Clostridium difficile in the Food Supply

Clostridium difficile in the Food Supply.jpeg

Clostridium difficile is one of our most urgent bacterial threats, sickening a quarter million Americans every year, and killing thousands at the cost of a billion dollars a year. And it's on the rise.

As shown in C. difficile Superbugs in Meat, uncomplicated cases have been traditionally managed with powerful antibiotics, but recent reports suggest that hypervirulent strains are increasingly resistant to medical management. There's been a rise in the percentage of cases that end up under the knife, which could be a marker of the emergence of these hypervirulent strains. Surgeons may need to remove our colon entirely to save our lives, although the surgery is so risky that the operation alone may kill us half the time.

Historically, most cases appeared in hospitals, but a landmark study published in the New England Journal of Medicine found that only about a third of cases could be linked to contact with an infected patient.

Another potential source is our food supply.

In the US, the frequency of contamination of retail chicken with these superbugs has been documented to be up to one in six packages off of store shelves. Pig-derived C. diff, however, have garnered the greatest attention from public health personnel, because the same human strain that's increasingly emerging in the community outside of hospitals is the major strain among pigs.

Since the turn of the century, C. diff is increasingly being reported as a major cause of intestinal infections in piglets. C. diff is now one of the most common causes of intestinal infections in baby piglets in the US. Particular attention has been paid to pigs because of high rates of C. diff shedding into their waste, which can lead to the contamination of retail pork. The U.S. has the highest levels of C. diff meat contamination tested so far anywhere in the world.

Carcass contamination by gut contents at slaughter probably contributes most to the presence of C. diff in meat and meat products. But why is the situation so much worst in the US? Slaughter techniques differ from country-to-country, with those in the United States evidently being more of the "quick and dirty" variety.

Colonization or contamination of pigs by superbugs such as C. difficile and MRSA at the farm production level may be more important than at the slaughterhouse level, though. One of the reasons sows and their piglets may have such high rates of C. diff is because of cross-contamination of feces in the farrowing crate, which are narrow metal cages that mother pigs are kept in while their piglets are nursing.

Can't you just follow food safety guidelines and cook the meat through? Unfortunately, current food safety guidelines are ineffective against C. difficile. To date, most food safety guidelines recommend cooking to an internal temperature as low as 63o C-the official USDA recommendation for pork-but recent studies show that C. diff spores can survive extended heating at 71o. Therefore, the guidelines should be raised to take this potentially killer infection into account.

One of the problems is that sources of C. diff food contamination might include not only fecal contamination on the surface of the meat, but transfer of spores from the gut into the actual muscles of the animal, inside the meat. Clostridia bacteria like C. diff comprise one of the main groups of bacteria involved in natural carcass degradation, and so by colonizing muscle tissue before death, C. diff can not only transmit to new hosts that eat the muscles, like us, but give them a head start on carcass break-down.

Never heard of C. diff? That's the Toxic Megacolon Superbug I've talked about before.

Another foodborne illness tied to pork industry practices is yersiniosis. See Yersinia in Pork.

MRSA (Methicillin-resistant Staph aureus) is another so-called superbug in the meat supply:

More on the scourge of antibiotic resistance and what can be done about it:

How is it even legal to sell foods with such pathogens? See Salmonella in Chicken & Turkey: Deadly But Not Illegal and Chicken Salmonella Thanks to Meat Industry Lawsuit.

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: USDA / Flickr. This image has been modified.

Original Link

Clostridium difficile in the Food Supply

Clostridium difficile in the Food Supply.jpeg

Clostridium difficile is one of our most urgent bacterial threats, sickening a quarter million Americans every year, and killing thousands at the cost of a billion dollars a year. And it's on the rise.

As shown in C. difficile Superbugs in Meat, uncomplicated cases have been traditionally managed with powerful antibiotics, but recent reports suggest that hypervirulent strains are increasingly resistant to medical management. There's been a rise in the percentage of cases that end up under the knife, which could be a marker of the emergence of these hypervirulent strains. Surgeons may need to remove our colon entirely to save our lives, although the surgery is so risky that the operation alone may kill us half the time.

Historically, most cases appeared in hospitals, but a landmark study published in the New England Journal of Medicine found that only about a third of cases could be linked to contact with an infected patient.

Another potential source is our food supply.

In the US, the frequency of contamination of retail chicken with these superbugs has been documented to be up to one in six packages off of store shelves. Pig-derived C. diff, however, have garnered the greatest attention from public health personnel, because the same human strain that's increasingly emerging in the community outside of hospitals is the major strain among pigs.

Since the turn of the century, C. diff is increasingly being reported as a major cause of intestinal infections in piglets. C. diff is now one of the most common causes of intestinal infections in baby piglets in the US. Particular attention has been paid to pigs because of high rates of C. diff shedding into their waste, which can lead to the contamination of retail pork. The U.S. has the highest levels of C. diff meat contamination tested so far anywhere in the world.

Carcass contamination by gut contents at slaughter probably contributes most to the presence of C. diff in meat and meat products. But why is the situation so much worst in the US? Slaughter techniques differ from country-to-country, with those in the United States evidently being more of the "quick and dirty" variety.

Colonization or contamination of pigs by superbugs such as C. difficile and MRSA at the farm production level may be more important than at the slaughterhouse level, though. One of the reasons sows and their piglets may have such high rates of C. diff is because of cross-contamination of feces in the farrowing crate, which are narrow metal cages that mother pigs are kept in while their piglets are nursing.

Can't you just follow food safety guidelines and cook the meat through? Unfortunately, current food safety guidelines are ineffective against C. difficile. To date, most food safety guidelines recommend cooking to an internal temperature as low as 63o C-the official USDA recommendation for pork-but recent studies show that C. diff spores can survive extended heating at 71o. Therefore, the guidelines should be raised to take this potentially killer infection into account.

One of the problems is that sources of C. diff food contamination might include not only fecal contamination on the surface of the meat, but transfer of spores from the gut into the actual muscles of the animal, inside the meat. Clostridia bacteria like C. diff comprise one of the main groups of bacteria involved in natural carcass degradation, and so by colonizing muscle tissue before death, C. diff can not only transmit to new hosts that eat the muscles, like us, but give them a head start on carcass break-down.

Never heard of C. diff? That's the Toxic Megacolon Superbug I've talked about before.

Another foodborne illness tied to pork industry practices is yersiniosis. See Yersinia in Pork.

MRSA (Methicillin-resistant Staph aureus) is another so-called superbug in the meat supply:

More on the scourge of antibiotic resistance and what can be done about it:

How is it even legal to sell foods with such pathogens? See Salmonella in Chicken & Turkey: Deadly But Not Illegal and Chicken Salmonella Thanks to Meat Industry Lawsuit.

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: USDA / Flickr. This image has been modified.

Original Link

Can You Eat Too Much Fruit?

Can You Eat Too Much Fruit?.jpeg

In my video If Fructose is Bad, What About Fruit?, I explored how adding berries to our meals can actually blunt the detrimental effects of high glycemic foods, but how many berries? The purpose of one study out of Finland was to determine the minimum level of blueberry consumption at which a consumer may realistically expect to receive antioxidant benefits after eating blueberries with a sugary breakfast cereal. If we eat a bowl of corn flakes with no berries, within two hours, so many free radicals are created that it puts us into oxidative debt. The antioxidant power of our bloodstream drops below where we started from before breakfast, as the antioxidants in our bodies get used up dealing with such a crappy breakfast. As you can see in How Much Fruit is Too Much? video, a quarter cup of blueberries didn't seem to help much, but a half cup of blueberries did.

What about fruit for diabetics? Most guidelines recommend eating a diet with a high intake of fiber-rich food, including fruit, because they're so healthy--antioxidants, anti-inflammatory, improving artery function, and reducing cancer risk. However, some health professionals have concerns about the sugar content of fruit and therefore recommend restricting the fruit intake. So let's put it to the test! In a study from Denmark, diabetics were randomized into two groups: one told to eat at least two pieces of fruit a day, and the other told at most, two fruits a day. The reduce fruit group indeed reduce their fruit consumption, but it had no effect on the control of their diabetes or weight, and so, the researchers concluded, the intake of fruit should not be restricted in patients with type 2 diabetes. An emerging literature has shown that low-dose fructose may actually benefit blood sugar control. Having a piece of fruit with each meal would be expected to lower, not raise the blood sugar response.

The threshold for toxicity of fructose may be around 50 grams. The problem is that's the current average adult fructose consumption. So, the levels of half of all adults are likely above the threshold for fructose toxicity, and adolescents currently average 75. Is that limit for added sugars or for all fructose? If we don't want more than 50 and there's about ten in a piece of fruit, should we not eat more than five fruit a day? Quoting from the Harvard Health Letter, "the nutritional problems of fructose and sugar come when they are added to foods. Fruit, on the other hand, is beneficial in almost any amount." What do they mean almost? Can we eat ten fruit a day? How about twenty fruit a day?

It's actually been put to the test.

Seventeen people were made to eat 20 servings a day of fruit. Despite the extraordinarily high fructose content of this diet, presumably about 200 g/d--eight cans of soda worth, the investigators reported no adverse effects (and possible benefit actually) for body weight, blood pressure, and insulin and lipid levels after three to six months. More recently, Jenkins and colleagues put people on about a 20 servings of fruit a day diet for a few weeks and found no adverse effects on weight or blood pressure or triglycerides, and an astounding 38 point drop in LDL cholesterol.

There was one side effect, though. Given the 44 servings of vegetables they had on top of all that fruit, they recorded the largest bowl movements apparently ever documented in a dietary intervention.


Cutting down on sugary foods may be easier said than done (see Are Sugary Foods Addictive?) but it's worth it. For more on the dangers of high levels of fructose in added sugars, see How Much Added Sugar Is Too Much?.

What's that about being in oxidative debt? See my three part series on how to pull yourself out of the red:

Ironically, fat may be more of a problem when it comes to diabetes than sugar, see:

In health,
Michael Greger, M.D.

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

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

Original Link

Can You Eat Too Much Fruit?

Can You Eat Too Much Fruit?.jpeg

In my video If Fructose is Bad, What About Fruit?, I explored how adding berries to our meals can actually blunt the detrimental effects of high glycemic foods, but how many berries? The purpose of one study out of Finland was to determine the minimum level of blueberry consumption at which a consumer may realistically expect to receive antioxidant benefits after eating blueberries with a sugary breakfast cereal. If we eat a bowl of corn flakes with no berries, within two hours, so many free radicals are created that it puts us into oxidative debt. The antioxidant power of our bloodstream drops below where we started from before breakfast, as the antioxidants in our bodies get used up dealing with such a crappy breakfast. As you can see in How Much Fruit is Too Much? video, a quarter cup of blueberries didn't seem to help much, but a half cup of blueberries did.

What about fruit for diabetics? Most guidelines recommend eating a diet with a high intake of fiber-rich food, including fruit, because they're so healthy--antioxidants, anti-inflammatory, improving artery function, and reducing cancer risk. However, some health professionals have concerns about the sugar content of fruit and therefore recommend restricting the fruit intake. So let's put it to the test! In a study from Denmark, diabetics were randomized into two groups: one told to eat at least two pieces of fruit a day, and the other told at most, two fruits a day. The reduce fruit group indeed reduce their fruit consumption, but it had no effect on the control of their diabetes or weight, and so, the researchers concluded, the intake of fruit should not be restricted in patients with type 2 diabetes. An emerging literature has shown that low-dose fructose may actually benefit blood sugar control. Having a piece of fruit with each meal would be expected to lower, not raise the blood sugar response.

The threshold for toxicity of fructose may be around 50 grams. The problem is that's the current average adult fructose consumption. So, the levels of half of all adults are likely above the threshold for fructose toxicity, and adolescents currently average 75. Is that limit for added sugars or for all fructose? If we don't want more than 50 and there's about ten in a piece of fruit, should we not eat more than five fruit a day? Quoting from the Harvard Health Letter, "the nutritional problems of fructose and sugar come when they are added to foods. Fruit, on the other hand, is beneficial in almost any amount." What do they mean almost? Can we eat ten fruit a day? How about twenty fruit a day?

It's actually been put to the test.

Seventeen people were made to eat 20 servings a day of fruit. Despite the extraordinarily high fructose content of this diet, presumably about 200 g/d--eight cans of soda worth, the investigators reported no adverse effects (and possible benefit actually) for body weight, blood pressure, and insulin and lipid levels after three to six months. More recently, Jenkins and colleagues put people on about a 20 servings of fruit a day diet for a few weeks and found no adverse effects on weight or blood pressure or triglycerides, and an astounding 38 point drop in LDL cholesterol.

There was one side effect, though. Given the 44 servings of vegetables they had on top of all that fruit, they recorded the largest bowl movements apparently ever documented in a dietary intervention.


Cutting down on sugary foods may be easier said than done (see Are Sugary Foods Addictive?) but it's worth it. For more on the dangers of high levels of fructose in added sugars, see How Much Added Sugar Is Too Much?.

What's that about being in oxidative debt? See my three part series on how to pull yourself out of the red:

Ironically, fat may be more of a problem when it comes to diabetes than sugar, see:

In health,
Michael Greger, M.D.

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

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

Original Link

Benefits of Nutritional Yeast to Prevent the Common Cold

Benefits of Nutritional Yeast to Prevent the Common Cold.jpeg

Natural immunomodulators that can help regulate our immune system without side-effects have been sought for centuries, and all the while they've been sitting in the produce aisle. Plants produce thousand of active compounds, many of which modulate our immune system, but we can't forget the fungi (see Boosting Immunity While Reducing Inflammation).

Mushrooms have used for centuries as folk remedies, and for good reason. Some have been shown to boost immune function, so much so that a type of fiber found in shiitake mushrooms is approved for use as adjunct chemotherapy, injected intravenously to help treat a variety of cancers by rallying our immune defenses.

More than 6,000 papers have been published on these so-called beta glucans, but almost all of the data about preventing infections had come from petri dish or lab animal studies, until a few years ago when a series of experiments on athletes showed beneficial effects in marathon runners (see Preserving Immune Function in Athletes With Nutritional Yeast). What about the rest of us? We didn't know... until now.

As I explore in my video, Nutritional Yeast to Prevent the Common Cold, beta glucan fiber found in baker's, brewer's and nutritional yeast helps to maintain our body's defense against pathogens even in nonathletes, according to a double-blind, randomized, placebo-controlled trial. The recurrence of infections with the common cold was reduced by 25% in those that ate the equivalent of about a spoonful of nutritional yeast a day, and had fewer cold-related sleeping difficulties when they did get sick.

What about half a spoonful a day? Still worked! Subjects experienced a big drop in common cold incidence and a reduction in symptoms as well. Why is this? This study found that not only were upper respiratory infection symptoms diminished, but that mood states appeared to improve, for example a significant boost in feelings of "vigor." So the researchers suggest that maybe the yeast fiber is able to counteract the negative effects of stress on the immune system.

In terms of side-effects, two folks reported stomachaches, but they were both in the placebo group.

Unlike antibiotics and antivirals, which are designed to kill the pathogen directly, these yeast compounds instead appear to work by stimulating our immune defenses, and as such don't share the same antibiotic side effects. They stimulate our immune defenses presumably because our body recognizes them as foreign. But if it's treated like an invader, might it trigger an inflammatory response? Turns out these fiber compounds may actually have an anti-inflammatory effect, suggesting nutritional yeast may offer the best of both worlds, boosting the infection fighting side of the immune system while suppressing inflammatory components.

Yeast is high in purines, so those with gout, uric acid kidney stones, and new organ transplant recipients may want to keep their intake to less than a teaspoon a day. But is there any downside for everyone else? In California some packages of nutritional yeast are slapped with prop 65 warning stickers, suggesting there's something in it exceeding cancer or birth defect safety limits. I called around to the companies and it turns out the problem is lead. California state law says a product cannot contain more than half of a microgram of lead per daily serving, so I contacted the six brands I knew about and asked them how much lead was in their products.

KAL originally said "<5 ppm," but when we called back they said "<3 ppm." Even if it's 3, that translates into less than 45 micrograms per serving, nearly a 100 times more than the California limit. But perhaps that's better than Bob's Red Mill or Frontier Coop, who evidently don't test at all. But at least they got back to me. Redstar brand failed to respond to multiple attempts to contact them. Now Foods said they test for lead and claim that at least their recent batches meet the less than a half a microgram California standard. Unfortunately, despite repeated requests they would not provide me with documentation to substantiate their numbers. My favorite response was from Bragg's who sent me the analysis certificate from the lab showing less than 0.01 ppm, which means at most less than half the California standard, which I believe is the most stringent in the world. To put the numbers in context, in determining how much lead manufacturers can put into candy likely to be frequently consumed by small children, the Food and Drug Administration would allow about 2 micrograms a day in the form of lollipops, but as far as I'm concerned the less lead the better.

I was so frustrated by the lack of transparency I decided to test them for lead myself. NutritionFacts.org hired an independent lab to conduct our own tests for lead and shipped out 8 samples of nutritional yeast in their original package. The lab used standard practices for lead testing known as Official Methods of Analysis set by AOAC International. Lab technicians determined the lead values based on California Prop 65 standards. Here are the results from the brands we tested:

Bob's Red Mill - Test report shows no detectable lead (<0.01 ppm).

Bragg - Test report shows no detectable lead (< 0.01 ppm).

Dr. Fuhrman - Test report shows no detectable lead (< 0.01 ppm).

Frontier Coop - Test report shows lead levels at 0.021 ppm. It would take six tablespoons a day (based on the manufacture's listed density) to exceed the California Office of Environmental Health Hazard Assessment Maximum Allowable Dose Level (MADL) for chemicals causing reproductive toxicity.*

KAL - Test report shows lead levels at 0.011 ppm. It would take seven tablespoons a day to exceed the MADL.*

NOW Foods - Test report shows no detectable lead (< 0.01 ppm).

Red Star - Test report shows no detectable lead (< 0.01 ppm).

Whole Foods - Test report shows lead levels at 0.012 ppm. It would take six tablespoons a day to exceed the MADL.*

So what do all those numbers mean? None of the brands tested exceeded California prop 65 standards. No matter what brand, consuming a typical serving (2 tablespoons) per day is still well within safe limits.

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:

* The Maximum Allowable Dose Level for lead as a developmental toxin is 0.5 micrograms a day. How are MADL's calculated? Basically scientists figure out what the "no observable effect level" is, the level at which no birth defects or reproductive toxicity can be found, and then introduce a 1000-fold safety buffer. So for example, let's say there's some chemical that causes birth defects if expectant moms are exposed to two drops of the chemical a day, but there's no evidence that one drop a day is harmful. Do they set the Maximum Allowable Dose Level at one drop? No, they set it at 1/1000th of a drop to account for scientific uncertainty and to err on the side of caution. So by saying six tablespoons a day of nutritional yeast may exceed the MADL is in effect saying that the level of lead found in 6,000 tablespoons of nutritional yeast may cause birth defects. Like mercury, though, as far as I'm concerned the less lead exposure the better. I hope this will inspire companies to do further testing to see if the levels we found were just flukes.

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

Original Link

Benefits of Nutritional Yeast to Prevent the Common Cold

Benefits of Nutritional Yeast to Prevent the Common Cold.jpeg

Natural immunomodulators that can help regulate our immune system without side-effects have been sought for centuries, and all the while they've been sitting in the produce aisle. Plants produce thousand of active compounds, many of which modulate our immune system, but we can't forget the fungi (see Boosting Immunity While Reducing Inflammation).

Mushrooms have used for centuries as folk remedies, and for good reason. Some have been shown to boost immune function, so much so that a type of fiber found in shiitake mushrooms is approved for use as adjunct chemotherapy, injected intravenously to help treat a variety of cancers by rallying our immune defenses.

More than 6,000 papers have been published on these so-called beta glucans, but almost all of the data about preventing infections had come from petri dish or lab animal studies, until a few years ago when a series of experiments on athletes showed beneficial effects in marathon runners (see Preserving Immune Function in Athletes With Nutritional Yeast). What about the rest of us? We didn't know... until now.

As I explore in my video, Nutritional Yeast to Prevent the Common Cold, beta glucan fiber found in baker's, brewer's and nutritional yeast helps to maintain our body's defense against pathogens even in nonathletes, according to a double-blind, randomized, placebo-controlled trial. The recurrence of infections with the common cold was reduced by 25% in those that ate the equivalent of about a spoonful of nutritional yeast a day, and had fewer cold-related sleeping difficulties when they did get sick.

What about half a spoonful a day? Still worked! Subjects experienced a big drop in common cold incidence and a reduction in symptoms as well. Why is this? This study found that not only were upper respiratory infection symptoms diminished, but that mood states appeared to improve, for example a significant boost in feelings of "vigor." So the researchers suggest that maybe the yeast fiber is able to counteract the negative effects of stress on the immune system.

In terms of side-effects, two folks reported stomachaches, but they were both in the placebo group.

Unlike antibiotics and antivirals, which are designed to kill the pathogen directly, these yeast compounds instead appear to work by stimulating our immune defenses, and as such don't share the same antibiotic side effects. They stimulate our immune defenses presumably because our body recognizes them as foreign. But if it's treated like an invader, might it trigger an inflammatory response? Turns out these fiber compounds may actually have an anti-inflammatory effect, suggesting nutritional yeast may offer the best of both worlds, boosting the infection fighting side of the immune system while suppressing inflammatory components.

Yeast is high in purines, so those with gout, uric acid kidney stones, and new organ transplant recipients may want to keep their intake to less than a teaspoon a day. But is there any downside for everyone else? In California some packages of nutritional yeast are slapped with prop 65 warning stickers, suggesting there's something in it exceeding cancer or birth defect safety limits. I called around to the companies and it turns out the problem is lead. California state law says a product cannot contain more than half of a microgram of lead per daily serving, so I contacted the six brands I knew about and asked them how much lead was in their products.

KAL originally said "<5 ppm," but when we called back they said "<3 ppm." Even if it's 3, that translates into less than 45 micrograms per serving, nearly a 100 times more than the California limit. But perhaps that's better than Bob's Red Mill or Frontier Coop, who evidently don't test at all. But at least they got back to me. Redstar brand failed to respond to multiple attempts to contact them. Now Foods said they test for lead and claim that at least their recent batches meet the less than a half a microgram California standard. Unfortunately, despite repeated requests they would not provide me with documentation to substantiate their numbers. My favorite response was from Bragg's who sent me the analysis certificate from the lab showing less than 0.01 ppm, which means at most less than half the California standard, which I believe is the most stringent in the world. To put the numbers in context, in determining how much lead manufacturers can put into candy likely to be frequently consumed by small children, the Food and Drug Administration would allow about 2 micrograms a day in the form of lollipops, but as far as I'm concerned the less lead the better.

I was so frustrated by the lack of transparency I decided to test them for lead myself. NutritionFacts.org hired an independent lab to conduct our own tests for lead and shipped out 8 samples of nutritional yeast in their original package. The lab used standard practices for lead testing known as Official Methods of Analysis set by AOAC International. Lab technicians determined the lead values based on California Prop 65 standards. Here are the results from the brands we tested:

Bob's Red Mill - Test report shows no detectable lead (<0.01 ppm).

Bragg - Test report shows no detectable lead (< 0.01 ppm).

Dr. Fuhrman - Test report shows no detectable lead (< 0.01 ppm).

Frontier Coop - Test report shows lead levels at 0.021 ppm. It would take six tablespoons a day (based on the manufacture's listed density) to exceed the California Office of Environmental Health Hazard Assessment Maximum Allowable Dose Level (MADL) for chemicals causing reproductive toxicity.*

KAL - Test report shows lead levels at 0.011 ppm. It would take seven tablespoons a day to exceed the MADL.*

NOW Foods - Test report shows no detectable lead (< 0.01 ppm).

Red Star - Test report shows no detectable lead (< 0.01 ppm).

Whole Foods - Test report shows lead levels at 0.012 ppm. It would take six tablespoons a day to exceed the MADL.*

So what do all those numbers mean? None of the brands tested exceeded California prop 65 standards. No matter what brand, consuming a typical serving (2 tablespoons) per day is still well within safe limits.

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:

* The Maximum Allowable Dose Level for lead as a developmental toxin is 0.5 micrograms a day. How are MADL's calculated? Basically scientists figure out what the "no observable effect level" is, the level at which no birth defects or reproductive toxicity can be found, and then introduce a 1000-fold safety buffer. So for example, let's say there's some chemical that causes birth defects if expectant moms are exposed to two drops of the chemical a day, but there's no evidence that one drop a day is harmful. Do they set the Maximum Allowable Dose Level at one drop? No, they set it at 1/1000th of a drop to account for scientific uncertainty and to err on the side of caution. So by saying six tablespoons a day of nutritional yeast may exceed the MADL is in effect saying that the level of lead found in 6,000 tablespoons of nutritional yeast may cause birth defects. Like mercury, though, as far as I'm concerned the less lead exposure the better. I hope this will inspire companies to do further testing to see if the levels we found were just flukes.

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

Original Link

The Saturated Fat Studies: Buttering Up the Public

NF-Sept29 The Saturated Fat Studies Buttering Up the Public.jpeg

Time magazine's cover exhorting people to eat butter could be viewed as a desperate attempt to revive dwindling print sales, but they claimed to be reporting on real science--a systematic review and meta-analysis published in a prestigious journal that concluded that current evidence does not clearly support cardiovascular guidelines that encourage cutting down on saturated fat, like the kind found in meat and dairy products like butter.

No wonder it got so much press, since reducing saturated fat intake is a major focus of most dietary recommendations worldwide, aiming to prevent chronic diseases including coronary heart disease. So, to quote the Center for Science in the Public Interest, "What gives? Evidently, shaky science...and a mission by the global dairy industry to boost sales."

They interviewed an academic insider, who noted that some researchers are intent on showing saturated fat does not cause heart disease, which can be seen in my video The Saturated Fat Studies: Buttering Up the Public. In 2008, the global dairy industry held a meeting where they decided that one of their main priorities was to "neutralize the negative impact of milk fat by regulators and medical professionals." And when they want to do something, they get it done. So they set up a major, well-funded campaign to come up with proof that saturated fat does not cause heart disease. They assembled scientists who were sympathetic to the dairy industry, provided them with funding, encouraged them to put out statements on milk fat and heart disease, and arranged to have them speak at scientific meetings. And the scientific publications we've seen emerging since the Mexico meeting have done just what they set out to do.

During this meeting, the dairy industry discussed what is the key barrier to increasing worldwide demand for dairy. There's global warming issues and other milks competing out there, but number one on the list is the "Negative messages and intense pressure to reduce saturated fats by governments and non- governmental organizations." In short, the negative messages are outweighing the positive, so indeed, their number one priority is to neutralize the negative image of milk fat among regulators and health professionals as related to heart disease.

So if we are the dairy industry, how are we going to do it? Imagine we work for Big Butter. We've got quite the challenge ahead of us. If we look at recommendations from around the globe, there is a global scientific consensus to limit saturated fat intake with most authoritative bodies recommending getting saturated fat at least under 10% of calories, with the prestigious U.S. Institute of Medicine and the European Food Safety Authority recommending to push saturated fat consumption down as low as possible.

The latest guidelines from the American Heart Association and the American College of Cardiology recommend reducing trans fat intake, giving it their strongest A-grade level of evidence. And they say the same same for reducing saturated fat intake. Since saturated and trans fats are found in the same place, meat and dairy, cutting down on foods with saturated fat will have the additional benefit of lowering trans fat intake. They recommend pushing saturated fat intake down to 5 or 6%. People don't realize how small that is. One KFC chicken breast could take us over the top. Or, two pats of butter and two cubes of cheese and we're done for the day--no more dairy, meat, or eggs. That'd be about 200 calories, so they are in effect saying 90% of our diet should be free of saturated fat-containing foods. That's like the American Heart Association saying, "two meals a week can be packed with meat, dairy, and junk, but the entire rest of the week should be unprocessed plant-foods." That's how stringent the new recommendations are.

So this poses a problem for Big Cheese and Chicken. The top contributors of cholesterol-raising saturated fat is cheese, ice cream, chicken, non-ice cream desserts like cake and pie, and then pork. So what are these industries to do? See The Saturated Fat Studies: Set Up to Fail.

For those unfamiliar with Trans Fat in Meat and Dairy (and refined vegetable oils), that's why I made a video about it.

The U.S. National Academy of Sciences Institute of Medicine "as low as possible" position, echoed by the European Food Safety Authority, is described in my video: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

What happened when a country tried to put the lower saturated fat guidance into practice? See the remarkable results in Dietary Guidelines: From Dairies to Berries.

Don't think the dietary guidelines process could be undermined by underhanded corporate tactics? Sad but true:

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: Johnathan Nightingale / Flickr

Original Link

Side-Effects of Aspartame on the Brain

NF-Sept1 Aspartame and the Brain.jpeg

The National Institutes of Health AARP study of hundreds of thousands of Americans followed for years found that frequent consumption of sweetened beverages, especially diet drinks, may increase depression risk among older adults. Whether soda, fruit-flavored drinks, or iced tea, those artificially sweetened drinks appeared to carry higher risk. There was a benefit in coffee drinkers compared to non-drinkers, but if they added sugar, much of the benefits appeared to disappear, and if they added Equal or Sweet-and-Low, the risk appeared to go up.

Various effects of artificial sweeteners, including neurological effects, have been suspected. For example, aspartame--the chemical in Equal and Nutrasweet--may modulate brain neurotransmitters such as dopamine and serotonin, although data have been controversial and inconsistent. Scientific opinions range from "safe under all conditions" to "unsafe at any dose." The controversy started in the 80's soon after aspartame was approved. Researchers at the Mass College of Pharmacy and MIT noted:

"given the very large number of Americans routinely exposed, if only 1% of the 100,000,000 Americans thought to consume aspartame ever exceed the sweetener's acceptable daily intake, and if only 1% of this group happen coincidentally to have an underlying disease that makes their brains vulnerable to the effects, then the number of people who might manifest adverse brain reactions attributable to aspartame could still be about 10,000, a number on the same order as the number of brain and nerve-related consumer complaints already registered with the FDA before they stopped accepting further reports on adverse reactions to the sweetener."

Those with a history of depression might be especially vulnerable. Researchers at Case Western designed a study I highlighted in my video Aspartame and the Brain to ascertain whether individuals with mood disorders are particularly vulnerable to adverse effects of aspartame. Although they had planned on recruiting 40 patients with depression and 40 controls, the project was halted early by the Institutional Review Board for safety reasons because of the severity of reactions to aspartame within the group of patients with a history of depression.

It was decided that it was unethical to continue to expose people to the stuff.

Normally when we study a drug or a food, the company donates the product to the researchers because they're proud of the benefits or safety of their product. But the Nutrasweet company refused to even sell it to these researchers. The researchers managed to get their hands on some, and within a week there were significantly more adverse effects reported in the aspartame group than in the placebo group. They concluded that individuals with mood disorders may be particularly sensitive to aspartame, and therefore its use in this population should be discouraged.

In a review of the direct and indirect cellular effects of aspartame on the brain, it was noted that there are reports of aspartame causing neurological and behavioral disturbances in sensitive individuals, such as headaches, insomnia and seizures. The researchers go even further and propose that excessive aspartame ingestion might be involved in the development of certain mental disorders and also in compromised learning and emotional functioning. They conclude that "due to all the adverse effects caused by aspartame, it is suggested that serious further testing and research be undertaken to eliminate any and all controversies," to which someone responded in the journal that "there really is no controversy," arguing that aspartame was conclusively toxic.

But what do they mean by excessive ingestion? The latest study on the neuro-behavioral effects of aspartame consumption put people on a high aspartame diet compared to a low aspartame diet. But even the high dose at 25 mg/kg was only half the adequate daily intake set by the FDA. The FDA says one can safely consume 50mg a day, but after just eight days on half of that, participants had more irritable mood, exhibited more depression, and performed worse on certain brain function tests. And these weren't people with a pre-existing history of mental illness; these were just regular people. The researchers concluded that "given that the higher intake level tested here was well below the maximum acceptable daily intake level [40mg in Europe, 50mg here] careful consideration is warranted when consuming food products that may affect neurobehavioral health."

Easier said than done, since it's found in more than 6,000 foods, apparently making artificial sweeteners "impossible to completely eradicate from daily exposure." While that may be true for the great majority of Americans, it's only because they elect to eat processed foods. If we stick to whole foods, we don't even have to read the ingredients lists, because the healthiest foods in the supermarket are label-free, they don't even have ingredients lists--produce!

I've previously touched on artificial sweeteners before:

The healthiest caloric sweeteners are blackstrap molasses and date sugar (whole dried powdered dates). The least toxic low-calorie sweetener is probably erythritol (Erythritol May Be a Sweet Antioxidant).

Coffee may decrease suicide and cancer risk (Preventing Liver Cancer with Coffee? and Coffee and Cancer) but may impair blood flow to the heart (Coffee and Artery Function).

Other ways to improve mood include:

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: Mike Mozart / Flickr

Original Link

GMO Soy and Breast Cancer

July12.jpg

In response to concerns raised about the toxicity of Monsanto's roundup pesticide, which ends up in GMO foods (See Is Monsanto's Roundup Pesticide Glyphosate Safe?), Monsanto's scientists countered that these in vitro experiments used physiological irrelevant concentrations, meaning dripping roundup on cells in a petri dish at levels far above what would be realistically found in the human body.

Sure, it's probably not a good idea to mix up your alcohol with your roundup and chug the stuff, or try to commit suicide by drinking or injecting it. And there are rare cases of Parkinson's reported after getting directly sprayed with it, or working for years in a pesticide production plant, but that's not your typical consumer exposure.

As shown in my video GMO Soy and Breast Cancer, some of the researchers responded to the accusation claiming they used the kinds of concentrations that are used out in the fields. Therefore every little droplet we spray worldwide is above the threshold concentration they found to cause adverse effects. Monsanto's folks responded saying, "Yes, that's the concentration we spray, but that's not the concentration that human cells are bathing in. Once it gets into drinking water or food, it's highly diluted." And, they're quick to point out, if we look at people with the greatest exposure--pesticide workers--the vast majority of studies show no link between the use of Roundup and cancer or non-cancer diseases. There are a few suggestive findings suggesting a link with non-Hodgkin's lymphoma. One study of pesticide applicators suggested an association with multiple myeloma, and one study of the children of pesticide applicators found a tentative association with ADHD, but again these are folks experiencing a much greater exposure level than the general population that may just get a few parts per million in their food. But there had never been any studies done on the tiny levels found circulating in people's bodies, until now.

In a study out of Thailand, the maximum residue levels were set at parts per million (the concentrations found within human bodies is measured in parts per billion). The study found glyphosate can activate estrogen receptors at a few parts per trillion, increasing the growth of estrogen receptor positive human breast cancer cells in a petri dish. These results indicate "that truly relevant concentrations of the pesticide found on GMO soybeans possesses estrogenic activity."

But consumption of soy is associated with lower breast cancer risk (See BRCA Breast Cancer Genes and Soy), and improved breast cancer survival (See Breast Cancer Survival and Soy).

That may be because most GMO soy in the U.S. is fed to chickens, pigs, and cows as livestock feed, whereas most of the major soy food manufacturers use non-GMO soy. Or it could be because the benefits of eating any kind of soy may far outweigh the risks, but why accept any risk at all when we can choose organic soy products, which by law exclude GMOs.

The bottom-line is that there is no direct human data suggesting harm from eating GMOs, though in fairness such studies haven't been done, which is exactly the point that critics counter. This is why we need mandatory labeling on GMO products so that public health researchers can track whether GMOs are having any adverse effects.

It is important to put the GMO issue in perspective though. As I've shown (See Lifestyle Medicine: Treating the Causes of Disease), there are dietary and lifestyle changes we can make that could eliminate most heart disease, strokes, diabetes, and cancer. Millions of lives could be saved. A healthy enough diet can even reverse our number one killer, heart disease. So, I'm sympathetic to the biotech industry's exasperation about GMO concerns when we still have people dropping dead from everything else they're eating. As one review concluded "consumption of genetically modified food entails risk of undesirable effects... similar to the consumption of traditional food." In other words, buying the non-GMO Twinkie isn't doing our body much of a favor.

For more on the public health implications of genetically engineered crops in our food supply, check out the these 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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image: Nesbitt_Photo / Flickr

Original Link

Is Monsanto’s Roundup Pesticide Glyphosate Safe?

July7.jpg

GMO soy has been found to be contaminated with pesticide residues (see Are GMOs Safe? The Case of Roundup Ready Soy), but are these levels anything to worry about? I explore this question in my video Is Monsanto's Roundup Pesticide Glyphosate Safe?.

Researchers out of Norway described the amount of pesticide residues found in GMO soy as high compared to the maximum allowable residue levels. The legal limit for glyphosate in foods had been set at 0.1-0.2 mg/kg; so these exceed the legal limits by an average of about 2000%, whereas organic and conventional non-GMO soy both had none.

So what did Monsanto do? Did the industry ditch the whole GMO thing, go back to using less pesticides so that residue levels wouldn't be so high? Or, they could just change the definition of high. What if they could get authorities to raise the maximum residue level from 0.1 or 0.2 up to 20? Then the residue levels won't look so high anymore. And this is exactly what they did. The acceptance level of glyphosate in food and animal feed has been increased by authorities in countries that use Roundup-Ready GM crops. In Brazil, they went up to ten, and the U.S. and Europe now accept up to 20. In all of these cases, the maximum residue level values appear to have been adjusted, not based on new evidence indicating glyphosate toxicity was less than previously understood, but pragmatically in response to actual observed increases in the content of residues in GMO soybeans--otherwise it wouldn't be legal to sell the stuff.

What evidence do we have, though, that these kinds of residues are harmful? For 12 years we've heard that Roundup interferes with embryonic development, but that study was about sea urchin embryos. For 14 years we heard that Roundup may disrupt hormones, but that's in mouse testicles.

Blogs will dish about concerning new studies implicating Roundup in male fertility, but if we look at the study, it's about rat testicles. Some blogs cite studies with disturbing titles like "prepubertal exposure alters testosterone levels and testicular shape," but they're talking about puberty in rats, though that doesn't make as catchy a blog title.

Why not use human tissue? Women are having babies every day--why not just experiment on human placentas, which would otherwise just get thrown away? In 2005, researchers did just that. And despite all the negative effects in rodents, glyphosate, the active ingredient in Roundup didn't seem to have much of a toxic effect on human cells even at high doses, or have much effect on a hormone regulating enzyme, leading Monsanto-funded reviewers to conclude that regardless of what hazards might be alleged based on animal studies, "glyphosate is not anticipated to produce adverse developmental and reproductive effects in humans."

But pure glyphosate isn't sprayed on crops, Roundup is, which contains a variety of adjuvants and surfactants meant to help the glyphosate penetrate into tissues. And indeed when the study was repeated with what's actually sprayed on GMO crops, there were toxic and hormonal effects even at doses smaller than the 1 or 2% concentration that's used out on the fields.

Similar results were found for other major pesticides. It took until 2014, but eight out of nine pesticide formulations tested were up to one thousand times more toxic than their so-called active ingredients, so when we just test the isolated chemicals, we may not get the whole story. Roundup was found to be 100 times more toxic than glyphosate itself. Moreover, Roundup turned out to be among the most toxic pesticides they tested. It's commonly believed that Roundup is among the safest, though, an idea spread by Monsanto, the manufacturer. However, this inconsistency between scientific fact and industrial claim may be attributed to the huge economic interests involved.

What is glyphosate? Check out: Are GMOs Safe? The Case of BT Corn.

It's the dose that makes the poison, though. Do we have evidence that the levels of Roundup chemicals not only found on crops, but also in our bodies after eating those crops actually have adverse effects? That's the subject of the video: GMO Soy and Breast Cancer.

Commercial interests can have a corrupting effect on the science of nutrition and hold sway over institutions that are supposed to operate in the public interest. See for example:

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: Mike Mozart / Flickr

Original Link