Optimal Bowel Movement Frequency

Optimal Bowel Movement Frequency.jpeg

Lasting for 3,000 years, ancient Egypt was one of the greatest ancient civilizations--with a vastly underestimated knowledge of medicine. They even had medical subspecialties. The pharaohs, for example, had access to dedicated physicians to be "guardian[s] of the royal bowel movement," a title alternately translated from the hieroglyphics to mean "Shepherd of the Anus." How's that for a resume builder?

Today, the primacy of the bowel movement's importance continues. Some have called for bowel habits to be considered a vital sign on how the body is functioning, along with heart rate, blood pressure, and breathing rate. Medical professionals may not particularly relish hearing all about their patients' bowel movements, but it is a vital function that nurses and doctors need to assess.

Surprisingly, the colon has remained relatively unexplored territory, one of the body's final frontiers. For example, current concepts of what "normal" stools are emanated primarily from the records of 12 consecutive bowel movements in 27 healthy subjects from the United Kingdom, who boldly went where no one had gone before. Those must have been some really detailed records.

It's important to define what's normal. When it comes to frequency, for example, we can't define concepts like constipation or diarrhea unless we know what's normal. Standard physiology textbooks may not be helpful in this regard. One text implies that anything from one bowel movement every few weeks or months to 24 in just one day can be regarded as normal. Once every few months is normal?

Out of all of our bodily functions, we may know the least about defecation. Can't we just ask people? It turns out people tend to exaggerate. There's a discrepancy between what people report and what researchers find when they record bowel habits directly. It wasn't until 2010 when we got the first serious look. In my video, How Many Bowel Movement's Should You Have Everyday? you'll see the study that found that normal stool frequency was between three per week and three per day, based on the fact that that's where 98% of people tended to fall. But normal doesn't necessarily mean optimal.

Having a "normal" salt intake can lead to a "normal" blood pressure, which can help us to die from all the "normal" causes like heart attacks and strokes. Having a normal cholesterol level in a society where it's normal to drop dead of heart disease--our number-one killer--is not necessarily a good thing. Indeed, significant proportions of people with "normal bowel function" reported urgency, straining, and incomplete defecation, leading the researchers of the 2010 study to conclude that these kinds of things must be normal. Normal, maybe, if we're eating a fiber-deficient diet, but not normal for our species. Defecation should not be a painful exercise. This is readily demonstrable. For example, the majority of rural Africans eating their traditional fiber-rich, plant-based diets can usually pass without straining a stool specimen on demand. The rectum may need to accumulate 4 or 5 ounces of fecal matter before the defecation reflex is fully initiated, so if we don't even build up that much over the day, we'd have to strain to prime the rectal pump.

Hippocrates thought bowel movements should ideally be two or three times a day, which is what we see in populations on traditional plant-based diets. These traditional diets have the kind of fiber intakes we see in our fellow Great Apes and may be more representative of the type of diets we evolved eating for millions of years. It seems somewhat optimistic, though, to expect the average American to adopt a rural African diet. We can, however, eat more plant-based and bulk up enough to take the Hippocratic oath to go two or three times a day.

There's no need to obsess about it. In fact, there's actually a "bowel obsession syndrome" characterized in part by "ideational rambling over bowel habits." But three times a day makes sense. We have what's called a gastrocolic reflex, which consists of a prompt activation of muscular waves in our colon within 1 to 3 minutes of the ingestion of the first mouthfuls of food to make room for the meal. Even just talking about food can cause our brains to increase colon activity. This suggests the body figured that one meal should be about enough to fill us up down there. So maybe we should eat enough unprocessed plant foods to get up to three a day--a movement for every meal.

I know people are suckers for poop videos--I'm so excited to finally be getting these up! There actually is a recent one--Diet and Hiatal Hernia--that talks about the consequences of straining on stool. Hernias are better than Bed Pan Death Syndrome, though, which is what I talk about in in my video, Should You Sit, Squat, or Lean During a Bowel Movement?

Here are some older videos on bowel health:

For more on this concept of how having "normal" health parameters in a society where it's normal to drop dead of heart attacks and other such preventable fates, see my video When Low Risk Means High Risk.

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 Frequency

Optimal Bowel Movement Frequency.jpeg

Lasting for 3,000 years, ancient Egypt was one of the greatest ancient civilizations--with a vastly underestimated knowledge of medicine. They even had medical subspecialties. The pharaohs, for example, had access to dedicated physicians to be "guardian[s] of the royal bowel movement," a title alternately translated from the hieroglyphics to mean "Shepherd of the Anus." How's that for a resume builder?

Today, the primacy of the bowel movement's importance continues. Some have called for bowel habits to be considered a vital sign on how the body is functioning, along with heart rate, blood pressure, and breathing rate. Medical professionals may not particularly relish hearing all about their patients' bowel movements, but it is a vital function that nurses and doctors need to assess.

Surprisingly, the colon has remained relatively unexplored territory, one of the body's final frontiers. For example, current concepts of what "normal" stools are emanated primarily from the records of 12 consecutive bowel movements in 27 healthy subjects from the United Kingdom, who boldly went where no one had gone before. Those must have been some really detailed records.

It's important to define what's normal. When it comes to frequency, for example, we can't define concepts like constipation or diarrhea unless we know what's normal. Standard physiology textbooks may not be helpful in this regard. One text implies that anything from one bowel movement every few weeks or months to 24 in just one day can be regarded as normal. Once every few months is normal?

Out of all of our bodily functions, we may know the least about defecation. Can't we just ask people? It turns out people tend to exaggerate. There's a discrepancy between what people report and what researchers find when they record bowel habits directly. It wasn't until 2010 when we got the first serious look. In my video, How Many Bowel Movement's Should You Have Everyday? you'll see the study that found that normal stool frequency was between three per week and three per day, based on the fact that that's where 98% of people tended to fall. But normal doesn't necessarily mean optimal.

Having a "normal" salt intake can lead to a "normal" blood pressure, which can help us to die from all the "normal" causes like heart attacks and strokes. Having a normal cholesterol level in a society where it's normal to drop dead of heart disease--our number-one killer--is not necessarily a good thing. Indeed, significant proportions of people with "normal bowel function" reported urgency, straining, and incomplete defecation, leading the researchers of the 2010 study to conclude that these kinds of things must be normal. Normal, maybe, if we're eating a fiber-deficient diet, but not normal for our species. Defecation should not be a painful exercise. This is readily demonstrable. For example, the majority of rural Africans eating their traditional fiber-rich, plant-based diets can usually pass without straining a stool specimen on demand. The rectum may need to accumulate 4 or 5 ounces of fecal matter before the defecation reflex is fully initiated, so if we don't even build up that much over the day, we'd have to strain to prime the rectal pump.

Hippocrates thought bowel movements should ideally be two or three times a day, which is what we see in populations on traditional plant-based diets. These traditional diets have the kind of fiber intakes we see in our fellow Great Apes and may be more representative of the type of diets we evolved eating for millions of years. It seems somewhat optimistic, though, to expect the average American to adopt a rural African diet. We can, however, eat more plant-based and bulk up enough to take the Hippocratic oath to go two or three times a day.

There's no need to obsess about it. In fact, there's actually a "bowel obsession syndrome" characterized in part by "ideational rambling over bowel habits." But three times a day makes sense. We have what's called a gastrocolic reflex, which consists of a prompt activation of muscular waves in our colon within 1 to 3 minutes of the ingestion of the first mouthfuls of food to make room for the meal. Even just talking about food can cause our brains to increase colon activity. This suggests the body figured that one meal should be about enough to fill us up down there. So maybe we should eat enough unprocessed plant foods to get up to three a day--a movement for every meal.

I know people are suckers for poop videos--I'm so excited to finally be getting these up! There actually is a recent one--Diet and Hiatal Hernia--that talks about the consequences of straining on stool. Hernias are better than Bed Pan Death Syndrome, though, which is what I talk about in in my video, Should You Sit, Squat, or Lean During a Bowel Movement?

Here are some older videos on bowel health:

For more on this concept of how having "normal" health parameters in a society where it's normal to drop dead of heart attacks and other such preventable fates, see my video When Low Risk Means High Risk.

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

The Natural Human Diet

NF-Nov15 The Problem with the Paleo Diet Argument copy.jpg

Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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: Nathan Rupert / Flickr

Original Link

The Natural Human Diet

NF-Nov15 The Problem with the Paleo Diet Argument copy.jpg

Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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: Nathan Rupert / Flickr

Original Link

Why Certain Plant Compounds May Mimic Dietary Restriction

NF-Sep3 Xenohormesis- What doesn't kill plants may make us stronger.jpg

A new concept, called xenohormesis, has arisen to explain the mystery of why so many plant molecules interact with and modulate key regulators of our physiology in ways that are beneficial to our health (explained further in my video, Xenohormesis: What Doesn't Kill Plants May Make Us Stronger).

Basically, hormesis is the biological principle of "no pain, no gain." Mild stresses like exercise can trigger a protective response that leads to strengthened defenses in the long run. But instead of exposing ourselves to the stressor to trigger our bodies' defenses and shore up protection against future stressors, why not let plants take the hit? Let the plants get stressed because, incredibly, the stress response molecules in plants may activate the same protective responses in humans. Xenohormesis "explains how environmentally stressed plants produce bioactive compounds that can confer stress resistance and survival benefits to animals that consume them." We can piggyback off of their sophisticated stress response. Indeed, the majority of known health-beneficial effects of edible plants are attributable to the pharmacologically active substances of plants' stress responses.

Hormesis may be why dietary restriction can lead to lifespan extension. The mild stress placed upon the body by not eating enough may activate a wide variety of protective pathways within the body, ramping up anti-inflammatory and antioxidant defenses. Our bodies are preparing themselves for the coming famine they think is about to occur. So is there a way to exploit the benefits of dietary restriction to prevent chronic disease? Obviously, "chronically restricting food intake is not a realistic health strategy for the majority of people--it's hard for most people to even cut food intake 10-20%, [given the powerful evolutionary drive to eat]. A more feasible alternative may be to activate dietary restriction-induced stress response pathways by other means."

In other words, xenohormesis.

If we starve plants, they do the same thing mammals do: activate preservation pathways. So let's let the plant face the adversity to create the molecules that trigger cell stress resistance, alter metabolism, and improve disease resistance, and then just come along and appropriate them for the same uses in our own bodies.

The reason phytonutrients like resveratrol in grapes, curcumin in the spice turmeric, and ECGC in green tea are called "dietary restriction mimetics" is that they mimic the physiological effects of dietary restriction. This may be no coincidence, because the plants produced these compounds to save their own green butts from scarcity. So instead of having to walk around starving all the time, thanks to xenohormesis, we may be able to let the plants bear the brunt and enable us to harness other species' hardships as a means to promote our own health.

If this subject interests you, make sure you see my video where I introduce the topic: Appropriating Plant Defenses.

I previously introduced the concept of hormesis in my videos Enhanced Athletic Recovery Without Undermining Adaptation and Is Liquid Smoke Carcinogenic?

How else might we get the benefits of dietary restriction without starving ourselves? See:

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my videos for free by clicking here and watch my full 2012 - 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: KylaBorg / Flickr

Original Link

How Humans Benefit From Stressed Plants

NF-Sep1 Appropriating Plant Defenses.jpg

Plants live the ultimate sedentary lifestyle--most of us usually think of plants more as objects than as organisms. Because plants can't move, they've had to evolve a whole other way to escape threats to their well-being. Plants can "sense and respond dynamically to all sorts of stimuli: chemical concentrations in the air and soil, water, touch, motion, vibration, pathogens, predators, and, of course, light." How do they respond? Biochemically. They manufacture, from scratch, a dizzying array of compounds to deal with specific threats.

If we get too hot, we can move into the shade. If plants get too hot, they're stuck--they are the shade! As a result, "the complexity of the plant stress response humbles that of animals. Plants and their stress response have been evolving for almost a billion years." And in that time they've created a whole chemistry lab of protective substances, some of which can induce similarly protective responses in those of us who eat them.

The "best grapes in terms of health benefit often grow in relatively dry, sun-exposed, infertile soil. Similarly, drought-stressed strawberries have more antioxidants and phytonutrients. Indeed, commonly consumed foods like lettuce and fruits can be nutritionally enhanced by cold stress, light stress, water deficit, or nutrient deficit stress." Why are stressed plants often the healthiest?

Studies (such as those highlighted in my video, Appropriating Plant Defenses) suggest that plants and animals largely share the same molecular pathways in order to respond to stress, so it's conceivable that a molecule produced in plants can also be effective in people. Plants have DNA; humans have DNA. The UV rays in sunlight can damage the DNA in plants in the same way it can damage our DNA (by creating free radicals). Plants figured out how to cook up all these complex antioxidants, and instead of reinventing the wheel, animals can just expropriate those antioxidants from plants and commandeer them for the same purpose.

We get attacked by bacteria; plants get attacked by bacteria. When a particular fungus is getting muscled in on by bacteria, it creates a molecule called penicillin--provided free for us.

When plants get infected, they produce aspirin (See Aspirin Levels in Plant Foods), which can come in handy when we get infected. Plants heal wounds; we heal wounds, using similar fatty-acid signaling systems. It is "increasingly evident that plants and animals differ less than we thought in how we respond to stimuli, sharing elements of fatty acid, protein, steroidal, neurotransmitter, free radical, nitric oxide, and even plant growth hormone signaling systems." So in a sense, we're just opening up nature's drug store when we pull out the crisper in our fridge.

This whole co-evolution concept reminds me of Human Neurotransmitters In Plants and The Broccoli Receptor: Our First Line of Defense.

More on the power of plants in Power Plants.

Some of the wilder things that Phytochemicals: The Nutrition Facts Missing from the Label can do are explored in:

We evolved eating a lot of plants: Paleolithic Lessons.

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my videos for free by clicking here and watch my full 2012 - 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Hernan Pinera / Flickr

Original Link

How a Tick Bite Can Lead to Food Allergies

NF-Aug25 Alpha Gal and the Lone Star Tick.jpg

In the beginning, Aristotle defined two forms of life on planet Earth: plants and animals. Two thousand years later, the light microscope was invented and we discovered tiny, single-celled organisms like amoebas. Then, the electron microscope was invented and we discovered bacteria. Finally, in 1969, biologists recognized fungi as a separate category, and we've had at least five kingdoms of life ever since.

In my video, Higher Quality May Mean Higher Risk, I talk about the potential downsides of consuming proteins from within our own kingdom, such as the impact our fellow animal proteins can have on boosting our liver's production of a cancer-promoting hormone called IGF-1.

In Eating Outside Our Kingdom, I talked about other potential advantages of preferably dipping into the plant and mushroom kingdoms for dinner, not only from a food safety perspective (we're more likely to get infected by animal pathogens than Dutch Elm Disease), but because of the potential for cross-reactivity between animal and human proteins. Our immune system is more likely to get confused between a chicken leg and our own legs than it is with a banana, so there may be less potential to trigger an autoimmune reaction, like degenerative brain diseases or inflammatory arthritis (See Diet & Rheumatoid Arthritis). In attacking some foreign animal meat protein, some of our own similarly composed tissues may get caught in the crossfire.

It's not just proteins. If you remember the Neu5Gc story (see Inflammatory Meat Molecule Neu5GC), sialic acid in other animals may cause inflammation in our arteries (see Nonhuman Molecules Lining Our Arteries) and help breast tumors and other human cancers to grow (see How Tumors Use Meat to Grow: Xeno-Autoantibodies). Now a new twist has been added to the story.

The reason Neu5Gc triggers inflammation is because humans lost the ability to make it two million years ago, and so when our body is exposed to it through animal products, it's treated as a foreign molecule, causing inflammation. But there's also another oligosaccharide called alpha-gal that humans, chimps, and apes lost the ability to make 20 million years ago, but is still made by a variety of animals, including many animals we eat.

Anti-gal antibodies may be involved in a number of detrimental processes that may result in allergic, autoimmune, and autoimmune-like diseases, such as auto-immune thyroid disorders. We see higher levels of anti-gal antibodies in Crohn's disease victims. These antibodies even react against about half of human breast tumors, and we can find them in atherosclerotic plaques in people's necks. However, those are all mostly speculative risks. We do know that alpha-gal is a major obstacle to transplanting pig organs into people, like kidneys, because our bodies reject alpha-gal as foreign. In fact, alpha-gal is thought to be the major target for human anti-pig antibodies.

It's interesting that if we look at those that abstain from pork for whatever reason, they have fewer swine-specific immune cells in their bloodstream. Researchers speculate that oral intake of pork could ferry swine molecules into the bloodstream via gut-infiltrating lymphocytes to prime the immune response. So we can have an allergic reaction to eating pig kidneys too, but such severe meat allergies were considered rare, until an unusual report surfaced. First described in 2009, the report included details on 24 cases of meat allergies triggered by tick bites.

Within a year, it was obvious that the cases should be counted in hundreds rather than dozens. By 2012, there were thousands of cases across a large area of the southern and eastern U.S., and new cases are now popping up in several countries around the world.

The culprit, the lone star tick, so-called because females have a white spot on their back, are famous for causing Masters' disease, a disease similar to Lyme syndrome, also known as STARI (southern tick associated rash illness). But thanks to the lone star tick steadily expanding its range (even as far as Long Island, NY), it's not necessarily just so Southern any more.

What is the relevance of tick bites to the production of allergy-causing anti-meat antibodies to alpha-gal? Good question. What we know is that if you get bitten by one of these ticks, you can develop an allergy to meat (See Alpha Gal and the Lone Star Tick). This appears to be the first example of a response to an external parasite giving rise to an important form of food allergy. We don't know the exact mechanism, but it may be because there's something in the tick saliva that's cross-reacting with alpha-gal, or because the tick is injecting you with animal allergens from its last meal.

What role may these tick-bite induced allergies play in the development of chronic hives and other allergic skin reactions in children? See Tick Bites, Meat Allergies, and Chronic Urticaria.

Here's some videos unearthing the IGF-1 story:

Neu5Gc is what opened up this whole can of worms:

I wonder if alpha gal is playing a role in the improvements in arthritis and Crohn's on plant-based diets: Dietary Treatment of Crohn's Disease and Diet & Rheumatoid Arthritis.

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my videos for free by clicking here and watch my full 2012 - 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: USGS Bee Inventory and Monitoring Lab / Flickr

Original Link

Exploiting Autophagy to Live Longer

NF-June11 Why do we age.jpg

Thanks to advances in modern medicine, we are living longer lives, but we're doing it by lengthening the morbidity phase. In other words, we live longer, but sicker, lives (see my video: Americans Are Live Longer, but Sicker Lives). So, traditional medicine increases the number of old people in bad health. Ideally, though, we'd extend lifespan by slowing aging to delay the onset of deterioration, rather than extending the period of deterioration.

That's exactly what a new compound appears to do. It sounds like science fiction. A bacteria in a vial of dirt taken from a mysterious island creating a compound that prolongs life. And not in the traditional medical sense. Researchers in a study profiled in my video, Why Do We Age?, called it rapamycin--named after the bacteria's home, Easter Island, which is known locally as Rapa Nui. Rapamycin inhibits an enzyme called TOR, or "target of rapamycin." TOR may be a master determinant of lifespan and aging. The action of TOR has been described as the engine of a speeding car without brakes.

Rather than thinking of aging as slowly rusting, a better analogy may be a speeding car that enters the low-speed zone of adulthood and damages itself because it does not and cannot slow down. Why don't living organisms have brakes? Because they've never needed them. In the wild, animals don't live long enough to experience aging. Most die before they even reach adulthood. The same used to be true for humans. For example, just a few centuries ago, average life expectancy in London was less than 16 years old.

Therefore, living beings need to grow as fast as possible to start reproduction before they die from external causes. The best evolutionary strategy may be to run at full speed. However, once we pass the finish line, once we win the race to pass on our genes, we're still careening forward at an unsustainable pace, all thanks to this enzyme TOR. In our childhood, TOR is an engine of growth, but in adulthood, it is the engine of aging. "Nature simply selects for the brightest flame, which in turn casts the darkest shadow."

Sometimes, though, even in our youth, our bodies need to turn down the heat. When we were evolving, there were no grocery stores; periodic famine was the norm. So sometimes even young people had to slow down or they might never even make it to reproductive age. So we did evolve one braking mechanism: caloric restriction. Caloric restriction may extend lifespan mainly through the inhibition of TOR.

When food is abundant, TOR activity goes up, prompting the cells in our body to divide. When TOR detects that food is scarce, it shifts the body into conservation mode, slowing down cell division and kicking in a process called autophagy, from the Greek auto meaning "self," and phagy meaning "to eat." Autophagy essentially means eating yourself. Our body realizes there isn't much food around and starts rummaging through our cells looking for anything we don't need. Defective proteins, malfunctioning mitochondria, stuff that isn't working anymore, and cleans house. Clears out all the junk and recycles it into fuel or new building materials, renewing our cells.

So caloric restriction has been heralded as a fountain of youth. The potential health and longevity benefits of such a diet regimen may be numerous, but symptoms may include dropping our blood pressure too low, loss of libido, menstrual irregularities, infertility, loss of bone, cold sensitivity, loss of strength, slower wound healing, and psychological conditions such as depression, emotional deadening, and irritability. And you walk around starving all the time! There's got to be a better way, and there is. Check out my video Caloric Restriction vs. Animal Protein Restriction.

More tips for preserving youthful 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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Arian Zwegers / Flickr

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Slowing Cognitive Decline with Berries

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A plant-based diet is thought to have played a significant role in human evolution and the consumption of whole plant foods and even just extracts have repeatedly been associated with a decreased risk of aging related diseases. And by healthy aging I'm not talking preventing wrinkles, what about protecting our brain? "Two of the most dreaded consequences of dementia with aging are problems moving around and difficulty remembering things. Dementia robs older adults of their independence, control, and identity."

Fruits and vegetables help reduce the risk of other chronic diseases, so might they work for brain diseases as well?

There has been a proliferation of recent interest in plant polyphenols as agents in the treatment of dementia. There are 4,000 different kinds of polyphenols found ubiquitously in foods of plant origin, but berries are packed with them, possessing powerful antioxidant and anti-inflammatory properties. There's a subset of polyphenols called anthocyanidins, which are found in blue and purple pigmented fruits and berries. These polyphenols are uniquely and specifically capable of "both crossing the blood-brain barrier and localizing in brain regions involved in learning and memory." And that's precisely where we need them.

The brain takes up less than 2% of body weight but may burn up to 50% of the body's fuel, creating a potential firestorm of free radicals. Maybe these brain-seeking phytonutrients in berries could fight oxidation and inflammation, and even increase blood flow? This raised a thought-provoking idea. Maybe a "nutritional intervention with blueberries may be effective in forestalling or even reversing the neurological changes associated with aging?" It would be a decade before the first human trial was conducted, but it worked! "Blueberry supplementation improves memory in older adults," suggesting that "consistent supplementation with blueberries may offer an approach to forestall or mitigate brain degeneration with age."

What other blue or purple foods can we try? Concord grape juice was also tested and had a similar benefit, suggesting that supplementation with purple grape juice may enhance cognitive function for older adults with early memory decline. Why use juice and not whole concord grapes? Because then you couldn't design a placebo that looked and tasted exactly the same to rule out the very real and powerful placebo effect. And also because the study was funded by the Welch's grape juice company.

This effect was confirmed in a follow-up study, showing for the first time an increase in neural activation in parts of the brain associated with memory using functional MRI scans. But this brain scan study was tiny: just four people in each group. And same problem in the blueberry study: it had only nine people in it.

Why haven't large population-based studies been done? Because we haven't had good databases on where these phytonutrients are found. We know how much vitamin C is in a blueberry, but not how much anthocyanidin--until now. The Harvard Nurses' Health Study, highlighted in my video, How to Slow Brain Aging by Two Years, followed the cognitive function of more than 16,000 women for years, and found that "long-term consumption of berries was related to significantly slower rates of cognitive decline, even after careful consideration of confounding socioeconomic status" (that is, even after taking into account the fact that rich people eat more berries). The Harvard Nurses' Health Study was the first population-based evidence that greater intakes of blueberries and strawberries were highly associated with slower rates of cognitive decline, and not just by a little bit. "The magnitude of associations were equivalent to the cognitive differences that one might observe in women up to two and a half years apart in age." In other words, women with higher intake of berries appeared to have delayed cognitive aging by as much as two and a half years.

Why shouldn't we just take some anthocyanidin supplement? Because there hasn't been a single study that found any kind of cognitive benefit by just giving single phytonutrients. In fact, the opposite is true. "Whole blueberries appear to be more effective than individual components, showing that the whole is greater than the sum of its parts." These findings have potentially substantial public health implications, as increasing berry intake represents a fairly simple dietary modification to test in older adults for maintaining our brain function.

What other ways could we improve our memory and cognitive function?

What other near-miraculous properties of berries are there?

I add them to my morning smoothie: A Better Breakfast.

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Angelo Desantis / Flickr

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