What Animal Protein Does in Your Colon

What Animal Protein Does in Your Colon.jpeg

There's a take-off of the industry slogan, "Beef: It's What's For Dinner" - "Beef: It's What's Rotting in Your Colon." I saw this on a shirt once with some friends and I was such the party pooper--no pun intended--explaining to everyone that meat is fully digested in the small intestine, and never makes it down into the colon. It's no fun hanging out with biology geeks.

But I was wrong!

It's been estimated that with a typical Western diet, up to 12 grams of protein can escape digestion, and when it reaches the colon, it can be turned into toxic substances like ammonia. This degradation of undigested protein in the colon is called putrefaction, so a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.

It's generally accepted that carbohydrate fermentation--the fiber and resistant starches that reach our colon--results in beneficial effects because of the generation of short-chain fatty acids like butyrate, whereas protein fermentation is considered detrimental. Protein fermentation mainly occurs in the lower end of colon and results in the production of potentially toxic metabolites. That may be why colorectal cancer and ulcerative colitis tends to happen lower down--because that's where the protein is putrefying.

Probably the simplest strategy to reduce the potential harm of protein fermentation is to reduce dietary protein intake. But the accumulation of these toxic byproducts of protein metabolism may be attenuated by the fermentation of undigested plant matter. In my video, Bowel Wars: Hydrogen Sulfide vs. Butyrate, you can see a study out of Australia showed that if you give people foods containing resistant starch you can block the accumulation of potentially harmful byproducts of protein metabolism. Resistant starch is resistant to small intestine digestion and so it makes it down to our colon where it can feed our good bacteria. Resistant starch is found in cooked beans, split peas, chickpeas, lentils, raw oatmeal, and cooled cooked pasta (like macaroni salad). Apparently, the more starch that ends up in the colon, the less ammonia that is produced.

Of course, there's protein in plants too. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine, which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that may play a role in the development of the inflammatory bowel disease, ulcerative colitis (see Preventing Ulcerative Colitis with Diet).

The toxic effects of hydrogen sulfide appear to be a result of blocking the ability of the cells lining our colon from utilizing butyrate, which is what our good bacteria make from the fiber and resistant starch we eat. It's like this constant battle in our colon between the bad metabolites of protein, hydrogen sulfide, and the good metabolites of carbohydrates, butyrate. Using human colon samples, researchers were able to show that the adverse effects of sulfide could be reversed by butyrate. So we can either cut down on meat, eat more plants, or both.

There are two ways hydrogen sulfide can be produced, though. It's mainly present in our large intestine as a result of the breakdown of sulfur-containing proteins, but the rotten egg gas can also be generated from inorganic sulfur preservatives like sulfites and sulfur dioxide.

Sulfur dioxide is used as a preservative in dried fruit, and sulfites are added to wines. We can avoid sulfur additives by reading labels or by just choosing organic, since they're forbidden from organic fruits and beverages by law.

More than 35 years ago, studies started implicating sulfur dioxide preservatives in the exacerbation of asthma. This so-called "sulfite-sensitivity" seems to affect only about 1 in 2,000 people, so I recommended those with asthma avoid it, but otherwise I considered the preservative harmless. I am now not so sure, and advise people to avoid it when possible.

Cabbage family vegetables naturally have some sulfur compounds, but thankfully, after following more than a hundred thousand women for over 25 years, researchers concluded cruciferous vegetables were not associated with elevated colitis risk.

Because of animal protein and processed food intake, the standard American diet may contain five or six times more sulfur than a diet centered around unprocessed plant foods. This may help explain the rarity of inflammatory bowel disease among those eating traditional whole food, plant-based diets.

How could companies just add things like sulfur dioxide to foods without adequate safety testing? See Who Determines if Food Additives are Safe? For other additives that may be a problem, see Titanium Dioxide & Inflammatory Bowel Disease and Is Carrageenan Safe?

More on this epic fermentation battle in our gut in Stool pH and Colon Cancer.

Does the sulfur-containing amino acid methionine sound familiar? You may remember it from such hits as Starving Cancer with Methionine Restriction and Methionine Restriction as a Life Extension Strategy.

These short-chain fatty acids released by our good bacteria when we eat fiber and resistant starches are what may be behind the second meal effect: Beans and the Second Meal Effect.

I mentioned ulcerative colitis. What about the other inflammatory bowel disease Crohn's? See Preventing Crohn's Disease With Diet and Dietary Treatment of Crohn's 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:

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

Original Link

What Animal Protein Does in Your Colon

What Animal Protein Does in Your Colon.jpeg

There's a take-off of the industry slogan, "Beef: It's What's For Dinner" - "Beef: It's What's Rotting in Your Colon." I saw this on a shirt once with some friends and I was such the party pooper--no pun intended--explaining to everyone that meat is fully digested in the small intestine, and never makes it down into the colon. It's no fun hanging out with biology geeks.

But I was wrong!

It's been estimated that with a typical Western diet, up to 12 grams of protein can escape digestion, and when it reaches the colon, it can be turned into toxic substances like ammonia. This degradation of undigested protein in the colon is called putrefaction, so a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.

It's generally accepted that carbohydrate fermentation--the fiber and resistant starches that reach our colon--results in beneficial effects because of the generation of short-chain fatty acids like butyrate, whereas protein fermentation is considered detrimental. Protein fermentation mainly occurs in the lower end of colon and results in the production of potentially toxic metabolites. That may be why colorectal cancer and ulcerative colitis tends to happen lower down--because that's where the protein is putrefying.

Probably the simplest strategy to reduce the potential harm of protein fermentation is to reduce dietary protein intake. But the accumulation of these toxic byproducts of protein metabolism may be attenuated by the fermentation of undigested plant matter. In my video, Bowel Wars: Hydrogen Sulfide vs. Butyrate, you can see a study out of Australia showed that if you give people foods containing resistant starch you can block the accumulation of potentially harmful byproducts of protein metabolism. Resistant starch is resistant to small intestine digestion and so it makes it down to our colon where it can feed our good bacteria. Resistant starch is found in cooked beans, split peas, chickpeas, lentils, raw oatmeal, and cooled cooked pasta (like macaroni salad). Apparently, the more starch that ends up in the colon, the less ammonia that is produced.

Of course, there's protein in plants too. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine, which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that may play a role in the development of the inflammatory bowel disease, ulcerative colitis (see Preventing Ulcerative Colitis with Diet).

The toxic effects of hydrogen sulfide appear to be a result of blocking the ability of the cells lining our colon from utilizing butyrate, which is what our good bacteria make from the fiber and resistant starch we eat. It's like this constant battle in our colon between the bad metabolites of protein, hydrogen sulfide, and the good metabolites of carbohydrates, butyrate. Using human colon samples, researchers were able to show that the adverse effects of sulfide could be reversed by butyrate. So we can either cut down on meat, eat more plants, or both.

There are two ways hydrogen sulfide can be produced, though. It's mainly present in our large intestine as a result of the breakdown of sulfur-containing proteins, but the rotten egg gas can also be generated from inorganic sulfur preservatives like sulfites and sulfur dioxide.

Sulfur dioxide is used as a preservative in dried fruit, and sulfites are added to wines. We can avoid sulfur additives by reading labels or by just choosing organic, since they're forbidden from organic fruits and beverages by law.

More than 35 years ago, studies started implicating sulfur dioxide preservatives in the exacerbation of asthma. This so-called "sulfite-sensitivity" seems to affect only about 1 in 2,000 people, so I recommended those with asthma avoid it, but otherwise I considered the preservative harmless. I am now not so sure, and advise people to avoid it when possible.

Cabbage family vegetables naturally have some sulfur compounds, but thankfully, after following more than a hundred thousand women for over 25 years, researchers concluded cruciferous vegetables were not associated with elevated colitis risk.

Because of animal protein and processed food intake, the standard American diet may contain five or six times more sulfur than a diet centered around unprocessed plant foods. This may help explain the rarity of inflammatory bowel disease among those eating traditional whole food, plant-based diets.

How could companies just add things like sulfur dioxide to foods without adequate safety testing? See Who Determines if Food Additives are Safe? For other additives that may be a problem, see Titanium Dioxide & Inflammatory Bowel Disease and Is Carrageenan Safe?

More on this epic fermentation battle in our gut in Stool pH and Colon Cancer.

Does the sulfur-containing amino acid methionine sound familiar? You may remember it from such hits as Starving Cancer with Methionine Restriction and Methionine Restriction as a Life Extension Strategy.

These short-chain fatty acids released by our good bacteria when we eat fiber and resistant starches are what may be behind the second meal effect: Beans and the Second Meal Effect.

I mentioned ulcerative colitis. What about the other inflammatory bowel disease Crohn's? See Preventing Crohn's Disease With Diet and Dietary Treatment of Crohn's 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:

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

Original Link

High Blood Pressure: Normal but Not Natural

High Blood Pressure - Normal but Not Natural.jpeg

The most comprehensive and systematic analysis of causes of death ever undertaken allows us to answer questions like, how many lives could we save if people cut back on soda? The answer is 299,521. Soft drinks aren't just bad because they're empty calories. More than just not being a health-promoting item, soda appears to be an actively death-promoting item. Of course, it's not as deadly as processed meats such as bacon, bologna, ham, or hot dogs, which account for about 800,000 deaths every year--killing twice as many women as domestic violence and five times more people than all illegal drugs combined.

On the other hand, eating more whole grains could save 1.7 million lives. And more vegetables could save 1.8 million lives every year. If only we ate more nuts and seeds, we'd save 2 and a half million lives. But fruit is apparently what the world needs most (they didn't look at beans) with 4.9 million lives hanging in the balance every year. The cure is not drugs or vaccines; the cure is fruit. The #1 dietary risk factor for death in the world may be not eating enough fruit.

One reason why plant-based diets can save so many millions is because the #1 killer risk factor in the world is high blood pressure, laying to waste nine million people year after year. In the United States, high blood pressure affects nearly 78 million--that's one in three of us. As we age our pressures get higher and higher, such that by age 60, it strikes more than half of that population. If it affects most of us when we get older, maybe it's less a disease and more just a natural, inevitable consequence of getting older?

No.

We've known for nearly a century that high blood pressure need never occur. Researchers measured the blood pressure of a thousand people in rural Kenya. Up until age 40, the blood pressures of rural Africans were about the same as Europeans and Americans, down around 120's over 80's, but as Westerners age, our pressures creep up such that by age 60 the average person is hypertensive, exceeding 140 over 90. But the pressures of those in rural Africa improved with age; not only did they not develop hypertension, their blood pressures actually got better.

The 140/90 cut-off is arbitrary. Just like studies that show the lower our cholesterol the better--there's really no safe level above about 150--blood pressure studies also support a "lower the better" approach. Even people who start out with blood pressure under 120/80 appear to benefit from blood pressure reduction. The ideal blood pressure, the no-benefit-from-reducing-it-further blood pressure, appears to be 110/70. Is it possible to get blood pressures under 110 over 70? It's not just possible, it can be normal for those eating healthy enough diets (see How Not to Die from High Blood Pressure).

Over two years at a rural Kenyan hospital, 1,800 patients were admitted. How many cases of high blood pressure were found? Zero. Wow. They must have had low rates of heart disease. Actually, they had no rates of heart disease. Not low risk--no risk. Not a single case of arteriosclerosis was found.

Having a "normal" blood pressure may set you up for dying from "normal" causes such as heart attacks and strokes. For more on this concept, see When Low Risk Means High Risk. It's like having a normal cholesterol level (see Optimal Cholesterol Level).

It seems high blood pressure is a choice. Like cavities: Cavities and Coronaries: Our Choice.

Even end-stage malignant hypertension can be reversed with diet (thereby demonstrating it was the diet and not other lifestyle factors that protected traditional plant-based populations). See Kempner Rice Diet: Whipping Us Into Shape.

Flax seeds, hibiscus tea, whole grains, and nitrate-rich vegetables may offer additional protection:

Why not just take the drugs? See The Actual Benefit of Diet vs. Drugs and Why Prevention is Worth a Ton of Cure. And be sure to check out my summary video, How Not to Die from High Blood Pressure, as well as The Evidence that Salt Raises Blood Pressure.

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

High Blood Pressure: Normal but Not Natural

High Blood Pressure - Normal but Not Natural.jpeg

The most comprehensive and systematic analysis of causes of death ever undertaken allows us to answer questions like, how many lives could we save if people cut back on soda? The answer is 299,521. Soft drinks aren't just bad because they're empty calories. More than just not being a health-promoting item, soda appears to be an actively death-promoting item. Of course, it's not as deadly as processed meats such as bacon, bologna, ham, or hot dogs, which account for about 800,000 deaths every year--killing twice as many women as domestic violence and five times more people than all illegal drugs combined.

On the other hand, eating more whole grains could save 1.7 million lives. And more vegetables could save 1.8 million lives every year. If only we ate more nuts and seeds, we'd save 2 and a half million lives. But fruit is apparently what the world needs most (they didn't look at beans) with 4.9 million lives hanging in the balance every year. The cure is not drugs or vaccines; the cure is fruit. The #1 dietary risk factor for death in the world may be not eating enough fruit.

One reason why plant-based diets can save so many millions is because the #1 killer risk factor in the world is high blood pressure, laying to waste nine million people year after year. In the United States, high blood pressure affects nearly 78 million--that's one in three of us. As we age our pressures get higher and higher, such that by age 60, it strikes more than half of that population. If it affects most of us when we get older, maybe it's less a disease and more just a natural, inevitable consequence of getting older?

No.

We've known for nearly a century that high blood pressure need never occur. Researchers measured the blood pressure of a thousand people in rural Kenya. Up until age 40, the blood pressures of rural Africans were about the same as Europeans and Americans, down around 120's over 80's, but as Westerners age, our pressures creep up such that by age 60 the average person is hypertensive, exceeding 140 over 90. But the pressures of those in rural Africa improved with age; not only did they not develop hypertension, their blood pressures actually got better.

The 140/90 cut-off is arbitrary. Just like studies that show the lower our cholesterol the better--there's really no safe level above about 150--blood pressure studies also support a "lower the better" approach. Even people who start out with blood pressure under 120/80 appear to benefit from blood pressure reduction. The ideal blood pressure, the no-benefit-from-reducing-it-further blood pressure, appears to be 110/70. Is it possible to get blood pressures under 110 over 70? It's not just possible, it can be normal for those eating healthy enough diets (see How Not to Die from High Blood Pressure).

Over two years at a rural Kenyan hospital, 1,800 patients were admitted. How many cases of high blood pressure were found? Zero. Wow. They must have had low rates of heart disease. Actually, they had no rates of heart disease. Not low risk--no risk. Not a single case of arteriosclerosis was found.

Having a "normal" blood pressure may set you up for dying from "normal" causes such as heart attacks and strokes. For more on this concept, see When Low Risk Means High Risk. It's like having a normal cholesterol level (see Optimal Cholesterol Level).

It seems high blood pressure is a choice. Like cavities: Cavities and Coronaries: Our Choice.

Even end-stage malignant hypertension can be reversed with diet (thereby demonstrating it was the diet and not other lifestyle factors that protected traditional plant-based populations). See Kempner Rice Diet: Whipping Us Into Shape.

Flax seeds, hibiscus tea, whole grains, and nitrate-rich vegetables may offer additional protection:

Why not just take the drugs? See The Actual Benefit of Diet vs. Drugs and Why Prevention is Worth a Ton of Cure. And be sure to check out my summary video, How Not to Die from High Blood Pressure, as well as The Evidence that Salt Raises Blood Pressure.

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

What’s the Mediterranean Diet’s Secret?

Why Was Heart Disease Rare in the Mediterranean?.jpg

The Mediterranean Diet is an "in" topic nowadays in both the medical literature and the lay media. As one researcher put it, "Uncritical laudatory coverage is common, but specifics are hard to come by: What is it? Where did it come from? Why is it good? Merits are rarely detailed; possible downsides are never mentioned." So, let's dig in....

After World War II, the government of Greece asked the Rockefeller foundation to come in and assess the situation. Impressed by the low rates of heart disease in the region, nutrition scientist Ancel Keys--after which "K" rations were named--initiated his famous seven countries study. In this study, he found the rate of fatal heart disease on the Greek isle of Crete was 20 times lower than in the United States. They also had the lowest cancer rates and fewest deaths overall. What were they eating? Their diets were more than 90% plant-based, which may explain why coronary heart disease was such a rarity. A rarity, that is, except for a small class of rich people whose diet differed from that of the general population--they ate meat every day instead of every week or two.

So, the heart of the Mediterranean diet is mainly plant-based, and low in meat and dairy, which Keys considered the "major villains in the diet" because of their saturated fat content. Unfortunately, no one is really eating the traditional Mediterranean diet anymore, even in the Mediterranean. The prevalence of coronary heart disease skyrocketed by an order of magnitude within a few decades in Crete, blamed on the increased consumption of meat and cheese at the expense of plant foods.

Everyone is talking about the Mediterranean diet, but few do it properly. People think of pizza or spaghetti with meat sauce, but while "Italian restaurants brag about the healthy measuring in diet, they serve a travesty of it." If no one's really eating this way anymore, how do you study it?

Researchers came up with a variety of Mediterranean diet adherence scoring systems to see if people who are eating more Mediterranean-ish do better. You get maximum points the more plant foods you eat, and effectively you get points deducted by eating just a single serving of meat or dairy a day. So it's no surprise those that eat relatively higher on the scale have a lower risk of heart disease, cancer, and death overall. After all, the Mediterranean diet can be considered to be a "near vegetarian" diet. "As such, it should be expected to produce the well-established health benefits of vegetarian diets." That is, less heart disease, cancer, death, and inflammation; improved arterial function; a lower risk of developing type 2 diabetes; a reduced risk for stroke, depression, and cognitive impairment.

How might it work? I've talked about the elegant studies showing that those who eat plant-based diets have more plant-based compounds, like aspirin, circulating within their systems. Polyphenol phytonutrients in plant foods are associated with a significantly lower risk of dying. Magnesium consumption is also associated with a significantly lower risk of dying, and is found in dark green leafy vegetables, as well as fruits, beans, nuts, soy, and whole grains.

Heme iron, on the other hand--the iron found in blood and muscle--acts as a pro-oxidant and appears to increase the risk of diabetes, whereas plant-based, non-heme iron appears safe. Similarly, with heart disease, animal-based iron was found to significantly increase the risk of coronary heart disease, our number one killer, but not plant-based iron. The Mediterranean diet is protective compared to the Standard American Diet--no question--but any diet rich in whole plant foods and low in animal-fat consumption could be expected to confer protection against many of our leading killers.

Here are some more videos on the Mediterranean Diet:

For more information on heme iron, see Risk Associated With Iron Supplements.

More on magnesium is found in How Do Nuts Prevent Sudden Cardiac Death? and Mineral of the Year--Magnesium.

And more on polyphenols can be seen in videos like How to Slow Brain Aging by Two Years and Juicing Removes More Than Just Fiber.

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: Couleur / Pixabay. This image has been modified.

Original Link

What’s the Mediterranean Diet’s Secret?

Why Was Heart Disease Rare in the Mediterranean?.jpg

The Mediterranean Diet is an "in" topic nowadays in both the medical literature and the lay media. As one researcher put it, "Uncritical laudatory coverage is common, but specifics are hard to come by: What is it? Where did it come from? Why is it good? Merits are rarely detailed; possible downsides are never mentioned." So, let's dig in....

After World War II, the government of Greece asked the Rockefeller foundation to come in and assess the situation. Impressed by the low rates of heart disease in the region, nutrition scientist Ancel Keys--after which "K" rations were named--initiated his famous seven countries study. In this study, he found the rate of fatal heart disease on the Greek isle of Crete was 20 times lower than in the United States. They also had the lowest cancer rates and fewest deaths overall. What were they eating? Their diets were more than 90% plant-based, which may explain why coronary heart disease was such a rarity. A rarity, that is, except for a small class of rich people whose diet differed from that of the general population--they ate meat every day instead of every week or two.

So, the heart of the Mediterranean diet is mainly plant-based, and low in meat and dairy, which Keys considered the "major villains in the diet" because of their saturated fat content. Unfortunately, no one is really eating the traditional Mediterranean diet anymore, even in the Mediterranean. The prevalence of coronary heart disease skyrocketed by an order of magnitude within a few decades in Crete, blamed on the increased consumption of meat and cheese at the expense of plant foods.

Everyone is talking about the Mediterranean diet, but few do it properly. People think of pizza or spaghetti with meat sauce, but while "Italian restaurants brag about the healthy measuring in diet, they serve a travesty of it." If no one's really eating this way anymore, how do you study it?

Researchers came up with a variety of Mediterranean diet adherence scoring systems to see if people who are eating more Mediterranean-ish do better. You get maximum points the more plant foods you eat, and effectively you get points deducted by eating just a single serving of meat or dairy a day. So it's no surprise those that eat relatively higher on the scale have a lower risk of heart disease, cancer, and death overall. After all, the Mediterranean diet can be considered to be a "near vegetarian" diet. "As such, it should be expected to produce the well-established health benefits of vegetarian diets." That is, less heart disease, cancer, death, and inflammation; improved arterial function; a lower risk of developing type 2 diabetes; a reduced risk for stroke, depression, and cognitive impairment.

How might it work? I've talked about the elegant studies showing that those who eat plant-based diets have more plant-based compounds, like aspirin, circulating within their systems. Polyphenol phytonutrients in plant foods are associated with a significantly lower risk of dying. Magnesium consumption is also associated with a significantly lower risk of dying, and is found in dark green leafy vegetables, as well as fruits, beans, nuts, soy, and whole grains.

Heme iron, on the other hand--the iron found in blood and muscle--acts as a pro-oxidant and appears to increase the risk of diabetes, whereas plant-based, non-heme iron appears safe. Similarly, with heart disease, animal-based iron was found to significantly increase the risk of coronary heart disease, our number one killer, but not plant-based iron. The Mediterranean diet is protective compared to the Standard American Diet--no question--but any diet rich in whole plant foods and low in animal-fat consumption could be expected to confer protection against many of our leading killers.

Here are some more videos on the Mediterranean Diet:

For more information on heme iron, see Risk Associated With Iron Supplements.

More on magnesium is found in How Do Nuts Prevent Sudden Cardiac Death? and Mineral of the Year--Magnesium.

And more on polyphenols can be seen in videos like How to Slow Brain Aging by Two Years and Juicing Removes More Than Just Fiber.

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: Couleur / Pixabay. This image has been modified.

Original Link

How to Cook Broccoli

NF-Feb9 Second Strategy to Cooking Broccoli.jpeg

When I used to teach medical students at Tufts, I gave a lecture about this amazing new therapeutic called "iloccor-B." I'd talk about all the new science, all the things it could do, its excellent safety profile. Just as they were all scrambling to buy stock in the company and prescribe it to all their patients, I'd do the big reveal. Apologizing for my "dyslexia," I would admit that I'd got it backwards. All this time I had been talking about broccoli.

The main active ingredient in broccoli is thought to be sulforaphane, which may protect our brains, protect our eyesight, protect our bodies against free radicals, boost our detoxification enzymes, and help prevent and treat cancer.

In my videos The Best Detox and Sometimes the Enzyme Myth is the Truth, I talked about how the formation of sulforaphane is like a chemical flare reaction, requiring the mixing of a precursor compound with an enzyme, which is destroyed by cooking. This may explain why we get dramatic suppression of cancer cell growth from raw broccoli, cauliflower and Brussels sprouts, but hardly anything from boiled, microwaved or steamed (except for microwaved broccoli, which actually retains some cancer fighting abilities). But who wants to eat raw Brussels sprouts?

There is a strategy to get the benefits of raw in cooked form. In raw broccoli, the sulforaphane precursor, called glucoraphanin, mixes with the enzyme (myrosinase) when you chew or chop it. If given enough time--such as when sitting in your upper stomach waiting to get digested--sulforaphane is born. The precursor and sulforaphane are resistant to heat and therefore cooking, but the enzyme is destroyed. No enzyme = no sulforaphane.

That's why I described the "hack and hold" technique--if we chop the broccoli, Brussels sprouts, kale, collards, or cauliflower first and then wait 40 minutes, we can cook them all we want. The sulforaphane is already made; the enzyme has already done its job, so we don't need it anymore.

When most people make broccoli soup, for example, they're doing it wrong. Most people cook the broccoli first, then blend it. We now know it should be done the exact opposite way. Blend it first, wait, and then cook it.

What if we're using frozen broccoli, though? In my video, Second Strategy to Cooking Broccoli, you can see the amount of sulforaphane in someone's body after they eat broccoli soup made from fresh broccoli versus from frozen broccoli. The difference is dramatic. Commercially produced frozen broccoli lacks the ability to form sulforaphane because vegetables are blanched (flash-cooked) before they're frozen for the very purpose of deactivating enzymes. This prolongs shelf life in the frozen foods section, but the myrosinase is dead by the time you take it out of your freezer. It doesn't matter how much you chop it, or how long you wait, no sulforaphane is going to be made. This may be why fresh kale suppresses cancer cell growth up to ten times more than frozen.

The frozen broccoli is still packed with the precursor--remember that's heat resistant--and we could get lots of sulforaphane out of the frozen broccoli by adding some outside enzyme. Where do we get myrosinase enzyme from? Researchers just buy theirs from a chemical company. But we can just walk into any grocery store.

All cruciferous vegetables have this myrosinase. Mustard greens, a cruciferous vegetable, grow out of little mustard seeds, which we can buy ground up in the spice aisle as mustard powder. If we sprinkled some mustard powder on our cooked frozen broccoli, would it start churning out sulforaphane? We didn't know...until now.

Boiling broccoli prevents the formation of any significant levels of sulforaphane due to inactivation of the enzyme. However, researchers from the University of Reading found that the addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane. In the video I mentioned earlier, Second Strategy to Cooking Broccoli, you can see the amount of sulforaphane in boiled broccoli versus the amount after half a teaspoon or a teaspoon of mustard powder is added. Both a half teaspoon and a full teaspoon increase sulforaphane by the same amount, suggesting that we could use even use less mustard powder for the same effect. Therefore, although domestic cooking leads to the deactivation of myrosinase and stops sulforaphane formation, the addition of powdered mustard seeds to cooked cabbage-family vegetables provides a natural source of the enzyme such that it's practically like eating them raw.

So, if we forget to chop our greens in the morning for the day, or are using frozen, we can just sprinkle some mustard powder on top at the dinner table and we're all set. Daikon radish, horseradish, or wasabi--all cruciferous vegetables packed with the enzyme--work as well. Just a quarter teaspoon of Daikon radish root for seven cups of broccoli worked--just a tiny pinch can do it. Or you can add a small amount of fresh greens to your cooked greens, because the fresh greens have myrosinase enzyme that can go to work on the cooked greens.

I love kitchen chemistry--it totally revolutionized my daily greens prep. One of the first things I used to do in the morning is chop my greens for the day, so when lunch and supper rolls around they'd be good to go. But now with the mustard powder plan, I don't have to pre-chop.

This helps explain the results I presented in Raw Broccoli and Bladder Cancer Survival.

OK, but what's so great about this sulforaphane stuff? For a taste, 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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Jessica Spengler / Flickr

Original Link

Bile Binding Beets

NF-Jan21 Which Vegetable Binds Bile Best.001.jpeg

In my video Breast Cancer and Constipation, I discussed how fruits and veggies bind carcinogenic bile acids in our gut. Since bile acids are absorbed back into our systems, they may increase our risk of not only colon cancer but also other cancers as well. In light of this, researchers publishing in the journal, Nutrition Research, concluded that to "lower the risk of diet and lifestyle-related premature degenerative diseases and to advance human nutrition research, relative bile acid-binding potential of foods and fractions need to be evaluated."

They found that some vegetables bind bile acids better than others. We know that those eating more plant-based diets are at a lower risk of heart disease and cancer. This could partly be because of phytonutrients in plants that act as antioxidants and potent stimulators of natural detoxifying enzymes in our bodies. Veggies can also lower cholesterol and detoxify harmful metabolites, functions that can be predicted by their ability to bind bile acids.

A group of USDA researchers studying this topic discovered three important things. First, they found an over five-fold variability in bile acid binding among various vegetables that had similar fiber content, suggesting that bile acid binding is not just related to total dietary fiber content (as previously thought), but instead some combination of unique phytonutrients yet to be determined.

Second, they discovered that steaming significantly improves the bile acid binding of collards, kale, mustard greens, broccoli, peppers, cabbage, beets, eggplant, asparagus, carrots, green beans, and cauliflower, suggesting that in this way steaming vegetables may be more healthful than those consumed raw.

Finally, they ranked multiple vegetables for bile binding ability. Which vegetables kicked the most bile butt? (in my video, Which Vegetable Binds Bile Best?, you can see a visual comparison of bile binding ability.) Turnips turned up last. Then came cabbage, cauliflower, bell peppers, spinach, asparagus and green beans. Mustard greens and broccoli were better. Eggplant, carrots and Brussels sprouts basically tie for the #5 slot. Then collards at #4. Kale got the bronze, okra the silver, and beets the gold. Kale, surprisingly, got beet.

The researchers concluded that inclusion of all these vegetables in our daily diets should be encouraged. When consumed regularly, they concluded, these vegetables may lower the risk of premature degenerative diseases and improve public health.

More raw versus cooked comparisons in

Beets also have a number of other remarkable properties. Check out my video series on Doping with Beet Juice as well as Hearts Shouldn't Skip a Beet, and Whole Beets vs. Juice for Improving Athletic Performance.

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: Robert Couse-Baker / Flickr

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How to Suppress the Aging Enzyme TOR

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Over the last decade, more than 5,000 papers have been published about TOR, an engine-of-aging enzyme inhibited by the drug rapamycin. (What is TOR? Check out my videos Why Do We Age? and Caloric Restriction vs. Animal Protein Restriction.) Rapamycin has been used experimentally to extend lifespan, but is already in use clinically to prevent the rejection of kidney transplants. Patients who received rapamycin due to renal transplantation had a peculiar "side effect," a decrease in cancer incidence. In a set of 15 patients who had biopsy proven Kaposi's sarcoma (a cancer that often affects the skin), all cutaneous sarcoma lesions disappeared in all patients within three months after starting rapamycin therapy.

TOR functions as a master regulator of cellular growth and proliferation. For example, TOR is upregulated in nearly 100% of advanced human prostate cancers (See Prevent Cancer From Going on TOR). So, reductions in cancerous lesions after rapamycin therapy make sense. TOR may also be why dairy consumption has been found to be a major dietary risk factor for prostate cancer. We used to think it was just the hormones in milk, but maybe prostate cancer initiation and progression is also promoted by cow's milk stimulation of TOR.

Our understanding of mammalian milk has changed from a simple food to a "species-specific endocrine signaling system," which activates TOR, promoting cell growth and proliferation and suppressing our body's internal housecleaning mechanisms. Normally, milk-mediated TOR stimulation is restricted only to infancy where we really need that constant signal to our cells to grow and divide. So from an evolutionary perspective, "the persistent 'abuse' of the growth-promoting signaling system of cow's milk by drinking milk over our entire life span may maintain the most important hallmark of cancer biology, sustained proliferative signaling."

TOR appears to play a role in breast cancer, too. Higher TOR expression has been noted in breast cancer tumors, associated with more aggressive disease, and lower survival rate among breast cancer patients. Altered TOR expression could explain why women hospitalized for anorexia may end up with only half the risk of breast cancer. Severe caloric restriction in humans may confer protection from invasive breast cancer by suppressing TOR activation.

We don't have to starve ourselves to suppress TOR; just reducing animal protein intake can attenuate overall TOR activity. Moreover, diets emphasizing plants, especially cruciferous vegetables, have both decreased TOR activation from animal proteins and provide natural plant-derived inhibitors of TOR found in broccoli, green tea, soy, turmeric, and grapes, along with other fruits and vegetables such as onions, strawberries, blueberries, mangoes and the skin of cucumbers.

The downregulation of TOR may be one reason why plant-based in general are associated with lower risk for many cancers. "Are we finally on the threshold of being able to fundamentally alter human aging and age-related disease?" asks researchers in the journal Nature. Only time will tell, but if the pace and direction of recent progress are any indication, the next 5,000 studies on TOR should prove very interesting indeed.

More on dairy and prostate cancer in Prostate Cancer and Organic Milk vs. Almond Milk.

This story continues in my video: Saving Lives By Treating Acne With Diet.

-Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Grempz / Flickr

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Is Liquid Smoke Safe?

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We know smoke inhalation isn't good for us, but what about smoke ingestion? Decades ago, smoke flavorings were tested to see if they caused DNA mutations in bacteria--the tests came up negative. Even as more and more smoke flavoring was added, the DNA mutation rate remained about the same.

But the fact that something is not mutagenic in bacteria may have little predictive value for its effect on human cells. A group at MIT tested a hickory smoke flavoring they bought at the store against two types of human white blood cells. Unlike the bacteria, the mutation rate shot up as more and more liquid smoke was added. But, "there is no evidence that mutagenic activity in a particular human cell line is more closely related to human health risk than is mutagenic activity in bacteria." In other words: just because liquid smoke causes DNA mutations to human cells in a petri dish, doesn't mean that it does the same thing within the human body.

A good approach may be to just analyze liquid smoke for known carcinogens, chemicals that we know cause cancer.

Damaging DNA is just one of many ways chemicals can be toxic to cells. A decade later researchers tested to see what effect liquid smoke had on overall cell viability. If you drip water on cells, nothing happens, they keep powering away at around 100% survival, but drip on more and more wood fire smoke, and you start killing some of the cells off. Cigarette smoke is more toxic, but three out of four of the brands of liquid smoke they bought at the supermarket killed off even more cells, leading them to conclude that the cytotoxic potential of some commercial smoke flavorings is greater than that of liquid cigarette smoke, a finding they no doubt celebrated given that the researchers were paid employees of the R. J. Reynolds Tobacco Co.

Unfortunately they didn't name names of the offending brands. That's one of the reasons I was so excited about a new study, where they tested--and named--15 different brands of liquid smoke. This maximum "response" they were measuring was p53 activation.

P53 is a protein we make that binds to our DNA, you can see this illustrated in my video, Is Liquid Smoke Flavoring Carcinogenic?. It activates our DNA repair enzymes. So a big p53 response may be indicative of a lot of DNA damage,and a few of the liquid smoke flavorings activated p53 almost as much as a chemotherapy drug like etoposide, whose whole purpose is to break DNA strands.

Other flavorings didn't seem as bad, though there was a hickory smoke powder that ranked pretty high, as did the fish sauce, though smoked paprika didn't register at all.

The p53-activating property in liquid smoke was eliminated by standard baking conditions (350°F for 1h), so if you're baking something with liquid smoke for long enough, it should eliminate this effect, though just boiling--even for an hour, or slow cooking doesn't appear to work.

They conclude "If the DNA-damaging activities of liquid smoke were thought to be deleterious, it might be possible to replace liquid smoke with other safer, smoky substances." Why do they say if thought to be deleterious? That's because they're not really measuring DNA damage, they're measuring p53 activation, and that's not necessarily a bad thing.

P53 is considered "Guardian of our Genome," guardian of our DNA. It's considered a tumor suppressor gene, so if something boosts its activity is that good or bad? It's like the broccoli story. Cruciferous vegetables dramatically boost our liver's detoxifying enzymes. Is this because our body sees broccoli as toxic and is trying to get rid of it quicker? Either way, the end result is good, lower cancer risk.

It's a biological phenomenon known as hormesis - that which doesn't kill us may make us stronger. Like exercise is a stress on the body, but in the right amount can make us healthier in the long run. So, for example, teas and coffees caused p53 activation as well, but their consumption is associated with lower cancer risk. So it's hard to know what to make of this p53 data. Due to the limitations of the available tests it's hard to calculate the genotoxic potential of liquid smoke, or any other food for that matter. A better approach may be to just analyze liquid smoke for known carcinogens, chemicals that we know cause cancer.

This was first attempted back in 1971. One of the seven liquid smoke flavors researchers tested contained one polycyclic aromatic hydrocarbon known to be cancer-causing, but there's a bunch of similar carcinogens researchers didn't test for. A later study, however, tested across the board, looking specifically at five different carcinogens in retail liquid smoke seasonings.

The recommended daily upper safety limit for these carcinogens is 47. Hickory smoke flavoring has only 0.8 per teaspoon, so we'd have to drink three bottles a day to bump up against the limit. And mesquite liquid smoke has only 1.1.

It turns out that most of the carcinogens in smoke are fat soluble, so when we make a water-based solution, like liquid smoke, we capture the smoke flavor compounds without capturing most of the smoke cancer compounds. The only time we need to really worry is when eating smoked foods--foods directly exposed to actual smoke. For example, smoked ham has 21.3 per serving, and smoked turkey breast has 26.7 per serving. One sandwich and we may be halfway to the limit, and one serving of barbequed chicken takes us over the top. Eating less than a single drumstick and we nearly double our daily allotment of these carcinogens. Nothing, however, is as bad as fish. Smoked herring? 140 per serving. And smoked salmon? One bagel with lox could take us ten times over the limit.

I've touched on those cooked meat carcinogens before. In Estrogenic Cooked Meat Carcinogens I explored the role of these cooked meat chemicals in tumor growth. PhIP: The Three Strikes Breast Carcinogen explored their role in cancer invasion. Reducing Cancer Risk In Meateaters offered some mediation strategies. Heterocyclic Amines in Eggs, Cheese, and Creatine? showed how even vegetarians may be at risk and Cancer, Interrupted: Green Tea and Cancer, Interrupted: Garlic & Flavonoids explored some counter measures.

Some smoke compounds may be a concern even if we don't eat them. See Meat Fumes: Dietary Secondhand Smoke. Even the smell of frying bacon may be carcinogenic: Carcinogens in the Smell of Frying Bacon.

Some plant foods exposed to high temperatures may also present a concern. See Is Yerba Mate Tea Bad for You? and Acrylamide in French Fries. What about Carcinogens in Roasted Coffee?

The broccoli liver enzyme boost story is covered in The Best Detox.

-Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live year-in-review presentations Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: eric forsberg / Flickr

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