The Best Way to Wash Fruit and Vegetables

The Best Way to Wash Fruit and Vegetables.jpeg

How might we reduce our exposure to pesticide residues on fruits and vegetables? What about staying away from imported produce? Well, it turns out domestic produce may be even worse, dispelling the notion that imported fruits and vegetables pose greater potential health risks to consumers.

Buying organic dramatically reduces dietary exposure to pesticides, but it does not eliminate the potential risk. Pesticide residues are detectable in about one in ten organic crop samples, due to cross-contamination from neighboring fields, the continued presence of very persistent pesticides like DDT in the soil, and accidental or fraudulent use.

By choosing organic, one hopes to shift exposures from a range of uncertain risk to more of a range of negligible risk, but even if all we had to eat were the most pesticide-laden of conventional produce, there is a clear consensus in the scientific community that the health benefits from consuming fruits and vegetables outweigh any potential risks from pesticide residues. And we can easily reduce whatever risk there is by rinsing our fruits and vegetables under running water.

There are, however, a plethora of products alleged by advertisers to reduce fruit and produce pesticide residues more effectively than water and touted to concerned consumers. For example, Procter & Gamble introduced a fruit and vegetable wash. As part of the introduction, T.G.I. Friday's jumped on board bragging on their menus that the cheese and bacon puddles they call potato skins were first washed with the new product. After all, it was proclaimed proven to be 98% more effective than water in removing pesticides.

So researchers put it to the test and it did no better than plain tap water.

Shortly thereafter Procter & Gamble discontinued the product, but numerous others took its place claiming their vegetable washes are three, four, five or even ten times more effective than water, to which a researcher replied, "That's mathematically impossible." If water removes 50%, you can't take off ten times more than 50%. They actually found water removed up to 80% of pesticide residues like the fungicide, Captan, for example. So, for veggie washes to brag they are three, four, five, ten times better than water is indeed mathematically questionable.

Other fruit and vegetable washes have since been put to the test. Researchers compared FIT Fruit & Vegetable Wash, Organiclean, Vegi-Clean, and dishwashing soap to just rinsing in plain tap water. 196 samples of lettuce, strawberries, and tomatoes were tested, and researchers found little or no difference between just rinsing with tap water compared to any of the veggie washes (or the dish soap). They all just seemed like a waste of money. The researchers concluded that just the mechanical action of rubbing the produce under tap water seemed to do it, and that using detergents or fruit and vegetable washes do not enhance the removal of pesticide residues from produce above that of just rinsing with tap water alone.

That may not be saying much, though. Captan appears to be the exception. When plain water was tried against a half dozen other pesticides, less than half the residues were removed.

Fingernail polish works better, but the goal is to end up with a less toxic, not a more toxic tomato.

We need a straightforward, plausible, and safe method for enhanced pesticide removal. Is there anything we can add to the water to boost its pesticide-stripping abilities? Check out my video, How to Make Your Own Fruit & Vegetable Wash.

If you soak potatoes in water, between about 2% to 13% of the pesticides are removed, but a 5% acetic acid solution removes up to 100%. What's that? Plain white vinegar. But 5% is full strength.

What about diluted vinegar? Diluted vinegar only seemed marginally better than tap water for removing pesticide residues. Using full strength vinegar would get expensive, though. Thankfully there's something cheaper that works even better: salt water.

A 10% salt solution appears to work as good or better than full-strength vinegar. To make a 10% salt solution you just have to mix up about one-part salt to nine-parts water (though make sure to rinse all of the salt off before eating!).

There's not much you can do for the pesticides in animal products, though. The top sources of some pesticides are fruits and vegetables; but for other pesticides, it's dairy, eggs, and meat because the chemicals build up in fat. What do you do about pesticides in animal products? Hard boiling eggs appears to destroy more pesticides that scrambling, but for the pesticides that build up in the fat in fish or chicken, cooking can sometimes increase pesticide levels that obviously can't just wash off. In fact, washing meat, poultry, or eggs is considered one of the top ten dangerous food safety mistakes.

For more on organic foods, see:

The most important reason to wash produce is to reduce the risk of food-borne illness. Ironically, the food poisoning viruses may be found in the pesticides themselves. Check out my video Norovirus Food Poisoning from Pesticides.

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

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

Organic versus Conventional: Which has More Nutrients?

Organic versus Conventional - Which has More Nutrients?.jpeg

Are organic foods safer and healthier than conventional alternatives? Those are two separate questions. Some consumers are interested in getting more nutrients; others are more concerned about getting fewer pesticides. Let's do nutrition first.

As seen in my video, Are Organic Foods More Nutritious?, hundreds of studies have been reviewed and researchers didn't find significant differences for most of the traditional nutrients like vitamins and minerals. They concluded that despite the widespread perception that organically produced foods are more nutritious, they didn't find robust evidence to support that perception. They did, however, find higher levels of phenolic phytonutrients in organic.

These so-called "secondary metabolites" of plants are thought to be behind many of the benefits ascribed to eating fruits and vegetables. Organic fruits and vegetables had between 19 and 69% more of a variety of these antioxidant compounds. The theory was that these phytonutrients are created by the plant for its own protection. For example, broccoli releases the bitter compounds like sulforaphane when the plant is chewed to ward off those who might eat it. Bugs take one bite and say, "Ew, this tastes like broccoli!" But pesticide-laden plants are bitten less by bugs and so may be churning out fewer of these compounds. Plants raised organically, on the other hand, are in a fight for their lives and may necessarily have to produce more protection. That was the theory anyway, but we don't have good evidence to back it up. The more likely reason has to do with the fertilizer; plants given high dose synthetic nitrogen fertilizers may divert more resources to growth rather than defense.

These antioxidants may protect the plant, but what about us? More antioxidant phytonutrients are found in organic vegetables and so yes, they displayed more antioxidant activity, but also more antimutagenic activity. Researchers exposed bacteria to a variety of mutagenic chemicals like benzopyrene, the polycyclic aromatic hydrocarbon found in barbecued meat, or IQ, the heterocyclic amine found in grilled/broiled/fried meats (as well as cigarette smoke), and there were fewer DNA mutations in the petri dishes where they added organic vegetables compared to the petri dishes where they added conventional vegetables.

Preventing DNA damage in bacteria is one thing, but what about effects on actual human cells? Organic strawberries may taste better, and have higher antioxidant activity and more phenolic phytonutrients, but what happens when you stack them up head-to-head against human cancer cells? Extracts from organically grown strawberries suppressed the growth of colon cancer cells and breast cancer cells significantly better than extracts from conventional strawberries. Now this was dripping strawberries onto cancer cells growing in a petri dish, but as I showed in Strawberries versus Esophageal Cancer, there are real life circumstances in which strawberries come into direct contact with cancerous and precancerous lesions, and so presumably organic strawberries would work even better, but they haven't yet been tested in clinical trials.

Although in vitro studies show higher antioxidant and antimutagenic activity as well as better inhibition of cancer cell proliferation, clinical studies on the impact of eating organic on human disease simply haven't been done. Based on antioxidant phytonutrient levels, organic produce may be considered 20 to 40% healthier, the equivalent of adding one or two serving's worth to a five-a-day regimen. But organic produce may be 40% more expensive, so for the same money you could just buy the extra servings worth of conventional produce. From a purely nutrients-per-dollar standpoint, it's not clear that organic foods are any better. But people often buy organic foods to avoid chemicals, not because they are more nutritious. For more on the best available science comparing the nutritional content, pesticide risk, heavy metal toxicity, and food poisoning risk of organic versus conventionally raised foods )including practical tips for making your own DIY fruit and veggie wash), see:

I imagine that the reaction to this series will be similar to that for the one I did on GMO foods, riling up critics on both sides of the debate:

More on the nutritional implications of stressed-out plants here:

Production method aside, in vitro, Which Fruit Fights Cancer Better?

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

How Fruits and Vegetables Can Prevent Asthma

NF-June30 Preventing Asthma with Fruits and Vegetables.jpg

Asthma is the most common chronic disease in children and the prevalence is increasing around the world. Despite this, most research dollars are spent on adult chronic disease. "One might ask," a group of researchers posited "whether this is because our politicians and senior administrators feel themselves to be more likely to suffer from the latter, and thus ignore allergic diseases as they mostly impact children and young adults" - who don't vote.

An enormous study about asthma and allergies in childhood, highlighted in my video, Preventing Asthma with Fruits and Vegetables, was published that includes more than a million children in nearly a hundred countries, making it the most comprehensive survey of asthma and allergies ever undertaken. The researchers found striking worldwide variations in the prevalence and severity of asthma, allergies, and eczema--a 20 to 60-fold difference in prevalence of symptoms of asthma, allergic runny nose, and atopic eczema around the world. The large variability suggests a crucial role of local characteristics that are determining the differences in prevalence between one place and another.

What kind of environmental factors? Why does the prevalence of itchy eyes and runny noses range anywhere from 1% in India, for example, and up to 45% of kids elsewhere? There were some associations with regional air pollution and smoking rates, but the most significant associations were with diet. Adolescents showed a consistent pattern of decreases in symptoms of wheeze (current and severe), allergic rhinoconjunctivitis, and atopic eczema with increases in per capita consumption of plant foods. The more their calories and protein came from plant sources, the less allergies they tended to have.

In general, there seems to be an association between an increase in asthma prevalence and a decrease in consumption of fresh fruits, green vegetables, and other dietary sources of antioxidants, helping to explain why the prevalence of asthma and respiratory symptoms are lower in populations with high intake of foods of plant origin. High intakes of fat and sodium, and low intakes of fiber and carbohydrates, are linked with asthma, while traditional and vegetarian diets are associated with lower rates. For example, if we look closer within India, in a study of more than 100,000 people, "those who consumed meat (daily or occasionally) were more likely to report asthma than those who were strictly vegetarian." This also meant avoiding eggs.

Eggs have been associated (along with soft drink consumption) with increased risk of respiratory symptoms and asthma in schoolchildren. On the other hand, consumptions of soy foods and fruits were associated with reduced risk of respiratory symptoms. In fact, removing eggs and dairy from the diet may improve lung function in asthmatic children in as little as eight weeks. Therefore, it may be a combination of eating fewer animal foods and more plants.

High vegetable intake, for example, has been found protective in children, potentially cutting the odds of allergic asthma in half. And fruit has also shown a consistent protective association for current and severe wheeze and runny nose in adolescents, and for current and severe asthma, allergies, and eczema in children.

Why is this? I've talked about the endocrine-disrupting industrial pollutants (see Dietary Sources of Alkylphenol Endocrine Disruptors) building up in the meat supply that may increase the risk of allergic disease, but the increase in asthma may be a combination of both a more toxic environment and a more susceptible population. One review notes that, "The dietary changes which have occurred over recent years may have led to a reduction in these natural antioxidant defenses, resulting in a shift of the antioxidant status of the whole population and leading to increased susceptibility to oxidant attack and airway inflammation."

In adults, for example, the risk of airway hyper-reactivity may increase seven-fold among those with the lowest intake of vitamin C from plant foods, while those with the lowest intake of saturated fats may have a 10-fold protection, presumably because of saturated fat's role in triggering inflammation.

The protective effect of plant-based food may also be mediated through effects on intestinal microflora. It turns out that differences in the indigenous intestinal flora might affect the development and priming of the immune system in early childhood. Kids with allergies, for example, tend to be less likely to harbor lactobacilli, the good bacteria that's found in fermented foods, and naturally on many fruits and vegetables. Lactobacillus probiotics may actually help with childhood asthma, which may help explain why children raised on largely organic vegetarian diets may have a lower prevalence of allergic reactions. Infants raised this way tend to have more good lactobacilli in their guts compared to controls, though they were also more likely to have been born naturally, breastfed longer, and not been given antibiotics, so we can't really tell if it's the diet until we put it to the test (See Treating Asthma with Fruits and Vegetables).

More on preventing allergic diseases can be found in my videos Preventing Childhood Allergies and Preventing Allergies in Adulthood.

More on protecting lung function with fruits and vegetables can be found in Preventing COPD With Diet.

Surprised probiotics can affect immune function? Check out my video Preventing the Common Cold with Probiotics? And if you think that is wild, wait until you see Gut Feelings: Probiotics and Mental Health.

What might be in plants that's so beneficial? See Anti-inflammatory Antioxidants.

What might be in animal products that is harmful to lung function? There are endocrine-disrupting industrial pollutants that build up in the food chain that may be playing a role. See my video Alkylphenol Endocrine Disruptors and Allergies. Also there's an inflammatory omega-6 fatty acid found predominantly in chicken and eggs that may contribute to inflammation as well. See Inflammatory Remarks About Arachidonic Acid.

Choosing fragrance-free personal care products may also help reduce airway reactivity: Throw Household Products Off the Scent.

I compare the efficacy of plants to pills (Treating Asthma With Plants vs. Supplements?) and explore the role an entire diet filled with plants might play in Treating Asthma and Eczema With Plant-Based Diets.

-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: EdTech Stanford University School of Medicine / Flickr

Original Link

Reducing Arsenic in Chicken and Rice

NF-June23 How Many Cancers are Caused by Arsenic-laced Chicken?.jpg

In 2013, Maryland became the first state to ban the feeding of an arsenic-containing drug to chickens. This arsenic-containing drug is used to control parasites and gives chicken meat an "appealing pink color." In 2011, the FDA found that the livers of chickens fed this drug had elevated levels of inorganic arsenic, a known human carcinogen. In response, the drug's manufacturer, Pfizer, voluntarily pulled the drug off the U.S. market. However, it's still sold overseas--including to places that continue to export chicken back to us--and a similar arsenic-containing drug for use in poultry is still available in the United States. The Maryland ban was still some help, though; it kept Maryland farmers from using stockpiles of the drug.

How much arsenic gets into the actual meat and not just the internal organs? We didn't know until recently. In a study highlighted in my video, How Many Cancers Caused by Arsenic-Laced Chicken?, researchers at the Johns Hopkins School of Public Health coordinated the purchase of chicken breasts off grocery store shelves in ten cities across the country. They found that 70% of the samples of chicken meat from poultry producers that didn't prohibit arsenic drugs were contaminated with the cancer-causing form of arsenic at levels that exceeded the safety thresholds originally set by the FDA (before the FDA relented and admitted that there's really no safe level of this kind of arsenic).

When the drug was first approved, scientists believed that its organic arsenic base would be excreted unchanged (organic arsenic is much less dangerous than inorganic arsenic). Guess what appears to convert the drug into the carcinogenic form? Cooking. When chicken meat is cooked, levels of the arsenic-containing drug go down and levels of carcinogenic arsenic go up, suggesting the drug may degrade into the cancer-causing inorganic arsenic form during cooking.

How much cancer are we talking about? If we estimate that about three-quarters of Americans eat chicken, then the arsenic in that chicken has potentially been causing more than 100 cases of cancer every year. The John Hopkins researchers conclude that "eliminating the use of arsenic-based drugs in [poultry and pig] production could reduce the burden of arsenic-related disease in the U.S. population."

Arsenic-containing drugs fed to chickens is one of the ways arsenic gets into rice. When we feed arsenic to chickens, the resulting arsenic-bearing poultry manure is introduced to the environment, soil, and water, and rice sucks it up from contaminated soil and can transfer it to people who don't even eat chicken. There is massive environmental contamination from the poultry industry; nearly two million pounds of arsenic has been poured into the environment every year by the U.S chicken industry alone.

We're even seeing arsenic in foods sweetened with organic brown rice syrup. It reminds me of the arsenic in apple juice story. Although the U.S. made lead and arsenic-based pesticides illegal years ago, they still persist in the soil, so even organic products are not immune.

There are other sources of arsenic (such as naturally occurring arsenic deposits), but arsenic-containing poultry drugs have been deliberately administered to animals intended for human consumption for 70 years. Consequently, exposures resulting from use of these drugs are far more controllable than are exposures from environmental sources. And the good news is that, thanks to a lawsuit from the Center for Food Safety and other consumer groups, three out of the four arsenic-containing drugs fed to poultry have been officially pulled from the market.

I've previously addressed this issue in my video Arsenic in Chicken. It's nice to see there's been some progress!

The antibiotics the poultry industry continues to feed chickens present another public health hazard. See my videos:

Cooking may also create other carcinogens from the muscle itself:

-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: Stu Spivak / Flickr

Original Link

Viral Food Poisoning from Pesticides?

NF-Mar3 Did Pesticides Cause Your Food Poisoning?.jpg

Although the most serious causes of food poisoning like Salmonella come largely from animal products (for example, most foodborne-related deaths have been attributed to poultry), millions of Americans are sickened by produce every year, thanks to noroviruses. Noroviruses can spread person-to-person via the fecal-oral route or by the ingestion of aerosolized vomit, which together may explain most norovirus food outbreaks. But a substantial proportion remained unexplained. How else can fecal viruses get on our fruits and veggies?

The pesticide industry may be spraying them on (See Norovirus Food Poisoning from Pesticides).

The water that's used to spray pesticides on crops may be dredged up from ponds contaminated with fecal pathogens. When you hear of people getting infected with a stomach bug like E. coli from something like spinach, it's important to realize that the pathogen didn't originate from the spinach. Intestinal bugs come from intestines. Greens don't have guts; plants don't poop.

"The application of pesticides may therefore not only be a chemical hazard, but also a microbiological hazard for public health." What is the industry's solution? To add more chemicals! "The inclusion of antiviral substances in reconstituted pesticides," researchers assert, "may be appropriate to reduce the virological health risk posed by the application of pesticides." Or we could just choose organic.

Likewise the Salmonella in alfalfa sprout seeds (See Don't Eat Raw Alfalfa Sprouts) likely came from manure run-off or contaminated irrigation water. But this pesticide angle adds a whole new route for fecal pathogens to pollute produce. Broccoli Sprouts are safer, and organic sprouts may therefore be safer still (See Broccoli Sprouts).

Organic foods may also be healthier (see Cancer Fighting Berries) and don't carry the potential chemical hazards associated with pesticides. See my videos:

-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: jetsandzeppelins / Flickr

Original Link

Organic Milk and Prostate Cancer

NF-Feb12 The Link Between Milk and Prostate Cancer.jpg

Researchers have expressed concern that since cow's milk contains estrogens, dairy could stimulate the growth of hormone-sensitive tumors. The thought is that the consumption of dairy products could both "promote the conversion of precancerous lesions or mutated cells to invasive cancer and enhance the progression of hormone-dependent tumors."

This was initially postulated based on suggestive population-scale data like a 25 fold increase in prostate cancer in Japan since World War II. What was happening to their diets during that period? A 5, 10, and 20 fold increase in eggs, meat, and dairy consumption, respectively, whereas the rest of their diet remained pretty stable.

But diet wasn't the only major change in Japanese lifestyles over the latter half century. Similarly, even though countries with higher milk consumption tend to have more prostate cancer deaths and countries with lower milk consumption fewer deaths, there could be hundreds of confounding variables. But it certainly does spur interest in studying the possibility.

A recent study from Clemson University represents the other extreme, controlling for as many factors as possible by isolating prostate cancer cells out of the body in a petri dish and dripping cow milk on them directly. The researchers chose organic cow's milk, because they wanted to exclude the effect of added hormones so that they could test the effect of all the growth hormones and sex steroids found naturally in milk.

They found that cow's milk stimulated the growth of human prostate cancer cells in each of 14 separate experiments, producing an average increase in cancer growth rate of over 30%. In contrast, almond milk suppressed the growth of these cancer cells by over 30%.

But just because something happens in a petri dish or a test tube doesn't mean the same thing happens in a person. It's just suggestive evidence that we can use in a grant application to get money to study actual people. This can be done with a retrospective (looking backward) study where we take prostate cancer patients and figure out what they ate in the past, or a prospective (looking forward) study where we look at people's diets first and follow them for a few years and see who gets cancer. The looking back kind are typically referred to as case-control studies, because researchers look at cases of cancer and compare their diets to controls. The looking forward kind are often called cohort studies because a cohort of people is followed forward. Then, if we want to get fancy, we can do a so-called meta-analysis, where you combine all the best studies done to date and see what the balance of available evidence shows.

The latest meta-analysis of all the best case control studies ever done on the matter concludes that milk consumption is a risk factor for prostate cancer. And the latest meta-analysis of all the best cohort studies ever done also concludes that milk consumption is a risk factor for prostate cancer. An even newer study profiled in my video, Prostate Cancer and Organic Milk vs. Almond Milk, suggests that milk intake during adolescence may be particularly risky in terms of potentially setting one up for cancer later in life.

Despite hormone-related cancers being among our top killers, as pointed out in the Journal of the National Cancer Institute, "we simply do not know which hormones, and how much, are in the food that we ingest. More effort has been directed at the investigation of illicit use of designer steroids by Olympians and ballplayers than to the investigation of the effect of dietary hormones on cancer and other diseases that affect millions." A proposal is therefore made to monitor levels of steroid and other hormones and growth factors in all dairy and meat-containing foods, though to date this has not been done.

I touched previously on the prostate cancer data in one of my oldest videos, Slowing the Growth of Cancer. Other factors may play into the link between cancer and dairy consumption including industrial pollutants (Industrial Carcinogens in Animal Fat) and IGF-1 (How Plant-Based to Lower IGF-1?), but for more on the hormones in dairy see:

What about all the studies suggesting milk "does a body good"? See my video Food Industry "Funding Effect".

-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: Tilemahos Efthimiadis / Flickr

Original Link

Superbugs on Retail Chicken

NF-Jan13 Superbugs in Conventional Vs. Organic Chicken.jpg

One of the most concerning developments in medicine is the emergence of bacterial super-resistance--resistance not just to one class of drugs, like penicillin, but to multiple classes of drugs (so-called multi-drug resistance). In the 2013 Retail Meat Report, the FDA found that more than a quarter of the Salmonella contaminating retail chicken breast were resistant to not one but five or more different classes of antibiotic treatment drugs.

Throughout history there has been a continual battle between humans and pathogens. For the last half century, this battle has taken the form of bugs versus drugs. When we developed penicillin, the U.S. Surgeon General declared, "The war against infectious diseases has been won." However, the euphoria over the potential conquest of infectious diseases was short lived.

In response to our offensive, bacteria developed an enzyme that ate penicillin for breakfast. In fact, bacteria can excrete such large quantities of the enzyme that they can destroy the drug before it even comes into contact. So we developed a drug that blocks the penicillin-eating enzyme. That's why you may see two drug names on an antibiotic like Augmentin--one is the actual antibiotic (amoxicillin), and the other is a drug that blocks the enzyme the bacteria tries to use to block the antibiotic (clavulanate). But the bacteria outsmarted us again by developing a blocker blocking blocker--and so it goes back and forth. However hard we try and however clever we are, there is no question that organisms that have "been around for three billion years, and have adapted to survive under the most extreme conditions, will always overcome whatever we decide to throw at them."

So we went from first generation antibiotics, to second generation antibiotics, to third generation antibiotics. We now have bacteria that have evolved the capacity to survive our big-gun third generation cephalosporins like ceftriaxone, which is what we rely on to treat life-threatening Salmonella infections in children.

Where are these super-duper-superbugs found? According to one study profiled in my video, Superbugs in Conventional vs. Organic Chicken, "almost 90% were isolated from chicken carcasses or retail chicken meat."

But what if we only ate antibiotic-free organic chicken? In the first such study ever published, researchers compared multidrug-resistant bacteria in organic and conventional retail chicken meat. All of the conventional chicken samples were contaminated; however, the majority (84%) of organic chicken meat samples was also contaminated. So 100% versus 84%. Organic is definitely better, but odds are we could still be buying something that could make our family sick.

Where do these antibiotic resistant bacteria come from if organic producers are not using antibiotics? A possible explanation is that day-old chicks come from the hatcheries already infected with these bacteria before they arrive at the farms. Or, they could become contaminated after they leave the farm in the slaughter plant. Organic chickens and conventionally raised chickens are typically all slaughtered at the same plants, so there may be cross-contamination between carcasses. Finally, factory farms are dumping antibiotics and antibiotic-resistant bacteria-laden chicken manure out into the environment. Researchers can pick up antibiotic-resistant genes right out of the soil around factory farms. So even meat raised without antibiotics may be contaminated with multi-drug resistant bacteria.

In a cover story in which Consumer Reports urged retailers to stop selling meat produced with antibiotics, the researchers noted some store employee confusion: "An assistant store manager at one grocery store, when asked by a shopper for meats raised without antibiotics, responded, 'Wait, you mean like veggie burgers?'" On second thought maybe the employees weren't so confused after all.

I addressed this issue previously in video such as:

Isn't it illegal to sell meat contaminated with dangerous bacteria? Unfortunately no. See why in my video Salmonella in Chicken & Turkey: Deadly But Not Illegal. Reminds me of the case I wrote about in Supreme Court case: meat industry sues to keep downed animals in food supply.

-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: Chilanga Cement / Flickr

Original Link

Foods for Macular Degeneration

NF-Jan1 Plant-Based Foods that Fight Macular Degeneration.jpg

Anyone who has gotten a bad sunburn knows how damaging the UV rays in sunlight can be. Imagine what those same rays are doing to back of our eyeballs (our retinas). The eye is designed to take sunlight and focus it like a magnifying glass into the back of our eyes. Thankfully, we have a layer of cells called the retinal pigment epithelium that supports and protects our delicate retinal eyesight machinery. The layer builds up yellow plant pigments like zeaxanthin from our diet, absorbing blue light and protecting the retina from photo-oxidative damage. The yellowing of our corneas when we develop cataracts may actually be our bodies' defense mechanism to protect our retinas. In fact, when cataracts are removed, the risk of blindness from macular generation shoots up (because we removed the protection). Instead of trading one type of vision loss for another, it's better to pigment the back of our eyes through diet instead of pigmenting the front of our eyes with cataracts. The pigment in the back of our eyes is entirely of dietary origin, "suggesting that the most common cause of blind registration in the Western World could be delayed, or even averted, with appropriate dietary modification," according to authors of a study on age-related macular degeneration.

Where in our diet do we get these pigments? The egg industry brags that eggs are a good source, but have nearly six high-lutein, free-range, certified organic eggs a week for three months and the pigmentation in one's eyes may only marginally increase (see Egg Industry Blind Spot). Instead of getting the phytonutrients from the egg that came from the chicken that came from the corn and blades of grass the chicken pecked on, we could get it from the source. One cup of corn and a half cup of spinach a day for three months seems to dramatically boost the protective eye pigment in subjects. In the video, Dietary Prevention of Age Related Macular Degeneration, you can see a comparison of the amount of these phytonutrients from eggs compared to corn and spinach. If we cut out the middlehen and get these nutrients from plants directly, we see a substantially larger increase in protective eye pigment.

Three months after the subjects stopped eating the corn and spinach, the levels of these pigments remained relatively high, indicating that once we build our macular pigment up with a healthy diet, our eyeballs really try to hold on to it. So even if we go on vacation and end up eating more iceberg lettuce than spinach, our eyes will hold out until we get back.

Eggs can increase zeaxanthin levels in the blood, but they can also raise bad cholesterol levels and increase the risk of heart disease. Thus, as researchers conclude, "an egg yolk-based dietary strategy to increase plasma zeaxanthin cannot be recommended, and an alternative, cholesterol-free, food source is desirable." One such alternative would be goji berries, which have up to 60 times more zeaxanthin than eggs. A modest dose of goji markedly increases levels in our body. Consumption of goji berries may be an effective, safe whole food strategy to increase zeaxanthin in the bloodstream.

But we don't need it in our blood, we need it in our eyes. A group of researchers performed a double-blind randomized placebo-controlled trial to test the effectiveness of goji berries at increasing pigment levels. To preserve eyesight in the elderly in traditional Chinese medicine, people are often prescribed 40 to 100 goji berries a day. In this study, participants consumed only about 15 berries a day for three months. Even at this small dose researchers found that goji berries could protect against loss of pigment and prevent the buildup of debris that builds up in the back of the eye. Both loss of pigment and debris buildup are associated with age-related macular degeneration.

Macular degeneration is the leading cause of legal blindness in older men and women, affecting more than ten million Americans, so increasing our consumption of these pigments as a society could significantly decrease the prevalence of blindness. In the above study, researchers gave the goji berries in milk so the butterfat could increase the absorption of these carotenoid pigments. A healthier way to get the same effect would just be to eat goji berries with nuts or seeds--in other words, goji trail mix.

Though they didn't appear to boost a measure of immune function (Boosting Natural Killer Cell Activity), goji berries are one of the most antioxidant packed snacks out there. A tip on getting them inexpensively can be found in my video Are Goji Berries Good for You?

-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: Marufish / Flickr

Original Link