 We all want to eat the kinds of foods that make us feel better and live longer, but there's so much conflicting information out there. So many nutrition opinions. Welcome to the Nutrition Facts podcast. I'm your host, Dr. Michael Greger. It's my job to give you the information you need to make the healthiest choices possible. Kidney disease ranks as the ninth leading cause of death in the U.S., so what food should we eat to keep our kidneys healthy? Here's our first story. Chronic kidney disease is one of the top 10 leading causes of premature death in the United States, and its incidence is increasing. Chronic kidney disease affects more than 10% of the adult population, and each year more than 100,000 Americans develop end-stage kidney disease and have to go on dialysis. What's crazy is that a staggering 96% of individuals with mild to moderate decreases in kidney function about half of individuals with severely decreased kidney function go undiagnosed, meaning the vast majority, like 24 out of 25 people with chronic kidney disease, don't even know they have it. What can we do to maintain our kidney function? Well, in a study that followed more than 1,000 older women for a decade, those consuming a diet that was richer in plant-based protein had a slower decline in kidney function, extending support for the health benefits of plant-rich diets in the general population to maintain kidney health. Compared with protein from plant sources, animal protein has been associated with an increased risk of end-stage kidney disease in several such studies. We're not exactly sure why kidney damage from animal protein could result from the dietary acid load, excess phosphorus or gut microbiome bad bacteria and the resultant inflammation. The dietary acid load in a standard American diet is derived mostly from animal sources such as meats, eggs, and cheeses. In contrast, by including a higher proportion of foods with natural alkali, such as fruits and vegetables, a strictly plant-based diet is nearly acid-neutral. Even just eating plant-based two or three days a week can significantly bring down the acid load delivered to the kidneys and eating plant-based full-time, and you can actually flip over into alkaline territory. Even just cutting out meat can yield an alkaline load compared to the acid load in the non-vegetarians. All this is important since dietary acid may promote kidney injury and a progressive decline in kidney function. The intake of animal protein can also cause an imbalance in the composition of the gut microbiome by producing more ammonia and the rotten egg gas hydrogen sulfide and have a pro-inflammatory effect that may result in reduced kidney function. But it also may be the animal fat. In the Harvard Nurses study, higher intake of animal fat was directly associated with a loss of protein in the urine, which is a sign of kidney damage, and to protect against that they suggest dies lower in animal protein, animal fat, and cholesterol. That may help explain why vegetarians have better kidney function than non-vegetarians, matched for sex, age, size, physical activity, alcohol, smoking, etc. So effectively even a mediator who is just as slim as a vegetarian, just as healthy cholesterol, blood pressure, and blood sugar control-wise still has inferior kidney function. They think it might be the higher dietary fiber intake on more plant-based diets contributing to the protective effect on kidney function, again through a microbiome mechanism, whereas the consumption of animal protein may lead to a proliferation of meat-eating bugs, which can result in a leaky gut, uremic toxins, and resulting inflammation, oxidative stress, and chronic kidney disease progression. That can be blocked with the decreased inflammation in acetyl, thanks to the eating of more fiber-rich foods. No wonder an egg-free vegetarian dietary pattern was associated with a 37% decreased odds of developing chronic kidney disease. But what about plant-based diets for not just the prevention, but the management of chronic kidney disease? Can comprehensive lifestyle change alter the course of chronic kidney disease? This was the case report of someone diagnosed with minimal changes to disease. That's when someone's kidneys start leaking protein, even though there are minimal changes seen in biopsies under the microscope. You give people steroids, and in a few months you can knock it down, but a significant fraction may fail to respond to the steroid therapy. He was diagnosed 18 years prior, but only by replacing animal protein with plant-based protein was he able to put his chronic kidney disease into remission. At age 44, he suddenly developed swelling that crept up throughout his body since he was losing so much protein. He was weak, unable to concentrate, lethargic, diagnosed with minimal change disease and treated with a water pill and four different blood pressure-lowering agents. Because of unresponsiveness to high-dose steroids, a powerful immunosuppressant was added, yet severe protein loss continued, and his hypertension and kidney function worsened until he started eating plant-based, started exercising, lost 60 pounds, and his kidney disease went away and stayed away. Let's hear it in his own words. I appreciate the recommendations my doctor gave me about making dietary modifications replace your protein intake with plant-based protein. This one change has had a monumental impact on my life. I came back a quality of life that I thought was gone forever. My benchmark for normal has been my ability to keep up with my professional work demands and still be able to exercise. For the last seven months, I now swim over three miles every other day, a distance that surpasses my pre-kidney disease life. I perceived I lived a healthy lifestyle before kidney disease. Today, I live a healthier, happier lifestyle and I have my kidneys to thank for it. In our next story, we look at the significant dietary risk factors for declining kidney function. Kidney failure may be both prevented and treated with a plant-based diet, and no wonder. Kidneys are highly vascular organs. Harvard researchers found three significant dietary risk factors for declining kidney function— animal protein, animal fat, and cholesterol. Animal fat can alter the actual structure of the kidneys based on studies showing the plugs of fat literally clogging up the works in autopsies of human kidneys. And the animal protein can have a profound effect on normal kidney function, inducing what's called hyperfiltration, increasing the workload of the kidney, but not plant protein. Eat a meal of tuna fish, and you can see the increased pressure on the kidneys go up within one, two, three hours after the meal in both non-diabetics and diabetics. So we're not talking, you know, adverse effects decades down the road, but literally within hours of it going into our mouth. Now, if instead of having a tuna salad sandwich, though, you had a tofu salad sandwich with the exact same amount of protein, what happens? No effect. Dealing with plant protein is no problem. Why does animal protein cause the overloaded reaction but not plant protein? It appears to be due to the inflammation triggered by the consumption of animal products. Do we know that? Because if you give a powerful anti-inflammatory drug along with that tuna fish, you can abolish the hyperfiltration protein-leaked response to meat ingestion. Then, there's the acid load. Animal foods, meat, eggs, and dairy induce the formation of acid within the kidneys, which may lead to tubular toxicity damaged to the tiny, delicate urine-making tubes in the kidney. Animal foods tend to be acid-forming, especially fish, which is the worst in pork and poultry, whereas plant foods tend to be relatively neutral or actually alkaline, base-forming to counteract the acid, so the key to halting the progression of chronic kidney disease might be in the produce market, rather than the pharmacy. Finally today, I share a touching story of the power of plant-based eating for chronic kidney failure. Is it possible to ameliorate chronic kidney disease using a whole-food plant-based diet? In my last video on kidney disease, I talked about how randomizing people to cut just around 10 grams of protein from their daily diet could cut their risk of dialysis and death by a whopping 77%. That was cutting protein across the board, but while animal-based protein ingestion and meat, dairy, and egg white protein ingestion promotes an acidic environment in the kidneys, inflammation and stresses the kidneys to what's called hyperfiltration mode, plant-based protein can be alkaline-producing and anti-inflammatory and contain kidney protective properties. So what if you have kidney patients eat a plant-dominant low-protein diet, abbreviated adorably as Play-Doh, I guess for plant-dominant? If you fashion up a plant-based diet index score where you get points for healthy plant foods and get points deducted for eating animal foods, those with serious kidney disease with higher scores were found to have lower systemic inflammation, but does that actually translate into living a longer life? Apparently so, even a 10% increase in the proportion of plant-based protein was associated with a significant reduction in all-cause mortality. Even just eating more servings of fruits and vegetables, like 2 a day compared to 2 a week, is linked to living longer. Without fully functioning kidneys, there are concerns about phosphorus and potassium overload, though, on a plant-based diet. But the phosphorus in plant-based foods is not as much of a problem as the phosphorus additives in processed and animal foods. And the risk of potassium overload from plant-based diets appears overstated and not supported by the evidence, but you don't know about ameliorating chronic kidney disease using a whole-food plant-based diet until you put it to the test. Here's a case reported of a 69-year-old man with type 2 diabetes high blood pressure and stage 3 chronic kidney disease, resulting in elevated phosphorus and potassium in the blood interested in changing his diet to improve his medical condition. That's my kind of patient. He was on 12 different medications, eating a diet that may actually be slightly better than the average American, some whole grains and beans, but then his doctor advised to try eating whole-food plant-based. So, oatmeal with fruit and flax, beans and greens, whole wheat spaghetti and veggies, fruit and snacks, counseled to eat as much as he wanted, from whole healthy food to no carb counting, no calorie counting, no portion size restriction, improving the quality of food rather than restricting the quantity of food. He adopted the whole-food plant-based diet packed with carbs, yet rapidly reduced his insulin requirements by more than 50% and subsequently saw improvements in weight, blood pressure, and cholesterol. Because eating healthy can have such a rapid effect on improving your body's insulin sensitivity, immediate adjustments in insulin dosing were made within four days. His insulin dose was able to be reduced from roughly 210 units of insulin a day, down to 70 units daily, and an oral blood sugar-lowering medication had to be stopped due to rapidly improving blood sugar. He also was able to stop his carvetolol, hydrochlorothiazide, amlodipine, and citiclyptin. Within the first two months, due to improving blood pressure and blood sugars, his insulin dose was steadily titrated downward. His private statin dose was cut in half, and he lost about 50 pounds. OK, so what happened to his Stage 3 kidney failure? He was no longer in Stage 3 kidney failure. He experienced an increase in estimated GFR of 73%, suggesting that the improvement in an estimated kidney function was greater than what would be expected from weight loss alone. For example, lose about 60 pounds from bariatric surgery and you only get about a 12% to 15% boost. Bottom line, for individuals with chronic kidney disease, especially those with obesity, hypertension, or diabetes, a strict, all-you-care-to-eat, whole-food, plant-based diet may confer significant benefit. I mean, apart from the kidney-specific outcomes, overall mortality is significantly lower among kidney patients who eat more plants. And that's critical, because most kidney patients don't even make it to dialysis because they die first, most often from cardiovascular disease. Let's hear from the patient. At the outset, it seemed like this was going to be a difficult and restrictive way to eat, but I began feeling different almost immediately. We had to decrease my insulin after one day. It seemed like almost overnight I had more energy than I'd had in years. Weight I'd been trying to lose for a decade and began dropping off. As the weight came off, I felt lighter and more able to move my body again. This lifestyle change has been the greatest gift I've ever received. I'm off most of my medications. I've lost over 70 pounds and I've regained control over my health. I feel empowered by this lifestyle change. I finally feel like I've been in charge of my health and not just an unlucky victim shuffling from one specialist to the next. My only regret was that I didn't know about this sooner. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to NutritionFacts.org slash testimonials with maybe able to share it on social media to help inspire others. If you'd like to see any graphs, charts, graphics, images or studies mentioned here, go to the Nutrition Facts podcast landing page. There you'll find all the detailed information you need plus links to all the sources we cite for each of these topics. My last two books were How to Survive a Pandemic and My How Not to Diet Cookbook. Get ready this year for the launch of How Not to Age and of course all the proceeds for the sales of all my books goes directly to charity. NutritionFacts.org is a nonprofit science-based public service where you can sign up for free daily updates on the latest new nutrition research with bite-sized videos and articles uploaded nearly every day. Everything on the website is free. There are no ads, no corporate sponsorships, no kickbacks, it's strictly non-commercial, not selling anything. I just put it up as a public service as a labor of love as a tribute to my grandmother whose own life was saved with evidence-based nutrition.