zone_blog_cellinflam-1

What is Cellular Inflammation?

 

People (including virtually all physicians) are constantly confused what cellular inflammation is. So I decided to take the opportunity to explain the concept in more detail.

  

There are two types of inflammation. The first type is classical inflammation, which generates the inflammatory response we associate with pain such as, heat, redness, swelling, pain, and eventually loss of organ function. The other type is cellular inflammation, which is below the perception of pain. Cellular inflammation is the initiating cause of chronic disease because it disrupts hormonal signaling networks throughout the body.

 

Definition of Cellular Inflammation

The definition of cellular inflammation is increased activity of the gene transcription factor know as Nuclear Factor-kappaB (NF-κB). This is the gene transcription factor found in every cell, and it activates the inflammatory response of the innate immune system. Although the innate immune system is the most primitive part of our immune response, it has been resistant to study without recent breakthroughs in molecular biology. In fact, the 2011 Nobel Prize in Medicine was awarded for the earliest studies on the innate immune system and its implications in the development of chronic disease.

 

There are several extracellular events through which NF-κB can be activated by distinct mechanisms. These include microbial invasion recognized by toll-like receptors (TLR), generation of reactive oxygen species (ROS), cellular generation of inflammatory eicosanoids, and interaction with inflammatory cytokines via defined cell surface receptors. We also know that several of these initiating events are modulated by dietary factors. This also means that appropriate use of the diet can either turn on or turn off the activation of NF-κB. This new knowledge is the foundation of anti-inflammatory nutrition (1-3).

 

Understanding Cellular Inflammation

Although the innate immune system is exceptionally complex, it can be illustrated in a relatively simple diagram as shown below in Figure 1.

 

Figure 1. Simplified View of the Innate Immune System

 

 

Essential fatty acids are the most powerful modulators of NF-κB. In particular, the omega-6 fatty acid arachidonic acid (AA) activates NF-κB, whereas the omega-3 fatty acid eicosapentaenoic acid (EPA) does not (4). Recent work suggests that a subgroup of eicosanoids known as leukotrienes that are derived from AA may play a significant factor in NF-κB activation (5,6)

Extracellular inflammatory cytokines can also activate NF-κB by their interaction with specific receptors on the cell surface. The primary cytokine that activates NF-κB is tumor necrosis factor (TNF) (7). Toll-like receptors (TLR) are another starting point for the activation of NF-κB. In particular, TLR-4 is sensitive to dietary saturated fatty acids (8). The binding of saturated fatty acids to TLR-4 can be inhibited by omega-3 fatty acids such as EPA. Finally ROS either induced by ionizing radiation or by excess free radical formation are additional activators of NF-κB (9).

 

Anti-inflammatory Nutrition To Inhibit Cellular Inflammation

Anti-inflammatory nutrition is based on the ability of certain nutrients to reduce the activation of NF-κB.

The most effective way to lower the activation of NF-κB is to reduce the levels of AA in the target cell membrane thus reducing the formation of leukotrienes that can activate NF-κB. Having the patient follow an anti-inflammatory diet, such as the Zone Diet coupled with the simultaneous lowering omega-6 fatty acid intake are the primary dietary strategies to accomplish this goal (1-3).

 

Another effective dietary approach (and often easier for the patient to comply with) is the dietary supplementation with adequate levels of high-dose fish oil rich in omega-3 fatty acids, such as EPA and DHA. These omega-3 fatty acids taken at high enough levels will lower AA levels and increase EPA levels. This change of the AA/EPA ratio in the cell membrane will reduce the likelihood of the formation of inflammatory leukotrienes that can activate NF-κB. This is because leukotrienes derived from AA are pro-inflammatory, whereas those from EPA are non-inflammatory. The increased intake of omega-3 fatty acids is also a dietary approach that can activate the anti-inflammatory gene transcription factor PPAR-γ (10-12), decrease the formation of ROS (13) and decrease the binding of saturated fatty acids to TLR-4 (14). This illustrates the multi-functional roles that omega-3 fatty acids have in controlling cellular inflammation.

 

A third dietary approach is the adequate intake of dietary polyphenols. These are compounds that give fruits and vegetables their color. At high levels they are powerful anti-oxidants to reduce the generation of ROS (15). They can also inhibit the activation of NF-κB (16).

 

Finally, the least effective dietary strategy (but still useful) is the reduction of dietary saturated fat intake. This is because saturated fatty acids will cause the activation of the TLR-4 receptor in the cell membrane (8,14).

Obviously, the greater the number of these dietary strategies implemented by the patient, the greater the overall effect on reducing cellular inflammation.

 

Clinical Measurement of Cellular Inflammation

Since cellular inflammation is confined to the cell itself, there are few blood markers that can be used to directly measure the levels of systemic cellular inflammation in a cell. However, the AA/EPA ratio in the blood appears to be a precise and reproducible marker of the levels of the same ratio of these essential fatty acids in the cell membrane.

 

As described above, the leukotrienes derived from AA are powerful modulators of NF-κB. Thus a reduction in the AA/EPA ratio in the target cell membrane will lead to a reduced activation of NF-κB by decreased formation of inflammatory leukotrienes. The cell membrane is constantly being supplied by AA and EPA from the blood. Therefore the AA/EPA ratio in the blood becomes an excellent marker of the same ratio in the cell membrane (17). Currently the best and most reproducible marker of cellular inflammation is the AA/EPA ratio in the blood as it represents an upstream control point for the control of NF-κB activation.

 

The most commonly used diagnostic marker of inflammation is C-reactive protein (CRP). Unlike the AA/EPA ratio, CRP is a very distant downstream marker of past NF-κB activation. This is because one of inflammatory mediators expressed in the target cell is IL-6. It must eventually reach a high enough level in the blood to eventually interact with the liver or the fat cells to produce CRP. This makes CRP a more long-lived marker in the blood stream compared to the primary inflammatory gene products (IL-1, IL-6, TNF, and COX-2) released after the activation of NF-κB. As a consequence, CRP is easier to measure than the most immediate inflammatory products generated by NF-κB activation. However, easier doesn’t necessarily translate into better. In fact, an increase AA/EPA ratio in the target cell membrane often precedes any increase of C-reactive protein by several years. An elevated AA/EPA ratio indicates that NF-κB is at the tipping point and the cell is primed for increased genetic expression of a wide variety of inflammatory mediators. The measurement of CRP indicates that NF-κB has been activated for a considerable period of time and that cellular inflammation is now causing systemic damage.

 

In Summary

I believe the future of medicine lies in the control of cellular inflammation. This is most effectively accomplished by the constant application of anti-inflammatory nutrition. The success of such dietary interventions can be measured clinically by the reduction of the AA/EPA ratio in the blood.

 

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References:

  1. Sears B. The Anti-Inflammation Zone. Regan Books. New York, NY (2005).
  2. Sears B. Toxic Fat. Thomas Nelson. Nashville, TN (2008).
  3. Sears B and Riccordi C. “Anti-inflammatory nutrition as a pharmacological approach to treat obesity.” J Obesity doi:10.1155/2011/431985 (2011).
  4. Camandola S, Leonarduzzi G,Musso T, Varesio L, Carini R, Scavazza A, Chiarpotto E, Baeuerle PA, and Poli G. “Nuclear factor kB is activated by arachidonic acid but not by eicosapentaenoic acid.” Biochem Biophys Res Commun 229:643-647 (1996).
  5. Sears DD, Miles PD, Chapman J, Ofrecio JM, Almazan F, Thapar D, and Miller YI. “12/15-lipoxygenase is required for the early onset of high fat diet-induced adipose tissue inflammation and insulin resistance in mice.” PLoS One 4:e7250 (2009).
  6. Chakrabarti SK, Cole BK, Wen Y, Keller SR, and Nadler JL. “12/15-lipoxygenase products induce inflammation and impair insulin signaling in 3T3-L1 adipocytes.” Obesity 17:1657-1663 (2009).
  7. Min JK, Kim YM, Kim SW, Kwon MC, Kong YY, Hwang IK, Won MH, Rho J, and Kwon YG. “TNF-related activation-induced cytokine enhances leukocyte adhesiveness: induction of ICAM-1 and VCAM-1 via TNF receptor-associated factor and protein kinase C-dependent NF-kappaB activation in endothelial cells.” J Immunol 175: 531-540 (2005).
  8. Kim JJ and Sears DD. “TLR4 and Insulin Resistance.” Gastroenterol Res Pract doi:10./2010/212563 (2010).
  9. Bubici C, Papa S, Dean K, and Franzoso G. “Mutual cross-talk between reactive oxygen species and nuclear factor-kappa B: molecular basis and biological significance.” Oncogene 25: 6731-6748 (2006).
  10. Li H, Ruan XZ, Powis SH, Fernando R, Mon WY, Wheeler DC, Moorhead JF, and Varghese Z. “EPA and DHA reduce LPS-induced inflammation responses in HK-2 cells: Evidence for a PPAR-gamma-dependent mechanism.” Kidney Int 67: 867-874 (2005).
  11. Kawashima A, Harada T, Imada K, Yano T, and Mizuguchi K. “Eicosapentaenoic acid inhibits interleukin-6 production in interleukin-1beta-stimulated C6 glioma cells through peroxisome proliferator-activated receptor-gamma.” Prostaglandins LeukotEssent Fatty Acids 79: 59-65 (2008).
  12. Chambrier C, Bastard JP, Rieusset J, Chevillotte E, Bonnefont-Rousselot D, Therond P, Hainque B, Riou JP, Laville M, and Vidal H. “Eicosapentaenoic acid induces mRNA expression of peroxisome proliferator-activated receptor gamma.” Obes Res 10: 518-525 (2002).
  13. Mas E, Woodman RJ, Burke V, Puddey IB, Beilin LJ, Durand T, and Mori TA. “The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes.” Free Radic Res 44: 983-990 (2010).
  14. Lee JY, Plakidas A, Lee WH, Heikkinen A, Chanmugam P, Bray G, and Hwang DH. “Differential modulation of Toll-like receptors by fatty acids: preferential inhibition by n-3 polyunsaturated fatty acids.” J Lipid Res 44: 479-486 (2003).
  15. Crispo JA, Ansell DR, Piche M, Eibl JK, Khaper N, Ross GM, and Tai TC. “Protective effects of polyphenolic compounds on oxidative stress-induced cytotoxicity in PC12 cells.” Can J Physiol Pharmacol 88: 429-438 (2010).
  16. Romier B, Van De Walle J, During A, Larondelle Y, and Schneider YJ. “Modulation of signaling nuclear factor-kappaB activation pathway by polyphenols in human intestinal Caco-2 cells.” Br J Nutr 100: 542-551 (2008).
  17. Yee LD, Lester JL, Cole RM, Richardson JR, Hsu JC, Li Y, Lehman A, Belury MA, and Clinton SK. “Omega-3 fatty acid supplements in women at high risk of breast cancer have dose-dependent effects on breast adipose tissue fatty acid composition.” Am J Clin Nutr 91: 1185-1194 (2010).

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062524---Keto-Blog

Ketogenic Diets and Aging

Chances are, you or someone you know has tried the keto diet at some point in time. This high-fat, very low-carbohydrate eating plan appeals to many due to its promise of rapid weight loss. In this blog, Dr. Sears explores some of the latest scientific findings on ketogenic diets and provides caution before hopping on this trend. What is a Ketogenic Diet? The ketogenic diet is a high-fat, very low-carbohydrate eating plan. This significant reduction in carbohydrates to induce a metabolic state is called ketosis. This only occurs when there is not enough carbohydrates in your liver to completely convert fatty acids to carbon dioxide and water. The normal conversion generates the chemical energy (ATP) that keeps us alive. In the absence of ketosis, each fatty acid generates 108 molecules of ATP when oxidized in the mitochondria. Ketone bodies make less ATP when they are metabolized by mitochondria. How much less? About five times less. This is like switching the gasoline in your car from high-octane fuel to low octane fuel as ketone bodies increase in the blood. Furthermore, contrary to popular belief, ketones are not an ideal energy source for the brain, as glucose remains the preferred fuel for ATP production in brain cells. Lack of blood glucose is a highly stressful situation for the brain. This is why the body secretes the stress hormone cortisol from the adrenal glands during ketosis to breakdown protein and convert the amino acids into glucose for the brain. This explains why even under complete starvation for 38 days, the blood glucose levels never dropped below 68 mg/dL. This is still considered as a normal blood sugar level. Where did this blood glucose come from if there was none in the diet for 38 days? The answer is neo-glucogenesis primarily using lean body mass. Ketogenic Diets Pros and Cons Interest in ketogenic diets rises and falls about every 20 years. They’re very low-carbohydrate diets that claim that carbohydrates make you fat and keep you fat. This is simply not true. It is not carbohydrates per se but a disrupted metabolism that makes you fat. To be more specific, it is the inhibition of AMPK, the master regulator of your metabolism that makes you fat. Why? As AMPK activity increases, you burn stored fat faster. Frankly, I’ve always been amazed by the re-emergence of ketogenic diets. Eighteen years ago, I published the premier clinical study demonstrating that, under equal calorie intake in which all the food was provided to the subjects for six weeks, the Zone Diet was better than a ketogenic diet in reducing total weight, excess body fat, and inflammation. Now, a recent study revealed some more very concerning findings about the long-term effects of ketogenic diets. This new study indicated that following a keto diet causes a rise in senescent cells, popularly known as “zombie cells.” Zombie Cells are damaged cells that no longer divide but don't die. That’s bad enough, but zombie cells continue spreading inflammation throughout the body. As the number of zombie cells increases in your body, they become a living nightmare. Why? Zombie cells accelerate aging because they cause the earlier development of many chronic diseases. In this study they found that zombie cells in the animals began to appear while they were on a ketogenic diet. The zombie cells then disappeared when researchers changed the diet to a “non-ketogenic diet” (i.e., the Zone diet). And when the animals were given a Keto diet again, the zombie cells reappeared. Notice a trend? If you want to hear more about this study you can listen to our recent podcast at Dr.Sears.com. Based on earlier blogs, this adds to the list of downsides for following a ketogenic diet versus the Zone Diet. PROS Rapid initial weight loss: This is primarily due to the loss of retained water from the glycogen stores in the liver, which is rapidly used up to maintain blood sugar levels. Since these glycogen stores in the liver contain significant levels of retained water, much of the initial weight loss is water rather than stored body fat. If your main goal is loss retained water, this can be seen as a benefit. Of course, going to a sauna would also work. Reduced hunger: Ketogenic diets are rich in protein. Any increase in protein intake can help reduce hunger. CONS Production of acetone: One of the ketone bodies produced during ketosis is acetone, which is also the main chemical in nail polish. Increased calcium loss: A ketogenic diet can lead to higher calcium loss from bones. Limited fat utilization: High levels of dietary fat reduce the likelihood of using stored body fat for energy unless you also significantly restrict calories. Reduced energy levels: The lack of ATP production on a ketogenic diet can lead to easier fatigue during mild exercise. Damage from cheat meals: After seven days on a keto diet, a single high-carb cheat meal can damage blood vessels. Lack of polyphenols: This makes it difficult to activate genes that optimize metabolism by improving mitochondrial efficiency in converting fat into ATP. No long-term weight loss advantage: Long-term studies show no difference in weight loss between a ketogenic diet and a low-fat, high-carb diet. No short-term metabolic advantage: Careful studies demonstrate that fat loss on a ketogenic diet is the same as on a low-fat, high-carb diet with the same caloric intake. Compromised gut health: A lack of fermentable fiber from carbohydrates can lead to poor gut health and an increased risk of developing a leaky gut, which can cause significant inflammation. Furthermore, short-chain fatty acids (SCFA) are the metabolic product of fermentable fiber. These SCFA are powerful epigenetic signaling agents that enhance gene transcription. Ketosis generates a different type of hydroxylated short fatty acid (3-hydroxyl butyrate, that has no effect on gene transcription. In addition, the lack of SCFA has significant negative consequences on the gut-brain axis. Cortisol build-up: To produce glucose for the brain, cortisol levels increase to breakdown protein to make sufficient glucose via neoglucogenesis. Excess cortisol can lead to insulin resistance that cause regain of some of initially loss body fat. In addition, increased cortisol levels cause a depressed immune system as well as destruction of memory cells in the hippocampus. The initial benefits of following the ketogenic diet result in some initial weight loss (primarily water weight rather than fat loss), long-term studies show no significant differences in overall weight loss. Now new findings show a ketogenic diet may lead to significant adverse health consequences by accelerating the formation of zombie cells. Call me crazy, but I feel the key to longevity and wellness comes down to better metabolic control instead of living in a constant state of ketosis. Following Metabolic Engineering® for a lifetime provides that pathway of losing body fat without ketosis. References 1. Johnston CS, Tjonn SL, Swan PD, White A, Hutchins H, and Sears B. “Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets.” Am J Clin Nutr 2006 83:1055-61. 2. White AM, Johnston CS, Swan PD, Tjonn SL, and Sears B. “Blood ketones are directly related to fatigue and perceived effort during exercise in overweight adults adhering to low-carbohydrate diets for weight loss: a pilot study.” J Am Diet Assoc. 2007 107:1792-1796. 3. Sung-Jen Wei, Joseph R Schell, E Sandra Chocron, Mahboubeh Varmazyad, Guogang Xu, Wan Hsi Chen, Gloria M Martinez, Felix F Dong, Prethish Sreenivas, Rolando Trevino Jr , Haiyan Jiang, Yan Du, Afaf Saliba, Wei Qian, Brandon Lorenzana, Alia Nazarullah, Jenny Chang, Kumar Sharma, Erin Munkácsy, Nobuo Horikoshi, David Gius. Ketogenic diet induces p53-dependent cellular senescence in multiple organs. Sci Adv. 2024 May 17;10(20):eado1463. doi: 10.1126/sciadv.ado1463. 4. Owen OE, Felig P, Morgan AP, Wahren J, Cahill GF Jr. Liver and kidney metabolism during prolonged starvation. J Clin Invest. 1969 Mar;48(3):574-83. doi: 10.1172/JCI106016. 5. Chriett, S., Dąbek, A., Wojtala, M. et al. Prominent action of butyrate over β-hydroxybutyrate as histone deacetylase inhibitor, transcriptional modulator and anti-inflammatory molecule. Sci Rep 9, 742 (2019). https://doi.org/10.1038/s41598-018-36941-9. 6. Silva YP, Bernardi A, Frozza RL. The Role of Short-Chain Fatty Acids From Gut Microbiota in Gut-Brain Communication. Front Endocrinol (Lausanne). 2020 Jan 31;11:25. doi: 10.3389/fendo.2020.00025. 

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050824---Tofu-Blog

Tofu: Tips and Recipes Ideas

I have been eating tofu for a very long time, much longer than the 30 or so years I have been following the Zone Diet. Back then many of my favorite recipes came from the Tassajara cookbooks by Edward Espe Brown, the celebrated chef from the kitchen at California’s famous Zen Mountain Center, and cookbooks by Louise Hagler, a.k.a. Wendy Louise, a well-known authority on vegetarian cooking who is associated with a community in Tennessee known as The Farm. Those books are still among the best resources for tofu recipes. My mantra has always been if you don’t like something, don’t eat it. Keep this in mind if you’re new to tofu, start slowly by combining it with flavors and foods you like.    Tips and Suggestions    Firm-sprouted tofu is my preference for the Zone Diet. Unlike traditional tofu, which contains significant amounts of both protein and carbohydrate, sprouted has almost no carbohydrates. It’s lighter tasting, refreshing, and very filling.   Freezing tofu results in a chewy, sponge-like texture. I don’t recommend freezing, but some people prefer it when using tofu to substitute for meat in a recipe.    Baked tofu comes in a variety of flavors and makes an excellent quick meal with some vegetables and fruit added. It’s also great in salads.     Tofu made it into the book “The Top 100 Zone Foods” by Barry Sears.    Some recipes call for draining the tofu first. I find that usually isn’t necessary.   Tofu takes on the flavor of whatever is added to it.    Add nutritional yeast flakes to give a cheesy flavor to vegan tofu scrambles and dips. It’s also rich in protein and vitamin B12.   Cherry Vanilla Tofu “Ice Cream”   Tip: This doesn’t freeze or store well, so prepare only the amount you plan to serve immediately.   Using an immersion blender or a food processor blend equal parts of frozen dark cherries and firm tofu, plus some vanilla extract (preferably alcohol-free for best flavor). Serve immediately.  Tofu Scramble  This is great for breakfast, lunch, or dinner, and we’ve even brought it on long day hikes for a snack.   Crumble some firm tofu and stir in a generous amount of seasonings, taking care not to overdo it with the salt. Heat in a well-seasoned or nonstick skillet with a little Zone-friendly oil to the desired doneness.    Optional: If time allows, sauté some chopped onion in the skillet before adding the tofu and seasonings.    My favorite seasoning combination for this dish at my house is onion powder, garlic powder, turmeric, paprika, some oregano or thyme, nutritional yeast flakes, salt, and ground black pepper. The yellow color of the turmeric makes it somewhat like scrambled eggs.   Tofu Veggie Almond Pasta Salad   Dressing: Thin some smooth almond butter by stirring in some water, a little vinegar, and either soy sauce or Bragg’s Liquid Aminos (an unfermented soy sauce found in the health food section of most grocery stores).    Toss together cooked Dr. Sears’ Zone PastaRx Fusilli, tofu cut into cubes, matchstick cut red bell pepper, chopped green parts of scallions (a.k.a. green onions), and the almond butter dressing. Serve immediately or chill to serve later. It will keep well in the fridge for two or three days.   Use your imagination and see what you can come up with.  Experiment and have fun with it. Try using tofu to make cheesecakes, whipped desserts, tofu chocolate pudding, tofu “cream” based soups, tofu pot pie (think chicken pot pie), tofu burgers, tofu burritos, Buffalo tofu (like Buffalo wings), layered Mediterranean dips, tofu “meatballs”, grilled tofu, and more.    Enjoy! 

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