Comparing Pollutant Levels Between Different Diets

Comparing Pollutant Levels Between Different Diets.jpeg

The results of the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study were published recently. This study of a California birth cohort investigated the relationship between exposure to flame retardant chemical pollutants in pregnancy and childhood, and subsequent neurobehavioral development. Why California? Because California children's exposures to these endocrine disruptors and neurotoxins are among the highest in the world.

What did they find? The researchers concluded that both prenatal and childhood exposures to these chemicals "were associated with poorer attention, fine motor coordination, and cognition" (particularly verbal comprehension) by the time the children reached school age. "This study, the largest to date, contributes to growing evidence suggesting that PBDEs [polybrominated diphenyl ethers, flame retardant chemicals] have adverse impacts on child neurobehavioral development." The effects may extend into adolescence, again affecting motor function as well as thyroid gland function. The effect on our thyroid glands may even extend into adulthood.

These chemicals get into moms, then into the amniotic fluid, and then into the breast milk. The more that's in the milk, the worse the infants' mental development may be. Breast milk is still best, but how did these women get exposed in the first place?

The question has been: Are we exposed mostly from diet or dust? Researchers in Boston collected breast milk samples from 46 first-time moms, vacuumed up samples of dust from their homes, and questioned them about their diets. The researchers found that both were likely to blame. Diet-wise, a number of animal products were implicated. This is consistent with what's been found worldwide. For example, in Europe, these flame retardant chemical pollutants are found mostly in meat, including fish, and other animal products. It's similar to what we see with dioxins--they are mostly found in fish and other fatty foods, with a plant-based diet offering the lowest exposure.

If that's the case, do vegetarians have lower levels of flame retardant chemical pollutants circulating in their bloodstreams? Yes. Vegetarians may have about 25% lower levels. Poultry appears to be the largest contributor of PBDEs. USDA researchers compared the levels in different meats, and the highest levels of these pollutants were found in chicken and turkey, with less in pork and even less in beef. California poultry had the highest, consistent with strict furniture flammability codes. But it's not like chickens are pecking at the sofa. Chickens and turkeys may be exposed indirectly through the application of sewer sludge to fields where feed crops are raised, contamination of water supplies, the use of flame-retarded materials in poultry housing, or the inadvertent incorporation of fire-retardant material into the birds' bedding or feed ingredients.

Fish have been shown to have the highest levels overall, but Americans don't eat a lot of fish so they don't contribute as much to the total body burden in the United States. Researchers have compared the level of PBDEs found in meat-eaters and vegetarians. The amount found in the bloodstream of vegetarians is noticeably lower, as you can see in my video Flame Retardant Pollutants and Child Development. Just to give you a sense of the contribution of chicken, higher than average poultry eaters have higher levels than omnivores as a whole, and lower than average poultry eaters have levels lower than omnivores.

What are the PBDE levels in vegans? We know the intake of many other classes of pollutants is almost exclusively from the ingestion of animal fats in the diet. What if we take them all out of the diet? It works for dioxins. Vegan dioxin levels appear markedly lower than the general population. What about for the flame retardant chemicals? Vegans have levels lower than vegetarians, with those who've been vegan around 20 years having even lower concentrations. This tendency for chemical levels to decline the longer one eats plant-based suggests that food of animal origin contributes substantially. But note that levels never get down to zero, so diet is not the only source.

The USDA researchers note that there are currently no regulatory limits on the amount of flame retardant chemical contamination in U.S. foods, "but reducing the levels of unnecessary, persistent, toxic compounds in our diet is certainly desirable."

I've previously talked about this class of chemicals in Food Sources of Flame Retardant Chemicals. The same foods seem to accumulate a variety of pollutants:

Many of these chemicals have hormone- or endocrine-disrupting effects. See, for example:

In health,

Michael Greger, M.D.

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

Image Credit: Mitchell Haindfield / Flickr. This image has been modified.

Original Link

Comparing Pollutant Levels Between Different Diets

Comparing Pollutant Levels Between Different Diets.jpeg

The results of the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study were published recently. This study of a California birth cohort investigated the relationship between exposure to flame retardant chemical pollutants in pregnancy and childhood, and subsequent neurobehavioral development. Why California? Because California children's exposures to these endocrine disruptors and neurotoxins are among the highest in the world.

What did they find? The researchers concluded that both prenatal and childhood exposures to these chemicals "were associated with poorer attention, fine motor coordination, and cognition" (particularly verbal comprehension) by the time the children reached school age. "This study, the largest to date, contributes to growing evidence suggesting that PBDEs [polybrominated diphenyl ethers, flame retardant chemicals] have adverse impacts on child neurobehavioral development." The effects may extend into adolescence, again affecting motor function as well as thyroid gland function. The effect on our thyroid glands may even extend into adulthood.

These chemicals get into moms, then into the amniotic fluid, and then into the breast milk. The more that's in the milk, the worse the infants' mental development may be. Breast milk is still best, but how did these women get exposed in the first place?

The question has been: Are we exposed mostly from diet or dust? Researchers in Boston collected breast milk samples from 46 first-time moms, vacuumed up samples of dust from their homes, and questioned them about their diets. The researchers found that both were likely to blame. Diet-wise, a number of animal products were implicated. This is consistent with what's been found worldwide. For example, in Europe, these flame retardant chemical pollutants are found mostly in meat, including fish, and other animal products. It's similar to what we see with dioxins--they are mostly found in fish and other fatty foods, with a plant-based diet offering the lowest exposure.

If that's the case, do vegetarians have lower levels of flame retardant chemical pollutants circulating in their bloodstreams? Yes. Vegetarians may have about 25% lower levels. Poultry appears to be the largest contributor of PBDEs. USDA researchers compared the levels in different meats, and the highest levels of these pollutants were found in chicken and turkey, with less in pork and even less in beef. California poultry had the highest, consistent with strict furniture flammability codes. But it's not like chickens are pecking at the sofa. Chickens and turkeys may be exposed indirectly through the application of sewer sludge to fields where feed crops are raised, contamination of water supplies, the use of flame-retarded materials in poultry housing, or the inadvertent incorporation of fire-retardant material into the birds' bedding or feed ingredients.

Fish have been shown to have the highest levels overall, but Americans don't eat a lot of fish so they don't contribute as much to the total body burden in the United States. Researchers have compared the level of PBDEs found in meat-eaters and vegetarians. The amount found in the bloodstream of vegetarians is noticeably lower, as you can see in my video Flame Retardant Pollutants and Child Development. Just to give you a sense of the contribution of chicken, higher than average poultry eaters have higher levels than omnivores as a whole, and lower than average poultry eaters have levels lower than omnivores.

What are the PBDE levels in vegans? We know the intake of many other classes of pollutants is almost exclusively from the ingestion of animal fats in the diet. What if we take them all out of the diet? It works for dioxins. Vegan dioxin levels appear markedly lower than the general population. What about for the flame retardant chemicals? Vegans have levels lower than vegetarians, with those who've been vegan around 20 years having even lower concentrations. This tendency for chemical levels to decline the longer one eats plant-based suggests that food of animal origin contributes substantially. But note that levels never get down to zero, so diet is not the only source.

The USDA researchers note that there are currently no regulatory limits on the amount of flame retardant chemical contamination in U.S. foods, "but reducing the levels of unnecessary, persistent, toxic compounds in our diet is certainly desirable."

I've previously talked about this class of chemicals in Food Sources of Flame Retardant Chemicals. The same foods seem to accumulate a variety of pollutants:

Many of these chemicals have hormone- or endocrine-disrupting effects. See, for example:

In health,

Michael Greger, M.D.

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

Image Credit: Mitchell Haindfield / Flickr. This image has been modified.

Original Link

Stomach Stapling Kids

Stomach Stapling Kids.jpeg

Weight loss surgery for children and adolescents is becoming widespread and is being performed in children as young as five years old. Roux-en-Y gastric bypass is the most common type of procedure, in which surgeons cut out nearly the entire stomach, as you can see in my video, Stomach Stapling Kids. Bariatric surgery in pediatric patients does result in weight loss, but also has the potential for serious complications. These include pulmonary embolism, shock, intestinal obstruction, postoperative bleeding, leaking along the staple line, severe malnutrition, and even death at a rate of 0.5%. This means that 1 in 200 kids who go under the knife may die. Infection is identified as the leading cause of death and is most often associated with leaking of intestinal contents into the abdominal cavity.

Sometimes the surgery doesn't work, and you have to go in and do another procedure. If that doesn't work either, you can always try implanting electrodes into patients' brains, a "novel antiobesity strategy" reported in the Journal of Neurosurgery. The concept of deep brain stimulation "since its inception has been that placing an electrode somewhere in the brain could make people eat less." You drill two little holes in the patient's skull, snake in some electrodes a few inches, and then tunnel the wires under the scalp into a pulse generator implanted under the skin on the chest. You evidently can't crank it up past 5 volts because it induces anxiety and nausea. But even without the nausea, people with electrodes stuck in their brains lost an average of about 10 pounds a year.

The childhood obesity epidemic is so tragic. It pains me to see insult piled on injury. Too often, medical treatments can be worse than the disease. See my video, Why Prevention Is Worth a Ton of Cure.

Speaking of prevention, what might be the best diet for our young ones? See:

There are complications associated with gastric bypass in adults, too. See my video The Dangers of Broccoli?.

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: ReSurge International / Flickr. This image has been modified.

Original Link

Stomach Stapling Kids

Stomach Stapling Kids.jpeg

Weight loss surgery for children and adolescents is becoming widespread and is being performed in children as young as five years old. Roux-en-Y gastric bypass is the most common type of procedure, in which surgeons cut out nearly the entire stomach, as you can see in my video, Stomach Stapling Kids. Bariatric surgery in pediatric patients does result in weight loss, but also has the potential for serious complications. These include pulmonary embolism, shock, intestinal obstruction, postoperative bleeding, leaking along the staple line, severe malnutrition, and even death at a rate of 0.5%. This means that 1 in 200 kids who go under the knife may die. Infection is identified as the leading cause of death and is most often associated with leaking of intestinal contents into the abdominal cavity.

Sometimes the surgery doesn't work, and you have to go in and do another procedure. If that doesn't work either, you can always try implanting electrodes into patients' brains, a "novel antiobesity strategy" reported in the Journal of Neurosurgery. The concept of deep brain stimulation "since its inception has been that placing an electrode somewhere in the brain could make people eat less." You drill two little holes in the patient's skull, snake in some electrodes a few inches, and then tunnel the wires under the scalp into a pulse generator implanted under the skin on the chest. You evidently can't crank it up past 5 volts because it induces anxiety and nausea. But even without the nausea, people with electrodes stuck in their brains lost an average of about 10 pounds a year.

The childhood obesity epidemic is so tragic. It pains me to see insult piled on injury. Too often, medical treatments can be worse than the disease. See my video, Why Prevention Is Worth a Ton of Cure.

Speaking of prevention, what might be the best diet for our young ones? See:

There are complications associated with gastric bypass in adults, too. See my video The Dangers of Broccoli?.

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: ReSurge International / Flickr. This image has been modified.

Original Link

Stomach Stapling Kids

Stomach Stapling Kids.jpeg

Weight loss surgery for children and adolescents is becoming widespread and is being performed in children as young as five years old. Roux-en-Y gastric bypass is the most common type of procedure, in which surgeons cut out nearly the entire stomach, as you can see in my video, Stomach Stapling Kids. Bariatric surgery in pediatric patients does result in weight loss, but also has the potential for serious complications. These include pulmonary embolism, shock, intestinal obstruction, postoperative bleeding, leaking along the staple line, severe malnutrition, and even death at a rate of 0.5%. This means that 1 in 200 kids who go under the knife may die. Infection is identified as the leading cause of death and is most often associated with leaking of intestinal contents into the abdominal cavity.

Sometimes the surgery doesn't work, and you have to go in and do another procedure. If that doesn't work either, you can always try implanting electrodes into patients' brains, a "novel antiobesity strategy" reported in the Journal of Neurosurgery. The concept of deep brain stimulation "since its inception has been that placing an electrode somewhere in the brain could make people eat less." You drill two little holes in the patient's skull, snake in some electrodes a few inches, and then tunnel the wires under the scalp into a pulse generator implanted under the skin on the chest. You evidently can't crank it up past 5 volts because it induces anxiety and nausea. But even without the nausea, people with electrodes stuck in their brains lost an average of about 10 pounds a year.

The childhood obesity epidemic is so tragic. It pains me to see insult piled on injury. Too often, medical treatments can be worse than the disease. See my video, Why Prevention Is Worth a Ton of Cure.

Speaking of prevention, what might be the best diet for our young ones? See:

There are complications associated with gastric bypass in adults, too. See my video The Dangers of Broccoli?.

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: ReSurge International / Flickr. This image has been modified.

Original Link

Music as Medicine

Music as Medicine.jpeg

We've been playing music since the Paleolithic Era, 40,000 years ago. Music as therapy has been documented since at least biblical times. The first music therapy experiment was published in the Journal of the American Medical Association in 1914. As to why he placed a phonograph in the operating room as his patients lay fully conscious and awake during surgery, the surgeon explained it was "a means of calming and distracting my patients from the horror of the situation."

Now that we have anesthesia, music is used to calm nerves before surgery. Normally we use Valium-type drugs like midazolam (sold as Versed), but they can have a variety of side effects, including sometimes even making people more agitated. A study from Sweden sought to determine if relaxing music has a greater anxiety-reducing effect than a standard dose of midazolam. Researchers whipped out some Kenny G, and the music worked significantly better than the drug. Those listening to Mr. G had lower anxiety scores, heart rates, and blood pressures. This is perhaps the first report of any anti-anxiety therapy working not only as good as, but even better than, benzodiazepine drugs. The difference in side effects of relaxing music compared to the drug is obvious: There were none. Soft jazz causes no post-operative hangover. The researchers suggest we should start using music instead of midazolam.

Music may also reduce anxiety and pain in children undergoing minor medical and dental procedures, helping with blood draws and shots. It may even reduce the pain of spinal taps. However, Mozart is evidently powerless against the pain of circumcision.

It doesn't take a randomized controlled trial to demonstrate that listening to music can be relaxing. Tell me something I don't know. Well, if you take someone with a latex allergy and inject their skin with latex, they get a big, red, angry bump. But if you repeat the test after they've been listening to Mozart for 30 minutes, they develop a much smaller bump (as you can see in my video, Music as Medicine). That is, they have less of an allergic reaction. If you think that's wild, get ready for this: Beethoven didn't work. The subjects had the same reaction before and after listening to his music! Schubert, Hayden, and Brahms didn't work either, as all failed to reduce the allergic skin response. The reducing effect on allergic responses may be specific to Mozart.

So Mozart's looking pretty good, but what if he could be suppressing our immune systems in general? That would not be good. The same researchers also injected a chemical that causes reactions in everyone, not just in allergic people. Mozart had no effect. It seems Mozart suppresses only the pathological allergic reaction. If that isn't crazy enough for you, the researchers drew subjects' blood after the music, stuck their white blood cells in a petri dish with a little latex, and measured the allergic antibody response. The white blood cells from those exposed to Mozart had less of an allergic response even outside the body compared to cells taken from Beethoven blood. How cool is that?

Music may even impact our metabolism. This inquiry started with a 2012 study published in the journal Pediatrics, which found the resting energy expenditure (the number of calories burned when just lying around) was lower in preterm infants when researchers piped in Mozart. This may explain why infants exposed to music put on weight faster, so much so they are able to go home earlier.

Gaining weight faster is great for premature babies, but not necessarily for adults. Could listening to music slow our metabolism and contribute to weight gain? Well, one study found no effect on adults. But the researchers used Bach, not Mozart. Bach doesn't cause a drop in energy expenditure in babies either. These data suggest there may be "more a 'Mozart effect' than a universal 'music effect'."

What if we just listen to music of our choice? Does that affect our metabolism? We didn't know... until now. It turns out that listening to music appears to actually increase our metabolic rate, such that we burn an average of 27.6 more calories a day just lying in bed. That's only like six M&M's worth, though, so it's better to use music to get up and start dancing or exercising. Music can not only improve exercise enjoyment but also performance--a way to improve athletic performance that's legal.

Male bodybuilders may be less enthused music's effects. After listening to music for just 30 minutes, testosterone levels drop 14% in young men and go up 21% in young women. Do all kinds of music have this effect or just some types? Thirty minutes of silence had no effect on testosterone levels at all, while a half-hour of Mozart, jazz, pop, or Gregorian chants (no relation :) all suppressed testosterone. What about a half-hour of people's personal favorites? Testosterone levels were cut in half! Testosterone decreased in males under all music conditions, whereas testosterone increased in females. What is going on? Well, in men, testosterone is related to libido, dominance, and aggressiveness, whereas women get a bigger boost in testosterone from cuddling than from sex. So maybe we evolved using music as a way to ensure we all got along, like a melodious cold shower to keep everyone chill.

Is that crazy or what? I'm fascinated by the whole topic. For more, see Music for Anxiety: Mozart vs. Metal.

Sounds are the only sensory-stimulators that can have an effect on us--so can scents! See:

Exposure to industrial pollutants may also affect both allergic diseases and testosterone levels:

In health,

Michael Greger, M.D.

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

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

Original Link

Music as Medicine

Music as Medicine.jpeg

We've been playing music since the Paleolithic Era, 40,000 years ago. Music as therapy has been documented since at least biblical times. The first music therapy experiment was published in the Journal of the American Medical Association in 1914. As to why he placed a phonograph in the operating room as his patients lay fully conscious and awake during surgery, the surgeon explained it was "a means of calming and distracting my patients from the horror of the situation."

Now that we have anesthesia, music is used to calm nerves before surgery. Normally we use Valium-type drugs like midazolam (sold as Versed), but they can have a variety of side effects, including sometimes even making people more agitated. A study from Sweden sought to determine if relaxing music has a greater anxiety-reducing effect than a standard dose of midazolam. Researchers whipped out some Kenny G, and the music worked significantly better than the drug. Those listening to Mr. G had lower anxiety scores, heart rates, and blood pressures. This is perhaps the first report of any anti-anxiety therapy working not only as good as, but even better than, benzodiazepine drugs. The difference in side effects of relaxing music compared to the drug is obvious: There were none. Soft jazz causes no post-operative hangover. The researchers suggest we should start using music instead of midazolam.

Music may also reduce anxiety and pain in children undergoing minor medical and dental procedures, helping with blood draws and shots. It may even reduce the pain of spinal taps. However, Mozart is evidently powerless against the pain of circumcision.

It doesn't take a randomized controlled trial to demonstrate that listening to music can be relaxing. Tell me something I don't know. Well, if you take someone with a latex allergy and inject their skin with latex, they get a big, red, angry bump. But if you repeat the test after they've been listening to Mozart for 30 minutes, they develop a much smaller bump (as you can see in my video, Music as Medicine). That is, they have less of an allergic reaction. If you think that's wild, get ready for this: Beethoven didn't work. The subjects had the same reaction before and after listening to his music! Schubert, Hayden, and Brahms didn't work either, as all failed to reduce the allergic skin response. The reducing effect on allergic responses may be specific to Mozart.

So Mozart's looking pretty good, but what if he could be suppressing our immune systems in general? That would not be good. The same researchers also injected a chemical that causes reactions in everyone, not just in allergic people. Mozart had no effect. It seems Mozart suppresses only the pathological allergic reaction. If that isn't crazy enough for you, the researchers drew subjects' blood after the music, stuck their white blood cells in a petri dish with a little latex, and measured the allergic antibody response. The white blood cells from those exposed to Mozart had less of an allergic response even outside the body compared to cells taken from Beethoven blood. How cool is that?

Music may even impact our metabolism. This inquiry started with a 2012 study published in the journal Pediatrics, which found the resting energy expenditure (the number of calories burned when just lying around) was lower in preterm infants when researchers piped in Mozart. This may explain why infants exposed to music put on weight faster, so much so they are able to go home earlier.

Gaining weight faster is great for premature babies, but not necessarily for adults. Could listening to music slow our metabolism and contribute to weight gain? Well, one study found no effect on adults. But the researchers used Bach, not Mozart. Bach doesn't cause a drop in energy expenditure in babies either. These data suggest there may be "more a 'Mozart effect' than a universal 'music effect'."

What if we just listen to music of our choice? Does that affect our metabolism? We didn't know... until now. It turns out that listening to music appears to actually increase our metabolic rate, such that we burn an average of 27.6 more calories a day just lying in bed. That's only like six M&M's worth, though, so it's better to use music to get up and start dancing or exercising. Music can not only improve exercise enjoyment but also performance--a way to improve athletic performance that's legal.

Male bodybuilders may be less enthused music's effects. After listening to music for just 30 minutes, testosterone levels drop 14% in young men and go up 21% in young women. Do all kinds of music have this effect or just some types? Thirty minutes of silence had no effect on testosterone levels at all, while a half-hour of Mozart, jazz, pop, or Gregorian chants (no relation :) all suppressed testosterone. What about a half-hour of people's personal favorites? Testosterone levels were cut in half! Testosterone decreased in males under all music conditions, whereas testosterone increased in females. What is going on? Well, in men, testosterone is related to libido, dominance, and aggressiveness, whereas women get a bigger boost in testosterone from cuddling than from sex. So maybe we evolved using music as a way to ensure we all got along, like a melodious cold shower to keep everyone chill.

Is that crazy or what? I'm fascinated by the whole topic. For more, see Music for Anxiety: Mozart vs. Metal.

Sounds are the only sensory-stimulators that can have an effect on us--so can scents! See:

Exposure to industrial pollutants may also affect both allergic diseases and testosterone levels:

In health,

Michael Greger, M.D.

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

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

Original Link

Foods that Affect Testosterone Levels

Foods that Affect Testosterone Levels.jpeg

A number of studies suggest that exposure to industrial pollutants may affect sexual function, for example, loss of libido, sexual dysfunction, and impotence. This may be due to effects on testosterone levels. In a study of men who ate a lot of contaminated fish, an elevation in PCB levels in the blood was associated with a lower concentration of testosterone levels. These pollutants are found predominantly in fish, but also meat and dairy. The lowest levels are found in plants (see Dietary Pollutants May Affect Testosterone Levels).

Testosterone doesn't just play a role in the determination of secondary sex characteristics like facial hair at puberty. It also regulates normal sexual functioning and the overall physical and psychological well-being of adult men. Abnormally low levels of testosterone can lead to decreased physical endurance and memory capacity, loss of libido, drop in sperm count, loss of bone density, obesity, and depression.

Endocrine-disrupting compounds that build up in fish may be able to mimic or block hormone receptors, or alter rates of synthesis or breakdown of sex steroid hormones. In children, these pollutants may actually impair sexual development. Boys who are exposed may grow up with smaller penises (although only by about two-thirds of an inch shorter at most). Researchers have tried exposing cells from aborted fetal human penises to these kinds of dietary pollutants, and gene expression related to genital development is indeed affected at real-life exposure levels. We're not sure if the effects on penis length are due to the pro-estrogenic effects of the toxins, though, or the anti-testosterone effects.

You've heard of save the whales? Well, male reproductive organs may be at risk from environmental hazards as well.

I previously addressed how we discovered the endocrine disruptor phenomenon in Alkylphenol Endocrine Disruptors and Allergies, as well as where they're found (Dietary Sources of Alkylphenol Endocrine Disruptors).

For more on sustaining male virility, see Male Fertility and Diet, The Role of Diet in Declining Sperm Counts, and Dairy Estrogen and Male Fertility.

I've talked about the role a plastics chemical may play in male sexual functioning (BPA Plastic and Male Sexual Dysfunction). But it's not just toxins, it's the total diet (Survival of the Firmest: Erectile Dysfunction and Death), and not only in men (Cholesterol and Female Sexual Dysfunction). My latest on the topic is Best Foods to Improve Sexual Function.

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. Image has been modified.

Original Link

Foods that Affect Testosterone Levels

Foods that Affect Testosterone Levels.jpeg

A number of studies suggest that exposure to industrial pollutants may affect sexual function, for example, loss of libido, sexual dysfunction, and impotence. This may be due to effects on testosterone levels. In a study of men who ate a lot of contaminated fish, an elevation in PCB levels in the blood was associated with a lower concentration of testosterone levels. These pollutants are found predominantly in fish, but also meat and dairy. The lowest levels are found in plants (see Dietary Pollutants May Affect Testosterone Levels).

Testosterone doesn't just play a role in the determination of secondary sex characteristics like facial hair at puberty. It also regulates normal sexual functioning and the overall physical and psychological well-being of adult men. Abnormally low levels of testosterone can lead to decreased physical endurance and memory capacity, loss of libido, drop in sperm count, loss of bone density, obesity, and depression.

Endocrine-disrupting compounds that build up in fish may be able to mimic or block hormone receptors, or alter rates of synthesis or breakdown of sex steroid hormones. In children, these pollutants may actually impair sexual development. Boys who are exposed may grow up with smaller penises (although only by about two-thirds of an inch shorter at most). Researchers have tried exposing cells from aborted fetal human penises to these kinds of dietary pollutants, and gene expression related to genital development is indeed affected at real-life exposure levels. We're not sure if the effects on penis length are due to the pro-estrogenic effects of the toxins, though, or the anti-testosterone effects.

You've heard of save the whales? Well, male reproductive organs may be at risk from environmental hazards as well.

I previously addressed how we discovered the endocrine disruptor phenomenon in Alkylphenol Endocrine Disruptors and Allergies, as well as where they're found (Dietary Sources of Alkylphenol Endocrine Disruptors).

For more on sustaining male virility, see Male Fertility and Diet, The Role of Diet in Declining Sperm Counts, and Dairy Estrogen and Male Fertility.

I've talked about the role a plastics chemical may play in male sexual functioning (BPA Plastic and Male Sexual Dysfunction). But it's not just toxins, it's the total diet (Survival of the Firmest: Erectile Dysfunction and Death), and not only in men (Cholesterol and Female Sexual Dysfunction). My latest on the topic is Best Foods to Improve Sexual Function.

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. Image has been modified.

Original Link

What Are the Benefits of Organic?

What Are the Benefits of Organic?.jpeg

The medical literature has been historically hostile to organic foods, blaming in part erroneous information supplied by the health food movement for our ignorance of nutrition. But until just a few generations ago, all food was organic. It's kind of ironic that what we now call conventional food really isn't very conventional for our species.

By eating organic we can reduce our exposure to pesticides, but it remains unclear whether such a reduction in exposure is clinically relevant. In my video, Are Organic Foods Safer?, I talked about some of the test tube studies comparing health-related properties of organic versus conventional foods. Organic produce was found to have higher antioxidant and antimutagenic activity combined with better inhibition of cancer cell proliferation, but in terms of studies on actual people rather than petri dishes, there isn't much science either way.

Why can't you just compare the health of those who buy organic to those who don't? Organic consumers do report being significantly healthier than conventional consumers, but they also tend to eat more plant foods in general and less soda and alcohol, processed meat, or milk, and just eat healthier in general. No wonder they feel so much better!

Therefore, there is an urgent need for interventional trials, or studies following cohorts of people eating organic over time like the Million Women Study in the UK, which was the first to examine the association between the consumption of organic food and subsequent risk of cancer. The only significant risk reduction they found, though, was for non-Hodgkin's lymphoma. This is consistent with data showing a higher risk of developing lymphoma in those who have higher levels of pesticides stored in their butt fat, a study undertaken because farmworkers have been found to have higher rates of lymphoma.

Parental farmworker exposure is also associated with a birth defect of the penis called hypospadias, and so researchers decided to see if moms who failed to choose organic were at increased risk. Indeed they found that frequent consumption of conventional high-fat dairy products was associated with about double the odds of the birth defect. This could just be because those that choose organic have other related healthy behaviors, or it could be that high-fat foods like dairy products bioamplify the fat-soluble toxins in our environment.

In my video, Are Organic Foods Healthier?, you can see two other general population pesticide studies that have raised concerns. One study found about a 50 to 70% increase in the odds of ADHD among children with pesticide levels in their urine, and another that found triple the odds of testicular cancer among men with higher levels of organochlorine pesticides in their blood. 90% of such pollutants come from fish, meat, and dairy, which may help explain rising testicular cancer rates in many western countries since World War II.

What about interventional trials? All we have in the medical literature so far are studies showing organically grown food provides health benefits to fruit flies raised on diets of conventional versus organic produce when subjected to a variety of tests designed to assess overall fly health. And what do you know--flies raised on diets made from organically grown produce lived longer. Hmm, insects eating insecticides don't do as well. Not exactly much of a breakthrough!


For how to best get pesticides off of conventional produce, see my video How to Make Your Own Fruit and Vegetable Wash.

Pesticides are one thing, but Are Organic Foods More Nutritious?

Overall, Are the Benefits of Organic Food Underrated or Overrated?

For more on the impact of food contaminants during pregnancy, 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:

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