Hyperglycemia makes our brain produce fructose

[kp]

Fascinating abstract on recent studies that our brain creates fructose when the body has too much glucose. Just before the conclusion, it mentions HFI
www.ncbi.nlm.nih.gov/pmc/articles/PMC6684314/

[colormist]

Great article!
Relevant bit right at the end: "Even though the blockade of fructokinase has been shown to be effective, no pharmacological treatment has been clinically tested or approved to date for HFI and the only recommended approach is to avoid the intake of sugar. However, even with little or no ingestion of fructose, individuals with HFI often develop episodes of hypoglycemia, show signs of general ill health and exhibit symptoms of chronic fructose intoxication. One possibility that could explain these episodes relates to the fact that fructose is heavily substituted in the diet by foods with high glycemic index like dextrose. Excessive glucose consumption in aldolase b deficient subjects could lead to the activation of the polyol pathway and endogenous production of fructose."

[antonia]

Fascinating. Thanks for sharing. It explains so much. Not only about refined starches and dextrose, but salty foods as well. Dr. Tolan has been warning against starchy and salty foods for HFIers for several years now. Now I understand why.

[lazerlee]

Thank you.

Interesting how the body regulates sugars, oxidents, hormones and other chemicals.

[Stefanie (Ziba)]

Whether the fructose comes from diet or is produced endogenously, perhaps the inhibition of an enzyme early in the pathway is the key not just to controlling diabetes (which is where all the research funding has gone) but also to treating HFI! We’ve been waiting for enzyme therapy to induce ALDOB activity, but perhaps what we need to do is inactivate enzymes higher up on the pathway! The benign genetic condition known as Essential Fructosuria results from deficiency of the first enzymes in the pathway of fructose metabolism. In this article, endogenous fructose is never produced when the fructokinase enzymes is turned off in mice! Maybe aldose reductase could be inhibited to prevent the conversion of glucose into sorbitol which would end the pathway there or sorbitol dehydrogenase inhibited to prevent the conversion of sorbitol to fructose!
All of this screams to me that if we can mute these early enzymes, all the dysfunction in enzymes further down the path (i.e. ALDOB and F1,6BP) would be avoided because glucose and sorbitol when converted to endogenous fructose as well as dietary fructose would never get absorbed into the intestines and would never reach the liver to cause metabolic distress.
Until/Unless the pathway is deactivated, it is best to follow Dr. Tolan’s advice and avoid spikes in glucose levels by:
1. coupling carbs with fats and proteins to slow absorption
2. limiting salt intake (salt increases the enzymes involved in converting glucose to endogenous fructose)
3. limiting oxidative stress (to keep uric acid levels normal)
4. using dextrose only in an emergency, and even then, in small amounts over time instead of bolus treatment to reverse hypoglycemia.
It is not just severe and acute symptoms HFIers need to be cognizant of and try to avoid, but also long-term damage. I found research from 2020 (Dr. Tolan was one of the authors) which correlated fructose with increased uric acid and ultimately cancer which suggests that blocking fructose metabolism could also be a way to prevent cancer!
link.springer.com/article/10.1186/s40170-020-00222-9?fbclid=IwAR0wNsu_ZCrTil8cfRazbn1oJ3pn8-LnuvNjmnqK2Vns6ydPKVy94W5FDuU

[kp]

Thank you for the replies. I didn’t know about the starchy or salty foods and this explains why I don’t feel great sometimes even when avoiding fructose. Appreciate the list too of what to watch out for! Thanks

[kp]

Stephanie as you mentioned I found this article on that enzyme further up . I’m so grateful these studies are happening
www.ncbi.nlm.nih.gov/pmc/articles/PMC5983342/

[ashley1988]

KP, I was just curious as to what you feel like when you feel sick and how often this happens to you, when you're following the diet.

[ukbill]

Ashley I can say I have not had a bad reaction to Fructose in many many years.
The number of really bad reactions is below 4 in the last 50 years for certain.
If I eat something that is miss labeled or push the boundaries a little too far I know well before it is in anyway more than a little short term discomfort.
There are so very many things that are far worse to be born with, for example diabetes or an allergy to peanuts of similar can really mess with your life, however given a fructose free diet we have no symptoms at all.
Should foods containing fructose be eaten by most HFI'ers (those who have not been given glucose) then the food is rejected as "nasty" "Ucky" etc long before enough is eaten to make an HFI person ill.
An occasional excess of Fructose does no long term damage so long as the average intake is kept as to a safe level.
Do not worry and rejoice at your pregnancy your child is going to be a healthy happy child with all the fun love and tribulations that it will bring with it!
Congratulations, relax and enjoy your mother hood.
Keep smiling all will be well. xxoo