1 February 2009

Food of the Month with Catherine Saxelby

Pomegranates: are they a superfood?

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Catherine Saxelby

With their impressive line-up of polyphenols (a type of antioxidant) matching some of those found in red wine, some found in berries, tea, cranberries and some grapefruit, are pomegranates on their way to becoming the next ‘super fruit’ poised to knock over goji and acai? For example, they have:

  • Punicalagin and punicalin, the two most abundant polyphenols unique to pomegranates, chemically known as hydrolysable tannins.
  • Anthocyananins, which give pomegranates their bright pink colour and have been extensively studied in blueberries where they help delay ageing and boost brain power.
  • Ellagic acid, also found in berries and dark grapes. These keep arteries flexible. Pomegranate extract supplements are standardised to ellagic acid usually 500 mg.
  • Quercetin, kaempferol, catechins and gallic acid, big-name polyphenols from wine and tea with their well-known anti-inflammatory properties.
  • Chlorogenic acid, usually in coffee.
Pressing the seeds to make juice extracts additional polyphenols from the white membrane surrounding the clusters of seeds (pericarp), so the juice is richer than the fruit on its own. Commercial juices have been reported to have antioxidants such as luteolin and narigenin (like grapefruit). Most of the studies have been funded by POM Wonderful and based on drinking a glass 8 oz/235 mL of juice daily. Smaller amounts may not achieve the same end-results. The studies so far are promising, but pomegranate – although clearly rich in antioxidants – can’t substitute for all the antioxidants in wine, tea and fruit in general. You can download the original research papers.

Nutritionally speaking, the juice is similar to other juices. There’s some potassium and a little iron, but not much in the way of fibre (seeds and pulp strained away) or vitamin C, thanks to the flash pasteurisation process which is needed to destroy bacteria and maintain shelf life in the commercial juice.

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The really big problem with pomegranate juice is that it is very concentrated and high in sugar. At 16.5% carbs (mostly sugars), it’s more concentrated than soft drink (11%) or orange juice (8-10%). One 8 fl oz/235 mL glass will load you up with 39 g carbs and 150 cals/630 kJ. It also has a moderate GI (67), so it’s a drink to be cautious with rather than gulp down.

Tips for using pomegranate juice
Look for 100% pomegranate juice if you’re after antioxidants. Many pomegranate juices are blended with apple or pear or mango juice so have less pomegranate. Avoid these.
Dilute it. Start with one part pomegranate juice, top with four parts sparkling water or chilled tap water. Add a squeeze of lime or lemon juice to lower the GI.
Use it as a marinade for duck, chicken or pork or in sauces and dressings.
Mix it into plain yoghurt or over ice-cream to flavour desserts. It’s quite thick and syrupy so pours well.
Limit yourself to half a cup (125 mL) a day. With around 15 g carbs, count this as one carb portion.

Is it a superfood? Not really. It’s an antioxidant all-rounder up there with berries and tea but it’s not something we can afford to guzzle in great quantity. Like wine and chocolate, a little is all that we can fit into our daily diets without overloading ourselves with sugar and calories. It can’t replace a variety of low-kilojoule fruit or vegetables which is where most of your antioxidants should come from.

Catherine Saxelby is an accredited nutritionist and runs the Foodwatch Nutrition Centre at www.foodwatch.com.au. For more information on pomegranates, super foods and healthy eating, visit Catherine’s website.

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9 comments:

Anonymous said...

As I consumed pomegrante juice I have been concerned about the GI and relieved to read that it is not exceptionally high.
I can't drink it straight and do add water but love the idea of moderating the GI through the addtion of lemon or lime juice.

Anonymous said...

You posed the question is pomegrante a super food and came to the conclusion that pomegrante juice is not a super food.

What about the fruit itself. I regularly use pomegrantes in cooking and for breakfast am I still consuming a high level of sugar or is this in the juice only?

Rose Dorofeeva said...

What about the anti-oxidant value of pomegranate molasses? In Australia it's more readily available and of more consistent in quality. Having tasted pomegranate juice in Thailand, Russia and Iran I would actually question what they sell here as juice.

Anonymous said...

I am on a medication which says to avoid grapefruit and grapefruit juice. As you mention pomegrante and grapefruit have something in common does that mean I should avoid pomegrantes as well?

Maija Haavisto said...

Rubicon has a great tasting juice which contains pomegranate, blueberries, cranberries and chokeberries. No, it's not 100% juice, but no added sugar or sweeteners either.

Anonymous: Pomegranate juice is known to interact with some meds, but generally the interactions have been thought to be different from grapefruit.

Caitlin said...

I agree - what about the fruit itself? I very rarely drink the juice but the fruit is a favourite.

GI Group said...

Catherine answers your pomegranate questions.

Question 1: ‘What about the fruit itself. I regularly use pomegranates in cooking and for breakfast am I still consuming a high level of sugar or is this in the juice only?’

Answer: Due to space limitations, I didn’t have room to cover the fruit. Yes it too is high in natural sugars but the range is wider than the juice. The fruit can be as low as 8 per cent sugars and as high as 20 per cent whilst the juice sits around 15 to 20 per cent. This is comparable with dark grapes at 16 per cent and sweeter than most berries at around 10 per cent. So you’re consuming one of the sweeter fruits but it’s still nutritious.

On the plus side, like all fruit, the pomegranate is very low in fat and protein. It offers a little vitamin C, a little potassium (a mineral which is required for fluid balance), as well as generous dose of fibre as you consume the small edible seeds, just like a passionfruit.

Interestingly for once, the juice turns out to be richer in antioxidants than the fruit, since pressing out the juice extracts many of the antioxidants from the white membrane surrounding the seeds. Usually it’s the other way around. And no the fruit doesn’t really qualify as a super food either.

Question 2: ‘What about the anti-oxidant value of pomegranate molasses? In Australia it's more readily available and of more consistent in quality. Having tasted pomegranate juice in Thailand, Russia and Iran I would actually question what they sell here as juice.’

Answer: I’m still chasing an analysis of pomegranate molasses but as it’s a concentrated syrup made by boiling down pomegranate juice, it’s going to be more concentrated and higher in sugars than the juice. I haven’t seen it listed on any ORAC scale or other antioxidant measure but – like other concentrated cooked syrups – I suspect some of the more fragile heat-sensitive antioxidants have gone but there’s no doubt a few still remaining. How many and how much is anyone’s guess.

Question 3: ‘I am on a medication which says to avoid grapefruit and grapefruit juice. As you mention pomegranate and grapefruit have something in common does that mean I should avoid pomegranates as well?’

Answer: Pomegranate juice is not listed as one of the fruits to be careful with. If you consume a lot of pomegranate juice and are concerned, check with your pharmacist.

Christie @ fig & cherry said...

Great article Catherine. Answered a lot of questions about pomegranate juice.

I received some bottles from POM wonderful to experiment with and made a delicious granita with it.

GI Group said...

More on pomegranate molasses from Catherine:

"What I now can say after having found an analysis ... Pomegranate molasses is made by concentrating pomegranate juice. My guess is it’s heated and heated to evaporate much of the water and leave a reduced thick syrup.

According to the label of the Cortas brand from Lebanon, it’s 50 per cent carbohydrate which includes 39 per cent sugars, all derived from the juice. This is less than honey at 80 per cent carbs or regular molasses 96 per cent but on a par with blackcurrant cordial 56 per cent and more than lime juice cordial 40 per cent.

Like pomegranate juice, it’s high in carbs but the difference here is a little goes a long way. I can flavour a whole glass of water with one teaspoon (5g) which gives me 2.5g of carbs. Not a lot really for so much flavour. Ditto for salad dressing and marinade. And there’s not a skerrick of fat or salt.

It adds a wonderful combination of understated sweetness with an astringency that you only find in balsamic vinegar or too-strong tea (must be those amazing polyphenols aka tannins which the tea blenders tell me is what makes you mouth pucker).

Is it rich in antioxidants? Who knows for sure? I haven’t spied one analysis in all the ORAC tables I’ve combed. No commercial company is out there paying for it to be done unlike the folk at Pom Wonderful. Interestingly it’s one of those food finds that seems to have slipped under the analytical radar.

With the boiling down of the juice to concentrate the syrup, any vitamin C and heat-sensitive antioxidants would be gone. But there may be well plenty of others still there. If the polyphenols can survive wine making and tea brewing, then they can doubtless survive molasses concentrating! I can taste that astringency so I’m fairly positive there’s some antioxidants there. But I await confirmation one day."