I had the opportunity to speak on nutrition at our annual meeting of the American College of Cardiology, which was recently held in New Orleans. I was curious to know what this large group of cardiologists considered to be the ideal diet. So I polled the audience asking: What diet is most heart-healthy?
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Vegan diet
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Paleo diet
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Mediterranean diet or
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Ketogenic diet
The clear winner among this group of cardiologists was the Mediterranean diet. Now keep in mind that when most Americans hear “the Mediterranean diet,” they think - pasta, pizza and bread.
But this was a group of cardiologists, so they were surely much more knowledgeable about nutrition, right? Well, not necessarily.
As Elizabeth Klodas, M.D., a cardiologist friend wrote, “It took more than 80,000 hours of training for me to become a cardiologist. How much of that time was spent on nutrition? Zero.”
Paying Lip Service to Nutrition
Dr. Klodas trained at some of the top medical institutions in the world, including Mayo Clinic and Johns Hopkins, and now practices in Minneapolis, Minn. She wrote, “My waiting room was full of patients whose numbers I had made perfect, but who still looked sick and felt terrible.
Some even felt worse with all the drugs I had put them on. No cures, just a never-ending revolving door of follow-up visits. High cholesterol? Here’s a pill. High blood pressure? Here’s two pills. High blood sugar? Here’s two pills and an injection.”
This is what many doctors in America routinely do without ever addressing why the cholesterol, blood pressure and blood sugar are abnormal in the first place.
Dr. Klodas said she used to practice this way, until she realized that she was just was covering up the downstream effects of poor diet with a bunch of drugs, instead of having her patients change their eating habits.
Twenty years ago the National Institutes of Health deemed that changing diet should be tried for three months as the first step in treating high cholesterol, before putting anyone on drugs. But today, many physicians are skeptical that any food-based solution provides significant benefits for treating common health conditions.
To make matters worse, treatment guidelines from national health organizations only pay lip service to nutrition. For instance, the 2018 cholesterol management guideline is a comprehensive document that was a collaborative effort from the American Heart Association, the American College of Cardiology, the American Diabetes Association, the National Lipid Association, as well as several other organizations. How much of this 120-page authoritative report is devoted to diet? A single paragraph!
Instead, this widely followed guideline exhaustively instructs doctors about which drugs to use, at what doses, and for which patients. According to this new cholesterol guideline, 10-year-old kids are candidates to be started on the most potent statin medications, including atorvastatin and rosuvastatin.
Dr. Klodas goes on to say, “Did you know that doctors are monitored according to whether they prescribe medications? If I don’t follow the cholesterol guidelines by prescribing statins, insurers will send letters scolding me. If I don’t talk to you about the cholesterol-lowering effects of walnuts and oat bran, nobody cares.
... If a physician uses some of the very limited time with patients to talk about antioxidants and omega-3 fatty acids, they get nothing more.”
Listen closely - I’m going to let you in on a secret - diet is an extraordinarily effective weapon against premature aging and disease, but it has to be the right diet. So let’s get back to discussing the best diet to follow if you are interested in taking charge of your own destiny by eating the foods and drinking the beverages to keep you youthful, bright and energetic.
Original Ketogenic Diet
Dr. Russell Wilder at Mayo Clinic in 1923 designed a very high-fat diet to help prevent seizures. He called it “the Ketogenic Diet” because when followed, it increased ketones in the bloodstream. His version of the keto diet, called for 90% of calories from fat, and it reduced seizures by about 50%.
About 37 years ago I met my wife, Joan, when we were both interns at the Mayo Clinic. She was a dietetic intern and I was fresh out of medical school. For the next six years, while I was training in cardiology at Mayo, Joan worked as a dietitian there. During this time, she was occasionally asked to start this ketogenic diet in a child with seizures that couldn’t be controlled with medications. This involved drinking a lot of heavy cream, and MCT oil. She recalls that it was an exceedingly difficult diet for the kids to stick with. One side effect is what one keto diet guru calls “disaster pants.”
A century later, Dr. Wilder’s ketogenic diet is now succeeding beyond his wildest dreams. The keto diet is the most searched-for diet on Google, far surpassing the vegan diet. We have four kids who are Millennials - and they tell me this diet is all the rage with their contemporaries.
The keto diet today generally recommends getting at least 70% of calories from fat, 5 to 10% from carbs and about 15 to 20% from protein. Unlike the Paleo diet, you do need to be mindful about not overeating protein, otherwise, you stimulate gluconeogenesis (the manufacturing of sugar) in the liver, and that prevents ketosis.
To get into ketosis, most people will need to limit their carb intake somewhere between 20 to 50 grams per day. Most keto devotees do this by consuming a lot of cheese, real butter, cream and coconut butter, olive oil, nuts, avocados, and eggs.
Ideally, you need to be eating large quantities of non-starchy vegetables like leafy greens, cruciferous vegetables, onions and garlic. But as Joan says, most Americans don’t really like vegetables. Consequently, people who are following the keto diet, eat lots of cheese, cream, butter and meat, and shun the most healthful component - vegetables … and that is a big problem.
Carbies Don’t Make Barbies
“Carbage” like cookies, cake, bread, beer, candy, crackers, pie, doughnuts, rice, bagels, chips, tortillas, potatoes, pasta and sweetened beverages are strictly verboten on the keto diet. This kind of food is not only addictive, but it also triggers insulin spikes that deposit those calories in and around the abdomen. Sherief is a dear family friend who’s a 31-year-old hipster radiology resident and likes to remind my daughters, “Carbies don’t make Barbies.”
Water is a crucial element of a keto diet. Thankfully, coffee and tea, both unsweetened of course, are also beverages of choice. Dry wine or distilled spirits are metabolized as fats, and are okay in moderation. Some cynical health care insiders joke that a moderate drinker is someone who’s consuming less alcohol than their doctor.
High insulin levels cause obesity, whether that insulin is being secreted from your pancreas or you are injecting it with a needle. Insulin ushers glucose into fat cells, especially inside the abdomen, and insulin also makes you crave carbs.
High insulin also causes fluid retention. Thus, if you are doing the keto diet correctly, you’ll reduce your daily carb intake from the typical U.S. adult level of 300 grams to one-tenth of this. Your insulin levels will plunge, and, to be blunt, you will pee like crazy in the first week or two as you get rid of excess retained fluid.
A very low-carb diet for most people is the most reliable way to lose weight. I could show you 25 studies proving this point. In a nation where two out of three of us is overweight or obese, it’s not hard to understand why these very low-carb diets, like keto or Atkin’s are popular - they work if your goal is dramatic weight loss.
Ketones as a Superfuel
What fascinates me most about the keto diet is not the weight loss, but the ketones. Most physicians tend to wince when we think of past of experiences we’ve had with patients in diabetic ketoacidosis - a dangerous complication of diabetes when the ketones spike to toxic levels, generally in people who are gravely ill.
But for virtually everyone else, ketones are friendly molecules that trim our waistlines and boost our sense of well-being. Ketones are an alternate fuel source our liver generates when we have run out of circulating glucose, and exhausted our glycogen (glucose stored in the liver and muscles).
If we don’t take in calories for 12 to 24 hours or longer, or if we just markedly lower carbohydrate consumption, the body starts melting belly fat and then the liver converts fatty acids that are released into ketones. The default fuel for the brain is glucose, and the preferred fuel for the heart is fatty acids - but when those fuels aren’t available, these organs, along with the kidneys, are perfectly happy to burn ketone bodies for energy.
ATP is the chemical energy that powers life. Every 24 hours you generate your body weight in ATP. It blows my mind to know that I generate 74 Kg of ATP per day, which of course is recycled so we don’t see the pile of ATP we produce each day, but we sure feel it - if our mitochondria stopped making ATP we would die in a few seconds.
When your body burns 100 grams (about 3 ounces) of glucose in the Krebs cycle, it generates about 8 Kg of ATP. But instead, if we are burning ketones - the two major ones are acetoacetate and beta hydroxybutyrate - we generate about 10 Kg of ATP, or 20% more energy.
And even more importantly, burning ketones also throws off much lower levels of reactive oxygen species - evil chemicals that over time can cause corrosive rust throughout your system. In this way, burning ketones rather than sugar or other carbs will confer potent anti-inflammatory effects, allowing your brain and heart to function better - which helps you to think more clearly, and feel stronger and healthier.
When you follow a strict keto diet, you quickly evolve into a fat-melting, keto-burning machine that generates more power, and throws off a lot less exhaust - more like a Tesla, less like a diesel truck belching smoke. Wow, sounds great. All aboard the “Keto Express!” Get on the fast track to a whole new you.
The Dark Side of Keto
Not so fast. Let me tell you about the nefarious alter ego of Keto’s Jekyll and Hyde nature. Mark is a 57-year-old executive with heavy plaque in his coronaries. On the advice of an internet keto guru, he ditched his statin and started the keto diet. He followed it closely and cut his carbs to not more than 20 to 30 grams per day.
He lost 15 pounds and his blood pressure came down to the point where he had to stop his hypertension (high blood pressure) medicine. But his LDL rose about 400%, from an ideal level of 68 to 275. Many self-proclaimed diet experts insist high levels of saturated fats and cholesterol are nothing to worry about. But from where I sit as a cardiologist, I’m not buying it - this is a recipe for disaster!
In fact, a recent meta-analysis of 430,000 subjects from the best long-term nutritional studies showed that both high-carb and low-carb diets shortened life expectancy. The keto diet is an extremely low-carb diet with less than 10% of calories from carbohydrates, corresponding to a 50% increased risk of dying during the 25-year follow-up period in this study.
A fascinating deeper dive into this data showed that when it comes to macronutrients, the type of fat you eat makes all the difference. Substituting in high-saturated fat foods like butter, cheese, cream, fried foods and fatty red meat plus carbs will shorten your life expectancy. In contrast, if you take carbs out by substituting in monounsaturated and polyunsaturated fats from natural foods such as fish, nuts, seeds, olive oil and avocados, then your life expectancy improves significantly.
Become a Ketone-Burning Machine
Still, if you don’t want to count carbs or drink cream, there are a few other practical ways to get into ketosis and reap the impressive benefits to mind and body. For example, you could just stop consuming calories for at least 12 hours per day. After about 12 hours, when your system starts to run out of glucose for fuel, you start generating ketones. They don’t call it break-fast for nothing. You need to fast for at least 12 hours or better yet, 14 to 16 hours each day before eating your next meal.
Drinking coffee is another way to increase ketones. A recent study showed that consuming the equivalent of 1.5 to 3 cups of coffee first thing in the morning will double your blood level of ketones. Incidentally, if you get some exercise after drinking your coffee, but before you consume any calories, you will really crank up your ketone production. Coffee’s ability to increase ketones is probably a major reason why this beverage helps to prevent Parkinson’s disease and Alzheimer’s, and also reduces the risk for developing diabetes and cardiovascular complications.
Bottom Line
Carbohydrates are bad when you choose cookies, doughnuts, candy and processed foods made from refined flour and/or added sugar.
Yet, carbs from foods like non-starchy vegetables and legumes are arguably some of the healthiest foods on the planet. Most of the cultures with exceptional longevity make legumes, such as lentils and/or beans, a staple in their diet.
Fats are bad when you get them from processed meats, fried foods, high-fat dairy and fatty animal foods.
However, fats can be super healthy when you’re eating natural high-fat foods from plants and fish.
To summarize, if you want to get the benefits of the ketogenic diet, like weight loss, lower blood pressure, reduced inflammation and clearer thinking, without suffering cardiovascular complications from high cholesterol, you need to eat lots of nuts, olive oil, avocados (or guacamole), seeds and fatty fish. We go through a liter of olive oil a week around my household. I am a connoisseur of nuts, and I eat one or two avocados per day. I consider myself to be a pescetarian, eating salmon, scallops, trout, or sardines most every day.
Other important habits for keeping ketones high include:
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Fast for at least 12 hours every day.
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Drink black coffee first thing in the morning.
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Go get some exercise before breakfast.
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Consume generous amounts of non-starchy vegetables, and modest amounts of low-glycemic index fruits like berries.
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Avoid added sugar and refined carbs like the plague.