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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022724---Weight-Loss-Blog

Dr. Sears Q&A: Weight Loss

With so much interest in weight loss and so much buzz around weight loss drugs, we put together some of the top questions we get in this latest Q&A blog. Here Dr. Sears answers your questions on weight loss, weight loss drugs and what he thinks is the most scientifically backed way to lose weight. See what he has to say.Question: What medical conditions could impede weight loss, and how can they be identified?  Answer:  Any condition associated with insulin resistance will make it difficult to lose weight.  This would include diabetes, heart disease, neurological disease, etc.  Also, any drug that induces insulin resistance will also make it difficult to lose weight.  These include corticosteroids and many neurological drugs. Question: How do hormones affect weight loss, and which imbalances are most detrimental? Answer: High levels of insulin (caused by insulin resistance), high levels of cortisol (caused by stress), and low levels of satiety hormones such as GLP-1 will make weight loss difficult. Question: Is there a connection between sleep quality and weight loss? Answer: Poor quality sleep increases cortisol levels that lead to insulin resistance. The higher your level of insulin resistance, the more difficult it is for any organ to remove glucose from the blood for transport into the cell, where it can be converted to energy. This i Question: Do any weight loss supplements work?  Answer: Not really. You have to restrict calories to activate AMPK which causes your body to effectively burn excess stored body fat.   Question: What medications are FDA approved for weight loss? Answer: There are number of approved older drugs, but the most widely used is still an old drug (Phentermine) that was only recently approved for long-term use. However, the new injectable GLP-1 receptor agonists are more powerful and more popular. The scientific name for the most well-known injectable weight-loss drug is semaglutide, which is marketed under the tradenames Ozempic and Wegovy. In simple terms, these injectable drugs activate the release of the hormone GLP-1 from the gut that goes directly to the brain to tell you to stop eating. These drugs were initially developed to treat type 2 diabetes, but the clinical studies in overweight and obese individuals demonstrated significant weight loss at higher levels. Question: What are the unintended side effects of weight loss medications (i.e. GLP-1s, dual GIP/GLP-1). Answer: One major problem is that the lack of hunger caused by the drug makes you less likely to consume sufficient protein to maintain lean body mass.  Lean body mass is defined as functional tissue such as organs (including the brain) and bone.  Nearly 40 percent of the weight loss in obese patients comes from loss of lean body mass.  Without adequate protein (especially on a diet that is calorie-restricted because of lack of hunger), the replacement of damaged cells is compromised.  The skin and hair are the first site to suffer.  This lack of protein also makes it difficult to maintain mitochondrial function that provides energy for each of your 30 trillion cells. As a result, fatigue (both mental and physical) is often experienced. Question: Would you recommend an injectable weight loss drug? Answer: The answer is no. There is a big difference between weight loss and fat loss. Weight loss is the combined loss of stored body fat and lean body mass (i.e., muscle). You want to lose fat but not muscle. Although the weight loss using weekly semaglutide injections is impressive according to the literature, a deeper look shows that about 40 percent of that weight loss is due to loss of lean body mass. That is not a good sign. It suggests that the injections reduce hunger to the extent that the person has little desire to eat enough protein to maintain muscle mass. In essence, the drug increases the patients' sarcopenia (muscle loss). One of the consequences of sarcopenia is increased frailty. Also once you stop using these weight loss drugs, the weight quickly returns. Question: Does a high protein diet help with weight loss? Answer: Most high protein diets are ketogenic diets that disrupt metabolism in addition to being high fat.  The appropriate diet is protein-adequate (about 30 grams of protein at each meal), carbohydrate-moderate (primarily non-starchy vegetables, low-fat (to reduce calories) and rich in fermentable fiber.  The common name for such a diet is the Zone diet. The ideal amount of protein at each meal for weight loss is about 30 grams. Less than 30 grams of protein at meal will not generate the hormonal signals from the gut to stop hunger. Too much protein at meal, greater than 30 grams, will inhibit AMPK activity which helps cells burn excess stored fat.  

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