Boosting Brown Fat Through Diet

Sept 26 Boosting Brown Fat copy.jpeg

Until about ten years ago, brown adipose tissue (BAT) was considered to be biologically active only in babies and small children where it generates heat by burning fat. But now, there is no doubt that active brown fat is present in adult humans and is involved in cold-induced increases in whole-body calorie expenditure and, thereby, helps control of not only body temperature but also how fat we are.

In 2013, researchers showed that one could activate brown adipose tissue if you chill out people long enough, specifically, by exposing them to two hours of cold every day for six weeks, which can lead to a significant reduction in body fat. You can see an illustrative graph in my video Boosting Brown Fat Through Diet. Although researchers demonstrated the effective recruitment of human brown fat, it would seem difficult to increase exposure to cold in daily life. Thankfully, our brown fat can also be activated by some food ingredients, such as capsaicin, the compound that makes hot peppers hot.

While physical activity is usually recommended to increase energy expenditure, there are specific food components, such as capsaicin, that are known to burn off calories. For example, one study found that there was a significant rise in energy expenditure within 30 minutes of eating the equivalent of a jalapeño pepper.

Normally when we cut down on calories, our metabolism slows down, undercutting our weight loss attempts; but sprinkling a third of a teaspoon of red chili pepper powder onto our meals counteracts that metabolic slow down and promotes fat burning. Researchers wanted to try giving participants more chili pepper in order to try to match some of the studies done in Asia, but the Caucasian subjects couldn't take it. But by adding more than a tablespoon of red pepper powder to a high-fat meal, Japanese women burned significantly more fat.

We've known for decades that cayenne pepper increases metabolic rate, but we didn't know how. But studies show that this class of compounds increases energy expenditure in human individuals with brown fat, but not in those without it, indicating that individuals increase expenditure right off the BAT. Additionally, there is a variety of structurally similar flavor molecules in other foods, like black pepper and ginger, that may activate thermogenesis as well, but they haven't been directly tested.

All these results suggest that the anti-obesity effects of pepper compounds are based on the heat-generating activity of recruited brown fat. Thus, repeated ingestion can mimic the chronic effects of cold exposure without having to freeze ourselves.

Consumption of spicy foods may help us lose weight, but what about the sensory burn and pain on our tongues and sometimes in our stomachs as well as further on down? Are our only two options for boosting brown fat to freeze our legs or burn our butts?

Arginine-rich foods may also stimulate brown adipose tissue growth and development through a variety of mechanisms, which is achieved by consuming more soy foods, seeds, nuts, and beans.


For more on brown adipose tissue, see Brown Fat: Losing Weight Through Thermogenesis.

What about arginine? Check out Fat Burning Via Arginine. And, did you know arginine may also play a role in the effects nuts may have on penile blood flow? I discuss this in Pistachio Nuts for Erectile Dysfunction.

For more on spicy foods, see my videos Cayenne Pepper for Irritable Bowel Syndrome and Chronic Indigestion to learn how digestive disorders may be helped and Hot Sauce in the Nose for Cluster Headaches? for information on how the hot pepper compound can be a lifesaver for people suffering from "suicide" headaches.

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

Boosting Brown Fat Through Diet

Sept 26 Boosting Brown Fat copy.jpeg

Until about ten years ago, brown adipose tissue (BAT) was considered to be biologically active only in babies and small children where it generates heat by burning fat. But now, there is no doubt that active brown fat is present in adult humans and is involved in cold-induced increases in whole-body calorie expenditure and, thereby, helps control of not only body temperature but also how fat we are.

In 2013, researchers showed that one could activate brown adipose tissue if you chill out people long enough, specifically, by exposing them to two hours of cold every day for six weeks, which can lead to a significant reduction in body fat. You can see an illustrative graph in my video Boosting Brown Fat Through Diet. Although researchers demonstrated the effective recruitment of human brown fat, it would seem difficult to increase exposure to cold in daily life. Thankfully, our brown fat can also be activated by some food ingredients, such as capsaicin, the compound that makes hot peppers hot.

While physical activity is usually recommended to increase energy expenditure, there are specific food components, such as capsaicin, that are known to burn off calories. For example, one study found that there was a significant rise in energy expenditure within 30 minutes of eating the equivalent of a jalapeño pepper.

Normally when we cut down on calories, our metabolism slows down, undercutting our weight loss attempts; but sprinkling a third of a teaspoon of red chili pepper powder onto our meals counteracts that metabolic slow down and promotes fat burning. Researchers wanted to try giving participants more chili pepper in order to try to match some of the studies done in Asia, but the Caucasian subjects couldn't take it. But by adding more than a tablespoon of red pepper powder to a high-fat meal, Japanese women burned significantly more fat.

We've known for decades that cayenne pepper increases metabolic rate, but we didn't know how. But studies show that this class of compounds increases energy expenditure in human individuals with brown fat, but not in those without it, indicating that individuals increase expenditure right off the BAT. Additionally, there is a variety of structurally similar flavor molecules in other foods, like black pepper and ginger, that may activate thermogenesis as well, but they haven't been directly tested.

All these results suggest that the anti-obesity effects of pepper compounds are based on the heat-generating activity of recruited brown fat. Thus, repeated ingestion can mimic the chronic effects of cold exposure without having to freeze ourselves.

Consumption of spicy foods may help us lose weight, but what about the sensory burn and pain on our tongues and sometimes in our stomachs as well as further on down? Are our only two options for boosting brown fat to freeze our legs or burn our butts?

Arginine-rich foods may also stimulate brown adipose tissue growth and development through a variety of mechanisms, which is achieved by consuming more soy foods, seeds, nuts, and beans.


For more on brown adipose tissue, see Brown Fat: Losing Weight Through Thermogenesis.

What about arginine? Check out Fat Burning Via Arginine. And, did you know arginine may also play a role in the effects nuts may have on penile blood flow? I discuss this in Pistachio Nuts for Erectile Dysfunction.

For more on spicy foods, see my videos Cayenne Pepper for Irritable Bowel Syndrome and Chronic Indigestion to learn how digestive disorders may be helped and Hot Sauce in the Nose for Cluster Headaches? for information on how the hot pepper compound can be a lifesaver for people suffering from "suicide" headaches.

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

Brown Fat: Losing Weight Through Thermogenesis

Sept 21 Brown Fat Thermo copy.jpeg

During World War I, it was discovered that many of the chemicals for new explosives had toxic or even lethal effects on the workers in the munitions factories. Chemicals such as di-nitro-phenol (DNP) can boost metabolism so much that workers were too often found wandering along the road after work, covered in sweat with temperatures of 106 to 109 degrees Fahrenheit before they died. Even after death, their temperatures kept going up, as if they were having a total body meltdown. At subacute doses, however, workers claimed to have grown thin to a notable extent after several months working with the chemical.

That got some Stanford pharmacologists excited about the "promising metabolic applications" of DNP. Our resting metabolic rate jumps up 30% after one dose of DNP, and therefore, it becomes an actual fat-burning drug. People started losing weight, as you can see in my video Brown Fat: Losing Weight Through Thermogenesis, with no apparent side effects. They felt great... and then thousands of people started going blind and users started dropping dead from hyperpyrexia, fatal fever due to the heat created by the burning fat. Of course, it continued to be sold. Ad copy read:

"Here, at last, is a [weight] reducing remedy that will bring you a figure men admire and women envy, without danger to your health or change in your regular mode of living....No diet, no exercise!"

It did work, but the therapeutic index--the difference between the effective dose and the deadly dose--was razor thin. It was not until thousands suffered irreversible harm that it got pulled from the market and remained unavailable. Unavailable, that is, until it was brought back by the internet for those dying to be thin.

There is, however, a way our body naturally burns fat to create heat. When we're born, we go from a nice tropical 98.6 in our mother's womb straight to room temperature, just when we're still all wet and slimy. As an adaptive mechanism to maintain warmth, the appearance of a unique organ around 150 million years ago allowed mammals to maintain our high body temperatures.

That unique organ is called brown adipose tissue, or BAT, and its role is to consume fat calories by generating heat in response to cold exposure. The white fat in our bellies stores fat, but the brown fat, located up between our shoulder blades, burns fat. BAT is essential for thermogenesis, the creation of heat in newborns, but has been considered unnecessary in adults who have higher metabolic rates and increased muscle mass for shivering to warm us up when we get chilled. We used to think brown tissue just shrank away when we grew up, but, if it was there, then it could potentially make a big difference for how many calories we burn every day.

When PET scans were invented to detect metabolically active tissues like cancer, oncologists kept finding hot spots in the neck and shoulder regions that on CT scans turned out not to be cancer, just fat. Then, some observant radiologists noticed they appeared in patients mostly during the cold winter months. When they looked closer at tissue samples taken from people who had undergone neck surgery, they found it: brown fat in adults.

The common message from a number of studies is that BAT is present and active in adults, and the more we have and the more active it is, the thinner we are. And we can rapidly activate our fat-burning brown fat by exposure to cold temperatures. For example, if you hang out in a cold room for two hours in your undies and put your legs on a block of ice for four minutes every five minutes, you can elicit a marked increase in energy expenditure, thanks to brown fat activation. So, the studies point to a potential "natural" intervention to stimulate energy expenditure: Turn down the heat to burn calories (and reduce the carbon footprint in the process).

Thankfully, for those of us who would rather not lay our bare legs on blocks of ice, our brown fat can also be activated by some food ingredients such as those that are covered in my Boosting Brown Fat Through Diet video.


I briefly touch on the role cold temperatures can play in weight loss in The Ice Diet and talk more about calories in (Nutrient-Dense Approach to Weight Management) and calories out (How Much Exercise to Sustain Weight Loss).

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

Brown Fat: Losing Weight Through Thermogenesis

Sept 21 Brown Fat Thermo copy.jpeg

During World War I, it was discovered that many of the chemicals for new explosives had toxic or even lethal effects on the workers in the munitions factories. Chemicals such as di-nitro-phenol (DNP) can boost metabolism so much that workers were too often found wandering along the road after work, covered in sweat with temperatures of 106 to 109 degrees Fahrenheit before they died. Even after death, their temperatures kept going up, as if they were having a total body meltdown. At subacute doses, however, workers claimed to have grown thin to a notable extent after several months working with the chemical.

That got some Stanford pharmacologists excited about the "promising metabolic applications" of DNP. Our resting metabolic rate jumps up 30% after one dose of DNP, and therefore, it becomes an actual fat-burning drug. People started losing weight, as you can see in my video Brown Fat: Losing Weight Through Thermogenesis, with no apparent side effects. They felt great... and then thousands of people started going blind and users started dropping dead from hyperpyrexia, fatal fever due to the heat created by the burning fat. Of course, it continued to be sold. Ad copy read:

"Here, at last, is a [weight] reducing remedy that will bring you a figure men admire and women envy, without danger to your health or change in your regular mode of living....No diet, no exercise!"

It did work, but the therapeutic index--the difference between the effective dose and the deadly dose--was razor thin. It was not until thousands suffered irreversible harm that it got pulled from the market and remained unavailable. Unavailable, that is, until it was brought back by the internet for those dying to be thin.

There is, however, a way our body naturally burns fat to create heat. When we're born, we go from a nice tropical 98.6 in our mother's womb straight to room temperature, just when we're still all wet and slimy. As an adaptive mechanism to maintain warmth, the appearance of a unique organ around 150 million years ago allowed mammals to maintain our high body temperatures.

That unique organ is called brown adipose tissue, or BAT, and its role is to consume fat calories by generating heat in response to cold exposure. The white fat in our bellies stores fat, but the brown fat, located up between our shoulder blades, burns fat. BAT is essential for thermogenesis, the creation of heat in newborns, but has been considered unnecessary in adults who have higher metabolic rates and increased muscle mass for shivering to warm us up when we get chilled. We used to think brown tissue just shrank away when we grew up, but, if it was there, then it could potentially make a big difference for how many calories we burn every day.

When PET scans were invented to detect metabolically active tissues like cancer, oncologists kept finding hot spots in the neck and shoulder regions that on CT scans turned out not to be cancer, just fat. Then, some observant radiologists noticed they appeared in patients mostly during the cold winter months. When they looked closer at tissue samples taken from people who had undergone neck surgery, they found it: brown fat in adults.

The common message from a number of studies is that BAT is present and active in adults, and the more we have and the more active it is, the thinner we are. And we can rapidly activate our fat-burning brown fat by exposure to cold temperatures. For example, if you hang out in a cold room for two hours in your undies and put your legs on a block of ice for four minutes every five minutes, you can elicit a marked increase in energy expenditure, thanks to brown fat activation. So, the studies point to a potential "natural" intervention to stimulate energy expenditure: Turn down the heat to burn calories (and reduce the carbon footprint in the process).

Thankfully, for those of us who would rather not lay our bare legs on blocks of ice, our brown fat can also be activated by some food ingredients such as those that are covered in my Boosting Brown Fat Through Diet video.


I briefly touch on the role cold temperatures can play in weight loss in The Ice Diet and talk more about calories in (Nutrient-Dense Approach to Weight Management) and calories out (How Much Exercise to Sustain Weight Loss).

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

How Doctors Responded to Being Named a Leading Killer

Sept 19 Doctors copy.jpeg

In my video Why Prevention Is Worth a Ton of Cure, I profiled a paper that added up all the deaths caused by medical care in this country, including the hundred thousand deaths from medication side effects, all the deaths caused by errors, and so on. The author of the paper concluded that the third leading cause of death in America is the American medical system.

What was the medical community's reaction to this revelation? After all, the paper was published in one of the most prestigious medical journals, the Journal of the American Medical Association, and was authored by one of our most prestigious physicians, Barbara Starfield, who literally wrote the book on primary care. When she was asked in an interview what the response was, Starfield replied that her primary care work had been widely embraced, but her findings on how harmful and ineffective healthcare could be received almost no attention.

This inspires the recollection of "the dark dystopia of George Orwell's 1984, where awkward facts are swallowed up by the 'memory hole' as if they had never existed at all." Report after report has come out, and the response has been a deafening silence both in deed and in word, failing to even openly discuss the problem, leading to thousands of additional deaths. We can't just keep putting out reports, we have to actually do something.

As I discuss in my video How Doctors Responded to Being Named a Leading Killer, the first report was published in 1978, suggesting about 120,000 preventable hospital deaths a year. The response? Silence for another 16 years until another scathing reminder was published. If we multiply 120,000 by those 16 years, we get 1.9 million preventable deaths, about which there was near total doctor silence. There was no substantial effort to reduce the number of those deaths. The Institute of Medicine (IOM) then released its landmark study in 1999, asserting that yet another 600,000 patients died during that time when providers could have acted.

Some things have finally changed. Work hour limits were instituted for medical trainees. Interns and residents could no longer be worked more than 80 hours a week, at least on paper, and the shifts couldn't be more than 30 hours long. That may not sound like a big step, but when I started out my internship, I worked 36 hour shifts every three days, 117-hour work weeks.

When interns and residents are forced to pull all-nighters, they make 36% more serious medical errors, five times more diagnostic errors, and have twice as many "attentional failures." That doesn't sound so bad, until you realize that means things like nodding off during surgery.

The patient is supposed to be asleep during surgery, not the surgeon.

Performance is impaired as much as a blood alcohol level that would make it illegal to drive a car--but these overworked interns and residents can still do surgery. No surprise there were 300% more patient deaths. Residents consider themselves lucky if they get through training without killing anyone. Not that the family would ever find out. With rare exceptions, doctors are unaccountable for their actions.

The IOM report did break the silence and prompted widespread promises of change, but what they did not do is act as if they really believed their own findings. If we truly believed that a minimum of 120 people every day were dying preventable deaths in hospitals, we would draw a line in the sand. If an airliner was crashing every day, we'd expect that the FAA would step in and do something. The Institute of Medicine could insistently demand that doctors and hospitals immediately adopt at least a minimum set of preventive practices--for example, bar-coding drugs so there aren't any mix-ups, like they do for even a pack of Tic Tacs at the grocery store. Rather than just going on to write yet another report, they could bluntly warn colleagues they would publicly censure those who resisted implementing these minimum practices, calling for some kind of stringent sanctions.

Instead, we get silence. But not for Barbara Starfield, who is unfortunately no longer with us. Ironically, she may have died from one of the adverse drug reactions she so vociferously warned us about. She was placed on aspirin and the blood-thinner Plavix to keep a stent she had to have placed in her coronary artery from clogging up. She told her cardiologist she was bruising more, bleeding longer, but those side effects are the risks you hope don't outweigh the benefits. Starfield apparently hit her head while swimming and bled into her brain.

The question for me is not whether she should have been on two blood-thinners for that long or even whether she should have had the stent inserted. Instead, I question whether or not she could have outright avoided the heart disease, which is 96% avoidable in women.

The number-one killer of women need almost never happen.


For those curious about my time in medical training, you can read my memoir of sorts, Heart Failure: Diary of a Third Year Medical Student.

It isn't just medical treatment that can be harmful. Even medical diagnosis can be dangerous, as I discuss in my video Cancer Risk From CT Scan Radiation.

And, just as we're (finally) seeing some changes in training protocols, the times, they are a-changin' with the emergence of the field of lifestyle medicine, as I present in several videos, including:

I recently made some videos to give people a closer look at why I believe it's so important for us to take responsibility for our own health. You can see all of them on our new Introductory Videos page.

I'm excited to be part of this revolution in medicine. Please consider joining me by supporting the 501c3 nonprofit organization that keeps NutritionFacts.org alive by making a tax-deductible donation. Thank you so much for helping me help so many others.

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

How Doctors Responded to Being Named a Leading Killer

Sept 19 Doctors copy.jpeg

In my video Why Prevention Is Worth a Ton of Cure, I profiled a paper that added up all the deaths caused by medical care in this country, including the hundred thousand deaths from medication side effects, all the deaths caused by errors, and so on. The author of the paper concluded that the third leading cause of death in America is the American medical system.

What was the medical community's reaction to this revelation? After all, the paper was published in one of the most prestigious medical journals, the Journal of the American Medical Association, and was authored by one of our most prestigious physicians, Barbara Starfield, who literally wrote the book on primary care. When she was asked in an interview what the response was, Starfield replied that her primary care work had been widely embraced, but her findings on how harmful and ineffective healthcare could be received almost no attention.

This inspires the recollection of "the dark dystopia of George Orwell's 1984, where awkward facts are swallowed up by the 'memory hole' as if they had never existed at all." Report after report has come out, and the response has been a deafening silence both in deed and in word, failing to even openly discuss the problem, leading to thousands of additional deaths. We can't just keep putting out reports, we have to actually do something.

As I discuss in my video How Doctors Responded to Being Named a Leading Killer, the first report was published in 1978, suggesting about 120,000 preventable hospital deaths a year. The response? Silence for another 16 years until another scathing reminder was published. If we multiply 120,000 by those 16 years, we get 1.9 million preventable deaths, about which there was near total doctor silence. There was no substantial effort to reduce the number of those deaths. The Institute of Medicine (IOM) then released its landmark study in 1999, asserting that yet another 600,000 patients died during that time when providers could have acted.

Some things have finally changed. Work hour limits were instituted for medical trainees. Interns and residents could no longer be worked more than 80 hours a week, at least on paper, and the shifts couldn't be more than 30 hours long. That may not sound like a big step, but when I started out my internship, I worked 36 hour shifts every three days, 117-hour work weeks.

When interns and residents are forced to pull all-nighters, they make 36% more serious medical errors, five times more diagnostic errors, and have twice as many "attentional failures." That doesn't sound so bad, until you realize that means things like nodding off during surgery.

The patient is supposed to be asleep during surgery, not the surgeon.

Performance is impaired as much as a blood alcohol level that would make it illegal to drive a car--but these overworked interns and residents can still do surgery. No surprise there were 300% more patient deaths. Residents consider themselves lucky if they get through training without killing anyone. Not that the family would ever find out. With rare exceptions, doctors are unaccountable for their actions.

The IOM report did break the silence and prompted widespread promises of change, but what they did not do is act as if they really believed their own findings. If we truly believed that a minimum of 120 people every day were dying preventable deaths in hospitals, we would draw a line in the sand. If an airliner was crashing every day, we'd expect that the FAA would step in and do something. The Institute of Medicine could insistently demand that doctors and hospitals immediately adopt at least a minimum set of preventive practices--for example, bar-coding drugs so there aren't any mix-ups, like they do for even a pack of Tic Tacs at the grocery store. Rather than just going on to write yet another report, they could bluntly warn colleagues they would publicly censure those who resisted implementing these minimum practices, calling for some kind of stringent sanctions.

Instead, we get silence. But not for Barbara Starfield, who is unfortunately no longer with us. Ironically, she may have died from one of the adverse drug reactions she so vociferously warned us about. She was placed on aspirin and the blood-thinner Plavix to keep a stent she had to have placed in her coronary artery from clogging up. She told her cardiologist she was bruising more, bleeding longer, but those side effects are the risks you hope don't outweigh the benefits. Starfield apparently hit her head while swimming and bled into her brain.

The question for me is not whether she should have been on two blood-thinners for that long or even whether she should have had the stent inserted. Instead, I question whether or not she could have outright avoided the heart disease, which is 96% avoidable in women.

The number-one killer of women need almost never happen.


For those curious about my time in medical training, you can read my memoir of sorts, Heart Failure: Diary of a Third Year Medical Student.

It isn't just medical treatment that can be harmful. Even medical diagnosis can be dangerous, as I discuss in my video Cancer Risk From CT Scan Radiation.

And, just as we're (finally) seeing some changes in training protocols, the times, they are a-changin' with the emergence of the field of lifestyle medicine, as I present in several videos, including:

I recently made some videos to give people a closer look at why I believe it's so important for us to take responsibility for our own health. You can see all of them on our new Introductory Videos page.

I'm excited to be part of this revolution in medicine. Please consider joining me by supporting the 501c3 nonprofit organization that keeps NutritionFacts.org alive by making a tax-deductible donation. Thank you so much for helping me help so many others.

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

Does Rye Bread Protect Against Cancer?

Sept 14 Rye Bread copy.jpeg

Previously, I've explored the beneficial effects of flaxseeds on prostate cancer (Flaxseeds vs. Prostate Cancer), as well as breast cancer prevention and survival (Flaxseeds & Breast Cancer Prevention and Breast Cancer Survival & Lignan Intake). The cancer-fighting effect of flaxseeds is thought to be because of the lignans, which are cancer-fighting plant compounds found in red wine, whole grains, greens (cruciferous vegetables), and especially sesame seeds and flaxseeds, the most concentrated source on Earth. But this is based on per unit weight. People eat a lot more grains than seeds. Of the grains people eat, the highest concentration of lignans is found in rye. So, can rye intake decrease the risk of cancer? Theoretically yes, but unlike flaxseeds, it's never been directly put to the test... until now.

In my video Does Rye Bread Protect Against Cancer?, I discuss the evidence that does exist. If you measure the levels of lignans in the bloodstream of women living in a region where they eat lots of rye, the odds of breast cancer in women with the highest levels do seem to be just half that of women with the lowest levels. But lignans are also found in tea and berries, so we couldn't be sure where the protection is coming from. To get around this, researchers decided to measure alkylresorcinol metabolites, a class of phytonutrients relatively unique to whole grains.

Researchers collected urine from women with breast cancer and women without, and the women with breast cancer had significantly lower levels compared to those without. This suggests that women at risk for breast cancer consume significantly lower amounts of whole grains like rye. But if we follow older women in their 50s through 60s, the intake of whole grain products was not associated with risk of breast cancer. A similar result was found in older men for prostate cancer. Is it just too late at that point?

We know from data on dairy that diet in our early life may be important in the development of prostate cancer, particularly around puberty when the prostate grows and matures. If you look at what men were drinking in adolescence, daily milk consumption appeared to triple their risk of advanced prostate cancer later in life. (Learn more about milk and prostate cancer in my video Prostate Cancer and Organic Milk vs. Almond Milk.) So, researchers looked at daily rye bread consumption during adolescence.

Those who consumed rye bread daily as kids did appear to only have half the odds of advanced prostate cancer. This is consistent with immigrant studies suggesting that the first two decades of life may be most important for setting the pattern for cancer development in later life. These findings are certainly important for how we should feed our kids, but if we're already middle-aged, is it too late to change course? To answer this question, researchers in Sweden put it to the test.

Researchers took men with prostate cancer and split them into two groups. One group got lots of rye bread, while the other got lots of high-fiber, but low-lignan, wheat bread. There's been some indirect evidence that rye may be active against prostate cancer--like lower cancer rates in regions with high rye consumption--but it had never been directly investigated... until this study. Biopsies were taken from the subjects' tumors before and after three weeks of bread eating, and the number of cancer cells that were dying off were counted. Though there was no change in the cancer cell clearance of the control bread group, there was a 180% increase in the number of cancer cells being killed off in the rye group. A follow-up study lasting 6 weeks found a 14% decrease in PSA levels, a cancer marker suggesting a shrinkage of the tumor.

The researchers note they used very high rye bread intakes, and it remains to be tested if more normal intake levels would have effects that are of clinical importance. As a sadly typical American, my lack of intimate familiarity of the metric system did not flag the "485 grams" of rye bread a day as far out of the ordinary, but that translates to 15 slices! Rather than eating a loaf a day, the same amount of lignans can be found in a single teaspoon of ground flaxseeds.


I've created several videos on flaxseeds for both breast cancer prevention and treatment, including Flaxseeds & Breast Cancer Prevention, Breast Cancer Survival and Lignan Intake, Flaxseeds & Breast Cancer Survival Epidemiological Evidence, and Flaxseeds & Breast Cancer Survival: Clinical Evidence.

What's more, flaxseeds may help with cyclical breast pain (Flaxseeds for Breast Pain), prostate cancer (Flaxseed vs. Prostate Cancer), diabetes (Flaxseeds vs. Diabetes), and hypertension (Flaxseeds for Hypertension).

And if you're wondering Which Are Better: Chia Seeds or Flaxseeds?, get the answer in the video!

The wonders of whole grains are also discussed in Whole Grains May Work as Well as Drugs, Can Oatmeal Reverse Heart Disease?, and Can Oatmeal Help Fatty Liver Disease?.

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

Does Rye Bread Protect Against Cancer?

Sept 14 Rye Bread copy.jpeg

Previously, I've explored the beneficial effects of flaxseeds on prostate cancer (Flaxseeds vs. Prostate Cancer), as well as breast cancer prevention and survival (Flaxseeds & Breast Cancer Prevention and Breast Cancer Survival & Lignan Intake). The cancer-fighting effect of flaxseeds is thought to be because of the lignans, which are cancer-fighting plant compounds found in red wine, whole grains, greens (cruciferous vegetables), and especially sesame seeds and flaxseeds, the most concentrated source on Earth. But this is based on per unit weight. People eat a lot more grains than seeds. Of the grains people eat, the highest concentration of lignans is found in rye. So, can rye intake decrease the risk of cancer? Theoretically yes, but unlike flaxseeds, it's never been directly put to the test... until now.

In my video Does Rye Bread Protect Against Cancer?, I discuss the evidence that does exist. If you measure the levels of lignans in the bloodstream of women living in a region where they eat lots of rye, the odds of breast cancer in women with the highest levels do seem to be just half that of women with the lowest levels. But lignans are also found in tea and berries, so we couldn't be sure where the protection is coming from. To get around this, researchers decided to measure alkylresorcinol metabolites, a class of phytonutrients relatively unique to whole grains.

Researchers collected urine from women with breast cancer and women without, and the women with breast cancer had significantly lower levels compared to those without. This suggests that women at risk for breast cancer consume significantly lower amounts of whole grains like rye. But if we follow older women in their 50s through 60s, the intake of whole grain products was not associated with risk of breast cancer. A similar result was found in older men for prostate cancer. Is it just too late at that point?

We know from data on dairy that diet in our early life may be important in the development of prostate cancer, particularly around puberty when the prostate grows and matures. If you look at what men were drinking in adolescence, daily milk consumption appeared to triple their risk of advanced prostate cancer later in life. (Learn more about milk and prostate cancer in my video Prostate Cancer and Organic Milk vs. Almond Milk.) So, researchers looked at daily rye bread consumption during adolescence.

Those who consumed rye bread daily as kids did appear to only have half the odds of advanced prostate cancer. This is consistent with immigrant studies suggesting that the first two decades of life may be most important for setting the pattern for cancer development in later life. These findings are certainly important for how we should feed our kids, but if we're already middle-aged, is it too late to change course? To answer this question, researchers in Sweden put it to the test.

Researchers took men with prostate cancer and split them into two groups. One group got lots of rye bread, while the other got lots of high-fiber, but low-lignan, wheat bread. There's been some indirect evidence that rye may be active against prostate cancer--like lower cancer rates in regions with high rye consumption--but it had never been directly investigated... until this study. Biopsies were taken from the subjects' tumors before and after three weeks of bread eating, and the number of cancer cells that were dying off were counted. Though there was no change in the cancer cell clearance of the control bread group, there was a 180% increase in the number of cancer cells being killed off in the rye group. A follow-up study lasting 6 weeks found a 14% decrease in PSA levels, a cancer marker suggesting a shrinkage of the tumor.

The researchers note they used very high rye bread intakes, and it remains to be tested if more normal intake levels would have effects that are of clinical importance. As a sadly typical American, my lack of intimate familiarity of the metric system did not flag the "485 grams" of rye bread a day as far out of the ordinary, but that translates to 15 slices! Rather than eating a loaf a day, the same amount of lignans can be found in a single teaspoon of ground flaxseeds.


I've created several videos on flaxseeds for both breast cancer prevention and treatment, including Flaxseeds & Breast Cancer Prevention, Breast Cancer Survival and Lignan Intake, Flaxseeds & Breast Cancer Survival Epidemiological Evidence, and Flaxseeds & Breast Cancer Survival: Clinical Evidence.

What's more, flaxseeds may help with cyclical breast pain (Flaxseeds for Breast Pain), prostate cancer (Flaxseed vs. Prostate Cancer), diabetes (Flaxseeds vs. Diabetes), and hypertension (Flaxseeds for Hypertension).

And if you're wondering Which Are Better: Chia Seeds or Flaxseeds?, get the answer in the video!

The wonders of whole grains are also discussed in Whole Grains May Work as Well as Drugs, Can Oatmeal Reverse Heart Disease?, and Can Oatmeal Help Fatty Liver Disease?.

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

Fish Consumption and Suicide

Sept 12 Fish Consumption copy.jpeg

Depression is a serious and common mental disorder responsible for the majority of suicides. As I've covered in Antioxidants & Depression, intake of fruits, vegetables, and naturally occurring antioxidants have been found to be protectively associated with depression. Therefore, researchers have considered that "it may be possible to prevent depression or to lessen its negative effects through dietary intervention."

But not so fast. Cross-sectional studies are snapshots in time, so we don't know "whether a poor dietary pattern precedes the development of depression or if depression causes poor dietary intake." Depression and even treatments for depression can affect appetite and dietary intake. Maybe people who feel crappier just eat crappier, instead of the other way around.

What we need is a prospective study (a study performed over time) where we start out with people who are not depressed and follow them for several years. In 2012, we got just such a study, which ran over six years. As you'll see in my video Fish Consumption and Suicide, those with higher carotenoid levels in their bloodstream, which is considered a good indicator of fruit and vegetable intake, had a 28% lower risk of becoming depressed within that time. The researchers conclude that having low blood levels of those healthy phytonutrients may predict the development of new depressive symptoms. What about suicide?

Worldwide, a million people kill themselves every year. Of all European countries, Greece appears to have the lowest rates of suicide. It may be the balmy weather, but it may also have something to do with their diet. Ten thousand people were followed for years, and those following a more Mediterranean diet pattern were less likely to be diagnosed with depression. What was it about the diet that was protective? It wasn't the red wine or fish; it was the fruit, nuts, beans, and effectively higher plant to animal fat ratio that appeared protective. Conversely, significant adverse trends were observed for dairy and meat consumption.

A similar protective dietary pattern was found in Japan. A high intake of vegetables, fruits, mushrooms, and soy products was associated with a decreased prevalence of depressive symptoms. The healthy dietary pattern was not characterized by a high intake of seafood. Similar results were found in a study of 100,000 Japanese men and women followed for up to 10 years. There was no evidence of a protective role of higher fish consumption or the long-chain omega 3s EPA and DHA against suicide. In fact, they found a significantly increased risk of suicide among male nondrinkers with high seafood omega 3 intake. This may have been by chance, but a similar result was found in the Mediterranean. High baseline fish consumption with an increase in consumption were associated with an increased risk of mental disorders.

One possible explanation could be the mercury content of fish. Could an accumulation of mercury compounds in the body increase the risk of depression? We know that mercury in fish can cause neurological damage, associated with increased risk of Alzheimer's disease, memory loss, and autism, but also depression. Therefore, "the increased risk of suicide among persons with a high fish intake might also be attributable to the harmful effects of mercury in fish."

Large Harvard University cohort studies found similar results. Hundreds of thousands were followed for up to 20 years, and no evidence was found that taking fish oil or eating fish lowered risk of suicide. There was even a trend towards higher suicide mortality.

What about fish consumption for the treatment of depression? When we put together all the trials done to date, neither the EPA nor DHA long-chain omega-3s appears more effective than sugar pills. We used to think omega-3 supplementation was useful, but several recent studies have tipped the balance the other way. It seems that "[n]early all of the treatment efficacy observed in the published literature may be attributable to publication bias," meaning the trials that showed no benefit tended not to get published at all. So, all doctors saw were a bunch of positive studies, but only because a bunch of the negative ones were buried.

This reminds me of my Is Fish Oil Just Snake Oil? video. Just like we thought omega-3 supplementation could help with mood, we also thought it could help with heart health, but the balance of evidence has decidedly shifted. I still recommend the consumption of pollutant-free sources of preformed long-chain omega 3s for cognitive health and explain my rationale in Should We Take DHA Supplements to Boost Brain Function? and Should Vegans Take DHA to Preserve Brain Function?


For more on the neurotoxic nature of mercury-contaminated seafood, see:

What can we do to help our mood? See:

What about antidepressant drugs? Sometimes they can be absolutely life-saving, but other times they may actually do more harm than good. See my controversial video Do Antidepressant Drugs Really Work?.

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

Fish Consumption and Suicide

Sept 12 Fish Consumption copy.jpeg

Depression is a serious and common mental disorder responsible for the majority of suicides. As I've covered in Antioxidants & Depression, intake of fruits, vegetables, and naturally occurring antioxidants have been found to be protectively associated with depression. Therefore, researchers have considered that "it may be possible to prevent depression or to lessen its negative effects through dietary intervention."

But not so fast. Cross-sectional studies are snapshots in time, so we don't know "whether a poor dietary pattern precedes the development of depression or if depression causes poor dietary intake." Depression and even treatments for depression can affect appetite and dietary intake. Maybe people who feel crappier just eat crappier, instead of the other way around.

What we need is a prospective study (a study performed over time) where we start out with people who are not depressed and follow them for several years. In 2012, we got just such a study, which ran over six years. As you'll see in my video Fish Consumption and Suicide, those with higher carotenoid levels in their bloodstream, which is considered a good indicator of fruit and vegetable intake, had a 28% lower risk of becoming depressed within that time. The researchers conclude that having low blood levels of those healthy phytonutrients may predict the development of new depressive symptoms. What about suicide?

Worldwide, a million people kill themselves every year. Of all European countries, Greece appears to have the lowest rates of suicide. It may be the balmy weather, but it may also have something to do with their diet. Ten thousand people were followed for years, and those following a more Mediterranean diet pattern were less likely to be diagnosed with depression. What was it about the diet that was protective? It wasn't the red wine or fish; it was the fruit, nuts, beans, and effectively higher plant to animal fat ratio that appeared protective. Conversely, significant adverse trends were observed for dairy and meat consumption.

A similar protective dietary pattern was found in Japan. A high intake of vegetables, fruits, mushrooms, and soy products was associated with a decreased prevalence of depressive symptoms. The healthy dietary pattern was not characterized by a high intake of seafood. Similar results were found in a study of 100,000 Japanese men and women followed for up to 10 years. There was no evidence of a protective role of higher fish consumption or the long-chain omega 3s EPA and DHA against suicide. In fact, they found a significantly increased risk of suicide among male nondrinkers with high seafood omega 3 intake. This may have been by chance, but a similar result was found in the Mediterranean. High baseline fish consumption with an increase in consumption were associated with an increased risk of mental disorders.

One possible explanation could be the mercury content of fish. Could an accumulation of mercury compounds in the body increase the risk of depression? We know that mercury in fish can cause neurological damage, associated with increased risk of Alzheimer's disease, memory loss, and autism, but also depression. Therefore, "the increased risk of suicide among persons with a high fish intake might also be attributable to the harmful effects of mercury in fish."

Large Harvard University cohort studies found similar results. Hundreds of thousands were followed for up to 20 years, and no evidence was found that taking fish oil or eating fish lowered risk of suicide. There was even a trend towards higher suicide mortality.

What about fish consumption for the treatment of depression? When we put together all the trials done to date, neither the EPA nor DHA long-chain omega-3s appears more effective than sugar pills. We used to think omega-3 supplementation was useful, but several recent studies have tipped the balance the other way. It seems that "[n]early all of the treatment efficacy observed in the published literature may be attributable to publication bias," meaning the trials that showed no benefit tended not to get published at all. So, all doctors saw were a bunch of positive studies, but only because a bunch of the negative ones were buried.

This reminds me of my Is Fish Oil Just Snake Oil? video. Just like we thought omega-3 supplementation could help with mood, we also thought it could help with heart health, but the balance of evidence has decidedly shifted. I still recommend the consumption of pollutant-free sources of preformed long-chain omega 3s for cognitive health and explain my rationale in Should We Take DHA Supplements to Boost Brain Function? and Should Vegans Take DHA to Preserve Brain Function?


For more on the neurotoxic nature of mercury-contaminated seafood, see:

What can we do to help our mood? See:

What about antidepressant drugs? Sometimes they can be absolutely life-saving, but other times they may actually do more harm than good. See my controversial video Do Antidepressant Drugs Really Work?.

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