Fructose Short-Circuits Glycolysis

First some terminology.

Fructose ... a five carbon sugar that occurs naturally in fruit, does not cause as much insulin to be secreted as glucose and tastes sweeter than glucose.

Glucose ... a six carbon sugar that is the breakdown product of glycogen(a polymer of glucose, multiple glucose units hooked together) that occurs naturally in potatoes and grains.

Glycogen ... multiple units of glucose hooked together (a polymer). What is typically called "complex carbohydrate" today.

Glycolysis ... derived from the Greek stem glyk- "sweet" and lysis meaning dissolution. The metabolic pathway for the initial utilization of glucose.

Phosphofructokinase ... the enzyme that catalyzes the reaction of fructose 6-phosphate to fructose 1,6-biphosphate. You don't need to understand anything more about this reaction other than the fact that if fructose comes from a source other than the degradation of glucose, it blocks this step for glucose until all the non-glucose derived fructose has been metabolized.

Glucose and Fructose Are Both Metabolized via Gylcolysis

Both fructose and glucose are metabolized via glycolysis. Both end up at some point as three carbon fragments. In order for glucose to be broken down into three carbon fragments it must first be metabolized to a five carbon sugar, actually fructose. This is where the trouble starts, since fructose is already a five carbon sugar. The following analogy I hope will aid in explaining this. The analogy, however, is far from perfect.

Whether we start out with separate glucose and fructose as in high fructose corn syrup or honey, or with fructose and glucose hooked together as in sucrose(common table sugar), makes no difference. As soon as sucrose hits the bloodstream, it is immediately broken down (hydrolyzed) to fructose and glucose.

Freda Fructose gets married to Gary (Glucose) Sucrose. They live happily on Sugar Lane. Both work in muscle and liver cells where they are metabolized usually into fat and slow the immune system to a crawl. They get up early in the morning and both have to get on the Glycolysis Road to get to work. Gary (Glucose) is one carbon atom heavier than Freda Fructose and because of that, he cannot cross the river on one of the lighter and faster bridges on their way to work. Freda Fructose however, being lighter, has no problem crossing the faster bridge and making the short-cut to the Glycolysis Road. Gary Glucose, however, has to get on the road well above the short-cut, since he is too heavy to take the lighter bridge short-cut.

The Phosphofructokinase Intersection

As usual Freda Fructose gets to the Phosphofructokinase intersection well before Gary Glucose. By the time Gary Glucose gets to the intersection, the traffic directing policeman is once again allowing all the Freda Fructoses to make the turn onto Glycolysis Road while, all the Gary Glucoses can do is sit in traffic and wait. Once again, Gary, and all the other Glucoses on their way to work, must sit and wait for all the Freda Fructoses to get on Glycolysis Road before they can continue.

LA Traffic Control

Traffic control sees all these Glucoses sitting stuck in traffic, just like traffic backs up everyday in LA. It reacts by injecting a lot of green lights (insulin) into the pathway for the Glucoses to get to work. Finally, all the Fructoses pass and now because there are too many green lights, all the Glucoses pass quickly. All of the sudden there are no Glucoses to be found on the Glycolysis Road. All the cells along the way that used to be able to snag some Glucose can't because there isn't any. Whether it is the excessive insulin that is the cause of so many of the lifestyle diseases we see today or, all the backed up Gary Glucoses decide to cause their own damage to the arteries they are in, I don't know. It is however, clearly established that the ingestion of sucrose (fructose and glucose) is related to many of our lifestyle diseases today including the extensive damage to the vascular system that occurs with adult onset diabetes mellitus. I know, my damaged arteries are up on this site.

Hypoglycemia

Now you begin to feel lightheaded, dizzy and a bit disoriented. Traffic control has injected too many green lights and the concentration of glucose drops precipitously. The brain starts to complain because it no longer has enough glucose to function. If the blood sugar gets low enough, serious complications can occur.

Fructose and Glucose Together

The combination of fructose and glucose should be avoided as much as possible. When you eat your fruit, try to allow at least an hour or preferably two, before eating potatoes, whole grains or rice. Also avoid as much as you can sucrose, high fructose corn syrup, honey and maple syrup or, any sweetener that has as it main ingredients, fructose and glucose.

Other Sweeteners

Brown Rice Syrup

Brown rice syrup is roughly about 45% maltose (two glucose units hooked together), 50% complex carbohydrates and 3% glucose. No glucose and fructose together but still sweet and I have known some people who can even get hypoglycemic from it.

Barley Malt Syrup

Made from whole barley it is about 65% Maltose and 30% complex carbohydrates.

Fruit Concentrates

These are usually combinations of glucose, fructose and sucrose and should be avoided.

Maple Syrup

Maple syrup is about 65% sucrose and should be avoided.

Today's Health Tip:

If you want sweet, you are safest with stevia. Next would be sweeteners derived from rice and barley. Sucrose, high fructose corn syrup, maple syrup and fruit juice concentrates should be avoided.

Reference:
Stryer Biochemistry Fourth Edition

Copyright John Mericle M.D. 2005 All Rights Reserved

**************
To really get off of sweets and "deprogram a sugar-coated palate," the MericleDiet is hard to beat. Generous servings of organic complex carbohydrates will keep you and your brain happy. To visit the MericleDiet follow the link below.
http://www.drmericle.com
**************

One of our readers Wendy in the UK writes:

Just to let you know that according to the website below that takes you to Carol Bond Health Foods it is spelt Stevita. I couldn't find it anywhere on the site and through asking the chat section it was spelt differently. Thought you would like to know so that you can let the other newsletter recipients know.
Regards...
Wendy

PS Really enjoy the newsletter. Find it very informing so thank you. Gave up drinking milk last year after reading your article! Feel much healthier as a result.
**************

To take Stevia for a test drive or purchase some online follow the link below. I had luck just searching stevia but you could also search the product "Stevita."
http://www.drmericle.com
Thanks for your time.

DrMericle.com is devoted to achieving optimal health and peak performance through diet and lifestyle change. Dr. Mericle brings together a unique blend of formal training in organic chemistry and biochemistry, medical education, 29 marathons, 3 Hawaii Ironman competitions and a lot of practical real life experience.

insured cleaning company Bannockburn ..
In The News:

A groundbreaking new study has uncovered disturbing AI blackmail behavior that many people are unaware of yet.
Four teams of autonomous humanoid robots competed in China's first AI soccer tournament, demonstrating advanced capabilities in ball detection and independent decision-making.
The ID. Buzz autonomous van features self-driving technology with 13 cameras, nine LiDAR units and five radars after Volkswagen partnered with Hamburg and Uber for 2026 deployments.
Social Security phishing scams use urgency and impersonation to steal personal data. Learn how to spot fake SSA emails and implement 10 protective measures.
French startup Pazzi Robotics created an AI-powered pizza robot that made pies in under five minutes without human help, but it closed in 2022 despite patents and expert partnerships.
Reclaim your time from big tech with effective screen time reduction strategies for iPhone and Android, featuring steps to limit app usage and create phone-free zones.
Amazon Prime Day shoppers face threats from 120,000-plus scam websites as cybercriminals prepare phishing traps and malware ahead of the July sales event.
Fox News' AI Newsletter brings you the latest on this rapidly evolving technology.
The AEON humanoid robot tackles labor challenges with Nvidia AI, Microsoft Azure cloud and advanced spatial awareness, working alongside industry leaders Schaeffler and Pilatus.
Google's Ask Photos feature brings AI-powered searches to your photo library, letting you find memories with natural language queries while maintaining privacy controls.
The return of blue book exams emerges as universities fight widespread AI academic dishonesty and educators debate whether to ban AI tools or teach responsible usage.
Signs your phone might be hacked include strange behavior, unauthorized texts, battery drain and pop-ups, while protection involves updating software and avoiding public Wi-Fi.
Tokyo startup H2L has launched Capsule Interface technology enabling full-body robot control with muscle sensors, offering immersive remote operation.
The A.I. industry seems set for growing pains as Big Tech companies scramble for solutions to the medium's unprecedented strain on the power grid.
Fourth of July fireworks cause a 60% spike in lost pets, but GPS trackers and AI photo-matching services like Love Lost can help reunite missing dogs with their families.
Protect yourself from jugging, the rising crime by which thieves monitor ATM users and follow them to steal cash, with six practical safety tips to stay alert and secure.
U.S. airlines like Delta, American and United are selling your domestic flight records to government agencies through the little-known Travel Intelligence Program.
Autonomous robots from Uber Eats are rolling out across U.S. cities, featuring LIDAR sensors, secure compartments and all-weather operation for food and grocery delivery.
Costco has expanded into EV infrastructure with new ultra-fast charging stations that can charge most electric vehicles to 80% in 20-60 minutes while shoppers browse the warehouse.
The new Gemini Robotics On-Device AI allows robots to perform complex tasks without internet, offering enhanced privacy, reliability and adaptability for real-world use.
Protect yourself from Amazon phishing scams by spotting red flags like suspicious sender addresses and spelling errors while using Amazon's Message Center to verify communications.
GAC Group's new Govy AirCab flying car combines lightweight design with advanced safety systems and smart cabin technology to revolutionize city travel with an 18.6-mile range.
The Berkeley Humanoid Light (BHL) is a lightweight, open source humanoid robot that anyone can build using 3D-printed parts and off-the-shelf components.
Meta’s new AI chatbot is getting personal, and it might be sharing more than you realize.
A new threat targets both Android and iPhone users: SparkKitty, a powerful mobile malware strain that scans private photos to steal cryptocurrency recovery phrases and other sensitive data.

Stay Healty, Eat more Fish and Seafood

There are a lot of very good reasons to eat... Read More

Vitamin and Mineral Facts

Vitamins & Minerals are essential to sustain life. Its what... Read More

Try a Slow-Carb Habit

Carbohydrates - found in grains, breads, pasta, and sugar, as... Read More

Vitamin D - The Sunshine Vitamin!

Vitamin D is a fat-soluble vitamin like A and E.... Read More

Cherries - The Next Wonder Fruit

Cherries?A Supercharged FruitThe little red fruit that has been enjoyed... Read More

Alcohol as a Key Ingredient to a Healthy Diet

Evidence suggesting that alcohol is "cardio-protective" first appeared in the... Read More

Five Reasons You Should Drink More Water

I know you've heard this many times - "Drink more... Read More

Eating ... Gaining Weight ... How to Control the Urge to Splurge

I confess: I'm completely addicted to Pringles. My determination weakens... Read More

Artificial Sweeteners - Are They Safe?

To research the health risks Sweet 'N Low and other... Read More

Fruit for Breakfast ? The Secret to a Healthy Life

Do you want more energy? How about more of the... Read More

The Joys of Being Healthy

It is amazing to be able to say I am... Read More

A Result Producing Guide to Nutrition

If you want to build muscle, lose body fat or... Read More

Fibromyalgia: How Simple Sugars Turned Fatigue into Energy

Several years ago, Marilyn M. couldn't even spell fibromyalgia.Now she... Read More

Soy Phytoestrogens and the Art of Propaganda

In this newsletter we will discuss the current controversy about... Read More

Allergy Approaches through Nutrition

Spring in New York City is a really magical time.... Read More

Autism and Nutritional Supplements

Unfortunately, it has been proved beyond doubt that a large... Read More

Five Steps to a Healthier Heart

Step 1: Eat five to ten servings per day of... Read More

The Five Keys to Healthy Eating

1. Enjoy what you eatWhether someone is following the Atkins... Read More

Snack Attack - How to Keep Your Hunger Between Meals from Getting the Best of You

The Benefits of SnackingYou may feel regretful about snacking, but... Read More

Who Said Bananas Are Not Good For You?

After reading this, you'll never look at a banana in... Read More

Water, The Magical Drink

Glowing skin comes free of charge to you. Our simple... Read More

Help Prevent Premature Aging With Nutrition-Science

Aging occurs when the body's cells die at faster rates... Read More

The Business Traveler?s Diet Problem: Staying Fit When on the Run

Despite the fact that accurate nutrition information can be accessed... Read More

Face Check Up

Mirror, Mirror on the wall, who's the healthiest of them... Read More

The Niacin Rush

Your face turns flush and your skin starts to itch.... Read More

expert residential cleaners Winnetka ..