cleanse fans claim that juicing is better for your cleanse than eating whole fruits and vegetables because it’s easier for your body to absorb nutrients, and your digestive system can take a breather from working on fiber. However, there’s really no strong scientific evidence to support the idea that extracted juices are somehow better for you than eating the whole vegetable itself.

9. We detox naturally eating whole foods.

Nutritionist and author Keri Glassman warns against long-term juicing, labeling it as extreme and dangerous, and explaining that they also lead to bad eating habits: “Long-term juice cleansing can lead to deficiencies as well as to yo-yo dieting, which itself can lead to a whole host of problems.” In her article Drop That Juice—Here’s How You Should Really Be Cleansing, Jasmine Garnsworthy writes:

“The best cleanses don’t follow an all-liquid diet, include any weight loss pills or powders and are not meant to be followed for a long period of time,” says Glassman. “Steer clear of a cleanse that requires you to invest a lot of money or requires really extreme practices.”

Oh, and you know your kidneys, skin, and urinary system? Well, all of those things do a pretty brilliant job of detoxing your body just fine, without the help of some crazy, liquid-only diet. “What many people don’t realize is that your body is a natural cleansing system built to detox all the time, if you treat it right,” explains Glassman.

Instead, she recommends eating an organic, whole food–based diet for about four days if you want to break unhealthy habits and reset your mind and body. Afterwards, you can expect to feel less bloated, more energetic, and could drop around two to six pounds.

“The best way to stay cleansed is to consistently eat organic greens and lots of other veggies, and carefully portioned organic fruit and healthy fats,” says Glassman. “[Have] plenty of water, and take out all packaged and processed foods.”

If you do feel compelled to cleanse, take a look at The Nourishing Cleanse by Amanda Love, which we recommend.

10. Damage to Teeth Enamel

Even dentists are concerned about this latest health trend. They’re seeing more cases of acid erosion — the softening and loss of tooth enamel caused by the acid in soft drinks — than ever before. As enamel is the material that protects teeth, softening it can lead to decay, fillings and crumbling molars. Frighteningly, surveys have shown that up to 30 per cent of 12-year-olds exhibit some signs of it. “Juice from fruits has a high acid content and can damage the enamel of your teeth in exactly the same way that a fizzy drink does,’ says Dr Uchenna Okoye, of London Smiling dental practice. ‘If you’re going to drink juices, always use a straw. Never brush your teeth straight after drinking, as the teeth are weakened by the exposure to acid.” Read more about dental health concerns in this article Kale? Juice? Trouble Ahead by Jennifer Berman.

What if I still feel compelled to juice?

Here are some guidelines from Jeanmarie Todd, food blogger:

  • Use a 3:1 ratio of vegetables to fruits.
  • Always prepare and drink juices fresh. [As soon as you juice fresh produce, you’re breaking open the cell walls and activating the nutrients – the vitamins, enzymes, minerals, phytonutrients, chlorophyll, etc. – found in the produce.A number of these nutrients are time-sensitive. The process that causes apples to go brown so quickly is called as oxidation, or exposure to oxygen. Juice is even more vulnerable to oxidation being that every part of the fruit or vegetable is being exposed to air. Oxidation reduces the enzymes and vitamins in the fruit and/or vegetable juices. Even when there’s no visible color alteration in the juice, as we see in apples, the same process of oxidation occurs.]
  • Cook cruciferous vegetables rather than juicing them – spinach, kale, broccoli, bok choy, kohlrabi, cabbages, collard greens, mustard greens, radish, turnips and Brussels sprouts.
  • Consume any homemade juices with a meal or with traditional fats including coconut oil, olive oil, raw cream or sour cream, raw eggs, and avocados. When consuming these as part of a meal or balanced with traditional fats and protein, optimal nutrient absorption can occur and prevent uneven blood sugar and an insulin spike in the body.
  • Prepare and consume lacto-fermented vegetable juices including sauerkraut juice or kvass such as beet or other vegetable combinations.
  • Avoid raw juices as an exclusive way to obtain nutrients.
  • Instead of a juice extractor, consider a Vita-Mix or Bosch which will allow you to prepare a blended veggie smoothie and retain fiber found in these foods.

We would add, avoid pasteurized juice. In conclusion: we recommend that if you are going to juice, that you do so at home, with low-oxalate vegetables, low or no fruit content, blended with traditional fats, as part of a well-balanced diet including other traditional foods.  We also recommend you do so under the guidance of a qualified healthcare practitioner.

Acknowledgement

I want to appreciate Raine Saunders of Heal Your Gut With Food who did some preliminary research and writing on this topic that contributed to the article I wrote! We are co-creating educational materials for Nourishing Ourselves.

Update

I published a subsequent article on what Dr. Weston A. Price Wrote About juice.

What has your experience of juicing been?


Disclosures