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fructose

poynedexterpoynedexter Posts: 283
can someone help me understand the different effect of glucose vs fructose on blood sugar levels and insulin response.

if what i read is correct, sugar is made up of glucose and fructose, and fruit sugars are fructose. glucose causes an insulin response directly, while the liver deals with the fructose which can also lead to a fat storing response.

so why then is is natural fructose, ie fruit, better in regard to blood sugar rises? is it puely down to the fibre content of fruit slowing down the digestion?

my new eating habit involves a fair amount of fresh berries, but less bananas than previously. am i getting the same insulin response from these berries as with other sugars?

ta.

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  • sungodsungod Posts: 14,363
    'sugar' is a general term for a number of chemicals

    glucose and fructose are both sugars, as is sucrose, the common white sugar you'll find in the local cafe, in digestion, sucrose is split into fructose and glucose

    they have different metabolic pathways

    'natural fructose' is irrelevant, how it's produced makes no difference, a molecule is a molecule

    fructose has a lower glycemic index than glucose, lower gi is generally regarded as preferable, it'll lead to a slower rise in insulin level than a high gi sugar, but there's increased risk of overeating as appetite is not suppressed as much

    but how your body handles fructose is dependent on your genetics, it's not the same for everyone

    if you want to dig into it, just use google, there's plenty of info out there
    my bike - faster than god's and twice as shiny
  • Mad_MalxMad_Malx Posts: 4,592
    As above, different uptake & metabolism of glucose & fructose, and where it comes from is irrelevant to this.

    Eating calories alone is not a great idea. Fructose is sweeter than glucose per calorie, which you might think is good. However there is strong evidence of an association of high fructose corn syrup consumption, used as a sweetener in most processed sweet (and often not so sweet) foods, with diabetes.

    If you are getting your sugar from a high fruit diet (including bananas), I really don't think you need to worry, and you also gain the benefit of fibre, minerals and vitamins.
  • team47bteam47b Posts: 6,424
    can someone help me understand the different effect of glucose vs fructose on blood sugar levels and insulin response. so why then is is natural fructose, ie fruit, better in regard to blood sugar rises? is it puely down to the fibre content of fruit slowing down the digestion?.

    Fibre in fruit and digestion rate slows down the uptake and insulin response. Some fruit causes insulin spikes (high GI fruit like bananas GI 60 or watermelon GI 72). Cherries are low Gi 22

    Carbohydrates (glucose) are either long chain molecules (complex carbs made up of at least 3 sugars) or short chain molecules (simple carbs single sugar), simple carbs cause insulin spikes, complex carbs don't.

    Simple carbs are white flour, pastry, white bread, pasta, potato, white rice.

    Complex carbs are wholemeal flour, wholemeal pasta, sweet potato, brown rice.

    Quantity affects insulin response, fat slows down digestion so combining fat with bread (cheese sandwich) helps to avoid spikes. Better to eat smaller amounts more often to spread the need for the body to produce insulin interspersed with exercise which burns off the glucose same as insulin does.
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  • markp80markp80 Posts: 444
    For a really interesting book about fructose, I would recommend anyone to read "Fat chance - The bitter truth about sugar" by Dr Robert Lustig. It'll give you all the information you need to know about the metabolic pathways of the various sugars, and is a bit of an eye opener.

    MarkP
    Boardman Road Comp - OK, I went to Halfords
    Tibia plateau fracture - the rehab continues!
  • dw300dw300 Posts: 1,642
    Banana f*cking sandwiches baby!
    All the above is just advice .. you can do whatever the f*ck you wana do!
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  • team47bteam47b Posts: 6,424
    dw300 wrote:
    Banana f*cking sandwiches baby!

    It's got a verb so it must be a sentence. :D
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  • stu-bimstu-bim Posts: 406
    dw300 wrote:
    Banana f*cking sandwiches baby!

    Love them. Breakfast before sunday morning ride
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  • MarkP80 wrote:
    For a really interesting book about fructose, I would recommend anyone to read "Fat chance - The bitter truth about sugar" by Dr Robert Lustig. It'll give you all the information you need to know about the metabolic pathways of the various sugars, and is a bit of an eye opener.

    MarkP

    watched the you tube video. fascinating stuff
  • MarkP80 wrote:
    For a really interesting book about fructose, I would recommend anyone to read "Fat chance - The bitter truth about sugar" by Dr Robert Lustig. It'll give you all the information you need to know about the metabolic pathways of the various sugars, and is a bit of an eye opener.

    MarkP

    watched the you tube video. fascinating stuff

    Didn't Asker Juekendrup do some research which showed a mixture of fructose & glucose works better than plain sugar?
    By the way, honey is a mixture of fructose & glucose.
  • markp80markp80 Posts: 444
    MarkP80 wrote:
    For a really interesting book about fructose, I would recommend anyone to read "Fat chance - The bitter truth about sugar" by Dr Robert Lustig. It'll give you all the information you need to know about the metabolic pathways of the various sugars, and is a bit of an eye opener.

    MarkP

    watched the you tube video. fascinating stuff

    Didn't Asker Juekendrup do some research which showed a mixture of fructose & glucose works better than plain sugar?
    By the way, honey is a mixture of fructose & glucose.
    Not sure what you're asking there, works better at what?
    Sucrose is a mixture of glucose and fructose too. Lustig's work suggests fructose is not "a very good thing", but the problem is the amount hidden in processed food and drinks. This was slightly of topic from the OP's original post, but I thought it was worthy of comment, and fructose does have some very strange metabolic effects, very unlike other sugars, which can result in all sorts of problems. Tom Dean posted an interesting link, and poyndexter has siad there's some good stuff on YouTube. As I said, I read his book, and found it very interesting, if a little scary to be honest. It's certainly made me think a lot more carefully about my diet.

    I don't see anything wrong in knowingly adding a bit of honey to some foods if you're eating a healthy, balanced, fresh diet. But I personally tend to steer clear of fructose when I possibly can (although we all have our vices!0

    MarkP
    Boardman Road Comp - OK, I went to Halfords
    Tibia plateau fracture - the rehab continues!
  • I think Jeukendrup found that a mixture of glucose and fructose was easier to absorb during exercise so you could get more calories in per hour.
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