How to Design a Misleading Study to Show Diet Doesn’t Work

How to Design a Misleading Study to Show Diet Doesn't Work.jpeg

A study out of the University of North Carolina found no association between dietary fiber intake and diverticulosis. They compared those who ate the highest amount of fiber, 25 grams, to those who ate the smallest amount, which was three times lower at only 8 grams. Finding no difference in disease rates, researchers concluded that a low-fiber diet was not associated with diverticulosis.

The university sent out a press release entitled: "Diets high in fiber won't protect against diverticulosis." The media picked it up and ran headlines such as "High-fiber diet may not protect against diverticulosis, study finds." It went all over the paleo blogs and even medical journals, publishing such statements as an "important and provocative paper...calls into question" the fiber theory of the development of diverticulosis. Other editorials, though, caught the study's critical flaw. To understand this, let's turn to another dietary deficiency disease: scurvy.

Medical experiments on prisoners at Iowa State Penitentiary showed that clinical signs of scurvy start appearing after just 29 days without vitamin C. Experiments on pacifists during World War II showed that it takes about 10 mg of vitamin C a day to prevent scurvy. Imagine going back a few centuries when they were still trying to figure scurvy out. Dr. James Linde had this radical theory that citrus fruits could cure scurvy. What if an experiment was designed to test this crazy theory, in which sailors were given the juice of either one wedge of lemon or three wedges of lemon each day? If a month later on the high seas there was no difference in scurvy rates, one might see headlines from printing presses touting that a low-vitamin C diet is not associated with scurvy.

Well, a wedge of lemon only yields about 2 mg of vitamin C, and it takes 10 mg to prevent scurvy. They would have been comparing one vitamin C-deficient dose to another vitamin C-deficient dose. No wonder there would be no difference in scurvy rates. We evolved eating so many plants that we likely averaged around 600 mg of vitamin C a day. That's what our bodies are biologically used to getting.

What about fiber? How much fiber are we used to getting? More than 100 grams a day! The highest fiber intake group in the North Carolina study was only eating 25 grams, which is less than the minimum recommended daily allowance of about 32 grams. The subjects didn't even make the minimum! The study compared one fiber-deficient diet to another fiber-deficient diet--no wonder there was no difference in diverticulosis rates.

The African populations with essentially no diverticulosis ate diets consisting in part of very large platefuls of leafy vegetables--similar, perhaps, to what we were eating a few million years ago. They were eating plant-based diets containing 70 to 90 grams of fiber a day. Most vegetarians don't even eat that many whole plant foods, although some do. At least vegetarians tend to hit the minimum mark, and they have less diverticulosis to show for it. A study of 47,000 people confirmed that "[c]onsuming a vegetarian diet and a high intake of dietary fiber were both associated with a lower risk of admission to hospital or death from diverticular disease." They had enough people to tease it out. As you'll see in my video Does Fiber Really Prevent Diverticulosis?, compared to people eating a single serving of meat a day or more, those who ate less than half a serving appeared to have a 16% lower risk and pescatarians (eating no meat except fish) had a risk down around 23%. Both of these results weren't in and of themselves statistically significant, but eating vegetarian was. Vegetarians had 35% lower risk, and those eating strictly plant-based appeared to be at 78% lower risk.

As with all lifestyle interventions, it only works if you do it. High-fiber diets only work if they're actually high in fiber.

There's more great information in my video Diverticulosis: When Our Most Common Gut Disorder Hardly Existed.

This reminds me of an ancient video I did: Flawed Study Interpretation.

People commonly ask Do Vegetarians Get Enough Protein?, but maybe they should be more concerned where everyone else is getting their fiber. Ninety-seven percent of Americans don't even reach the recommended daily minimum.

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:

Image Credit: Yoshihide Nomura / Flickr. This image has been modified.

Original Link

How to Design a Misleading Study to Show Diet Doesn’t Work

How to Design a Misleading Study to Show Diet Doesn't Work.jpeg

A study out of the University of North Carolina found no association between dietary fiber intake and diverticulosis. They compared those who ate the highest amount of fiber, 25 grams, to those who ate the smallest amount, which was three times lower at only 8 grams. Finding no difference in disease rates, researchers concluded that a low-fiber diet was not associated with diverticulosis.

The university sent out a press release entitled: "Diets high in fiber won't protect against diverticulosis." The media picked it up and ran headlines such as "High-fiber diet may not protect against diverticulosis, study finds." It went all over the paleo blogs and even medical journals, publishing such statements as an "important and provocative paper...calls into question" the fiber theory of the development of diverticulosis. Other editorials, though, caught the study's critical flaw. To understand this, let's turn to another dietary deficiency disease: scurvy.

Medical experiments on prisoners at Iowa State Penitentiary showed that clinical signs of scurvy start appearing after just 29 days without vitamin C. Experiments on pacifists during World War II showed that it takes about 10 mg of vitamin C a day to prevent scurvy. Imagine going back a few centuries when they were still trying to figure scurvy out. Dr. James Linde had this radical theory that citrus fruits could cure scurvy. What if an experiment was designed to test this crazy theory, in which sailors were given the juice of either one wedge of lemon or three wedges of lemon each day? If a month later on the high seas there was no difference in scurvy rates, one might see headlines from printing presses touting that a low-vitamin C diet is not associated with scurvy.

Well, a wedge of lemon only yields about 2 mg of vitamin C, and it takes 10 mg to prevent scurvy. They would have been comparing one vitamin C-deficient dose to another vitamin C-deficient dose. No wonder there would be no difference in scurvy rates. We evolved eating so many plants that we likely averaged around 600 mg of vitamin C a day. That's what our bodies are biologically used to getting.

What about fiber? How much fiber are we used to getting? More than 100 grams a day! The highest fiber intake group in the North Carolina study was only eating 25 grams, which is less than the minimum recommended daily allowance of about 32 grams. The subjects didn't even make the minimum! The study compared one fiber-deficient diet to another fiber-deficient diet--no wonder there was no difference in diverticulosis rates.

The African populations with essentially no diverticulosis ate diets consisting in part of very large platefuls of leafy vegetables--similar, perhaps, to what we were eating a few million years ago. They were eating plant-based diets containing 70 to 90 grams of fiber a day. Most vegetarians don't even eat that many whole plant foods, although some do. At least vegetarians tend to hit the minimum mark, and they have less diverticulosis to show for it. A study of 47,000 people confirmed that "[c]onsuming a vegetarian diet and a high intake of dietary fiber were both associated with a lower risk of admission to hospital or death from diverticular disease." They had enough people to tease it out. As you'll see in my video Does Fiber Really Prevent Diverticulosis?, compared to people eating a single serving of meat a day or more, those who ate less than half a serving appeared to have a 16% lower risk and pescatarians (eating no meat except fish) had a risk down around 23%. Both of these results weren't in and of themselves statistically significant, but eating vegetarian was. Vegetarians had 35% lower risk, and those eating strictly plant-based appeared to be at 78% lower risk.

As with all lifestyle interventions, it only works if you do it. High-fiber diets only work if they're actually high in fiber.

There's more great information in my video Diverticulosis: When Our Most Common Gut Disorder Hardly Existed.

This reminds me of an ancient video I did: Flawed Study Interpretation.

People commonly ask Do Vegetarians Get Enough Protein?, but maybe they should be more concerned where everyone else is getting their fiber. Ninety-seven percent of Americans don't even reach the recommended daily minimum.

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:

Image Credit: Yoshihide Nomura / Flickr. This image has been modified.

Original Link

How to Design a Misleading Study to Show Diet Doesn’t Work

How to Design a Misleading Study to Show Diet Doesn't Work.jpeg

A study out of the University of North Carolina found no association between dietary fiber intake and diverticulosis. They compared those who ate the highest amount of fiber, 25 grams, to those who ate the smallest amount, which was three times lower at only 8 grams. Finding no difference in disease rates, researchers concluded that a low-fiber diet was not associated with diverticulosis.

The university sent out a press release entitled: "Diets high in fiber won't protect against diverticulosis." The media picked it up and ran headlines such as "High-fiber diet may not protect against diverticulosis, study finds." It went all over the paleo blogs and even medical journals, publishing such statements as an "important and provocative paper...calls into question" the fiber theory of the development of diverticulosis. Other editorials, though, caught the study's critical flaw. To understand this, let's turn to another dietary deficiency disease: scurvy.

Medical experiments on prisoners at Iowa State Penitentiary showed that clinical signs of scurvy start appearing after just 29 days without vitamin C. Experiments on pacifists during World War II showed that it takes about 10 mg of vitamin C a day to prevent scurvy. Imagine going back a few centuries when they were still trying to figure scurvy out. Dr. James Linde had this radical theory that citrus fruits could cure scurvy. What if an experiment was designed to test this crazy theory, in which sailors were given the juice of either one wedge of lemon or three wedges of lemon each day? If a month later on the high seas there was no difference in scurvy rates, one might see headlines from printing presses touting that a low-vitamin C diet is not associated with scurvy.

Well, a wedge of lemon only yields about 2 mg of vitamin C, and it takes 10 mg to prevent scurvy. They would have been comparing one vitamin C-deficient dose to another vitamin C-deficient dose. No wonder there would be no difference in scurvy rates. We evolved eating so many plants that we likely averaged around 600 mg of vitamin C a day. That's what our bodies are biologically used to getting.

What about fiber? How much fiber are we used to getting? More than 100 grams a day! The highest fiber intake group in the North Carolina study was only eating 25 grams, which is less than the minimum recommended daily allowance of about 32 grams. The subjects didn't even make the minimum! The study compared one fiber-deficient diet to another fiber-deficient diet--no wonder there was no difference in diverticulosis rates.

The African populations with essentially no diverticulosis ate diets consisting in part of very large platefuls of leafy vegetables--similar, perhaps, to what we were eating a few million years ago. They were eating plant-based diets containing 70 to 90 grams of fiber a day. Most vegetarians don't even eat that many whole plant foods, although some do. At least vegetarians tend to hit the minimum mark, and they have less diverticulosis to show for it. A study of 47,000 people confirmed that "[c]onsuming a vegetarian diet and a high intake of dietary fiber were both associated with a lower risk of admission to hospital or death from diverticular disease." They had enough people to tease it out. As you'll see in my video Does Fiber Really Prevent Diverticulosis?, compared to people eating a single serving of meat a day or more, those who ate less than half a serving appeared to have a 16% lower risk and pescatarians (eating no meat except fish) had a risk down around 23%. Both of these results weren't in and of themselves statistically significant, but eating vegetarian was. Vegetarians had 35% lower risk, and those eating strictly plant-based appeared to be at 78% lower risk.

As with all lifestyle interventions, it only works if you do it. High-fiber diets only work if they're actually high in fiber.

There's more great information in my video Diverticulosis: When Our Most Common Gut Disorder Hardly Existed.

This reminds me of an ancient video I did: Flawed Study Interpretation.

People commonly ask Do Vegetarians Get Enough Protein?, but maybe they should be more concerned where everyone else is getting their fiber. Ninety-seven percent of Americans don't even reach the recommended daily minimum.

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:

Image Credit: Yoshihide Nomura / Flickr. This image has been modified.

Original Link

9 out of 10 That Die From it Never Knew They Even Had This Preventable Disease

9 out of 10 That Die From it Never Knew They Even Had This Preventable Disease.jpeg

Diverticula are out-pouchings of our intestine. Doctors like using a tire analogy: high pressures within the gut can force the intestines to balloon out through weak spots in the intestinal wall like an inner tube poking out through a worn tire tread. You can see what they actually look like in my video, Diverticulosis: When Our Most Common Gut Disorder Hardly Existed. These pockets can become inflamed and infected, and, to carry the tire analogy further, can blow out and spill fecal matter into the abdomen, and lead to death. Symptoms can range from no symptoms at all, to a little cramping and bloating, to "incapacitating pain that is a medical emergency." Nine out of ten people who die from the disease never even knew they had it.

The good news is there may be a way to prevent the disease. Diverticular disease is the most common intestinal disorder, affecting up to 70% of people by age 60. If it's that common, though, is it just an inevitable consequence of aging? No, it's a new disease. In 1907, 25 cases had been reported in the medical literature. Not cases in 25% of people, but 25 cases period. And diverticular disease is kind of hard to miss on autopsy. A hundred years ago, in 1916, it didn't even merit mention in medical and surgical textbooks. The mystery wasn't solved until 1971.

How did a disease that was almost unknown become the most common affliction of the colon in the Western world within one lifespan? Surgeons Painter and Burkitt suggested diverticulosis was a deficiency disease--i.e., a disease caused by a deficiency of fiber. In the late 1800s, roller milling was introduced, further removing fiber from grain, and we started to fill up on other fiber-deficient foods like meat and sugar. A few decades of this and diverticulosis was rampant.

This is what Painter and Burkitt thought was going on: Just as it would be easy to squeeze a lump of butter through a bicycle tube, it's easy to move large, soft, and moist intestinal contents through the gut. In contrast, try squeezing through a lump of tar. When we eat fiber-deficient diets, our feces can become small and firm, and our intestines have to really squeeze down hard to move them along. This buildup of pressure may force out those bulges. Eventually, a low-fiber diet can sometimes lead to the colon literally rupturing itself.

If this theory is true, then populations eating high­-fiber diets would have low rates of diverticulosis. That's exactly what's been found. More than 50% of African Americans in their 50s were found to have diverticulosis, compared to less than 1% in African Africans eating traditional plant-based diets. By less than 1%, we're talking zero out of a series of 2,000 autopsies in South Africa and two out of 4,000 in Uganda. That's about one thousand times lower prevalence.

What, then, do we make of a new study concluding that a low-fiber diet was not associated with diverticulosis. I cover that in my video Does Fiber Really Prevent Diverticulosis?

For more on bowel health, see:

What if your doctor says you shouldn't eat healthy foods like nuts and popcorn because of your diverticulosis? Share with them my Diverticulosis & Nuts video.

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:

Image Credit: Sean T Evans / Flickr. This image has been modified.

Original Link

9 out of 10 That Die From it Never Knew They Even Had This Preventable Disease

9 out of 10 That Die From it Never Knew They Even Had This Preventable Disease.jpeg

Diverticula are out-pouchings of our intestine. Doctors like using a tire analogy: high pressures within the gut can force the intestines to balloon out through weak spots in the intestinal wall like an inner tube poking out through a worn tire tread. You can see what they actually look like in my video, Diverticulosis: When Our Most Common Gut Disorder Hardly Existed. These pockets can become inflamed and infected, and, to carry the tire analogy further, can blow out and spill fecal matter into the abdomen, and lead to death. Symptoms can range from no symptoms at all, to a little cramping and bloating, to "incapacitating pain that is a medical emergency." Nine out of ten people who die from the disease never even knew they had it.

The good news is there may be a way to prevent the disease. Diverticular disease is the most common intestinal disorder, affecting up to 70% of people by age 60. If it's that common, though, is it just an inevitable consequence of aging? No, it's a new disease. In 1907, 25 cases had been reported in the medical literature. Not cases in 25% of people, but 25 cases period. And diverticular disease is kind of hard to miss on autopsy. A hundred years ago, in 1916, it didn't even merit mention in medical and surgical textbooks. The mystery wasn't solved until 1971.

How did a disease that was almost unknown become the most common affliction of the colon in the Western world within one lifespan? Surgeons Painter and Burkitt suggested diverticulosis was a deficiency disease--i.e., a disease caused by a deficiency of fiber. In the late 1800s, roller milling was introduced, further removing fiber from grain, and we started to fill up on other fiber-deficient foods like meat and sugar. A few decades of this and diverticulosis was rampant.

This is what Painter and Burkitt thought was going on: Just as it would be easy to squeeze a lump of butter through a bicycle tube, it's easy to move large, soft, and moist intestinal contents through the gut. In contrast, try squeezing through a lump of tar. When we eat fiber-deficient diets, our feces can become small and firm, and our intestines have to really squeeze down hard to move them along. This buildup of pressure may force out those bulges. Eventually, a low-fiber diet can sometimes lead to the colon literally rupturing itself.

If this theory is true, then populations eating high­-fiber diets would have low rates of diverticulosis. That's exactly what's been found. More than 50% of African Americans in their 50s were found to have diverticulosis, compared to less than 1% in African Africans eating traditional plant-based diets. By less than 1%, we're talking zero out of a series of 2,000 autopsies in South Africa and two out of 4,000 in Uganda. That's about one thousand times lower prevalence.

What, then, do we make of a new study concluding that a low-fiber diet was not associated with diverticulosis. I cover that in my video Does Fiber Really Prevent Diverticulosis?

For more on bowel health, see:

What if your doctor says you shouldn't eat healthy foods like nuts and popcorn because of your diverticulosis? Share with them my Diverticulosis & Nuts video.

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:

Image Credit: Sean T Evans / Flickr. This image has been modified.

Original Link

Optimal Bowel Movement Position

Optimal Bowel Movement Position.jpeg

Compared to rural African populations eating traditional plant-based diets, white South Africans and black and white Americans have more than 50 times more heart disease, 10 times more colon cancer, more than 50 times more gallstones and appendicitis, and more than 25 times the rates of "pressure diseases"--diverticulitis, hemorrhoids, varicose veins, and hiatal hernia.

As I discussed in my Should You Sit, Squat, or Lean During a Bowel Movement?, bowel movements should be effortless. When we have to strain at stool, the pressure may balloon out-pouchings from our colon, causing diverticulosis; inflate hemorrhoids around the anus; cause the valves in the veins of our legs to fail, causing varicose veins; and even force part of the stomach up through the diaphragm into our chest cavity, causing a hiatal hernia (as I covered previously). When this was first proposed by Dr. Denis Burkitt, he blamed these conditions on the straining caused by a lack of fiber in the diet. He did, however, acknowledge there were alternative explanations. For example, in rural Africa, they used a traditional squatting position when they defecated, which may have taken off some of the pressure.

For hundreds of thousands of years, everyone used the squatting position, which may help by straightening the "anorectal angle." There's actually a kink at almost a 90-degree angle right at the end of the rectum that helps keep us from pooping our pants when we're just out walking around. That angle only slightly straightens out in a common sitting posture on the toilet. Maximal straightening out of this angle occurs in a squatting posture, potentially permitting smoother defecation. (I remember sitting in geometry class wondering when I'd ever use the stuff I was learning. Little did I know I would one day be calculating anorectal angles with it! Stay in school, kids :)

How did they figure this out? Researchers filled latex tubes with a radiopaque fluid, stuck them up some volunteers, and took X-rays with the hips flexed at various angles. They concluded that flexing the knees towards the chest like one does when squatting may straighten that angle and reduce the amount of pressure needed to empty the rectum. This idea wasn't directly put to the test until 2002, when researchers used defecography (which are X-rays taken while the person is defecating) on subjects in sitting and squatting positions. Indeed, squatting increased the anorectal angle from around 90 degrees all the way up to about 140.

So should we all get one of those little stools for our stools, like the Squatty Potty that you put in front of your toilet to step on? No, they don't seem to work. Researchers tried adding a footstool to decrease sitting height, but it didn't seem to significantly affect the time it took to empty one's bowels or decrease the difficulty of defecating. They tried even higher footstools, but people complained of extreme discomfort using them. Nothing seemed to compare with actual squatting, which may give the maximum advantage. However, in developed nations, it may not be convenient. But, we can achieve a similar effect by leaning forward as we sit, with our hands on or near the floor. The researchers advise all sufferers from constipation to adopt this forward-leaning position when defecating, as the weight of our torso pressing against the thighs may put an extra squeeze on our colons.

Instead of finding ways to add more pressure, why not get to the root of the problem? "The fundamental cause of straining is the effort required to pass unnaturally firm stools." By manipulating the anorectal angle through squatting or leaning, we can more easily pass unnaturally firm stools. But why not just treat the cause and eat enough fiber-containing whole plant foods to create stools so large and soft that you could pass them effortlessly at any angle?

Famed cardiologist Dr. Joel Kahn once said that you know you know you're eating a plant-based diet when "you take longer to pee than to poop."

In all seriousness, even squatting does not significantly decrease the pressure gradient that may cause a hiatal hernia. It does not prevent the pressure transmission down into the legs that may cause varicose veins. And this is not just a cosmetic issue. Protracted straining can cause heart rhythm disturbances and reduction in blood flow to the heart and brain, resulting in defecation-related fainting and death. Just 15 seconds of straining can temporarily cut blood flow to the brain by 21% and blood flow to the heart by nearly one-half, thereby providing a mechanism for the well-known "bed pan death" syndrome. If you think you have to strain a lot while sitting, try having a bowel movement on your back. Bearing down for just a few seconds can send our blood pressure up to nearly 170 over 110, which may help account for the notorious frequency of sudden and unexpected deaths of patients while using bed pans in hospitals. Hopefully, if we eat healthy enough, we won't end up in the hospital to begin with.

Wondering How Many Bowel Movements Should You Have Every Day? Watch the video to find out!

The "forcing part of your stomach up through the diaphragm into our chest cavity" phenomenon is covered in my video Diet and Hiatal Hernia. The "ballooning of out-pouchings from our colon" is called diverticulosis. There's a video I did about 6 years ago (Diverticulosis & Nuts), but I have some new and improved ones available: Diverticulosis: When Our Most Common Gut Disorder Hardly Existed and Does Fiber Really Prevent Diverticulosis?

More on that extraordinary African data here:

So excited to be able to slip in a plug for Dr. Kahn's work. His brand of "interpreventional cardiology" can be found at www.drjoelkahn.com.

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:

Image Credit: Sally Plank. This image has been modified.

Original Link

Optimal Bowel Movement Position

Optimal Bowel Movement Position.jpeg

Compared to rural African populations eating traditional plant-based diets, white South Africans and black and white Americans have more than 50 times more heart disease, 10 times more colon cancer, more than 50 times more gallstones and appendicitis, and more than 25 times the rates of "pressure diseases"--diverticulitis, hemorrhoids, varicose veins, and hiatal hernia.

As I discussed in my Should You Sit, Squat, or Lean During a Bowel Movement?, bowel movements should be effortless. When we have to strain at stool, the pressure may balloon out-pouchings from our colon, causing diverticulosis; inflate hemorrhoids around the anus; cause the valves in the veins of our legs to fail, causing varicose veins; and even force part of the stomach up through the diaphragm into our chest cavity, causing a hiatal hernia (as I covered previously). When this was first proposed by Dr. Denis Burkitt, he blamed these conditions on the straining caused by a lack of fiber in the diet. He did, however, acknowledge there were alternative explanations. For example, in rural Africa, they used a traditional squatting position when they defecated, which may have taken off some of the pressure.

For hundreds of thousands of years, everyone used the squatting position, which may help by straightening the "anorectal angle." There's actually a kink at almost a 90-degree angle right at the end of the rectum that helps keep us from pooping our pants when we're just out walking around. That angle only slightly straightens out in a common sitting posture on the toilet. Maximal straightening out of this angle occurs in a squatting posture, potentially permitting smoother defecation. (I remember sitting in geometry class wondering when I'd ever use the stuff I was learning. Little did I know I would one day be calculating anorectal angles with it! Stay in school, kids :)

How did they figure this out? Researchers filled latex tubes with a radiopaque fluid, stuck them up some volunteers, and took X-rays with the hips flexed at various angles. They concluded that flexing the knees towards the chest like one does when squatting may straighten that angle and reduce the amount of pressure needed to empty the rectum. This idea wasn't directly put to the test until 2002, when researchers used defecography (which are X-rays taken while the person is defecating) on subjects in sitting and squatting positions. Indeed, squatting increased the anorectal angle from around 90 degrees all the way up to about 140.

So should we all get one of those little stools for our stools, like the Squatty Potty that you put in front of your toilet to step on? No, they don't seem to work. Researchers tried adding a footstool to decrease sitting height, but it didn't seem to significantly affect the time it took to empty one's bowels or decrease the difficulty of defecating. They tried even higher footstools, but people complained of extreme discomfort using them. Nothing seemed to compare with actual squatting, which may give the maximum advantage. However, in developed nations, it may not be convenient. But, we can achieve a similar effect by leaning forward as we sit, with our hands on or near the floor. The researchers advise all sufferers from constipation to adopt this forward-leaning position when defecating, as the weight of our torso pressing against the thighs may put an extra squeeze on our colons.

Instead of finding ways to add more pressure, why not get to the root of the problem? "The fundamental cause of straining is the effort required to pass unnaturally firm stools." By manipulating the anorectal angle through squatting or leaning, we can more easily pass unnaturally firm stools. But why not just treat the cause and eat enough fiber-containing whole plant foods to create stools so large and soft that you could pass them effortlessly at any angle?

Famed cardiologist Dr. Joel Kahn once said that you know you know you're eating a plant-based diet when "you take longer to pee than to poop."

In all seriousness, even squatting does not significantly decrease the pressure gradient that may cause a hiatal hernia. It does not prevent the pressure transmission down into the legs that may cause varicose veins. And this is not just a cosmetic issue. Protracted straining can cause heart rhythm disturbances and reduction in blood flow to the heart and brain, resulting in defecation-related fainting and death. Just 15 seconds of straining can temporarily cut blood flow to the brain by 21% and blood flow to the heart by nearly one-half, thereby providing a mechanism for the well-known "bed pan death" syndrome. If you think you have to strain a lot while sitting, try having a bowel movement on your back. Bearing down for just a few seconds can send our blood pressure up to nearly 170 over 110, which may help account for the notorious frequency of sudden and unexpected deaths of patients while using bed pans in hospitals. Hopefully, if we eat healthy enough, we won't end up in the hospital to begin with.

Wondering How Many Bowel Movements Should You Have Every Day? Watch the video to find out!

The "forcing part of your stomach up through the diaphragm into our chest cavity" phenomenon is covered in my video Diet and Hiatal Hernia. The "ballooning of out-pouchings from our colon" is called diverticulosis. There's a video I did about 6 years ago (Diverticulosis & Nuts), but I have some new and improved ones available: Diverticulosis: When Our Most Common Gut Disorder Hardly Existed and Does Fiber Really Prevent Diverticulosis?

More on that extraordinary African data here:

So excited to be able to slip in a plug for Dr. Kahn's work. His brand of "interpreventional cardiology" can be found at www.drjoelkahn.com.

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:

Image Credit: Sally Plank. This image has been modified.

Original Link

Diet and Hiatal Hernia

Diet and Hiatal Hernia.jpeg

In terms of preventing acid reflux heartburn, high-fat meals cause dramatically more acid exposure in the esophagus in the hours after a meal. I talked about this in Diet and GERD Acid Reflux Heartburn. High fiber intake decreases the risk, but why? One typically thinks of fiber as helping out much lower in the digestive tract.

A systematic review and meta-analysis published in 2013 found a highly significant protective association between esophageal adenocarcinoma and dietary fiber intake, suggesting that individuals with the highest fiber intakes have an approximately 30% lower risk of cancer. This could be because of the phytates in high-fiber foods slowing cancer growth, fiber's anti-inflammatory effects, or even fiber removing carcinogens. But those are all generic anti-cancer effects of whole plant foods. Specific to this type of acid irritation-induced esophageal cancer, fiber may reduce the risk of reflux in the first place. But how?

As you can see in my video, Diet and Hiatal Hernia, hiatus hernia occurs when part of the stomach is pushed up through the diaphragm into the chest cavity, which makes it easy for acid to reflux into the esophagus and throat. Hiatus hernia affects more than 1 in 5 American adults. In contrast, in rural African communities eating their traditional plant-based diets, the risk wasn't 1 in 5; it was closer to 1 in 1,000--almost unheard of. Hiatus hernia is almost peculiar to those who consume western-type diets. Why are plant-based populations protected? Perhaps because they pass such large, soft stools, three or four times the volume as Westerners.

What does the size and consistency of one's bowel movement have to do with hiatal hernia? A simple model may be helpful in illustrating the mechanism that produces upward herniation of the stomach through the hole (called the esophageal hiatus) in the diaphragm, which separates the abdomen from the chest. If a ball with a hole in its wall is filled with water and then squeezed, the water is pushed out through the hole. If we liken the abdominal cavity to the ball, the esophageal hiatus in the diaphragm corresponds with the hole in the ball. Abdominal straining during movement of firm feces corresponds to squeezing the ball and may result in the gradual expulsion of the upper end of the stomach from the abdominal cavity up into the chest. It's like when we squeeze a stress ball. Straining at stool raises pressures inside our abdominal cavity more than almost any other factor.

In effect, straining at stool puts the squeeze on our abdomen and may herniate part of our stomach up. "Consistent with this concept is the observation that in Africans the lower esophageal sphincter is entirely subdiaphragmatic, whereas it usually straddles the diaphragm in Westerners and is above the diaphragm in the presence of hiatus hernia."

This same abdominal pressure from straining may cause a number of other problems, too. Straining can cause herniations in the wall of the colon itself, known as diverticulosis. That same pressure can backup blood flow in the veins around the anus, causing hemorrhoids, and also push blood flow back into the legs, resulting in varicose veins.

Hiatal hernia is not the only condition that high-fiber diets may protect against. See:

I also have a load of other bowel movement videos:

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:

Image Credit: Sally Plank. This image has been modified.

Original Link

Diet and Hiatal Hernia

Diet and Hiatal Hernia.jpeg

In terms of preventing acid reflux heartburn, high-fat meals cause dramatically more acid exposure in the esophagus in the hours after a meal. I talked about this in Diet and GERD Acid Reflux Heartburn. High fiber intake decreases the risk, but why? One typically thinks of fiber as helping out much lower in the digestive tract.

A systematic review and meta-analysis published in 2013 found a highly significant protective association between esophageal adenocarcinoma and dietary fiber intake, suggesting that individuals with the highest fiber intakes have an approximately 30% lower risk of cancer. This could be because of the phytates in high-fiber foods slowing cancer growth, fiber's anti-inflammatory effects, or even fiber removing carcinogens. But those are all generic anti-cancer effects of whole plant foods. Specific to this type of acid irritation-induced esophageal cancer, fiber may reduce the risk of reflux in the first place. But how?

As you can see in my video, Diet and Hiatal Hernia, hiatus hernia occurs when part of the stomach is pushed up through the diaphragm into the chest cavity, which makes it easy for acid to reflux into the esophagus and throat. Hiatus hernia affects more than 1 in 5 American adults. In contrast, in rural African communities eating their traditional plant-based diets, the risk wasn't 1 in 5; it was closer to 1 in 1,000--almost unheard of. Hiatus hernia is almost peculiar to those who consume western-type diets. Why are plant-based populations protected? Perhaps because they pass such large, soft stools, three or four times the volume as Westerners.

What does the size and consistency of one's bowel movement have to do with hiatal hernia? A simple model may be helpful in illustrating the mechanism that produces upward herniation of the stomach through the hole (called the esophageal hiatus) in the diaphragm, which separates the abdomen from the chest. If a ball with a hole in its wall is filled with water and then squeezed, the water is pushed out through the hole. If we liken the abdominal cavity to the ball, the esophageal hiatus in the diaphragm corresponds with the hole in the ball. Abdominal straining during movement of firm feces corresponds to squeezing the ball and may result in the gradual expulsion of the upper end of the stomach from the abdominal cavity up into the chest. It's like when we squeeze a stress ball. Straining at stool raises pressures inside our abdominal cavity more than almost any other factor.

In effect, straining at stool puts the squeeze on our abdomen and may herniate part of our stomach up. "Consistent with this concept is the observation that in Africans the lower esophageal sphincter is entirely subdiaphragmatic, whereas it usually straddles the diaphragm in Westerners and is above the diaphragm in the presence of hiatus hernia."

This same abdominal pressure from straining may cause a number of other problems, too. Straining can cause herniations in the wall of the colon itself, known as diverticulosis. That same pressure can backup blood flow in the veins around the anus, causing hemorrhoids, and also push blood flow back into the legs, resulting in varicose veins.

Hiatal hernia is not the only condition that high-fiber diets may protect against. See:

I also have a load of other bowel movement videos:

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:

Image Credit: Sally Plank. This image has been modified.

Original Link