The 3 Vitamins that Prevent Brain Loss

The 3 Vitamins that Prevent Brain Loss.jpeg

By our seventies, one in five of us will suffer from cognitive impairment. Within five years, half of those cognitively impaired will progress to dementia and death. The earlier we can slow or stop this process, the better.

Although an effective treatment for Alzheimer's disease is unavailable, interventions just to control risk factors could prevent millions of cases. An immense effort has been spent on identifying such risk factors for Alzheimer's and developing treatments to reduce them.

In 1990, a small study of 22 Alzheimer's patients reported high concentrations of homocysteine in their blood. The homocysteine story goes back to 1969 when a Harvard pathologist reported two cases of children, one dating back to 1933, whose brains had turned to mush. They both suffered from extremely rare genetic mutations that led to abnormally high levels of homocysteine in their bodies. Is it possible, he asked, that homocysteine could cause brain damage even in people without genetic defects?

Here we are in the 21st century, and homocysteine is considered "a strong, independent risk factor for the development of dementia and Alzheimer's disease." Having a blood level over 14 (µmol/L) may double our risk. In the Framingham Study, researchers estimate that as many as one in six Alzheimer's cases may be attributable to elevated homocysteine in the blood, which is now thought to play a role in brain damage and cognitive and memory decline. Our body can detoxify homocysteine, though, using three vitamins: folate, vitamin B12, and vitamin B6. So why don't we put them to the test? No matter how many studies find an association between high homocysteinea and cognitive decline, dementia, or Alzheimer's disease, a cause-and-effect role can only be confirmed by interventional studies.

Initially, the results were disappointing. Vitamin supplementation did not seem to work, but the studies were tracking neuropsychological assessments, which are more subjective compared to structural neuroimaging--that is, actually seeing what's happening to the brain. A double-blind randomized controlled trial found that homocysteine-lowering by B vitamins can slow the rate of accelerated brain atrophy in people with mild cognitive impairment. As we age, our brains slowly atrophy, but the shrinking is much accelerated in patients suffering from Alzheimer's disease. An intermediate rate of shrinkage is found in people with mild cognitive impairment. The thinking is if we could slow the rate of brain loss, we may be able to slow the conversion to Alzheimer's disease. Researchers tried giving people B vitamins for two years and found it markedly slowed the rate of brain shrinkage. The rate of atrophy in those with high homocysteine levels was cut in half. A simple, safe treatment can slow the accelerated rate of brain loss.

A follow-up study went further by demonstrating that B-vitamin treatment reduces, by as much as seven-fold, the brain atrophy in the regions specifically vulnerable to the Alzheimer's disease process. You can see the amount of brain atrophy over a two-year period in the placebo group versus the B-vitamin group in my Preventing Brain Loss with B Vitamins? video.

The beneficial effect of B vitamins was confined to those with high homocysteine, indicating a relative deficiency in one of those three vitamins. Wouldn't it be better to not become deficient in the first place? Most people get enough B12 and B6. The reason these folks were stuck at a homocysteine of 11 µmoles per liter is that they probably weren't getting enough folate, which is found concentrated in beans and greens. Ninety-six percent of Americans don't even make the minimum recommended amount of dark green leafy vegetables, which is the same pitiful number who don't eat the minimum recommendation for beans.

If we put people on a healthy diet--a plant-based diet--we can drop their homocysteine levels by 20% in just one week, from around 11 mmoles per liter down to 9 mmoles per liter. The fact that they showed rapid and significant homocysteine lowering without any pills or supplements implies that multiple mechanisms may have been at work. The researchers suggest it may be because of the fiber. Every gram of daily fiber consumption may increase folate levels in the blood nearly 2%, perhaps by boosting vitamin production in the colon by all our friendly gut bacteria. It also could be from the decreased methionine intake.

Methionine is where homocysteine comes from. Homocysteine is a breakdown product of methionine, which comes mostly from animal protein. If we give someone bacon and eggs for breakfast and a steak for dinner, we can get spikes of homocysteine levels in the blood. Thus, decreased methionine intake on a plant-based diet may be another factor contributing to lower, safer homocysteine levels.

The irony is that those who eat plant-based diets long-term, not just at a health spa for a week, have terrible homocysteine levels. Meat-eaters are up at 11 µmoles per liter, but vegetarians at nearly 14 µmoles per liter and vegans at 16 µmoles per liter. Why? The vegetarians and vegans were getting more fiber and folate, but not enough vitamin B12. Most vegans were at risk for suffering from hyperhomocysteinaemia (too much homocysteine in the blood) because most vegans in the study were not supplementing with vitamin B12 or eating vitamin B12-fortified foods, which is critical for anyone eating a plant-based diet. If you take vegans and give them B12, their homocysteine levels can drop down below 5. Why not down to just 11? The reason meat-eaters were stuck up at 11 is presumably because they weren't getting enough folate. Once vegans got enough B12, they could finally fully exploit the benefits of their plant-based diets and come out with the lowest levels of all.

This is very similar to the findings in my video Vitamin B12 Necessary for Arterial Health.

For more details on ensuring a regular reliable source of vitamin B12:

There are more benefits to lowering your methionine intake. Check out Methionine Restriction as a Life Extension Strategy and Starving Cancer with Methionine Restriction.

For more on brain health in general, see these videos:

In health,

Michael Greger, M.D.

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

Image Credit: Thomas Hawk / Flickr. This image has been modified.

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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.

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The Food Safety Risk of Organic versus Conventional

The Food Safety Risk of Organic versus Conventional.jpeg

The stated principles of organic agriculture are "health, ecology, fairness, and care," but if you ask people why they buy organic, the strongest predictor is concern for their own health. People appear to spend more for organic foods for selfish reasons, rather than altruistic motives. Although organic foods may not have more nutrients per dollar (see my video Are Organic Foods More Nutritious?), consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Food safety-wise, researchers found no difference in the risk for contamination with food poisoning bacteria in general. Both organic and conventional animal products have been found to be commonly contaminated with Salmonella and Campylobacter, for example. Most chicken samples (organic and inorganic), were found to be contaminated with Campylobacter, and about a third with Salmonella, but the risk of exposure to multidrug-resistant bacteria was lower with the organic meat. They both may carry the same risk of making us sick, but food poisoning from organic meat may be easier for doctors to treat.

What about the pesticides? There is a large body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson's, Alzheimer's, and ALS, as well as birth defects and reproductive disorders--but these studies were largely on people who live or work around pesticides.

Take Salinas Valley California, for example, where they spray a half million pounds of the stuff. Daring to be pregnant in an agricultural community like that may impair childhood brain development, such that pregnant women with the highest levels running through their bodies (as measured in their urine) gave birth to children with an average deficit of about seven IQ points. Twenty-six out of 27 studies showed negative effects of pesticides on brain development in children. These included attention problems, developmental disorders, and short-term memory difficulties.

Even in urban areas, if you compare kids born with higher levels of a common insecticide in their umbilical cord blood, those who were exposed to higher levels are born with brain anomalies. And these were city kids, so presumably this was from residential pesticide use.

Using insecticides inside your house may also be a contributing risk factor for childhood leukemia. Pregnant farmworkers may be doubling the odds of their child getting leukemia and increase their risk of getting a brain tumor. This has lead to authorities advocating that awareness of the potentially negative health outcome for children be increased among populations occupationally exposed to pesticides, though I don't imagine most farmworkers have much of a choice.

Conventional produce may be bad for the pregnant women who pick them, but what about our own family when we eat them?

Just because we spray pesticides on our food in the fields doesn't necessarily mean it ends up in our bodies when we eat it, or at least we didn't know that until a study was published in 2006. Researchers measured the levels of two pesticides running through children's bodies by measuring specific pesticide breakdown products in their urine. In my video, Are Organic Foods Safer?, you can see the levels of pesticides flowing through the bodies of three to 11-year olds during a few days on a conventional diet. The kids then went on an organic diet for five days and then back to the conventional diet. As you can see, eating organic provides a dramatic and immediate protective effect against exposures to pesticides commonly used in agricultural production. The study was subsequently extended. It's clear by looking at the subsequent graph in the video when the kids were eating organic versus conventional. What about adults, though? We didn't know... until now.

Thirteen men and women consumed a diet of at least 80% organic or conventional food for seven days and then switched. No surprise, during the mostly organic week, pesticide exposure was significantly reduced by a nearly 90% drop.

If it can be concluded that consumption of organic foods provides protection against pesticides, does that also mean protection against disease? We don't know. The studies just haven't been done. Nevertheless, in the meantime, the consumption of organic food provides a logical precautionary approach.

For more on organic foods:

For more on the infectious disease implications of organic versus conventional, see Superbugs in Conventional vs. Organic Chicken. Organic produce may be safer too. See Norovirus Food Poisoning from Pesticides. Organic eggs may also have lower Salmonella risk, which is an egg-borne epidemic every year in the US. See my video Who Says Eggs Aren't Healthy or Safe?

More on Parkinson's and pesticides in Preventing Parkinson's Disease With Diet.

Those surprised by the California data might have missed my video California Children Are Contaminated.

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: IFPRI -IMAGES / Flickr. This image has been modified.

Original Link

The Food Safety Risk of Organic versus Conventional

The Food Safety Risk of Organic versus Conventional.jpeg

The stated principles of organic agriculture are "health, ecology, fairness, and care," but if you ask people why they buy organic, the strongest predictor is concern for their own health. People appear to spend more for organic foods for selfish reasons, rather than altruistic motives. Although organic foods may not have more nutrients per dollar (see my video Are Organic Foods More Nutritious?), consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Food safety-wise, researchers found no difference in the risk for contamination with food poisoning bacteria in general. Both organic and conventional animal products have been found to be commonly contaminated with Salmonella and Campylobacter, for example. Most chicken samples (organic and inorganic), were found to be contaminated with Campylobacter, and about a third with Salmonella, but the risk of exposure to multidrug-resistant bacteria was lower with the organic meat. They both may carry the same risk of making us sick, but food poisoning from organic meat may be easier for doctors to treat.

What about the pesticides? There is a large body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson's, Alzheimer's, and ALS, as well as birth defects and reproductive disorders--but these studies were largely on people who live or work around pesticides.

Take Salinas Valley California, for example, where they spray a half million pounds of the stuff. Daring to be pregnant in an agricultural community like that may impair childhood brain development, such that pregnant women with the highest levels running through their bodies (as measured in their urine) gave birth to children with an average deficit of about seven IQ points. Twenty-six out of 27 studies showed negative effects of pesticides on brain development in children. These included attention problems, developmental disorders, and short-term memory difficulties.

Even in urban areas, if you compare kids born with higher levels of a common insecticide in their umbilical cord blood, those who were exposed to higher levels are born with brain anomalies. And these were city kids, so presumably this was from residential pesticide use.

Using insecticides inside your house may also be a contributing risk factor for childhood leukemia. Pregnant farmworkers may be doubling the odds of their child getting leukemia and increase their risk of getting a brain tumor. This has lead to authorities advocating that awareness of the potentially negative health outcome for children be increased among populations occupationally exposed to pesticides, though I don't imagine most farmworkers have much of a choice.

Conventional produce may be bad for the pregnant women who pick them, but what about our own family when we eat them?

Just because we spray pesticides on our food in the fields doesn't necessarily mean it ends up in our bodies when we eat it, or at least we didn't know that until a study was published in 2006. Researchers measured the levels of two pesticides running through children's bodies by measuring specific pesticide breakdown products in their urine. In my video, Are Organic Foods Safer?, you can see the levels of pesticides flowing through the bodies of three to 11-year olds during a few days on a conventional diet. The kids then went on an organic diet for five days and then back to the conventional diet. As you can see, eating organic provides a dramatic and immediate protective effect against exposures to pesticides commonly used in agricultural production. The study was subsequently extended. It's clear by looking at the subsequent graph in the video when the kids were eating organic versus conventional. What about adults, though? We didn't know... until now.

Thirteen men and women consumed a diet of at least 80% organic or conventional food for seven days and then switched. No surprise, during the mostly organic week, pesticide exposure was significantly reduced by a nearly 90% drop.

If it can be concluded that consumption of organic foods provides protection against pesticides, does that also mean protection against disease? We don't know. The studies just haven't been done. Nevertheless, in the meantime, the consumption of organic food provides a logical precautionary approach.

For more on organic foods:

For more on the infectious disease implications of organic versus conventional, see Superbugs in Conventional vs. Organic Chicken. Organic produce may be safer too. See Norovirus Food Poisoning from Pesticides. Organic eggs may also have lower Salmonella risk, which is an egg-borne epidemic every year in the US. See my video Who Says Eggs Aren't Healthy or Safe?

More on Parkinson's and pesticides in Preventing Parkinson's Disease With Diet.

Those surprised by the California data might have missed my video California Children Are Contaminated.

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: IFPRI -IMAGES / Flickr. This image has been modified.

Original Link

How to Reduce Exposure to Alkylphenols Through Your Diet

NF-Apr28 Dietary Sources of Alkylphenol Endocrine Disruptors.jpg

Alkylphenols are industrial chemicals that are found in hair products, spermicides, cleaning products and detergents. They are considered endocrine disruptors. For more information on alkylphenols, check out my video Alkylphenol Endocrine Disruptors and Allergies.

Concern about alkylphenols first surfaced decades ago when a group at Tufts observed an excessive proliferation of human breast cancer cells in certain types of plastic containers, something that would normally only be seen if the cells were exposed to some type of estrogen. They identified an alkylphenol leaching from the plastic as the culprit, having "estrogen-like properties when tested in the human breast tumor cells." Excessive proliferation of human breast cancer cells is never good, so countries in Europe started banning and restricting the use of these chemicals. However, the U.S. EPA has been slow to respond.

A half million tons of alkylphenols continue to spew out into the environment every year, so much so that now that they come down in the rain and then accumulate up the food chain.

One study, highlighted in my video, Dietary Sources of Alkylphenol Endocrine Disruptors, examined the Japanese food supply to find out which foods had these potentially allergy-exacerbating endocrine disruptors. The researchers found that chicken and fish had the highest levels. Water animals and birds concentrate these compounds to levels several thousands of times greater than those in the environment because these are fat-soluble chemicals. "Therefore, they can easily contaminate foods of animal origin, which are thought to represent the most important source of human exposure to many organic pollutants," not just the alkylphenols. Another research group also found that fish was the worst.

Which kind of fish? Anchovies, mackerel, salmon and cod seem to have the highest levels. In fact, salmon was the only food found contaminated with nonylphenol diethoxylate, which is even more potent than regular nonylphenol. The levels of contamination in fish were at the concentrations that start to make breast cancer cells go crazy in vitro.

These findings are consistent with the fact that seafood consumption has been associated with severe asthma, current and severe rhinoconjunctivitis, (seasonal pollen allergies), and current and severe eczema (an allergic-type disease of the skin) in adolescent populations around the globe.

If these synthetic xenoestrogens are playing a role, what about natural phytoestrogens, such as those found in soy foods? It turns out that in patients with asthma, consumption of a diet with moderate to high amounts of soy phytoestrogens is associated with better lung function and better asthma control. If anything then, it's these chemical pollutants, which come down in the rain, contaminate the soil, the plants, and then concentrate up the food chain in the fat of animals. We're now the animals at the top of the food chain, like the polar bear or bald eagle, building up higher levels of these synthetic xenoestrogens.

Thankfully, there aren't many cannibals around anymore. However, there is one group that continues to feed off human tissues--babies (See The Wrong Way to Detox). Alkylphenols have been found to concentrate in human breast milk, particularly in women who eat fish. The highest levels of these endocrine-disrupting pollutants were recorded in milk samples from mothers who said they ate fish at least twice a week, consistent with the fact that seafood consumption represents an important source of alkylphenol intake. Even these "slightly elevated levels of endocrine disruptors in the milk of mothers with a seafood-rich diet may be associated with adverse effects on neurological development, fetal and postnatal growth, and memory functions on breastfed infants, because these contaminants may interfere with the endocrine [hormonal] system."

Since these toxins concentrate in fat, the highest concentrations may be found in straight animal fat, such as chicken fat, lard, tallow, or fish oil. Consumption of fish oil capsules and processed fish products has been associated with alkylphenol concentration in mothers' milk, again due to bioaccumulation up the food chain. And then we recycle the leftover remains of farm animals into farm animal feed, so the levels can get higher and higher in animal products.

As one commentator noted, while these pollutants do contaminate human milk, they also contaminate cow's milk--humans and cows live in the same polluted world. In fact, infant formula was found to be over five times more contaminated, so breast is still best, absolutely. But these kinds of studies are important in order to provide good suggestions for food choices to nursing mothers to prevent excess exposure to these pollutants in their infants.

We can kind of cut out the middlefish and move lower down the food chain in hopes of decreasing our exposure to industrial toxins.

Endocrine disruptors have also been linked to conditions such as male infertility (Male Fertility and Diet and Xenoestrogens and Sperm Counts) and early onset of puberty (Protein, Puberty, and Pollutants and Xenoestrogens and Early Puberty).

What other industrial pollutants build up in the aquatic fish chain? See, for example:

Farmed Fish vs. Wild Caught. Which is worse?

How Long to Detox from Fish Before Pregnancy? If it's too late, How Fast Can Children Detoxify from PCBs?

-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: Andrea Pokrzywinski / Flickr

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Slowing Cognitive Decline with Berries

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A plant-based diet is thought to have played a significant role in human evolution and the consumption of whole plant foods and even just extracts have repeatedly been associated with a decreased risk of aging related diseases. And by healthy aging I'm not talking preventing wrinkles, what about protecting our brain? "Two of the most dreaded consequences of dementia with aging are problems moving around and difficulty remembering things. Dementia robs older adults of their independence, control, and identity."

Fruits and vegetables help reduce the risk of other chronic diseases, so might they work for brain diseases as well?

There has been a proliferation of recent interest in plant polyphenols as agents in the treatment of dementia. There are 4,000 different kinds of polyphenols found ubiquitously in foods of plant origin, but berries are packed with them, possessing powerful antioxidant and anti-inflammatory properties. There's a subset of polyphenols called anthocyanidins, which are found in blue and purple pigmented fruits and berries. These polyphenols are uniquely and specifically capable of "both crossing the blood-brain barrier and localizing in brain regions involved in learning and memory." And that's precisely where we need them.

The brain takes up less than 2% of body weight but may burn up to 50% of the body's fuel, creating a potential firestorm of free radicals. Maybe these brain-seeking phytonutrients in berries could fight oxidation and inflammation, and even increase blood flow? This raised a thought-provoking idea. Maybe a "nutritional intervention with blueberries may be effective in forestalling or even reversing the neurological changes associated with aging?" It would be a decade before the first human trial was conducted, but it worked! "Blueberry supplementation improves memory in older adults," suggesting that "consistent supplementation with blueberries may offer an approach to forestall or mitigate brain degeneration with age."

What other blue or purple foods can we try? Concord grape juice was also tested and had a similar benefit, suggesting that supplementation with purple grape juice may enhance cognitive function for older adults with early memory decline. Why use juice and not whole concord grapes? Because then you couldn't design a placebo that looked and tasted exactly the same to rule out the very real and powerful placebo effect. And also because the study was funded by the Welch's grape juice company.

This effect was confirmed in a follow-up study, showing for the first time an increase in neural activation in parts of the brain associated with memory using functional MRI scans. But this brain scan study was tiny: just four people in each group. And same problem in the blueberry study: it had only nine people in it.

Why haven't large population-based studies been done? Because we haven't had good databases on where these phytonutrients are found. We know how much vitamin C is in a blueberry, but not how much anthocyanidin--until now. The Harvard Nurses' Health Study, highlighted in my video, How to Slow Brain Aging by Two Years, followed the cognitive function of more than 16,000 women for years, and found that "long-term consumption of berries was related to significantly slower rates of cognitive decline, even after careful consideration of confounding socioeconomic status" (that is, even after taking into account the fact that rich people eat more berries). The Harvard Nurses' Health Study was the first population-based evidence that greater intakes of blueberries and strawberries were highly associated with slower rates of cognitive decline, and not just by a little bit. "The magnitude of associations were equivalent to the cognitive differences that one might observe in women up to two and a half years apart in age." In other words, women with higher intake of berries appeared to have delayed cognitive aging by as much as two and a half years.

Why shouldn't we just take some anthocyanidin supplement? Because there hasn't been a single study that found any kind of cognitive benefit by just giving single phytonutrients. In fact, the opposite is true. "Whole blueberries appear to be more effective than individual components, showing that the whole is greater than the sum of its parts." These findings have potentially substantial public health implications, as increasing berry intake represents a fairly simple dietary modification to test in older adults for maintaining our brain function.

What other ways could we improve our memory and cognitive function?

What other near-miraculous properties of berries are there?

I add them to my morning smoothie: A Better Breakfast.

-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: Angelo Desantis / Flickr

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Two Kiwifruit an Hour Before Bedtime

NF-Apr1 Kiwis Might Improve Your Sleep!.jpg

The number one question in sleep research is “Why do we sleep?” followed by the question,“How much sleep do we need?” After literally hundreds of studies, we still don’t know the best answer to either question. A few years ago, I featured a large, 100,000-person study which suggested that both short and long sleep duration were associated with increased mortality, with people getting around seven hours of sleep living longest (See Optimal Sleep Duration). Since then, a meta-analysis that included over a million people was published, and found the same thing.

We still don’t know, however, whether "sleep duration is a cause or simply a marker of ill health." Maybe sleeping too little or too long does make us unhealthy—or maybe we see the associated shortened lifespan because being unhealthy causes us to sleep shorter or longer.

Similar work has now been published on cognitive function. After controlling for a long list of factors, men and women in their 50s and 60s getting seven or eight hours appeared to have the best short-term memory compared to those that got much more or much less. The same thing was just demonstrated with immune function where “both reduced and prolonged habitual sleep durations were associated with an increased risk of pneumonia.”

It’s easy to not get too much sleep—just set an alarm. But what if we’re having problems getting enough? What if we’re one of the one in three adults that suffer symptoms of insomnia? There are sleeping pills like Valium that we can take in the short term, but they have a number of adverse side effects. Non-pharmacological approaches such as cognitive behavioral therapy are often difficult, time-consuming, and not always effective. Wouldn’t it be great to have “natural treatments that can improve both sleep onset and help patients improve the quality of sleep while improving next-day symptoms over the long term?”

What about a study on kiwifruit, featured in my video, Kiwifruit for Insomnia? Participants were given two kiwifruit an hour before bed every night for four weeks. Why kiwifruits? Well, people with sleep disorders tend to have high levels of oxidative stress, so maybe antioxidant rich foods might help? But all fruits and vegetables have antioxidants. Kiwifruits contain twice the serotonin of tomatoes—but it shouldn’t cross the blood-brain barrier. Kiwifruit has folate, and a deficiency might cause insomnia—but there’s a lot more folate in some other plant foods.

The reason they studied kiwifruits is because they got grant money from a kiwifruit company. And I’m glad they did because they found some really remarkable results: significantly improved sleep onset, duration, and efficiency using both subjective and objective measurements. Participants went from sleeping an average of six hours a night to seven—by just eating a few kiwifruits.

More on the power of kiwis in my videos Kiwifruit and DNA Repair and Kiwifruit for Irritable Bowel Syndrome, and more on sleep in Sleep & Immunity.

Videos on other natural remedies for various conditions include:

-Michael Greger, M.D.

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

Image credit: Peter Miller / Flickr

Original Link

Two Kiwifruit an Hour Before Bedtime

 

 

 

 

 

 

 

 

Two Kiwifruit an Hour Before Bedtime

The number one question in sleep research is “Why do we sleep?” followed by the question,“How much sleep do we need?” After literally hundreds of studies, we still don’t know the best answer to either question. A few years ago, I featured a large, 100,000-person study which suggested that both short and long sleep duration were associated with increased mortality, with people getting around seven hours of sleep living longest (See Optimal Sleep Duration). Since then, a meta-analysis that included over a million people was published, and found the same thing.

We still don’t know, however, whether "sleep duration is a cause or simply a marker of ill health." Maybe sleeping too little or too long does make us unhealthy—or maybe we see the associated shortened lifespan because being unhealthy causes us to sleep shorter or longer.

Similar work has now been published on cognitive function. After controlling for a long list of factors, men and women in their 50s and 60s getting seven or eight hours appeared to have the best short-term memory compared to those that got much more or much less. The same thing was just demonstrated with immune function where “both reduced and prolonged habitual sleep durations were associated with an increased risk of pneumonia.”

It’s easy to not get too much sleep—just set an alarm. But what if we’re having problems getting enough? What if we’re one of the one in three adults that suffer symptoms of insomnia? There are sleeping pills like Valium that we can take in the short term, but they have a number of adverse side effects. Non-pharmacological approaches such as cognitive behavioral therapy are often difficult, time-consuming, and not always effective. Wouldn’t it be great to have “natural treatments that can improve both sleep onset and help patients improve the quality of sleep while improving next-day symptoms over the long term?”

What about a study on kiwifruit, featured in my video, Kiwifruit for Insomnia? Participants were given two kiwifruit an hour before bed every night for four weeks. Why kiwifruits? Well, people with sleep disorders tend to have high levels of oxidative stress, so maybe antioxidant rich foods might help? But all fruits and vegetables have antioxidants. Kiwifruits contain twice the serotonin of tomatoes—but it shouldn’t cross the blood-brain barrier. Kiwifruit has folate, and a deficiency might cause insomnia—but there’s a lot more folate in some other plant foods.

The reason they studied kiwifruits is because they got grant money from a kiwifruit company. And I’m glad they did because they found some really remarkable results: significantly improved sleep onset, duration, and efficiency using both subjective and objective measurements. Participants went from sleeping an average of six hours a night to seven—by just eating a few kiwifruits.

More on the power of kiwis in my videos Kiwifruit and DNA Repair and Kiwifruit for Irritable Bowel Syndrome, and more on sleep in Sleep & Immunity.

Videos on other natural remedies for various conditions include:

-Michael Greger, M.D.

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

Image credit: Peter Miller / Flickr

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Schoolchildren Should Drink More Water

 

 

 

 

 

 

 

 

Does a Drink of Water Make Kids Smarter?

Most children arrive at school in a state of mild dehydration that may negatively affect scholastic performance.

Preventing cellular dehydration is integral to hormonal, immune, neurological, cardiovascular, gastrointestinal, muscle and skeletal function. So researchers recently set out to determine the hydration status of healthy children in the United States. Urine samples were obtained from groups of 9 to 11 year olds in Los Angeles and Manhattan on their way to school to see how they were doing.

The study was motivated by recent studies in Israel showing children did not seem to be hydrated enough. But Israel’s in a desert, so they wanted to repeat the study under cooler and less arid conditions. It turns out the U.S. kids did just as bad as the Israelis.

As I show in my video Does a Drink Of Water Make Children Smarter?, urine from nearly two-thirds of the U.S. kids studied was considered too concentrated, an indicator that they were dehydrated. Why? They weren’t drinking enough water. Three-quarters of the kids did not drink water between the time they woke up and when they went off to school.

But most ate breakfast, so they must have been drinking something. The problem is that other beverages are not as hydrating. The levels of sodium, sugars, and amino acids in milk and juice can shrink cells and trigger the release of the hormone that spurs dehydration.

So what, though? Is there any actual negative impact of mild dehydration on one’s ability to function at school? Historically, most of the studies on hydration and mental functioning were done on adults under extreme conditions, like having people exercise in 113 degree heat, or giving people powerful diuretics like Lasix and putting them on a treadmill. Most of the studies on hydration and cognitive performance have been performed on military personnel to evaluate soldiers’ ability to function in extreme circumstances. It is easy to imagine that a soldier fighting in the desert with a heavy rucksack and a protective suit must be physically and cognitively at his best. It is, however, very difficult to translate this knowledge to normal real-life circumstances. Three new studies changed that.

They were simple studies. Researchers took a group of schoolchildren, randomly allocated them to drink a cup of water or not, and then gave them all a test to see who did better. And the winner was… the cup-of-water group. Conclusion: “The results of the present study suggest that even children in a state of mild dehydration, not induced by intentional water deprivation or by heat stress and living in a cold climate, can benefit from drinking more water and improve their cognitive performance.”

So water worked for 2nd and 3rd graders, what about 1st grade? Same experimental design but this time instead of forcing kids in the water group to drink a cup, the water group was just given some water and told to drink as much they wanted, and again found significant improvement in the performance of various tasks, leading to the same conclusion: “[E]ven under conditions of mild dehydration…children’s cognitive performance can be improved by having a drink of water.”

The latest study that just came out is the largest to date.  It too found a remarkable proportion of children were in a state of mild, voluntary dehydration at the beginning of the school day and a significant negative correlation between dehydration and, for example, the ability to remember numbers. The researchers offered a randomized group some water, and those kids on average felt better and performed better. “To conclude…[mild dehydration] is an adverse state that might render the school day more challenging for children.”

Even doctors often apparently fail to realize the connection. A recent survey found that healthcare professionals under-recognized the importance of proper hydration for mental health. Who would care enough about the importance of human hydration to even do a survey? A “Hydration Institute” founded in part by…The Coca-Cola company.

These three new studies found drinking resulted in a significant improvement in cognitive performance, but not with Coke. And not with Ritalin or some new drug, either. Just plain water. Think how much drug companies could make if they could sell sugar pills but just tell kids to take the fake pill with… a glass of water.

This is one of those groundbreaking findings (like my gargling video) that will likely never see the light of day because there’s no profit motive for promotion. We’re guaranteed to be assailed about all the new drugs and surgical advances because there’s big business behind getting the word out. But who profits from tap water? Or even broccoli for that matter? That’s one of the reasons I created NutritionFacts.org, to bring to light all the findings that would otherwise just get buried in medical library basements (or, increasingly, vast private databases).

The water content of plant foods may help explain why those eating plant-based diets are, on average, so slim. Like fiber, water is a source of Nutrition Without Calories. See Dietary Guidelines: It’s All Greek to the USDA for a country with the guts to suggest water might be preferable to drinking soda.

Juice and milk may not be as hydrating as water. What about tea? See my video Is Caffeinated Tea Dehydrating? What about Bottled Water vs. Tap?

More on children’s health in videos such as:

-Michael Greger, M.D.

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

Image credit: JefferyTurner / Flickr

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