1 June 2008

Food of the Month

Juices and juicing
We are often asked about the benefits of juice as a way of totting up those daily fruit and veggie serves. Here, dietitian and nutritionist Catherine Saxelby explains the pros and cons of juices and juicing and provides tips on enjoying these (usually) low GI drinks along with some great fruit and veggie combos.

Catherine Saxelby

The juice bar cult has created a whole new market for freshly-squeezed juices and smoothies, often enhanced with a shot of wheatgrass, guarana, echinacea or ginseng. You can sip orange and carrot; peach, guava and pineapple; apple, capsicum and celery; watermelon, mint and beetroot – all healthy and on-the-go. Driven by the youth market, juice bars are a place for young people to gather after school, just as cafes are meeting places for older generations. And juice bars make fruit and vegetables seem exciting, enjoyable and tasty.

Fresh juices, along with raw foods, have long been recommended by natural health practitioners since the nineteenth century. Juices are said to be an integral part of detox regimes, used to ‘cleanse the digestive system’, ‘draw out toxins’ and make the body more alkaline. Some of these claims are groundless, but are capitalised on by juice bars and all-fruit drinks to highlight the virtues of juice.

Juice pros
Juice is healthy and natural. Freshly-squeezed, 100% juice with no added sugar offers many health advantages. It:

  • Retains the maximum content of vitamins, minerals, enzymes and antioxidants. Juices are rich in all the nutrients of fruit and vegetables namely vitamin C, beta-carotene (which is converted to vitamin A in the body), folate, vitamin B1, niacin, vitamin K, potassium and magnesium.
  • Can provide some of your recommended 7 serves of fruit and vegetables a day.
  • Is helpful for fussy eaters who don’t eat many fruits or vegetables.
  • Packs in nutrition for an underweight person with a small appetite OR someone recovering from chemotherapy who can’t eat much.
Juice cons
Fruit juice is fruit that’s concentrated. Juices pack in a lot of kilojoules/calories and represent fruit in a form that’s all too easy to seriously over consume. The fibre and intact structure have been removed, and with that goes the ‘natural brake to over consumption. Look at this comparison:
  • A 200 g (7 oz) apple PROVIDES 3 g fibre and 300 kilojoules (71 calories) and TAKES 10 minutes to eat.
  • A 650 ml apple juice (2½ cups) PROVIDES zero fibre and 1300 kilojoules (309 calories) and TAKES 2 minutes to drink. In fact a large juice is equivalent in food value to 4 apples but takes a fraction of the time and volume to drink and you are missing out on the fibre in the skin.

The bottom line
  • Think of a large juice as more of a mini-meal or a substantial snack than just something to quench your thirst.
  • Order the smallest size or share one with a friend.
  • Try the fifty/fifty option and dilute juice with water or sparkling mineral water. Or fill up the glass with ice cube first then drizzle over the juice.
  • Drink water if you’re thirsty (no kilojoules/calories there) and eat a whole piece of fruit.
  • Fruit and vegetable juice combinations ‘dilute’ the sugars and calories so it’s not so concentrated. Try adding carrot, spinach or other green leafy veggies, celery, tomatoes or other vegetables you like with your fruit juice.
Juicy combos
Here are some fruit and veggie combos you can make at home or enjoy in a juice bar. Keep in mind that apple and carrot will work in just about anything and there's nothing like ginger for added zing.
  • Carrot, apple and ginger (add in a bit of celery too if you like)
  • Tomato, apple and parsley
  • Watercress and pear
  • Carrot and kiwi fruit
  • Beetroot, apple and carrot (add a little parsley too if you like)
  • Carrot and ruby grapefruit or orange
  • Watermelon, celery and pineapple



Anonymous said...

Catherine Saxelby needs to learn to do research before she writes. Too much juice is potentially fatal which Saxelby seems to be oblivious to. Juice concentrates and increases the amounts of nutrients one gets, including potassium which causes some kind iscemic
heart disturbance. I've had them and they went away after a nurse told me to stop drinking so much Juice. She told me they are potentially fatal.

Anonymous said...

I thought the GI movement was against counting calories... Here we have a lady just doing that... strange. I really do not think you can get fat by drinking 100 % fresh pressed juices...

HL said...

I think this article was both well researched and balanced. It gives the fors and againsts of juicing and doesn't say to avoid or not, just gives some sensible advice on how to include it in a well balanced diet. As for counting calories, the author gives the caloric values of foods so that readers can compare. It's a logical addition to the article.

Anonymous said...

Dieticians have long recommended that children NOT be given a whole carton of fruit juice to drink several times a day . At most one carton diluted with wateris recommended.Mothers mistakenly believe they are giving their children a healthier drink than cordial, when in fact the fruit juices are concentrated or have added sugarand and absolutely no fibre.Water would be a better alternative to increase hydration.
Krista Corlis B.Pharm

GI Group said...

Catherine Saxelby comments:
"I too am against counting calories – aside from using it as an initial learning exercise for someone who claims to ‘never to eat anything yet can’t lose weight’, I don’t use it – counting calories only makes you obsess about the ‘little things’ in nutrition.

"I only gave a calorie count in a fruit versus juice comparison. I wanted to highlight how one glass of juice contains 4 or 5 pieces of whole fruit. Counting the calories in each is a nice easy way to grasp it.

"And yes, drinking lots of 100% freshly-pressed juice IS a way to put on weight. They may be 'healthy calories' in that 100% juice, but they are still calories and you can all too easily pile on the pounds if you’re sedentary (as most of us these days are) and don’t exercise enough to burn it off! "

"You’ve hit the nail on the head! Juice DOES concentrate the nutrients and kilojoules of whole fruit – my exact point. Juice makes it easy to over-consume fruit – not that eating fresh fruit is a bad thing but for overweight sedentary folks like most people in Australia, US and Canada, too much fruit adds extra calories we don’t need. Most authorities recommend 2 pieces of fruit a day (and 5 serves of vegetables – twice as much as fruit as vegetables don’t add many calories and are nutrient-dense).

"You must have been drinking an awful lot of juice to take in enough potassium to cause a heart problem. The recommended day’s intake for potassium is 2800mg for women and 3800mg for men. When I was writing my book Nutrition for Life, I checked what’s the safe upper limit for potassium. Interestingly most authorities don’t give one, saying it’s impossible to set and excess only occurs if you overdo supplements AND have an existing kidney or heart problem. Over 10 grams (10,000mg) in a single dose was considered to be a dose that could potentially trigger a cardiac arrest.

"Now I’ve just looked at the potassium levels of popular juices. Two glasses 500ml home-squeezed orange juice gives you only 725mg potassium, while apple juice has 440mg and apple-blackcurrant has 515mg. Even if you could swallow 500ml of pure carrot juice (a hard task), it would set you back 1310mg; tomato and vegetable juice has 1000mg. So you can see that it’s hard work to reach that figure of 10,000mg from juice alone. For healthy people without any medical issues, overdoing potassium from juice just isn’t a problem. Usually they don’t get enough potassium."

"Agree totally. (Isn’t that what I said!?) Drink water if you are thirsty."

hermin said...

i know there has been lots of confusing information out there (e.g. should we count calories or
not). but i agree with Catherine and HL that we need to weigh the benefits against the risks, in
every decision that we are going to make -- whether we would count calories or not, would we eat this food and how much would we eat, etc.

so, could i restate Catherine's advice like this:

- it's better to eat fruit or veg as a whole rather than as a juice.
some people apparently don't eat enough, no matter how hard they (or their carers/parents)

have tried. maybe they have a small appetite, or they are fussy eaters, or they don't have much time to sit down and eat.

for these people, juice might be a happy compromise (i mean, a happy "complement")

- juices are better than other drinks that don't provide nutrition (soft drinks, for example).

- juices can help them top up their fruit and veg intake, especially if they have a small appetite (and they are underweight)

The dilemma is that, if we ban juices altogether, they might NEITHER eat fruit/veg NOR drink
juice. Instead, they might turn to energy-dense, nutrient-poor foods or drinks. and they are not
meeting their fruit and veg allowance either (this is a lose-lose situation).

BUT if we drink lots of juice simply because it's good for us, then we're at risk of putting on
weight, because there are lots of calories in, say, 3 litres of juice.

that's why the "moderation"
principle still applies. too much of a good thing is actually NOT a good thing. even drinking too
much water (3 litres at once) can be fatal.

in other words,

it'd be better to add a glass of juice to your meal and get enough nutrition than not having any juice at all in your busy day, and not getting enough nutrition.

but let's not have two litres of juice a day, especially if we need to control our weight!

hope this clears the confusion.

David D said...

I'm curious as to where I find data showing that juicing "retains the maximum content of vitamins, minerals, enzymes and antioxidants". Surely when you juice a carrot and throw away a large mass of orange stuff - all of the beta-carotene hasn't magically made its way into the juice?

Anonymous said...

I keep reading that juices are missing the fiber found in the fruits they are made from. If I make my juice in a Vita Mix machine and drink both the pulp and juice, am I getting the fiber, or is the fiber destroyed by pulverizing it?

GI Group said...

Catherine Saxelby (www.foodwatch.com.au) answers the question is the fibre destroyed by pulverizing it?

Generally the pulp is discarded from the juice so you don’t get all that goodness and fibre (although these days, many juicing companies suggest ways to utilize the pulp to overcome this e.g. apple or orange pulp can go into muffins, vegetable pulp can be added to soup or Bolognaise sauce. Or you can toss it into your compost bin).

Your Vitalmax juicer is a non-centrifugal machine – it has a slow-turning screw which crushes or squeezes the fruit or veg. Drinking the pulp AND the juice is the best way to maximize the fibre in your juice which you’re already doing.

However I suspect that because you’ve broken down the intact natural structure, you won’t get the same biological effect INSIDE YOUR DIGESTIVE TRACT as eating the original fruit. A bit like the GI value for intact whole grains compared to smooth flour with added fibre. Haven’t seen any research on this except for an old study from the 1980s where they compared whole apples with apple puree and apple juice and reported that people who ate the apples felt fuller sooner and consumed less calories than the people on the puree and juice. So I’d expect the same response with your fibre-added juice.

By the way, in Australia, Choice magazine did a nice test of juicers and gave the VitalMax a good rating, even though it was more expensive than the more common centrifugal juicer where the rotating blades cuts the fruit at high speed (Nov 2007 issue – find it online at www.choice.com.au). This machine can also juice wheatgrass and herbs as well mincing and chopping. A good choice.

Anonymous said...

Catherine, thank you for your clear and concise answer to my juice fiber question.
I think the complainers should re-read your original post, which I found to be clearly written and informative. I bet the person worried about the toxic levels of potassium weighs about 300 lbs!
I will look for your books.

GI Group said...

Catherine Saxelby (www.foodwatch.com.au) answers David D's question.

Surprisingly most of the beta-carotene and other nutrients DOES end up in the juice. I advised a prominent juicer manufacturer in Australia on lab tests they wanted to do to check exactly that! Their competitor was making claims that centrifugal juicers raised the heat of the juice produced and so “destroyed” all the vitamins. The lab tested apples and carrots for vitamin C, vitamin B1, alpha-carotene and beta-carotene. Then it juiced all the produce and analysed the end juices for the same things. What they found:

* The yield is 60 to 70 per cent of the starting peeled fruit, more for a centrifugal juicer. Using a higher speed setting produced more juice. So they started with 500 g trimmed apples or carrots and got 350 ml of juice.
* There was no real difference in any of the vitamins between the fruit and the resulting juice. Admittedly vitamin C levels were low to begin as apples and carrots are not rich in vitamin C but the other three were the same.
* In some case, the vitamin content of the juice actually increased – I guess due to the juicer’s ability to open cells and extract all their contents.
* The temperature rose only one or two degrees and sometimes not at all. It was the room temperature of 25 degrees C – not boiling at 100 degrees C as when you boil vegetables – so wouldn’t have affected the heat-sensitive vitamins.

While this small study never got published, I’m sure there must be ones out there showing just this. Apart from fibre (which would stay in the large mass of orange pulp left behind), if you’re not heating the fruit and drink it within 15-30 minutes, there’s nowhere for the vitamins, minerals, enzymes or antioxidants to go!

geo talbert said...

whats that facts on mona vie

GI Group said...

We'll pass your question on to Catherine. She is going to be writing a series on superfoods for GI News over the coming months, so all suggestions for topics our readers want covered welcome. Stay tuned: In July, Catherine puts the spotlight on goji berries.