Januray 24th, 2022

 In preparation for the upcoming podcast with Dr. Rick Johnson. We are going to discuss the survival switch and fructose metabolism in specific. It will be another life changing discussion for many of us.

We all are paying more attention to the effects of lifestyle choices on our health especially as it relates to Covid 19. One of the primary lifestyle choices that is hurting us is the over consumption of refined carbohydrates or sugars, in particular the molecule fructose.

Fructose is the natural sugar found in fruit, honey and root vegetables. Historically, humans consumed fructose in these natural whole foods and did so moderately. Since the 1970's, there has been a major rise in fructose consumption, primarily as a beverage. We are consuming it daily in fruit juices and sweetened drinks like soda, energy drinks and sports drinks. The advent of government subsidized high fructose corn syrup (HFCS) has provided companies a very cheap source of processed sugar to sweeten beverages and processed foods. Cheap and sweet. Not a good combination for humans. Fructose is much sweeter than glucose, the other half of the table sugar disaccharide, making it the driver of most sweet foods taste. From the 2010 National Health and Nutrition Examination Survey, we observe data that Americans consumed around 24 grams of fructose per day in the 1970's. Now that number is in the 55 gram per day range. Adolescents take the prize at 70+ grams a day. This is equal to 17+ teaspoons (packets of sugar) a day!!!!! This is a bolus of calories, but this is not the whole story.

Why does it matter?

Because it is driving metabolic disease in most Americans costing us all countless healthcare dollars and lost healthy days of life.

The story:

One major factor in the metabolic syndrome obesity epidemic is the constant and excessive exposure to the monosaccharide fructose and the disaccharide sucrose which is a combination of one molecule of glucose and one of fructose in something that we call table sugar.

How does the body see fructose?

The liver is the location for the metabolism of most of the fructose whereas glucose is metabolized everywhere especially the muscles and the brain. The majority of ingested fructose goes to the liver where it is metabolized to fat without the control of the hormone insulin and feedback negative regulation. This is not good. The body likes to control the metabolic system through feedback loops that shut off when calorie/sugar/fat contents are sufficient.

Fructose directly turns on genes that increase fat deposition! Why would this be??? Let us look at gorillas. They gorge on fruit during the natural fruit season in the fall in order to produce fat for the long winter. This is sort of like a polar bear gorging on seals in the fall to survive the winter. Nature has a plan. Where does it go wrong?


We take seasonal fruit and give access to them year round. We make juice and demand that children get juice or milk in school when water is the best choice. We make HFCS cheap and accessible all year long in soda and beverages. Oops. We have just produced a mismatch of our genetically perceived environment and the true environment. We have a genetically predisposed seasonal fruit metabolism style with fructose exposure all year long.

(Part of the Science: Fructose also causes a decrease in the enzyme lipoprotein lipase, which keeps fat particles in the blood circulation. Fructose also has an effect on increasing the transcription of genes that promote glucose production in the liver and thus more glucose release. The end result is excess blood sugar, the development of insulin resistance, type II diabetes mellitus and leptin resistance. The science gets much deeper and we will go there soon.)

So, fructose used to be useful during periods of feast and famine. What used to be helpful is now dangerous with constant exposure. Nature always has a plan.

And this is not the end of the story. Far from it as the upcoming podcast will show. We are even going to look at new data regarding the risk of preeclampsia and abnormal pregnancies from fructose. There is solid emerging evidence that diet is a main driver of abnormalities driving poor outcomes in pregnancy.

Fructose also is a well-known driver of reactive oxygen species (ROS) formation in the mitochondria, cellular energy centers. ROS are chemically reactive molecules that have an unpaired electron. Dr. Nagy has a great analogy for ROS. Imagine a single guy being invited to a couple's party. He doesn't care whom he hooks up with as long as he does. In the cellular world the unpaired electron will attack any cell and cause stress and damage as if the single guy goes after your wife. Cells suffer DNA and protein dysfunction, which in turn causes the cell to not perform properly.

In other words, excessive fructose intake promotes the production of detrimental chemicals in the blood stream that hurt our bodies at the cellular level. This is another root cause of disease. We will get deeper into this space in a few weeks, but there is now good evidence that fructose ingested or made in the liver in response to excess blood glucose, hypoxia (low oxygen), excess uric acid, dehydration, excess alcohol intake, excess salt intake will drive the system to go into survival mode whereby the body turns on metabolic pathways that preferentially store fat in the liver and periphery, elevate blood pressure, turn on hunger foraging brain signals and generally push you towards a survival activity type,

Now that the case for fructose has been basically laid out. What to do until we take a deeper dive?

The first thing to do is to reduce and preferably eliminate sugar-laden beverages including juice. Get soda or sports drinks out of the house. Drink mostly water or unsweetened teas.

Second, reduce how fast the sugar is absorbed by adding fiber to your diet. The best based sources of fiber are sweet potatoes, vegetables, beans and whole fruit as berries. Adding fiber to every meal is a brilliant idea to reduce blood sugar spikes.

Third, exercise more to burn sugar so that it can't be used to make fat. This also turns on more glucose transporters to push glucose into the muscle which decreases the amount that the liver sees thus decreasing fructose production via the polyol pathway.

Fourth, increase the intake of bright colored vegetables and fruits, which contain natural chemicals to reduce the burden of ROS. Spices, dark chocolate, nuts and berries have very high ORAC (Antioxidant strength) scores.

Fifth, read labels and avoid foods with fructose or HFCS in them.

Sixth, drink lots of water when you eat anything salty to reduce the sodium concentration in the blood which decreases the polyol pathway activation and thus fructose production with all of its downstream effects.

For further understanding, I would encourage the viewing of Dr. Lustig's webinar. http://www.sugarshockblog.com/2009/09/sugar-the-bitter-truth.html. Then get ready for an amazing podcast in a few weeks.

My take home point today: Fruit is ok in moderation, sugar drinks are not!

Now that you have read and understood this piece, we are going to go much deeper in a week.

Dr. M