Foods to Avoid to Help Prevent Diabetes

Oct 24 Foods to Avoid copy.jpeg

We've known that being overweight and obese are important risk factors for type 2 diabetes, but, until recently, not much attention has been paid to the role of specific foods. I discuss this issue in my video, Why Is Meat a Risk Factor for Diabetes?

A 2013 meta-analysis of all the cohorts looking at the connection between meat and diabetes found a significantly higher risk associated with total meat consumption--especially consumption of processed meat, particularly poultry. But why? There's a whole list of potential culprits in meat: saturated fat, animal fat, trans fats naturally found in meat, cholesterol, or animal protein. It could be the heme iron found in meat, which can lead to free radicals and iron-induced oxidative stress that may lead to chronic inflammation and type 2 diabetes, or advanced glycation end (AGE) products, which promote oxidative stress and inflammation. Food analyses show that the highest levels of these so-called glycotoxins are found in meat--particularly roasted, fried, or broiled meat, though any foods from animal sources (and even high fat and protein plant foods such as nuts) exposed to high dry temperatures can be potent sources of these pro-oxidant chemicals.

In another study, researchers fed diabetics glycotoxin-packed foods, like chicken, fish, and eggs, and their inflammatory markers--tumor necrosis factor, C-reactive protein, and vascular adhesion molecules--shot up. "Thus, in diabetes, environmental (dietary) AGEs promote inflammatory mediators, leading to tissue injury." The good news is that restriction of these kinds of foods may suppress these inflammatory effects. Appropriate measures to limit AGE intake, such as eliminating meat or using only steaming and boiling as methods for cooking it, "may greatly reduce the already heavy burden of these toxins in the diabetic patient." These glycotoxins may be the missing link between the increased consumption of animal fat and meats and the development of type 2 diabetes.

Since the 2013 meta-analysis was published, another study came out in which approximately 17,000 people were followed for about a dozen years. Researchers found an 8% increased risk for every 50 grams of daily meat consumption. Just one quarter of a chicken breast's worth of meat for the entire day may significantly increase the risk of diabetes. Yes, we know there are many possible culprits: the glycotoxins or trans fat in meat, saturated fat, or the heme iron (which could actually promote the formation of carcinogens called nitrosamines, though they could also just be produced in the cooking process itself). However, we did learn something new: There also appears to be a greater incidence of diabetes among those who handle meat for a living. Maybe there are some diabetes-causing zoonotic infectious agents--such as viruses--present in fresh cuts of meat, including poultry.

A "crucial factor underlying the diabetes epidemic" may be the overstimulation of the aging enzyme TOR pathway by excess food consumption--but not by the consumption of just any food: Animal proteins not only stimulate the cancer-promoting hormone insulin growth factor-1 but also provide high amounts of leucine, which stimulates TOR activation and appears to contribute to the burning out of the insulin-producing beta cells in the pancreas, contributing to type 2 diabetes. So, it's not just the high fat and added sugars that are implicated; critical attention must be paid to the daily intake of animal proteins as well.

According to a study, "[i]n general, lower leucine levels are only reached by restriction of animal proteins." To reach the leucine intake provided by dairy or meat, we'd have to eat 9 pounds of cabbage or 100 apples to take an extreme example. That just exemplifies the extreme differences in leucine amounts provided by a more standard diet in comparison with a more plant-based diet.

I reviewed the role endocrine-disrupting industrial pollutants in the food supply may play in a three-part video series: Fish and Diabetes, Diabetes and Dioxins, and Pollutants in Salmon and Our Own Fat. Clearly, the standard America diet and lifestyle contribute to the epidemic of diabetes and obesity, but the contribution of these industrial pollutants can no longer be ignored. We now have experimental evidence that exposure to industrial toxins alone induces weight gain and insulin resistance, and, therefore, may be an underappreciated cause of obesity and diabetes. Consider what's happening to our infants: Obesity in a six-month-old is obviously not related to diet or lack of exercise. They're now exposed to hundreds of chemicals from their moms, straight through the umbilical cord, some of which may be obesogenic (that is, obesity-generating).

The millions of pounds of chemicals and heavy metals released every year into our environment should make us all stop and think about how we live and the choices we make every day in the foods we eat. A 2014 review of the evidence on pollutants and diabetes noted that we can be exposed through toxic spills, but "most of the human exposure nowadays is from the ingestion of contaminated food as a result of bioaccumulation up the food chain. The main source (around 95%) of [persistent pollutant] intake is through dietary intake of animal fats."


For more on the information mentioned here, see the following videos that take a closer look at these major topics:

AGEs: Glycotoxins, Avoiding a Sugary Grave, and Reducing Glycotoxin Intake to Prevent Alzheimer's.

TOR: Why Do We Age?, Caloric Restriction vs. Animal Protein Restriction, Prevent Cancer From Going on TOR, and Saving Lives By Treating Acne With Diet

Viruses: Infectobesity: Adenovirus 36 and Childhood Obesity

Poultry workers: Poultry Exposure and Neurological Disease, Poultry Exposure Tied to Liver and Pancreatic Cancer, and Eating Outside Our Kingdom

Industrial pollutants: Obesity-Causing Pollutants in Food, Fish and Diabetes, Diabetes and Dioxins, and Pollutants in Salmon and Our Own Fat

The link between meat and diabetes may also be due to a lack of sufficient protective components of plants in the diet, which is discussed in my videos How May Plants Protect Against Diabetes?, Plant-Based Diets for Diabetes, Plant-Based Diets and Diabetes, and How Not to Die from Diabetes.

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:

Original Link

Foods to Avoid to Help Prevent Diabetes

Oct 24 Foods to Avoid copy.jpeg

We've known that being overweight and obese are important risk factors for type 2 diabetes, but, until recently, not much attention has been paid to the role of specific foods. I discuss this issue in my video, Why Is Meat a Risk Factor for Diabetes?

A 2013 meta-analysis of all the cohorts looking at the connection between meat and diabetes found a significantly higher risk associated with total meat consumption--especially consumption of processed meat, particularly poultry. But why? There's a whole list of potential culprits in meat: saturated fat, animal fat, trans fats naturally found in meat, cholesterol, or animal protein. It could be the heme iron found in meat, which can lead to free radicals and iron-induced oxidative stress that may lead to chronic inflammation and type 2 diabetes, or advanced glycation end (AGE) products, which promote oxidative stress and inflammation. Food analyses show that the highest levels of these so-called glycotoxins are found in meat--particularly roasted, fried, or broiled meat, though any foods from animal sources (and even high fat and protein plant foods such as nuts) exposed to high dry temperatures can be potent sources of these pro-oxidant chemicals.

In another study, researchers fed diabetics glycotoxin-packed foods, like chicken, fish, and eggs, and their inflammatory markers--tumor necrosis factor, C-reactive protein, and vascular adhesion molecules--shot up. "Thus, in diabetes, environmental (dietary) AGEs promote inflammatory mediators, leading to tissue injury." The good news is that restriction of these kinds of foods may suppress these inflammatory effects. Appropriate measures to limit AGE intake, such as eliminating meat or using only steaming and boiling as methods for cooking it, "may greatly reduce the already heavy burden of these toxins in the diabetic patient." These glycotoxins may be the missing link between the increased consumption of animal fat and meats and the development of type 2 diabetes.

Since the 2013 meta-analysis was published, another study came out in which approximately 17,000 people were followed for about a dozen years. Researchers found an 8% increased risk for every 50 grams of daily meat consumption. Just one quarter of a chicken breast's worth of meat for the entire day may significantly increase the risk of diabetes. Yes, we know there are many possible culprits: the glycotoxins or trans fat in meat, saturated fat, or the heme iron (which could actually promote the formation of carcinogens called nitrosamines, though they could also just be produced in the cooking process itself). However, we did learn something new: There also appears to be a greater incidence of diabetes among those who handle meat for a living. Maybe there are some diabetes-causing zoonotic infectious agents--such as viruses--present in fresh cuts of meat, including poultry.

A "crucial factor underlying the diabetes epidemic" may be the overstimulation of the aging enzyme TOR pathway by excess food consumption--but not by the consumption of just any food: Animal proteins not only stimulate the cancer-promoting hormone insulin growth factor-1 but also provide high amounts of leucine, which stimulates TOR activation and appears to contribute to the burning out of the insulin-producing beta cells in the pancreas, contributing to type 2 diabetes. So, it's not just the high fat and added sugars that are implicated; critical attention must be paid to the daily intake of animal proteins as well.

According to a study, "[i]n general, lower leucine levels are only reached by restriction of animal proteins." To reach the leucine intake provided by dairy or meat, we'd have to eat 9 pounds of cabbage or 100 apples to take an extreme example. That just exemplifies the extreme differences in leucine amounts provided by a more standard diet in comparison with a more plant-based diet.

I reviewed the role endocrine-disrupting industrial pollutants in the food supply may play in a three-part video series: Fish and Diabetes, Diabetes and Dioxins, and Pollutants in Salmon and Our Own Fat. Clearly, the standard America diet and lifestyle contribute to the epidemic of diabetes and obesity, but the contribution of these industrial pollutants can no longer be ignored. We now have experimental evidence that exposure to industrial toxins alone induces weight gain and insulin resistance, and, therefore, may be an underappreciated cause of obesity and diabetes. Consider what's happening to our infants: Obesity in a six-month-old is obviously not related to diet or lack of exercise. They're now exposed to hundreds of chemicals from their moms, straight through the umbilical cord, some of which may be obesogenic (that is, obesity-generating).

The millions of pounds of chemicals and heavy metals released every year into our environment should make us all stop and think about how we live and the choices we make every day in the foods we eat. A 2014 review of the evidence on pollutants and diabetes noted that we can be exposed through toxic spills, but "most of the human exposure nowadays is from the ingestion of contaminated food as a result of bioaccumulation up the food chain. The main source (around 95%) of [persistent pollutant] intake is through dietary intake of animal fats."


For more on the information mentioned here, see the following videos that take a closer look at these major topics:

AGEs: Glycotoxins, Avoiding a Sugary Grave, and Reducing Glycotoxin Intake to Prevent Alzheimer's.

TOR: Why Do We Age?, Caloric Restriction vs. Animal Protein Restriction, Prevent Cancer From Going on TOR, and Saving Lives By Treating Acne With Diet

Viruses: Infectobesity: Adenovirus 36 and Childhood Obesity

Poultry workers: Poultry Exposure and Neurological Disease, Poultry Exposure Tied to Liver and Pancreatic Cancer, and Eating Outside Our Kingdom

Industrial pollutants: Obesity-Causing Pollutants in Food, Fish and Diabetes, Diabetes and Dioxins, and Pollutants in Salmon and Our Own Fat

The link between meat and diabetes may also be due to a lack of sufficient protective components of plants in the diet, which is discussed in my videos How May Plants Protect Against Diabetes?, Plant-Based Diets for Diabetes, Plant-Based Diets and Diabetes, and How Not to Die from Diabetes.

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:

Original Link

Should Pregnant Women Drink Cow’s Milk?

NF-Sept15 Why Do Vegan Women Have 5x Fewer Twins_.jpeg

Foods of animal origin in general naturally contain hormones, but cow's milk may be of particular concern. The hormones naturally found even in organic cow's milk may have played a role in studies that found a relationship between dairy products and human illnesses, such as acne, certain cancers and male reproductive disorders. Milk consumption has also been associated with an increased risk of early puberty and endometrial cancer in postmenopausal women, but "hormonal levels in food could be particularly dangerous in the case of vulnerable populations, such as young children or pregnant women. To this critical population, even a small hormonal intake could lead to major changes in the metabolism."

If you check out my video Why Do Vegan Women Have 5x Fewer Twins, you can see that children are highly sensitive to sex steroids. Because their levels of sex steroids are very low, even a small variation would account for a major change in the total activity of the involved hormone. Because no lower threshold for estrogenic action has been established, caution should be taken to avoid unnecessary exposure of fetuses and children to exogenous sex steroids, even at very low levels.

In the AMA's Pediatrics Journal, the Chair of Boston Children's Hospital's Obesity Prevention Center along with the chair of Harvard's nutrition department questioned dairy industry recommendations that children should drink three glasses of milk a day. Dairy milk evolved to promote the growth of grazing animals at high risk for predation when small, so they needed to put on a few hundred pounds quickly in the first few months of life.

The consequences of lifetime human exposure to the growth factors in milk have not been well studied. "Milk consumption increases serum concentrations of insulin-like growth factor 1, which is linked to prostate and other cancers. In addition, modern industrial methods maintain dairy cows in active milk production throughout their pregnancies, resulting in a milk supply with high levels of reproductive hormones."

Pregnant cows excrete significantly higher levels of sex steroids into their milk than non-pregnant cows. The subsequent consumption of such dairy products from pregnancy results in additional consumer exposure. And it's not just dairy. Although dairy products are an important source of hormones, other products of animal origin must be considered as well. All edible tissues of animal origin contain estrogen. This may explain why, in a study of over a thousand women eating plant-based diets, vegan women have a twinning rate that is one fifth that of vegetarians and omnivores.

Twin pregnancies are risky pregnancies, with much higher complication rates. Many parents and physicians underestimate the negative consequences of multiple pregnancy, but "women with a multiple pregnancy face greater risks for themselves and their infants." Twin babies may be ten times more likely to die at birth. To avoid these complications, the research team writes, "women attempting conception should avoid milk and dairy products."

Minimizing dairy, our nation's #1 source of saturated fat may be a good idea for dads too: Dairy Estrogen and Male Fertility.

What about the endocrine-disrupting xenoestrogens--how do they compare with the natural hormones in our food supply? That was the topic of my video Estrogen in Meat, Dairy, and Eggs.

Then once they're born, best to stick to human milk:

Then as young children, dairy can sometimes cause another problem: Childhood Constipation and Cow's Milk

Here's a selection of other pregnancy-related 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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: LivingLandscapeArchitecture / Flickr

Original Link

The Role of Caffeine in Artery Function

Aug23.jpg

There are dietary guidelines for food, but what about for beverages? A Beverage Guidance Panel was "assembled to provide guidance on the relative health and nutritional benefits and risks of various beverage categories." They ranked them from one to six, and water was ranked number one.

Soda ranked last at number six. Whole milk was grouped with beer, with a recommendation for zero ounces a day, in part out of concern for links between milk and prostate cancer, as well as aggressive ovarian cancer due to IGF-1. Number two on the list, though, after water, was tea and coffee, preferably without creamer or sweetener.

Even without creamer, though, lots of unfiltered coffee can raise cholesterol, but the cholesterol-raising compounds are trapped by the paper filter in brewed coffee, so filtered coffee is probably better.

But about ten years ago, a study was published on the effects of coffee on endothelial function, the function of our arteries. I profile this study in my video Coffee and Artery Function, showing that within 30 minutes of drinking a cup of coffee there was a significant drop in the ability of our arteries to dilate, whereas decaf did not seem to have a significant effect. This was the first study to demonstrate an acute unfavorable effect on arterial function of caffeinated coffee, but one cup of decaf didn't seem to affect performance. And two cups of decaf appeared to have a beneficial effect. So maybe it's a "battle between caffeine and antioxidants." Something in caffeinated coffee appears to be hurting arterial function, whereas something in decaf appears to be helping.

It's similar to red wine. De-alcoholized red wine significantly improves arterial function, as there are grape components trying to help, but the presence of alcohol counteracts and erases the benefit.

Drinking really high antioxidant coffee, by preparing it Greek style for example (where we actually drink the grounds), coffee drinkers may actually be at an advantage

It might not be the caffeine in caffeinated coffee that appears to be harmful, though. In a randomized, double-blind, placebo-controlled, cross-over study, researchers found that caffeine alone--about two and a half cups of coffee worth--significantly improved arterial function in both people with and without heart disease.

Coffee contains more than a thousand different compounds other than caffeine, many of which are also removed by the decaffeination process, so there must be something else in the coffee bean that's causing the problem. In fact, caffeine may even enhance the repair of the fragile inner lining of our arteries by enhancing the migration of our endothelial progenitor cells, the stem cells that patch up potholes in our artery walls.

But how might we get the potential benefit of caffeine without the risky compounds in caffeinated coffee? Tea consumption enhances artery function, and there are substantial beneficial effects of both green tea and black tea. Instead of other components in tea leaves undermining caffeine's potential benefits, they appear to boost the benefit in healthy individuals, as well as heart disease patients, reversing some of their arterial dysfunction, both immediately and long-term.

All the measurements in the studies I've talked about so far were done on the brachial artery, the main artery in the arm (just because it's easier to get to). What we care about, though, is blood flow to the heart. And caffeine appears to impair blood flow to our heart muscle during exercise even in healthy folks, but especially in those with heart disease. Thankfully caffeine in tea form appears to have the opposite effect, significantly improving coronary blood flow, suggesting that tea consumption has a beneficial effect on coronary circulation, though the addition of milk may undermine the protective effects.

I'm fascinated by how complicated such a simple question can get. The take-home is that water is the healthiest beverage, followed by tea.

The effects of coffee on cancer risk are more salutary:

I've previously covered Walnuts and Artery Function and Dark Chocolate and Artery Function. Stay tuned for a few more coming up further exploring the effects of tea, olive oil, and plant-based diets on our lovely endothelium.

Low Carb Diets and Coronary Blood Flow is one of the few other studies I've done that measured blood flow within the coronary arteries themselves. For more background on the brachial artery test, see my video The Power of NO.

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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Original Link

Caloric Restriction vs. Plant-Based Diets

July14.jpg

Hundreds of thousands of deaths in the United States every year are attributed to obesity, now overtaking smoking as perhaps the main preventable cause of illness and premature death. In particular, excess body fatness is an important cause of most cancers, according to a meta-analysis of studies done to date. For some cancers, about half of the cases may be attributable to just being overweight or obese.

What's the connection, though? Why do individuals who are obese have increased cancer risk? To answer this question we must consider the biochemical consequences of obesity, like IGF-1; insulin like growth factor one is a cancer-promoting growth hormone associated with a variety of common cancers in adults, as well as children. Kids who got cancer had about four times the levels of IGF-1 circulating in their bloodstream, whereas people growing up with abnormally low levels of IGF-1 don't seem to get cancer at all.

I've talked about this cancer-proofing mutation (See Cancer-Proofing Mutation), the role animal protein intake plays in boosting IGF-1 production from our liver (Protein Intake & IGF-1 Production), which may explain plant-based protection from cancer (The Answer to the Pritikin Puzzle), and how plant-based one has to eat (How Plant-Based to Lower IGF-1?), but our liver is not the only tissue that produced IGF-1, fat cells produce IGF-1 too. That may help explain this "twenty-first century cancer epidemic caused by obesity."

So of course drug companies have come up with a variety of IGF-1 blocking chemo agents, with cute names like figitumamab, but with not-so-cute side effects "such as early fatal toxicities." So perhaps better to lower IGF-1 the natural way, by eating a plant-based diet, as vegan women and men have lower IGF-1 levels. Maybe, though, it's just because they're so skinny. The only dietary group that comes close to the recommended BMI of 21 to 23 were those eating strictly plant-based diets, so maybe it's the weight loss that did it. Maybe we can eat whatever we want as long as we're skinny.

To put that to the test, we'd have to find a group of people that eat meat, but are still as slim as vegans. And that's what researchers did - long-distance endurance runners, running an average of 48 miles a week for 21 years were as slim as vegans. If we run 50,000 miles we too can maintain a BMI of even a raw vegan. So what did they find?

If we look at blood concentrations of cancer risk factors among the groups of study subjects, we see that only the vegans had significantly lower levels of IGF-1. That makes sense given the role animal protein plays in boosting IGF-1 levels.

But the vegan group didn't just eat less animal protein, they ate fewer calories. And in rodents at least, caloric restriction alone reduces IGF-1 levels. So maybe low IGF-1 among vegans isn't due to their slim figures, but maybe the drop in IGF-1 in vegans is effectively due to their unintentional calorie restriction. So we have to compare vegans to people practicing severe calorie restriction.

To do this, the researchers recruited vegans from the St. Louis Vegetarian Society, and went to the Calorie Restriction Society to find folks practicing severe caloric restriction. What did they find?

Only the vegan group got a significant drop in IGF-1. These findings demonstrate that, unlike in rodents, long-term severe caloric restriction in humans does not reduce the level of this cancer-promoting hormone. It's not how many calories we eat, but the protein intake that may be the key determinant of circulating IGF-1 levels in humans, and so reduced protein intake may become an important component of anti-cancer and anti-aging dietary interventions.

That same data set that compared plant eaters to marathon runners was also featured in Hibiscus Tea vs. Plant-Based Diets for Hypertension and Arteries of Vegans vs. Runners.

These studies are highlighted in my video Caloric Restriction vs. Plant-based Diets.

More on the caloric consumption and longevity:

What exactly is IGF-1 and what is the relationship to animal protein consumption?:

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

Image Credit: Heather Hammond / 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

Dr. Greger’s 2015 Live Year-in-Review Presentation

Food as Medicine

View my new live presentation here: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet

Every year I scour the world's scholarly literature on clinical nutrition, pulling together what I find to be the most interesting, practical, and groundbreaking science on how to best feed ourselves and our families. I start with the thousands of papers published annually on nutrition (27,000 this year--a new record!) and, thanks to a crack team of volunteers (and now staff!), I'm able to whittle those down (to a mere 8,000 this year). They are then downloaded, categorized, read, analyzed, and churned into the few hundred short videos. This allows me to post new videos and articles every day, year-round, to NutritionFacts.org. This certainly makes the site unique. There's no other science-based source for free daily updates on the latest discoveries in nutrition. The problem is that the amount of information can be overwhelming.

Currently I have more than a thousand videos covering 1,931 nutrition topics. Where do you even begin? Many have expressed their appreciation for the breadth of material, but asked that I try to distill it into a coherent summary of how best to use diet to prevent and treat chronic disease. I took this feedback to heart and in 2012 developed Uprooting the Leading Causes of Death, which explored the role diet may play in preventing, arresting, and even reversing our top 15 killers. Not only did it rise to become one of the Top 10 Most Popular Videos of 2012, it remains my single most viewed video to date, watched over a million times (NutritionFacts.org is now up to more than 1.5 million hits a month!).

In 2013 I developed the sequel, More Than an Apple a Day, in which I explored the role diet could play in treating some of our most common conditions. I presented it around the country and it ended up #1 on our Top 10 Most Popular Videos of 2013. Then in 2014 I premiered the sequel-sequel, From Table to Able, in which I explored the role diet could play in treating some of our most disabling diseases, landing #1 on our Top 10 Most Popular Videos of 2014.

Every year I wonder how I'm going to top the year before. Knowing how popular these live presentations can be and hearing all the stories from folks about what a powerful impact they can have on people's lives, I put my all into this new 2015 one. I spent more time putting together this presentation than any other in my life. It took me an entire month, and when you see it I think you'll appreciate why.

This year, I'm honored to bring you Food as Medicine, in which I go through our most dreaded diseases--but that's not even the best part! I'm really proud of what I put together for the ending. I spend the last 20 minutes or so (starting at 56:22) going through a thought experiment that I'm hoping everyone will find compelling. I think it may be my best presentation ever. You be the judge.

You can watch it at no cost online, but it is also available on DVD through my website or on Amazon. If you want to share copies with others, I have a five for $40 special (enter coupon code 5FOR40FAM). All proceeds from the sales of all my books, DVDs, downloads, and presentations go to the 501c3 nonprofit charity that keeps NutritionFacts.org free for all, for all time. If you want to support this initiative to educate millions about eradicating dietary diseases, please consider making a donation.

After you've watched the new presentation, make sure you're subscribed to get my video updates daily, weekly, or monthly to stay on top of all the latest.

-Michael Greger

Original Link

Living Longer by Reducing Leucine Intake

NF-June16 How What We Eat (And Don't Eat) Impacts How We Age.jpg

Many studies have shown that calorie restriction, without malnutrition, can increase lifespan and lower the risk of age-related diseases, such as cancer.

However, for many people, calorie restriction clearly has its drawbacks. In the classic Minnesota Starvation Study, many of the volunteers suffered a preoccupation with food, constant hunger, binge eating, and lots of emotional and psychological issues. Even researchers who study caloric restriction rarely practice it. There's got to be a better way to suppress the aging engine enzyme, TOR (see Why Do We Age? for more on TOR).

That's why researchers were so excited about rapamycin, a drug that inhibits TOR, thinking it could be caloric restriction in a pill. But like any drug, it a long list of potentially serious side effects. There's got to be a better way.

The breakthrough came when scientists discovered that the benefits of dietary restriction may be coming not from restricting calories, but from restricting protein intake (See my video Caloric Restriction vs. Animal Protein Restriction). If we look at the first comprehensive, comparative meta-analysis of dietary restriction, "the proportion of protein intake was more important for life extension than the degree of caloric restriction." In fact, just "reducing protein without any changes in calorie level have been shown to have similar effects as caloric restriction."

That's good news. Protein restriction is much less difficult to maintain than dietary restriction, and it may even be more powerful because it suppresses both TOR and IGF-1, the two pathways thought responsible for the dramatic longevity and health benefits of caloric restriction.

Some proteins are worse than others. One amino acid in particular, leucine, appears to exert the greatest effect on TOR. In fact, just cutting down on leucine may be nearly as effective as cutting down on all protein. Where is leucine found? Predominantly animal foods: eggs, dairy, and meat (including chicken and fish). Plant foods, such as fruits, vegetables, grains, and beans, have much less.

"In general, lower leucine levels are only reached by restriction of animal proteins." To reach the leucine intake provided by dairy or meat, we'd have to eat nine pounds of cabbage--about four big heads--or 100 apples. These calculations exemplify the extreme differences in leucine amounts provided by a conventional diet in comparison to a plant-based diet. The functional role of leucine in regulating TOR activity may help explain the extraordinary results reported in the Cornell-Oxford-China Study, "since quasi-vegan diets of modest protein content tend to be relatively low in leucine."

This may also help explain the longevity of populations like the Okinawa Japanese, who have about half our mortality rate. The traditional Okinawan diet is only about 10% protein, and practically no cholesterol, because they ate almost exclusively plants. Less than one percent of their diet was fish, meat, eggs, and dairy - the equivalent of one serving of meat a month and one egg every two months. Their longevity is surpassed only by vegetarian Adventists in California, who have perhaps the highest life expectancy of any formally studied population in history.

This reminds of the study I profiled in The Benefits of Caloric Restriction Without the Actual Restricting.

Methionine is another amino acid that may be associated with aging. See Methionine Restriction as a Life Extension Strategy to find out which foods to avoid in that case. Both leucine and methionine content may be additional reasons why Plant Protein is Preferable.

Other reasons why those eating plant-based diets may live longer:

This all may help explain the results of Harvard's Meat and Mortality Studies.

-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: hslo / Flickr

Original Link

Why Do Vegan Women Have Fewer Female Cancers?

 

 

 

 

 

 

 

 

NF-Mar18 Why Might Vegetarians Have Less HPV?.jpg

Cervical cancer is now considered a sexually transmitted disease. It was originally suspected as such, but now we have DNA fingerprinting proof that virtually all cervical cancer is caused by a sexually transmitted virus, human papilloma virus, which also causes cancers of the penis, vagina, vulva and throat. HPV is considered a necessary, but not sufficient cause of cancer.

I profile a study in my four minute video, Why Might Vegetarians Have Less HPV?, that shows that while most young women contract HPV,  most don’t get cervical cancer because their immune systems are able to clear out the virus. Within one year, 70 percent of women clear the infection, and more than 90 percent clear it within two years — before the virus can cause cancer.

Might those with particularly strong immune systems clear the virus even faster? That’s what may be behind a new study that found vegetarian women had significantly lower infection rates with HPV, one of many studies reporting lower risk of HPV infection among those eating plant-based diets.

When researchers took a bunch of women with cancer-causing strains of HPV infecting their cervix and followed them out and retested at three months and nine months while analyzing their diets, what did they find? Higher levels of vegetable consumption appeared to cut their risk of HPV persistence in half, doubling one’s likelihood of clearing this potentially cancer-causing infection. And “higher” levels just meant about two or more servings a day. Antioxidants appear to suppress the activation of critical segments of the virus’ DNA. Maybe that’s why smearing green tea on genital warts—also caused by HPV—has been found so effective in clearing them (See my video, Treating Genital Warts with Green Tea).

In terms of preventing cervical cancer, phytonutrients like lutein (found in dark green leafy vegetables) and lycopene (the red pigment in tomatoes) may decrease viral load, thereby decreasing persistence and progression to disease. Bottom line: higher consumption of vegetables may decrease the risk of HPV persistence, which may help explain why a 2013 study found vegan women have significantly lower rates of all female cancers combined, including cancer of the cervix.

Vegetarians also have lower rates (see Vegetarians Versus Healthy Omnivores), but the Adventist Health Study 2 is the first study of cancer rates among thousands of North American vegans. There are other reasons that help explain these results, from lower levels of the cancer-promoting growth hormone IGF-1 (The Answer to the Pritikin Puzzle), the foreign meat molecule Neu5Gc (How Tumors Use Meat to Grow: Xeno-Autoantibodies), and heterocyclines in cooked meat (Estrogenic Cooked Meat Carcinogens) to more of the good stuff (#1 Anticancer Vegetable and Which Fruit Fights Cancer Better?).

Other viruses may actually be found in the food. See, for example:

More on improving immune function with improved nutrition can be found in Boosting Immunity While Reducing Inflammation and Boosting Immunity Through Diet.

-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 and More Than an Apple a Day.

Image credit: Peter Kemmer / Flickr

Original Link