Fruit, fructose and blood glucose

MrsA2 said:

Did the 2 apricots at 8g carb really bring my bg up over 2 points, or was it something else? If so what?

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What a great question you’ve Posted! I’m waiting for responses.

I would probably have reacted in the same way - I always eat first thing and then again in the evening to avoid fasting for too long - too many low calorie diets imposed by the Dr have left my metabolism a bit fragile. These days I am not so bad and now find that I can fast almost by accident, but I have been classed as in remission for some time.
I had some symptoms similar to RH on the way back to normal, but they have faded away.

MrsA2 said:

There's me just starting to think I understand when theres a curved ball
Waking this morning bg was 5.8 which is normal for me
Then did an hours yoga which was quite strenuous in parts and very relaxing in others.
Then tried to learn a new dance on zoom but couldn't concentrate
Ate 2 apricots.
Within an hour felt shaky, sweaty and quite weird.
Thought maybe needed food as (apart from the apricots) had been fasting since 7pm night before
Did another test expecting low but got 7.9
Ate eggs and cheese and 2 hours pp was back to 5.8

Can anyone explain to me fruits and fructose and carbs? I though fructose, the sugar in fruit, doesn't affect bg as it goes straight to the liver, but then I think again and a lot of fruit has higher carbs, so where do they come from?
Did the 2 apricots at 8g carb really bring my bg up over 2 points, or was it something else? If so what?

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Yes - good question - hopefully an expert will come along soon and explain - my understanding was that fruit was full of fibre and didn't adversely affect long term BG but low carbers say it is full of carbs and should not be eaten all the time, if at all. Before I decided to go low carb, I used to eat fruit daily and I don't think it affected my sugars too badly but I am not sure as I have changed a lot of my diet not just cut down on the fruit and my bg is coming down - so not sure - help?

Hi there, yes, fruit contains carbs no matter what type of 'sugar' they contain (carbs turn into glucose). To put it into perspective, I have to inject more insulin for an apple than I do for a chocolate eclair. The apple may well be better nutritionally but if viewed in terms of raising levels only then yes, it will, along with most other fruit. You sound like you are doing well by cutting out other carbs and your levels as you say are reducing but the simple answer to your question is that the 4 teaspoons equivalent of sugar in an apple for example is likely to shoot you up. As for it going straight to the liver?, not sure about that but it definitely goes straight into my system. In fact I use fruit as a hypo treatment it shoots it up so fast. x

MrsA2 said:

There's me just starting to think I understand when theres a curved ball
Waking this morning bg was 5.8 which is normal for me
Then did an hours yoga which was quite strenuous in parts and very relaxing in others.
Then tried to learn a new dance on zoom but couldn't concentrate
Ate 2 apricots.
Within an hour felt shaky, sweaty and quite weird.
Thought maybe needed food as (apart from the apricots) had been fasting since 7pm night before
Did another test expecting low but got 7.9
Ate eggs and cheese and 2 hours pp was back to 5.8

Can anyone explain to me fruits and fructose and carbs? I though fructose, the sugar in fruit, doesn't affect bg as it goes straight to the liver, but then I think again and a lot of fruit has higher carbs, so where do they come from?
Did the 2 apricots at 8g carb really bring my bg up over 2 points, or was it something else? If so what?

Click to expand...

This site has lots of info including visuals which should help.

https://www.dietdoctor.com/low-carb/fruits

Something else to bear in mind when eating fruit is that it isn’t digested in the stomach. It passes through the stomach unchanged and then gets digested in the small intestine.

obviously, the detailed process is complex and requires a degree (which I do not have!) to describe properly, but this is basically how it goes:

- I eat fruit by itself. My stomach says ‘oh, no protein here, I will just quickly shunt this along to the small intestine, where it will get digested and absorbed. This causes a rapid rise of blood glucose.

or

- I eat fruit at the end of a full meal including protein and fats, along with some complex carbs. Say, roast chicken, green beans, cauliflower cheese, peas, followed by fruit in cream. My stomach says ‘yum! Let me go to town digesting this lovely chicken using acid, which will take 1-3 hours. Then I will slowly release it, and the veg and fat and fruit and fibre from the veg, into the small intestine, where they will slowly be digested using bile from the bile duct (which is alkaline, and has to first neutralise the stomach acid, then alkalise all the food) to deal with the fat. All sorts of other enzymes and ‘stuff’ are also needed to deal with all those foods. This takes a while, and the fibre slows things down a bit more. At that point, the carbs (incl fruit sugars) will start to hit the bloodstream, but much more slowly than if the fruit had been on its own.

so eating fruit with fat and protein and fibre slows down digestion => slower sugar release.

(But with the slight downside that you are far more likely to see indigestion and flatulence from a mixed meal than a simple meal of just fruit, or just meat, because of all the different, sometimes conflicting, processes involved)

no wonder people often report less indigestion when they stop eating large mixed meals of carbs, proteins, fats and fibres.

Fructose passes directly through the liver and the liver responds converting it to triglicerides. Fructose blocks metabolism of glucose in the liver and the synthesis of glucose into glycogen. As a result, the pancreas secretes more insulin to overcome the glucose traffic jam at the liver and in turn induces the muscles to compensate by becoming more insulin resistant. Fructose elevates blood pressure more than an equivalent amount of glucose. Fructose is perhaps ten times more effective than glucose at inducing the cross-linking of proteins that leads to the cellural junk of advanced glycation end-products. It also oncreases markedly the occidation of LDL particles, which appears to be necessary step in atherosclerosis. Chronicly high doses of fructose intake lead to non alcoholic fatty liver disease and metabolic syndrome. I am T1D and I eat maybe 1 strawberry every week and this my body can tolerate. If I eat 6 blueberries I know it will raise my bg by approx 1.5mmol/l. The fruits are there in the summer and autumn to make people fat (the effects of fructose is lipogenesis and insulin resistance) to prepare them for food scarcity in winter and spring time. Lets remember we have invented fridges only 70 years ago.

I recommend Fat Chance: Fructose 2.0 by Prof. Lustig on youtube. It will blow your mind.

deszcznocity said:

Fructose passes directly through the liver and the liver responds converting it to triglicerides. Fructose blocks metabolism of glucose in the liver and the synthesis of glucose into glycogen. As a result, the pancreas secretes more insulin to overcome the glucose traffic jam at the liver and in turn induces the muscles to compensate by becoming more insulin resistant. Fructose elevates blood pressure more than an equivalent amount of glucose. Fructose is perhaps ten times more effective than glucose at inducing the cross-linking of proteins that leads to the cellural junk of advanced glycation end-products. It also oncreases markedly the occidation of LDL particles, which appears to be necessary step in atherosclerosis. Chronicly high doses of fructose intake lead to non alcoholic fatty liver disease and metabolic syndrome. I am T1D and I eat maybe 1 strawberry every week and this my body can tolerate. If I eat 6 blueberries I know it will raise my bg by approx 1.5mmol/l. The fruits are there in the summer and autumn to make people fat (the effects of fructose is lipogenesis and insulin resistance) to prepare them for food scarcity in winter and spring time. Lets remember we have invented fridges only 70 years ago.

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I can tolerate most fruit if I take a unit of insulin with it, or sometimes no insulin if I am low to start with. I'm not sure I'd bother with one strawberry though. I don't eat tropical fruit but I do enjoy an apple, a fig, an apricot and a selection of berries. I guess it's all about testing and not having gallons of the stuff. x

Sugar The Bitter Truth on YouTube explains sugar and fructose in great detail. Dr Robert Lustig MD of UCSF Benioff Hospital is a paediatric endocrinologist and now also a Professor at University of California. He's brilliant on sugar and fructose.