Rick Johnson, M.D.: Metabolic Effects of Fructose (Ep. #87 Rebroadcast)

Nov 22, 2021 1h 49m 18 insights

Today's episode of The Drive is a rebroadcast of the conversation with Rick Johnson (originally released January 6th, 2020). This episode was one of the most popular discussions to-date and is a prelude to an upcoming follow-up discussion which will be coming out in February 2022 along with the release of Rick's new book. In this episode, Rick Johnson, professor of nephrology at the University of Colorado, explains how his research into the causes of blood pressure resulted in a change of research direction to focus more on how fructose has such profound metabolic effects. Rick begins by talking about the relationship between salt and high blood pressure, then provides a masterclass into uric acid, and then expertly reveals the mechanisms and pathways by which sugar (specifically fructose) can profoundly impact metabolic health. From there, he explains how he applies this information to real life patients as well as touches on some of the most promising ideas around pharmacotherapy that are being developed in response to the epidemics of fatty liver, insulin resistance, diabetes, and obesity. Furthermore, Rick gives his take on artificial sweeteners compared to real sugar, discusses cancer's affinity for fructose, and much more. We discuss: <ul> <li>The connection between blood pressure and fructose that shifted Rick's professional focus [3:00]; </li> <li>The relationship between salt and blood pressure (and the role of sugar) [4:45]; </li> <li>Defining fructose, glucose, and sugar [18:30]; </li> <li>An ancient mutation in apes that explains why humans turn fructose into fat so easily [22:00]; </li> <li>The problems with elevated uric acid levels, and what it tells us about how sugar causes disease [30:30]; </li> <li>How sugar causes obesity—explaining the difference in glucose vs. fructose metabolism and the critical pathway induced by fructose [39:00]; </li> <li>Why drinking sugar is worse than eating it [49:00]; </li> <li>Unique ability of sugar to drive oxidative stress to the mitochondria, insulin resistance, and diabetes [53:00]; </li> <li>Why cancer loves fructose [59:20]; </li> <li>The many areas of the body that can use fructose [1:04:00]; </li> <li>Fructokinase inhibitors—a potential blockbuster? [1:06:15]; </li> <li>Treating high uric acid levels—Rick's approach with patients [1:09:00]; </li> <li>Salt intake—what advice does Rick give his patients? [1:15:30]; </li> <li>How excess glucose (i.e., high carb diets) can cause problems even in the absence of fructose [1:20:00]; </li> <li>Artificial sweeteners vs. real sugar—which is better? [1:28:15]; </li> <li>Umami, MSG, alcohol, beer—do these have a role in metabolic illness? [1:32:45]; </li> <li>Fructose consumption—Is any amount acceptable? Is fruit okay? Where does Rick draw a hard line? [1:37:45] </li> <li>How does Rick manage the sugar intake of his young kids? [1:42:00]; and </li> <li>More. </li> </ul> <div>Learn more: <a href="https://peterattiamd.com/">https://peterattiamd.com/</a> Show notes page for this episode: <a href="https://peterattiamd.com/rickjohnson/">https://peterattiamd.com/rickjohnson/</a> Subscribe to receive exclusive subscriber-only content: <a href="https://peterattiamd.com/subscribe/">https://peterattiamd.com/subscribe/</a> Sign up to receive Peter's email newsletter: <a href="https://peterattiamd.com/newsletter/">https://peterattiamd.com/newsletter/</a> Connect with Peter on Facebook | Twitter | Instagram.</div>

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Actionable Insights

1. Strictly Avoid Liquid Fructose

Draw a hard line against consuming any liquids containing added sugar, fructose, or high fructose corn syrup, as rapid consumption leads to high fructose concentration in the liver, significantly triggering metabolic issues like obesity and insulin resistance.

2. Minimize Fructose Intake

Reduce overall fructose consumption to prevent rapid ATP depletion in cells, which triggers a ‘survival mode’ that reduces metabolism, increases hunger, and shunts calories towards fat and glycogen storage, contributing to obesity, insulin resistance, and high blood pressure.

3. Reduce High Glycemic Carbohydrates

Limit intake of high glycemic carbohydrates (e.g., bread, potatoes, chips, rice), especially if overweight or metabolically compromised, as high glucose levels can induce an enzyme in the liver to convert glucose into fructose, driving metabolic disease even without dietary fructose.

4. Pair Salt Intake with Water

Always drink plenty of water when consuming salty foods to prevent a rise in serum sodium, which can trigger endogenous fructose production, acute blood pressure spikes, and other metabolic effects.

5. Maintain Adequate Hydration

Drink plenty of water (or zero-osmolarity beverages like diet soda, tea, or coffee) daily to help suppress the negative metabolic effects of fructose, prevent endogenous fructose production from dehydration, and potentially slow the progression of kidney disease.

6. Consider Uric Acid Management

Discuss with your doctor the potential benefits and risks of taking allopurinol if your serum uric acid levels are consistently above 5.5 mg/dL, especially if they are 8 mg/dL or higher, or if you have kidney disease, as high uric acid is linked to high blood pressure, insulin resistance, and fatty liver.

7. Limit Beer Consumption

Reduce beer intake, as its brewer’s yeast content and umami components can significantly raise uric acid, contributing to abdominal obesity, fatty liver, high blood pressure, and metabolic syndrome (the ‘beer belly syndrome’).

8. Be Mindful of Umami-Rich Foods

Be cautious with high umami foods, especially those rich in purines (e.g., shrimp, Parmesan cheese), as they may raise uric acid levels and contribute to metabolic risk, potentially bypassing the sugar pathway.

9. Consume Whole Fruits Judiciously

Eat whole fruits in moderation, prioritizing berries (blueberries, raspberries, strawberries) which are generally safe in larger quantities, and limiting high-fructose fruits like grapes and large apples to avoid overwhelming the body’s metabolic pathways.

10. Avoid Dried Fruit

Steer clear of dried fruit, as it is a concentrated source of fructose with many of the beneficial components of whole fruit lost during processing, making it metabolically less favorable.

11. Choose Diet Over Regular Soda

If choosing between regular sugar-sweetened beverages and diet versions, opt for diet drinks as they are the lesser of two evils compared to the significant metabolic harms of regular sugar.

12. Educate Children on Sugar

Teach children (e.g., 4th-6th grade) how to read food labels to understand sugar content and demonstrate the high amount of sugar in beverages like soft drinks to foster healthier eating habits.

13. Critically Evaluate Sugar Studies

Be critical of studies on sugar and weight gain that control for caloric intake, as they may not reflect real-world effects where sugar consumption can lead to increased overall food intake due to leptin resistance.

14. Contextualize High-Energy Foods

Consume high-energy foods like trail mix and sports drinks only when contextually appropriate (e.g., intense physical activity, mountaineering) rather than as general snacks or beverages, due to their high sugar content.

15. Target Optimal Blood Pressure

Aim for a blood pressure around 120/80 mmHg, as this is considered optimal and is associated with a lower risk of heart failure, stroke, and other cardiovascular diseases.

16. Understand Allopurinol Risks

If prescribed allopurinol, be aware of the risk of allergic reactions (e.g., rashes), particularly if you are of Asian or African-American descent, and stop the drug and contact your doctor immediately if a rash develops.

17. Use Sugar Substitutes for Baking

When baking at home, use sugar substitutes like Splenda to reduce sugar intake, especially for children, while still allowing for occasional treats.

18. Limit Purine-Rich Foods for Gout

To reduce the risk of gout, limit consumption of purine-rich foods like anchovies, small fish with high cellular density, and beer (due to brewer’s yeast), as these increase uric acid levels.