Study links fruit juice consumption with increased risk of diabetes

While fruit juices have a healthy reputation, I don’t believe their as healthy as their image suggests. Some of the issues I have with them are detailed here. One key property of fruit juices that causes me to advise their consumption with caution is the fact that they tend to be very sugary indeed. Many fruit juices have a sugar concentration similar to sugary soft drinks. And some juices (e.g. grape juice) contain considerably more sugar than this even. Now, if I had to drink fruit juice or a sugary soft drink I’d choose the former (the fruit juice wins hands down, I reckon, in terms of it ability to deliver some nourishment to the body). What I am saying, though, is that the intensely sugar nature of fruit juices make this far from an ideal beverage for those seeking to optimise their health.

With this in mind, I was interested to read the results of a recently-published study in which the relationship between the consumption of green vegetables, whole fruit and fruit juice and risk of diabetes was assessed in more than 73,000 women over a period of 18 years [1]. The results of this study showed that:

An increase in whole fruit consumption of 3 servings per day was associated with an 18 per cent reduced risk of diabetes.

An increase in green vegetable consumption of 1 serving a day was associated with a 9 per cent reduced risk of diabetes.

An increase in fruit juice consumption of one serving a day was associated with an 18 per cent INCREASED risk of diabetes.

Epidemiological studies of this nature may show that drinking fruit juice is associated with diabetes risk, but they cannot prove that fruit juices can cause diabetes. However, the high sugar nature of fruit juices means that they may indeed have a genuine diabetes-inducing effect. It is sometimes said that the fruit sugar (fructose) found in high levels in fruit juice is relatively harmless, on account of the fact that it does not tend to raise blood sugar levels. However, as I detail here, fructose is anything but safe, and its consumption has been found to induce something known as ‘insulin resistance’, which is a precursor of diabetes. Personally, I don’t think it’s any major surprise that the drinking of fruit juice has been implicated in the development of diabetes. My advice remains the same: give them a wide berth.


1. Bazzano LA, et al. Intake of Fruit, Vegetables, and Fruit Juices and Risk of Diabetes in Women. Diabetes Care [epub 4 April 2008]

12 Responses to Study links fruit juice consumption with increased risk of diabetes

  1. firstlunchthenwar 28 April 2008 at 8:45 pm #

    I must admit the title of this had me worried! Perhaps you need to add in “juice” after “fruit” to make the title more reflective of the article.

    Have always avoided fruit juices…why waste the money when you can drink water and buy much nicer whole fruit?

  2. Dr John Briffa 28 April 2008 at 8:55 pm #

    Thanks firstlunchthenwar – it’s been a long day….

  3. AuntWie 29 April 2008 at 3:18 am #

    Not a big surprise, but I’m always glad to see evidence that backs up what I “know” from my own experience. I had a really great “protein shake” at a local coffee house and only found out later that they made it with about 8 oz of pineapple juice. I bounced off the walls for a couple of hours then crashed like a meteor. Uunph!

  4. Anne 29 April 2008 at 8:18 am #

    You wrote: “It is sometimes said that the fruit sugar (fructose) found in high levels in fruit juice is relatively harmless, on account of the fact that it does not tend to raise blood sugar levels.”

    I don’t know where this idea ever arose. If I drink some fruit juice and check my blood glucose levels with my meter shortly after (I’m diabetic), the levels of blood glucose are really high !


  5. Dr John Briffa 29 April 2008 at 8:33 am #

    Fruit juice can be rich in glucose too – and this may explain the blood sugar spikes you get after drinking it.

  6. Anne 29 April 2008 at 10:24 am #

    I believe fruit must be rather rich in glucose too because it causes blood sugar spikes too for me, grapes, bananas, tangerines…I can’t eat them anymore without a big spike 🙁


  7. Anna 29 April 2008 at 5:59 pm #

    It drives me crazy to hear fruit sugars in juice described as “natural”, therefore they are “healthy” to consume in concentrated and copious amounts.

    I have a very smart European friend, who is a physician, who was drinking her second very large glass (12+ oz) glass of orange juice as we discussed how I was managing my health and glucose issues with carb restriction instead of medications, including my being careful about how much fruit I eat.

    She said, “surely OJ is ok, right? She was very surprised to learn I see a large glass of OJ in a very different way: the way many, if not most people consume it, is as an industrialized processed, heated (pasteurized) food product (no elves squeeze individual oranges, the bulk oranges go into huge presses, peel and pesticides included).

    A glass of OJ is a huge dose of processed sugars, equivalent to many, many oranges, far more oranges than anyone would normally eat at one time. Anyone who squeezes oranges at home knows why OJ used to be served in tiny glasses.

  8. Eduardo Rosenstein 9 May 2008 at 5:08 pm #

    Dr Briffa, what about the V8 juice? It’s pretty popular here in the US, not sure about the UK. It’s not really a “fruit” juice, it’s actually made with other vegetables such as carrots, celery, beets, parsley, lettuce, watercress, spinach and tomato (yes, I know tomato is actually a fruit!).

    Still, it’s a processed product, made with “reconstituted vegetable juice blend (water and concentrated juices)”. The “Nutrition Facts” table says 8g of sugars per serving, along with 2g of dietary fiber. Is that OK or too much?


  9. Donald Tiso 11 May 2008 at 9:59 pm #

    I used to be a big fan of V8 but I have gone off it somewhat due to the fairly high salt content & the fact that its heavily heat treated (presumably for a long shelf life) . I now prefer to seek out products with similair ingredients to V8 but without the extra salt , there are fresh versions & long life versions, even organic, from a number of companies avaliable in the more upmarket supermarkets & health food stores. There is also a great tomato juice branded “pure squeezed” which is just that ! no added anything. I can’t say I have ever had a “sugar crash” from a tomato based juice.

  10. Bonnie Lavoie 12 May 2008 at 3:34 pm #

    You may want to get another proof reader to make certain your website is correct. You used their instead of they are… Correct language is correct science and I am impressed by the study of orange juice and the relationship to diabetes. What is Epub publication?

  11. Gary Mullen 20 June 2008 at 12:08 am #

    This article is misleading. 100% fruit juice does not contribute to diabetes! It’s the misleading “fruit juice” that contains HIGH FRUCTOSE CORN SYRUP that contributes to diabetes! The doctor who wrote this book or article more than likely is backed by the government and the Diabetes Association to get people to consume more sodas, high fructose corn syrup laced “fruit juices” like cranberry juice from Ocean Spray! Read your labels people! The government knows that HIGH FRUCTOSE CORN SYRUP contributes and immensely to diabetes. The body CANNOT digest HIGH FRUCTOSE CORN SYRUP properly! HFCS is in almost everything from ketchup, jelly, jam, ice cream, fruit bars, cereal, etc. so don’t be mislead by this misleading article because it’s the HFCS in the “fruit juice” that man puts in the juice that’s contributing to diabetes. Anything that is in nature will not harm you; it’s when man process foods that’s when foods will harm you! READ YOUR LABELS AND STAY AWAY FROM HIGH FRUCTOSE CORN SYRUP!!!!!!!

  12. Mark 23 March 2011 at 4:43 am #

    “Anything that is in nature will not harm you” ? Guess I’ll run right out and eat some rhubarb leaves and cherry pits. Jeez, careful what you say. I think the key is that when you drink a glass of juice, it usually takes 3-4 fruits to make the quantity everyone is used to. You are getting 3-4x more than an average serving of sugar obtained by eating the fruit alone. That means more “empty” sugar calories. If you ate the fruit instead, the fiber will help you feel like you ate something, and you get all the other nutrients that juicing removes. I agree that HFCS is probably not good for anybody. Seems a lot like MSG – it keeps making you want more…

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