How the Egg Industry Tried to Bury the TMAO Risk

“Metabolomics is a term used to describe the measurement of multiple small-molecule metabolites in biological specimens, including bodily fluids,” with the goal of “[i]dentifying the molecular signatures.” For example, if we compared the metabolic profile of those with severe heart disease to those with clean arteries, we might be able to come up with a cheap, simple, and noninvasive way to screen people. If heart patients happened to have something in their blood that healthy people didn’t, we could test for that. What’s more, perhaps it would even help us understand the mechanisms of disease. “To refer to metabolomics as a new field is injustice to ancient doctors who used ants to diagnose the patients of diabetes” (because the ants could detect the sugar in the diabetics’ urine).

The first modern foray discovered hundreds of substances in a single breath, thanks to the development of computer technology that made it possible to handle large amounts of information—and that was in 1971, when a computer took up nearly an entire room. “[N]ew metabolomics technologies [have] allowed researchers to measure hundreds or even thousands of metabolites at a time,” which is good since more than 25,000 compounds may be entering our body through our diet alone.

Researchers can use computers to turn metabolic data into maps that allow them to try to piece together connections. You can see sample data and a map at 1:28 in my video Egg Industry Response to Choline and TMAO. Metabolomics is where the story of TMAO started. “Everyone knows that a ‘bad diet’ can lead to heart disease. But which dietary components are the most harmful?” Researchers at the Cleveland Clinic “screened blood from patients who had experienced a heart attack or stroke and compared the results with those from blood of people who had not.”

Using an array of different technology, the researchers identified a compound called TMAO, which stands for trimethylamine N-oxide. The more TMAO people had in their blood, the greater the odds they had heart disease and the worse their heart disease was.

Where does TMAO come from? At 2:19 in my video, you can see a graphic showing that our liver turns TMA into TMAO—but where does TMA come from? Certain bacteria in our gut turn the choline in our diet into TMA. Where is the highest concentration of choline found? Eggs, milk, and meats, including poultry and fish. So, when we eat these foods, our gut bacteria may make TMA, which is absorbed into our system and oxidized by our liver into TMAO, which may then increase our risk of heart attack, stroke, and death.

However, simply because people with heart disease tend to have higher TMAO levels at a snapshot in time doesn’t mean having high TMAO levels necessarily leads to bad outcomes. We’d really want to follow people over time, which is what researchers did next. Four thousand people were followed for three years, and, as you can see in the graph at 3:10 in my video, those with the highest TMAO levels went on to have significantly more heart attacks, strokes, or death.

Let’s back up for a moment. If high TMAO levels come from eating lots of meat, dairy, and eggs, then maybe the only reason people with high TMAO levels have lots of heart attacks is that they’re eating lots of meat, dairy, and eggs. Perhaps having high TMAO levels is just a marker of a diet high in “red meat, eggs, milk, and chicken”—a diet that’s killing people by raising cholesterol levels, for example, and has nothing to do with TMAO at all. Conversely, the reason a low TMAO level seems so protective may just be that it’s indicative of a more plant-based diet.

One reason we think TMAO is directly responsible is that TMAO levels predict the risk of heart attacks, strokes, or death “independently of traditional cardiovascular risk factors.” Put another way, regardless of whether or not you had high cholesterol or low cholesterol, or high blood pressure or low blood pressure, having high TMAO levels appeared to be bad news. This has since been replicated in other studies. Participants were found to have up to nine times the odds of heart disease at high TMAO blood levels even after “controll[ing] for meat, fish, and cholesterol (surrogate for egg) intake.”

What about the rest of the sequence, though? How can we be certain that our gut bacteria can take the choline we eat and turn it into trimethylamine in the first place? It’s easy. Just administer a simple dietary choline challenge by giving participants some eggs.

Within about an hour of eating two hard-boiled eggs, there is a bump of TMAO in the blood, as you can see at 4:51 in my video. What if the subjects are then given antibiotics to wipe out their gut flora? After the antibiotics, nothing happens after they eat more eggs. In fact, their TMAO levels are down at zero. This shows that our gut bacteria play a critical role. But, if we wait a month and give their guts some time to recover from the antibiotics, TMAO levels creep back up.

These findings did not thrill the egg industry. Imagine working for the American Egg Board and being tasked with designing a study to show there is no effect of eating nearly an egg a day. How could a study be rigged to show no difference? If we look at the effect of an egg meal (see 5:32 in my video), we see it gives a bump in TMAO levels. However, our kidneys are so good at getting rid of TMAO, by hours four, six, and eight, we’re back to baseline. So, the way to rig the study is just make sure the subjects hadn’t eaten those eggs in the last 12 hours. Then, you can show “no effect,” get your study published in the Journal of the Academy of Nutrition and Dietetics, and collect your paycheck.


Unfortunately, this appears to be part for the course for the egg industry. For more on their suspect activities, see:

For more on the TMAO story, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

How Not to Die from Kidney Disease

Kidney failure may be both prevented and treated with a plant-based diet, and it’s no wonder: Kidneys are highly vascular organs, packed with blood vessels. 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 our kidneys. In my video How Not to Die from Kidney Disease, you can see plugs of fat literally clogging up the works in autopsied human kidneys from a study published in The American Journal of Pathology.

Animal protein can have a “profound effect” on normal kidney function, inducing “hyperfiltration,” increasing the workload of the kidney. Not plant protein, though. After eating a meal of tuna fish, the increased pressure on the kidneys goes up within only a few hours. We aren’t talking about adverse effects decades down the road, but literally within hours of it going into our mouths. What happens if, instead of having a tuna salad sandwich, you had a tofu salad sandwich with the exact same amount of protein? No effect on your kidneys. Our kidneys have no problem dealing with plant protein is no problem.

Why does animal protein cause the overload reaction, but plant protein doesn’t? It appears to be due to the inflammation triggered by the consumption of animal products. Indeed, taking a powerful, anti-inflammatory drug along with that tuna fish sandwich can abolish the hyperfiltration, protein-leakage response to meat ingestion.

There’s also the acid load. Animal foods, such as meat, eggs, and dairy, induce the formation of acid within the kidneys, which may lead to “tubular toxicity,” damage to the tiny, delicate, urine-making tubes in the kidney. Animal foods tend to be acid-forming—especially fish, which is the worst, followed by pork and poultry—whereas plant foods tend to be relatively neutral, or actually alkaline or base-forming to counteract the acid, especialy green leafy vegetables. So, “[t]he key to halting progression of CKD [chronic kidney disease] might be in the produce market, not in the pharmacy.”

It’s no wonder plant-based diets have been used to treat kidney disease for decades. In my video, you can see a remarkable graph that follows the protein leakage of subjects first on a conventional, low-sodium diet, which is what physicians would typically put someone with declining kidney function on, then switched to a supplemented vegan diet, back to the conventional diet, once more on the plant-based diet, and back and forth again. The chart is filled with zig-zags, showing kidney dysfunction was effectively turned on and off like a light switch, based on what was going into their mouths.


The first time someone visits NutritionFacts.org can be overwhelming. With videos on more than 2,000 health topics, where do you even begin? Imagine stumbling onto the site not knowing what to expect and the new video-of-the-day is about how a particular spice can be effective in treating a particular form of arthritis. It would be easy to miss the forest for the trees, which is precisely why I created a series of overview videos that are essentially taken straight from my live, hour-long 2016 presentation How Not to Die: Preventing, Arresting, and Reversing Our Top 15 Killers.

For the other videos in this overview series, see:

Inspired to learn more about the role diet may play in preventing and treating kidney disease? Check out these other popular videos on the topic:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Reversing Massive Obesity With Diet

Dr. Walter Kempner introduced the first comprehensive dietary program to treat chronic kidney disease and, in doing so, also revolutionized the treatment of other disorders, including obesity. Kempner was Professor Emeritus of Medicine at Duke, where he came up with the so-called rice diet, which basically consisted of rice, sugar, fruit, and fruit juices, was extremely low in sodium and fat, and included no animal fat, no cholesterol, and no animal protein. The sugar was added as a source of calories so people wouldn’t lose too much weight. But some people need to lose weight, so he started treating obese patients with a lower calorie version of the diet, which I discuss in my Can Morbid Obesity Be Reversed Through Diet? video.

He published an analysis of 106 patients who each lost at least 100 pounds. Why 106? Kempner simply picked the last 100 people who lost more than 100 pounds, and, by the time he finished reviewing their charts, 6 more had joined the so-called century club. Average weight loss among them was 141 pounds. “This study demonstrates that massively obese persons can achieve marked weight reduction, even normalization of weight, without hospitalization, surgery, or pharmacologic intervention…[O]ne important fact to be gained from this study is that, despite the misconception to the contrary, massive obesity is not an uncorrectable malady. Weight loss can be achieved, massive obesity can be corrected, and it can be done without drastic intervention.”

Well, Kempner’s rice diet is pretty drastic, so definitely don’t try this at home. In fact, the rice diet is dangerous. It’s so restrictive that it may cause serious electrolyte imbalances, unless the patient is carefully medically supervised with frequent blood and urine lab testing. Dangerous? Says who? Said the world’s number-one advocate for the rice diet: Dr. Kempner himself.

The best, safe approximation of the diet, meaning low in sodium and without fat, protein, or cholesterol from animals, would be a vitamin B12-fortified diet centered around whole, unprocessed plant foods. However, even a medically supervised rice diet could be considered un-drastic compared to procedures like getting one’s internal organs stapled or rearranged, wiring someone’s jaws shut, or even undergoing brain surgery.

Attempts have been made to destroy the parts of the brain associated with the sensation of hunger, by irradiation or going in through the skull and burning them out. “It shows how ineffective most simpler forms of treatment are that anyone should think it reasonable to produce irreversible intracranial lesions in very obese patients.” The surgeons defended these procedures, however, explaining that their “justification in attempting the operation is, of course, the very poor results of conventional therapy in gross obesity, and the dark prognosis, mental and physical, of the uncorrected condition.” In reply, a critic countered, “Such strong feelings [about how dark the prognosis is] run the risk of being conveyed to the patient, to the effect of masking the operative dangers and steam-rolling the patient’s approval.” The surgeon replied, “If any ‘steamrolling’ is taking place, it comes rather from obese patients who sometimes threaten suicide unless they are accepted for experimental surgical treatment.”

As of 2013, the American Medical Association officially declared obesity a disease, by identifying the enormous humanitarian impact of obesity as requiring the medical care and attention of other diseases. Yet the way we treat diseases these days involves drugs and surgery. Anti-obesity drugs have been pulled from the market again and again after they started killing people—an unrelenting fall of the pharmacological treatment of obesity.

The same has happened with obesity surgeries. The procedure Kempner wrote about was discontinued because of the complication of causing irreversible cirrhosis of the liver. Current procedures include various reconfigurations of the digestive tract. Complications of surgery appear to occur in about 20 percent of patients, and nearly one in ten of which may be death. In one of the largest studies, 1.9 percent of patients died within a month of the surgery. “Even if surgery proves sustainably effective, the need to rely on the rearrangement of [our] anatomy as an alternative to better use of feet and forks [that is, diet and exercise] seems a societal travesty.”


For more on Kempner and his rice diet, see my videos:

Learn more on the surgical approach in Reversing Diabetes with Surgery and Stomach Stapling Kids.

And, for more on weight, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: