NutritionFacts.org http://nutritionfacts.org The Latest in Nutrition Research Thu, 30 Jul 2015 12:00:32 +0000 en-US hourly 1 Three Brands of Nutritional Yeast Contain Detectable Lead Levels But the Risk is Minimalhttp://nutritionfacts.org/2015/07/30/three-brands-of-nutritional-yeast-contain-detectable-lead-levels-but-the-risk-is-minimal/?utm_source=rss&utm_medium=rss&utm_campaign=three-brands-of-nutritional-yeast-contain-detectable-lead-levels-but-the-risk-is-minimal http://nutritionfacts.org/2015/07/30/three-brands-of-nutritional-yeast-contain-detectable-lead-levels-but-the-risk-is-minimal/#comments Thu, 30 Jul 2015 12:00:32 +0000 http://nutritionfacts.org/?p=26768 Note from Dr. Greger: In short, we found detectable amounts of lead in samples of Frontier, KAL, and Whole Foods brand nutritional yeast, but the lead levels were so low that they all comply with the exceedingly (and justifiably) strict California Prop 65 standards. Still, I advise pregnant women who eat more than a third […]]]>

Note from Dr. Greger: In short, we found detectable amounts of lead in samples of Frontier, KAL, and Whole Foods brand nutritional yeast, but the lead levels were so low that they all comply with the exceedingly (and justifiably) strict California Prop 65 standards. Still, I advise pregnant women who eat more than a third of a cup a day on a regular basis choose a different brand. No detectable lead levels were found in Bob’s Red Mill, Bragg, Dr. Fuhrman, Red Star, or NOW Foods brand nutritional yeast.

Nutritional yeast has grown in popularity and is being introduced into many new dishes and recipes. It has a nice “cheesy” flavor and texture that can be used in sauces and soups or sprinkled over salads and popcorn. Dr. Greger recently covered how the beta glucan fiber in nutritional yeast can modulate our immune system and help to maintain our body’s defense against pathogens (See Dr. Greger’s video on Nutritional Yeast to Prevent the Common Cold). It seems beta glucans can be found in many foods, including mushrooms, which have been shown to boost immunity as well.

A safety concern arose when Dr. Greger was notified that California’s prop 65 warning stickers were found on packages of nutritional yeast, suggesting there’s something in it exceeding cancer or reproductive safety limits. It turns out the problem was lead. There are many contaminants in the environment and in our food supply, even found in our children, which is probably why California has such strict guidelines on contamination. For example, California considers candies with lead levels in excess of 0.10 parts per million (ppm) to be excessively contaminated. State law requires products that contain more than half of a microgram of lead per daily serving carry a label warning consumers. Could nutritional yeast carry lead levels this high?

We reached out to some of the companies who produce nutritional yeast in hopes to better understand the situation. We asked if they perform lead testing and if they could share any information. The results of Dr. Greger’s inquiries can be found in his video here. He was frustrated by the lack of responsiveness and so decided we should take it upon ourselves to do our own testing. The NutritionFacts Research Fund was created and thanks to generous donor support we tested samples from 8 companies for the presence of lead in hopes to spur them to do their own testing.

We hired an independent lab to conduct our tests for lead. I shipped out 8 samples of nutritional yeast in their original package. The lab used standard practices for lead testing known as Official Methods of Analysis set by AOAC International. Lab technicians determined the lead values based on California Prop 65 standards. Here are the results from the brands we tested:

Bob’s Red Mill  - Test report shows no detectable lead (<0.01 ppm).

BraggTest report shows no detectable lead (< 0.01 ppm).

Dr. Fuhrman -  Test report shows no detectable lead (< 0.01 ppm).

Frontier CoopTest report shows lead levels at 0.021 ppm. It would take six tablespoons a day (based on the manufacture’s listed density) to exceed the California Office of Environmental Health Hazard Assessment Maximum Allowable Dose Level (MADL) for chemicals causing reproductive toxicity.*

KALTest report shows lead levels at 0.011 ppm. It would take seven tablespoons a day to exceed the MADL.*

NOW FoodsTest report shows no detectable lead (< 0.01 ppm).

Red StarTest report shows no detectable lead (< 0.01 ppm).

Whole Foods - Test report shows lead levels at 0.012 ppm. It would take six tablespoons a day to exceed the MADL.*

So what do all those numbers mean? None of the brands tested exceeded California prop 65 standards. No matter what brand, consuming a typical serving (2 tablespoons) per day is still well within safe limits. I will certainly continue to include the stuff in my diet. Dr. Neal Barnard once said, “It’s not about ALL foods in moderation, it’s about healthy foods in moderation. Broccoli is great, but you don’t want to just eat broccoli. Kids exercising is wonderful, but you don’t want them to exercise all the time.”

-Joseph Gonzales, R.D.

*Note from Dr. Greger: The Maximum Allowable Dose Level for lead as a developmental toxin is 0.5 micrograms a day. How are MADL’s calculated? Basically scientists figure out what the “no observable effect level” is, the level at which no birth defects or reproductive toxicity can be found, and then introduce a 1000-fold safety buffer. So for example, let’s say there’s some chemical that causes birth defects if expectant moms are exposed to two drops of the chemical a day, but there’s no evidence that one drop a day is harmful. Do they set the Maximum Allowable Dose Level at one drop? No, they set it at 1/1000th of a drop to account for scientific uncertainty and to err on the side of caution. So by saying six tablespoons a day of nutritional yeast may exceed the MADL is in effect saying that the level of lead found in 6,000 tablespoons of nutritional yeast may cause birth defects. Like mercury, though, as far as I’m concerned the less lead exposure the better. I hope this will inspire companies to do further testing to see if the levels we found were just flukes.

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Dioxins Stored in Our Own Fat May Increase Diabetes Riskhttp://nutritionfacts.org/2015/07/28/dioxins-stored-in-our-own-fat-may-increase-diabetes-risk/?utm_source=rss&utm_medium=rss&utm_campaign=dioxins-stored-in-our-own-fat-may-increase-diabetes-risk http://nutritionfacts.org/2015/07/28/dioxins-stored-in-our-own-fat-may-increase-diabetes-risk/#comments Tue, 28 Jul 2015 12:00:49 +0000 http://nutritionfacts.org/?p=27077 Finding higher diabetes rates among those heavily exposed to toxic pollutants—such as those exposed to Agent Orange, chemical plant explosions, toxic waste dumps, or heavy metals in fish from the Great Lakes—is one thing. Would the same link be found in a random sampling of the general population? Yes. A strong dose-dependent relationship was found […]]]>

Finding higher diabetes rates among those heavily exposed to toxic pollutants—such as those exposed to Agent Orange, chemical plant explosions, toxic waste dumps, or heavy metals in fish from the Great Lakes—is one thing. Would the same link be found in a random sampling of the general population? Yes. A strong dose-dependent relationship was found between the levels of these pollutants circulating in people’s blood and diabetes. Those with the highest levels of pollutants in their blood stream had 38 times the odds of diabetes.

Interestingly, there was “no association between obesity and diabetes among subjects with non-detectable levels of pollutants.” In other words, “obesity was a risk factor for diabetes only if people had blood concentrations of these pollutants above a certain level.” We know obesity predisposes us to diabetes, but according to this study, highlighted in my video, Diabetes and Dioxins, this is perhaps true only if our bodies are contaminated with industrial pollutants. This finding implies that virtually all the risk of diabetes conferred by obesity is attributable to these pollutants, and that obesity might only be a vehicle for such chemicals. Could we be carrying around our own little toxic waste dump on our hips?

Now it’s entirely possible that the six pollutants they looked at were not themselves causally related to diabetes. Rather, they could just be surrogates of exposure to a mixture of chemicals. After all, 90% of these pollutants in our diet come from animal foods. Except for individuals living or working around industrial sites where these chemicals were used or dumped, the most common source of exposure to PCBs is from diet, from foods of animal origin, especially seafood. The strong relationship the researchers found between certain pollutants and diabetes may just be pointing to other contaminants in animal products.

If these pollutants are particularly found in seafood, are people who eat fish at higher risk for diabetes? See my videos Fish and Diabetes, and Pollutants in Salmon and Our Own Fat.

For more on dioxins, see:

For more on PCBs, see:

These pollutants may also play a role in our rising epidemic of allergic diseases. See Alkylphenol Endocrine Disruptors and Allergies and Dietary Sources of Alkylphenol Endocrine Disruptors.

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Agustin Ruiz / Flickr

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Why Would Eating Fish Increase Diabetes Risk?http://nutritionfacts.org/2015/07/23/why-would-eating-fish-increase-diabetes-risk/?utm_source=rss&utm_medium=rss&utm_campaign=why-would-eating-fish-increase-diabetes-risk http://nutritionfacts.org/2015/07/23/why-would-eating-fish-increase-diabetes-risk/#comments Thu, 23 Jul 2015 12:00:17 +0000 http://nutritionfacts.org/?p=27071 In the past two years, six separate meta-analyses have been published on the relationship between fish consumption and type 2 diabetes. The whole point of a meta-analysis is to compile the best studies done to date and see what the overall balance of evidence shows. The fact that there are six different ones published recently […]]]>

In the past two years, six separate meta-analyses have been published on the relationship between fish consumption and type 2 diabetes. The whole point of a meta-analysis is to compile the best studies done to date and see what the overall balance of evidence shows. The fact that there are six different ones published recently highlights how open the question remains. One thread of consistency, though, was that fish consumers in the United States tended to be at greater risk for diabetes.

If we include Europe, then fish eaters appeared to have a 38% increased risk of diabetes. On a per serving basis, that comes out to be about a 5% increase in risk for every serving of fish one has per week. To put that into perspective, a serving of red meat per day is associated with 19% increase in risk. Just one serving per day of fish would be equivalent to a 35% increase in risk. But why might fish be worse than red meat?

Fish intake may increase type 2 diabetes risk by increasing blood sugar levels, as a review of the evidence commissioned by the U.S. government found. The review found that blood sugars increase in diabetics given fish oil. Another possible cause is that omega 3’s appear to cause oxidative stress. A recent study, highlighted in my video, Fish and Diabetes, found that the insulin producing cells in the pancreas don’t appear to work as well in people who eat two or more servings of fish a week. Or it may not be related to omega 3’s at all but rather the environmental contaminants that build up in fish.

It all started with Agent Orange. We sprayed 20 million gallons of the stuff on Vietnam, and some of it was contaminated with trace amounts of dioxins. Though the Red Cross estimates that a million Vietnamese were adversely affected, what about all the servicemen who were exposed spraying it across the countryside? Reports started showing up that veterans exposed to Agent Orange appeared to have higher diabetes rates than unexposed veterans, a link that’s now officially recognized.

These so-called “persistent organic pollutants” are mainly man-made industrial chemicals and are among the most hazardous compounds ever synthesized. They include dioxins, PCBs, and certain chlorine-containing pesticides, all of which are highly resistant to breakdown in the environment.

Initially condemned for their deleterious effect on reproductive function and their ability to cause cancer, there is now a growing body of evidence showing that exposure to these pollutants leads to metabolic diseases such as diabetes. This is a breakthrough that “should require our greatest attention.”

For more on the role industrial pollutants may play in our diabetes epidemic, see Diabetes and Dioxins and Pollutants in Salmon and Our Own Fat.

More on the changing views surrounding fish oil supplements in Is Fish Oil Just Snake Oil?

Other foods associated with diabetes risk include processed meat and eggs. See Bacon, Eggs, and Gestational Diabetes During Pregnancy and Eggs and Diabetes, while Indian gooseberries and flaxseeds may help (Amla Versus Diabetes and Flaxseed vs. Diabetes).

Other videos on how polluted our oceans now are 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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Gideon / Flickr

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Why Deep Fried Foods May Cause Cancerhttp://nutritionfacts.org/2015/07/21/why-deep-fried-foods-may-cause-cancer/?utm_source=rss&utm_medium=rss&utm_campaign=why-deep-fried-foods-may-cause-cancer http://nutritionfacts.org/2015/07/21/why-deep-fried-foods-may-cause-cancer/#comments Tue, 21 Jul 2015 12:00:49 +0000 http://nutritionfacts.org/?p=27066 In the latest study on dietary patterns and breast cancer risk among women, healthier eating was associated with eliminating three-quarters of the odds of breast cancer, whereas less healthy eating was associated with up to nearly eight times the odds. Included in the unhealthy eating pattern was the consumption of deep-fried foods, which have previously […]]]>

In the latest study on dietary patterns and breast cancer risk among women, healthier eating was associated with eliminating three-quarters of the odds of breast cancer, whereas less healthy eating was associated with up to nearly eight times the odds. Included in the unhealthy eating pattern was the consumption of deep-fried foods, which have previously been linked to breast cancer, pancreatic cancer, lung cancer, oral and throat cancers, esophageal cancer, and cancer of the voicebox. No deep fried foods? What’s a Southern belle to do? Instead of deep fried foods, how about the traditional Southern diet, characterized by high intakes of cooked greens, beans, legumes, cabbage, sweet potatoes and cornbread, which may reduce the risk of invasive breast cancer significantly.

What about the consumption of deep-fried foods and risk of prostate cancer? Researchers at the Fred Hutchinson Cancer Research Center and the University of Washington found that eating French fries, fried chicken, fried fish, and doughnuts was associated with about a third greater odds of prostate cancer. After stratifying for tumor aggressiveness, they found slightly stronger associations with more aggressive disease, suggesting that regular intake of deep-fried foods may contribute to the progression of prostate cancer as well.

What in deep fried foods is so bad for us? Just heating oil that hot can generate potentially carcinogenic compounds, and then known carcinogens such as heterocyclic amines and polycyclic aromatic hydrocarbons form when the muscles of chickens and fish are cooked at that temperature. Deep-fried plants, on the other hand, can form acrylamide.

I did a video about acrylamide back in 2008, suggesting it’s a probable human carcinogen (See Acrylamide in French Fries). Since then, studies have suggested pregnant women may want to cut back on French fries to protect the growth of their baby’s body and brain. Based on a study (highlighted in my video, Cancer Risk from French Fries) feeding people a little bag of potato chips every day for a month, it now seems acrylamide may also cause inflammation as well, which could explain its purported role in cancer progression.

Acrylamide intake has been associated with endometrial cancer, ovarian cancer, lung cancer, kidney cancer, and esophageal cancer. How much cancer risk are we talking about? Taiwanese researchers examined lifetime cancer risk and French fry consumption. The researchers picked on French fries because they comprise by far the greatest percentage contribution of acrylamide to the diets of children. They estimated that, at most, one or two boys and girls out of every ten thousand would develop cancer eating French fries that they would otherwise not have developed if they hadn’t eaten French fries. So it’s not as bad as eating something like fried fish, or fried chicken, but how much is that saying?

The level of cancer risk in both boys and girls associated with French fries depends on how long and hot they’re fried. In Europe, the food industry swore that they’d self-regulate and control fry times to decrease acrylamide levels, but we’ve yet to see any subsequent change in acrylamide levels in French fries.

Researchers continue to urge that the cooking temperature should be as low as possible and the cooking time should be as short as possible, “while still maintaining a tasty quality” of course. We wouldn’t want to reduce cancer risk too much—they might not taste as good!

Blanching the potatoes first reduces acrylamide formation, but potato chip companies complain that, not only would it muck with the flavor, but it would reduce the nutritional properties by leaching away some of the vitamin C. But if we’re relying on potato chips to get our vitamin C, acrylamide is probably the least of our worries.

More on heterocyclic amines:

There are some things we can do to counteract the effects of these carcinogens, though:

I touch on polycyclic aromatic hydrocarbons in Meat Fumes: Dietary Secondhand Smoke and Is Liquid Smoke Flavoring Carcinogenic?
Certain fats may play a role in breast cancer survival as well: Breast Cancer Survival, Butterfat, and Chicken and Breast Cancer Survival and Trans Fat.

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Kim Love / Flickr

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Do Cholesterol Statin Drugs Cause Breast Cancer?http://nutritionfacts.org/2015/07/16/do-cholesterol-statin-drugs-cause-breast-cancer/?utm_source=rss&utm_medium=rss&utm_campaign=do-cholesterol-statin-drugs-cause-breast-cancer http://nutritionfacts.org/2015/07/16/do-cholesterol-statin-drugs-cause-breast-cancer/#comments Thu, 16 Jul 2015 12:00:10 +0000 http://nutritionfacts.org/?p=27060 What does breast cancer have to do with cholesterol? There are many potential mechanisms by which cholesterol boosts breast cancer growth. For example, our bodies make estrogen, which is correlated with an increased risk of breast cancer, out of cholesterol. We also package cholesterol into LDL, which, as you can see in my video Cholesterol […]]]>

What does breast cancer have to do with cholesterol? There are many potential mechanisms by which cholesterol boosts breast cancer growth. For example, our bodies make estrogen, which is correlated with an increased risk of breast cancer, out of cholesterol. We also package cholesterol into LDL, which, as you can see in my video Cholesterol Feeds Breast Cancer Cells, appeared to increase cancer proliferation and decrease patient survival.

Cholesterol is a major component of “lipid rafts.” Compared to their normal counterparts, cancer cells have higher levels of these cholesterol-rich lipid rafts in their plasma membrane, which may be important for cancer cell survival and may serve in human cancer development in terms of tumor migration and invasion. Elevated levels of cholesterol-rich lipid rafts have been found in breast cancer cells, and the hypothesis is that reducing blood cholesterol levels “may disrupt lipid raft formation and thereby inhibit breast cancer development.” This suggests cholesterol targeting may be used as a cancer therapy.

Controlled laboratory experiments have shown that phytosterols in seeds and nuts at dietary relevant levels appear to inhibit the growth of several types of tumor cells including breast cancer cells, including both estrogen-receptor negative and estrogen-receptor positive cancer. The therapeutic implications are that “plant-based diets rich in phytosterols may offer protection against the development of breast cancer.” Of course, you can’t make a lot of money on pumpkin seeds, so researchers looked to cholesterol-lowering statin drugs (this study is highlighted in my video, Statin Cholesterol Drugs and Invasive Breast Cancer).

Some petri dish work looked promising, but population studies have shown mixed results. Some studies showed that women on statins had decreased breast cancer risk, some showed increased risk, and most showed no association. These were all relatively short-term studies, though. “Long-term” statin use was defined as mostly just three to five years, but breast cancer can take decades to grow. The one study that looked at ten or more years of statin use only included 62 cases.

Given the increase in statin use over the past few decades, and the fact that they’re commonly prescribed to be taken every day for the rest of women’s lives, the studies published to date only had limited ability to evaluate the impact of long durations of use. We better figure this out: about one in four women over 45 in this country are on these drugs.

But that all changed with the publication of a study in 2013 including thousands of breast cancer cases. Long term statin users—women taking statins for ten years or more—had more than double the risk of both major types of breast cancer: invasive ductal carcinoma and invasive lobular carcinoma. Once women do get breast cancer, though, recent studies in Finland and the UK suggest statin use may improve survival.

The number one killer of women is heart disease, not breast cancer, so we still do need to bring down cholesterol levels. Might there be a way to get the benefits of cholesterol reduction without the risks? Plant-based diets have been shown to lower LDL-cholesterol by over 30%, within just a couple weeks, equivalent to most of the standard cholesterol lowering statin drugs and without any breast cancer risk.

As drugs go, statins are remarkably safe, but they can still present rare but serious side effects in both men and women (Statin Muscle Toxicity).

How can we lower cholesterol without drugs? It’s Purely a Question of Diet. We can lower our cholesterol by lowering our intake of three things: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero. Where are trans fats found? Trans Fat in Meat and Dairy. Where is cholesterol found? Predominantly eggs: Eggs and Cholesterol: Patently False and Misleading Claims. There are also some foods particularly adept at lowering cholesterol levels:

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Ana C. / Flickr

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Breast Cancer Cells Feed on Cholesterolhttp://nutritionfacts.org/2015/07/14/breast-cancer-cells-feed-on-cholesterol/?utm_source=rss&utm_medium=rss&utm_campaign=breast-cancer-cells-feed-on-cholesterol http://nutritionfacts.org/2015/07/14/breast-cancer-cells-feed-on-cholesterol/#comments Tue, 14 Jul 2015 12:00:32 +0000 http://nutritionfacts.org/?p=27054 One in eight American women will be diagnosed with breast cancer in her lifetime. There are a number of compounds in plant foods that may protect against breast cancer by a variety of mechanisms. I’ve talked about the benefits of broccoli, flaxseeds, and soy foods before (See Breast Cancer Survival Vegetable,  Flaxseeds & Breast Cancer […]]]>

One in eight American women will be diagnosed with breast cancer in her lifetime. There are a number of compounds in plant foods that may protect against breast cancer by a variety of mechanisms. I’ve talked about the benefits of broccoli, flaxseeds, and soy foods before (See Breast Cancer Survival VegetableFlaxseeds & Breast Cancer Prevention, and Breast Cancer Survival and Soy) but a recent German study reported something new. The researchers found that sunflower and pumpkin seeds were associated with reduced breast cancer risk. They initially chalked the association up to the lignans in the seeds (See Breast Cancer Survival and Lignan Intake), but their lignan lead didn’t pan out. Maybe it’s the phytosterols found concentrated in seeds? (See Optimal Phytosterol Source).

There is evidence that phytosterols may be anticancer nutrients and play a role in reducing breast cancer risk. I thought phytosterols just lowered cholesterol? (See How Phytosterols Lower Cholesterol) What does cancer have to do with cholesterol?

Increasing evidence demonstrates the role that cholesterol may play in the development and progression of breast cancer. Cancer feeds on cholesterol. Transformed cells take up LDL, so-called “bad” cholesterol, and it’s capable of stimulating the growth of human breast cancer cells in a petri dish.

The ability to accumulate fat and cholesterol may enable cancer cells to take advantage of people eating high fat and high cholesterol diets and at least partially explain the benefit of a low-fat diet on lowering human breast cancer recurrence. Although the data has been mixed, the largest study to date (highlighted in my video, Cholesterol Feeds Breast Cancer Cells) found a 17% increased breast cancer risk in women who had a total cholesterol over 240 compared to women whose cholesterol was under 160. However, the researchers could not rule out that there may be something else in cholesterol-raising foods that’s increasing breast cancer risk.

Tumors suck up so much cholesterol that LDL has been considered a vehicle for delivering antitumor drugs to cancer cells. Since cancer feeds on cholesterol, maybe we could stuff some chemo into it like a Trojan horse poison pill?

The uptake of LDL into tumors may be why people’s cholesterol levels drop low after they get cancer—the tumor is eating it up. In fact, patient survival may be lowest when cholesterol uptake is highest. “High LDL receptor content in breast cancer tissue seems to indicate a poor prognosis, [suggesting] that breast tumors rich in LDL receptors may grow rapidly [in the body].” We’ve known about this for decades. You can tell that was an old study because, when it was published in the ‘80s, only 1 in 11 American women got breast cancer.

If cholesterol increases breast cancer risk, what about the use of cholesterol-lowering drugs? See Statin Cholesterol Drugs and Invasive Breast Cancer.

More videos on broccoli and soy’s protective effects against breast cancer:

Some I didn’t mention 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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Andrew Bennett / Flickr

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Using Diet to Treat Asthma and Eczemahttp://nutritionfacts.org/2015/07/09/using-diet-to-treat-asthma-and-eczema/?utm_source=rss&utm_medium=rss&utm_campaign=using-diet-to-treat-asthma-and-eczema http://nutritionfacts.org/2015/07/09/using-diet-to-treat-asthma-and-eczema/#comments Thu, 09 Jul 2015 12:00:28 +0000 http://nutritionfacts.org/?p=27051 I previously discussed the power of fruits and vegetables to help prevent and treat asthma and allergies. If adding a few more servings of fruits and vegetables may help asthma, what about a diet centered around plants? Twenty patients with allergic eczema were placed on a vegetarian diet.  At the end of two months, their […]]]>

I previously discussed the power of fruits and vegetables to help prevent and treat asthma and allergies. If adding a few more servings of fruits and vegetables may help asthma, what about a diet centered around plants? Twenty patients with allergic eczema were placed on a vegetarian diet.  At the end of two months, their disease scores, which covered both subjective and objective signs and symptoms, were cut in half, similar to what we might see using one of our most powerful drugs. The drug works much quicker, within about two weeks, but since drugs can often include dangerous side effects the dietary option is more attractive. This was no ordinary vegetarian diet, however. This was an in-patient study using an extremely calorically-restricted diet—the subjects were practically half fasting. Therefore, we don’t know which component was responsible for the therapeutic effect.

What about using a more conventional plant-based diet against a different allergic disease, asthma? In Sweden, there was an active health movement that claimed that a vegan diet could improve or cure asthma. This was a bold claim, so in order to test this, a group of orthopedic surgeons at Linköping University Hospital followed a series of patients who were treated with a vegan regimen for one year. (This study is highlighted in my video, Treating Asthma and Eczema with Plant-Based Diets.) Participants had to be willing to go completely plant-based, and they had to have physician-verified asthma of at least a year’s duration that wasn’t getting better or was getting worse despite the best medical therapies available.

The researchers found quite a sick group to follow. The thirty-five patients had long-established, hospital-verified bronchial asthma for an average duration of a dozen years. Of the 35 patients, 20 had been admitted to the hospital for acute asthmatic attacks during the last two years. Of these, one patient had received acute infusion therapy (emergency IV drugs) a total of 23 times during this period and another patient claimed he had been to the hospital 100 times during his disease and on every occasion had evidently required such treatments. One patient even had a cardiac arrest during an asthma attack and had been brought back to life on a ventilator. These were some pretty serious cases.

The patients were on up to eight different asthma medicines when they started, with an average of four and a half drugs, and were still not getting better. Twenty of the 35 were constantly using cortisone, which is a powerful steroid used in serious cases. These were all fairly advanced cases of the disease, more severe than the vegan practitioners were used to.

Eleven couldn’t stick to the diet for a year, but of the 24 that did, 71% reported improvement at four months and 92% at one year. These were folks that had not improved at all over the previous year. Concurrently with this improvement, the patients greatly reduced their consumption of medicine. Four had completely given up their medication altogether, and only two weren’t able to at least drop their dose. They went from an average of 4.5 drugs down to 1.2, and some were able to get off cortisone.

Some subjects said that their improvement was so considerable they felt like “they had a new life.” One nurse had difficulty at work because most of her co-workers were smokers, but after the plant-based regimen she could withstand the secondhand smoke without getting an attack and could tolerate other asthma triggers. Others reported the same thing. Whereas previously they could only live in a clean environment and felt more or less isolated in their homes, they could now go out without getting asthmatic attacks.

The researchers didn’t find only subjective improvements. They also found a significant improvement in a number of clinical variables, most importantly in measures of lung function, vital capacity, forced expiratory volume, and physical working capacity, as well as significant drops in sed rate (a marker of inflammation) and IgE (allergy associated antibodies).

The study started out with 35 patients who had suffered from serious asthma for an average of 12 years, all receiving long-term medication, with 20 using cortisone, who were “subjected to vegan food for a year,” and, in almost all cases, medication was withdrawn or reduced, and asthma symptoms were significantly reduced.

Despite the improved lung function tests and lab values, the placebo effect can’t be discounted since there was no blinded control group. However, the nice thing about a healthy diet is that there are only good side effects. The subjects’ cholesterol significantly improved, their blood pressures got better, and they lost 18 pounds. From a medical standpoint, I say why not give it a try?

If you missed the first three videos of this 4-part series here are the links:

More on eczema and diet can be found in my videos:

There are a number of other conditions plant-based diets have been found to be effective in treating:

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: KristyFaith / Flickr

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Treating Asthma With Plants vs. Pillshttp://nutritionfacts.org/2015/07/07/treating-asthma-with-plants-vs-pills/?utm_source=rss&utm_medium=rss&utm_campaign=treating-asthma-with-plants-vs-pills http://nutritionfacts.org/2015/07/07/treating-asthma-with-plants-vs-pills/#comments Tue, 07 Jul 2015 12:00:08 +0000 http://nutritionfacts.org/?p=26725 In my video Treating Asthma With Fruits and Vegetables, I highlighted a landmark study on manipulating antioxidant intake in asthma. The study found that just a few extra fruits and vegetables a day can powerfully reduce asthma exacerbation rates. If the antioxidants in the plants are ameliorating asthma, then why can’t we take antioxidant pills […]]]>

In my video Treating Asthma With Fruits and Vegetables, I highlighted a landmark study on manipulating antioxidant intake in asthma. The study found that just a few extra fruits and vegetables a day can powerfully reduce asthma exacerbation rates. If the antioxidants in the plants are ameliorating asthma, then why can’t we take antioxidant pills instead? Because antioxidant pills don’t appear to work.

Studies using antioxidant supplements on respiratory or allergic diseases have mostly shown no beneficial effects. This discrepancy between data relating to fruit and vegetable intake compared with those using antioxidant supplements may indicate the importance of the whole food, rather than individual components. For example, in the Harvard Nurse’s Health Study, women who got the most vitamin E from their diet appeared to be at half the risk for asthma, (which may help explain why nut consumption is associated with significantly lower rates of wheezing), but vitamin E supplements did not appear to help.

Men who eat a lot of apples appear to have superior lung function, as do kids who eat fresh fruit every day, as measured by FEV1 (basically how much air you can forcibly blow out in one second). The more fruit, salad, and green vegetables kids ate, the greater their lung function appeared.

Researchers are “cautious about concluding which nutrient might be responsible.” There’s vitamin C in fruits, salads, and green vegetables, but there are lots of other antioxidants, such as “vitamin P,” a term used to describe polyphenol phytonutrients found in grapes, flax seeds, beans, berries, broccoli, apples, citrus, herbs, tea, and soy. Polyphenol phytonutrients can directly bind to allergenic proteins and render them hypoallergenic, allowing them to slip under our body’s radar. If this first line of defense fails, polyphenols can also inhibit the activation of the allergic response and prevent the ensuing inflammation, and so may not only work for prevention, but for treatment as well.

Most of the available evidence is weak, though, in terms of using supplements containing isolated phytonutrients to treat allergic diseases. We could just give people fruits and vegetables to eat, but then we couldn’t perform a double-blind study to see if they work better than placebo. Some researchers decided to use pills containing plant food extracts. Plant extracts are kind of a middle ground. They are better than isolated plant chemicals, but are not as complete as whole foods. Still, since we can’t put whole foods in a capsule, we can compare the extracts to fake sugar pills that look and feel the same to see if they have an effect.

The first trial involved giving people extracts of apple skins. I’ve talked about the Japan’s big cedar allergy problem before (See Alkylphenol Endocrine Disruptors and Allergies), so apple extract pills were given every day for a few months starting right before pollen season started. The results were pretty disappointing. They found maybe a little less sneezing, but the extract didn’t seem to help their stuffy noses or itchy eyes.

What about a tomato extract? A randomized, double-blind, placebo-controlled eight-week trial was performed on perennial allergic rhinitis, this time not for seasonal pollen, but for year-round allergies to things like dust-mites. There are lots of drugs out there, but you may have to take them every day year-round, so how about some tomato pills instead? After oral administration of tomato extract for eight weeks, there was a significant improvement of total nasal symptom scores, combined sneezing, runny nose and nasal obstruction, with no apparent adverse effects.

Would whole tomatoes work even better? If only researchers would design an experiment directly comparing phytonutrient supplements to actual fruits and vegetables head-to-head against asthma, but such a study had never been done… until now. The same amazing study, highlighted in my video, Treating Asthma with Plants vs. Supplements?, that compared the seven-fruit-and-vegetables-a-day diet to the three-fruit-and-vegetables-a-day diet, after completion of its first phase, commenced a parallel, randomized, controlled supplementation trial with capsules of tomato extract, which boosted the power of five tomatoes in one little pill, and the study subjects were given three pills a day.

Who did better, the group that ate seven servings of actual fruits and vegetables a day, or the group that ate three servings a day but also took 15 supposed serving equivalents in pill form? The pills didn’t help at all. Improvements in lung function and asthma control were evident only after increased fruit and vegetable intake, which suggests that whole-food interventions are most effective. Both the supplements and increased fruit and vegetable intake were effective methods for increasing carotenoid concentrations in the bloodstream, but who cares? Clinical improvements—getting better from disease—were evident only as a result of an increase in plant, not pill, consumption. The results provide further evidence that whole-food approaches should be used to achieve maximum efficacy of antioxidant interventions.

And if this is what a few more plants can do, what might a whole diet composed of plants accomplish? See Treating Asthma and Eczema with Plant-Based Diets.

I also dealt with preventing asthma in the first place: Preventing Asthma With Fruits and Vegetables.

The theme of whole foods being more efficacious than supplements seems to come up over and over again. See for example:

More on “vitamin P” in How to Slow Brain Aging by Two Years.

The anti-inflammatory effects of nuts may explain the Harvard Nurse’s Health Study finding: Fighting Inflammation in a Nut Shell.

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Mike Mozart / Flickr

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How Fruits and Vegetables Can Treat Asthmahttp://nutritionfacts.org/2015/07/02/how-fruits-and-vegetables-can-treat-asthma/?utm_source=rss&utm_medium=rss&utm_campaign=how-fruits-and-vegetables-can-treat-asthma http://nutritionfacts.org/2015/07/02/how-fruits-and-vegetables-can-treat-asthma/#comments Thu, 02 Jul 2015 12:00:23 +0000 http://nutritionfacts.org/?p=26718 In my video Preventing Asthma With Fruits and Vegetables, I highlighted an international study of asthma and allergies involving more than a million kids. The study found a consistent inverse relationship between prevalence rates of asthma, allergies, and eczema and the intake of plants, starch, grains, and vegetables. Researchers speculated “over a decade ago that […]]]>

In my video Preventing Asthma With Fruits and Vegetables, I highlighted an international study of asthma and allergies involving more than a million kids. The study found a consistent inverse relationship between prevalence rates of asthma, allergies, and eczema and the intake of plants, starch, grains, and vegetables. Researchers speculated “over a decade ago that if these findings could be generalized, and if the average daily consumption of these foods increased, an important decrease in symptom prevalence could be achieved.” No need to speculate any more, though, because plants were finally put to the test.

Researchers have proposed that “by eating fewer fruits and vegetables, the susceptibility to potentially harmful inhaled substances of the population as a whole may be increased because of the reduction in antioxidant defenses of the lungs.” The thin lining of fluid that forms the interface between our respiratory tract and the external environment is our first line of defense against oxidative damage. Oxidative damage is important in asthma, contributing to airway contraction, excessive mucous production, and hypersensitivity. Antioxidants protect against oxidative stress, so our lung lining contains a range of antioxidants our body makes itself, as well as those obtained from our diet, particularly from fruits and vegetables.

We can even quantify the level of oxidative stress in people by measuring the level of oxidation products in their exhaled breath, which drops as we start eating more fruits and vegetables, and drops further as we combine more plants with fewer animal foods.

Do those with asthma really have lower levels of antioxidants than people without asthma? Compared to healthy controls, subjects with asthma had lower whole blood levels of total carotenoids and lower levels of each of the individual phytonutrients they measured: cryptoxanthin, lycopene, lutein, alpha-carotene and beta-carotene compared to healthy controls.

Therefore, they posit, “the accumulating evidence does suggest that diet has an influence in modulating the response of the lung to inhaled allergens and irritants. However, it is possible that the reduced carotenoid levels in asthma are a result of increased utilization in the presence of excess free radicals.” So it’s like a chicken-or-the-egg phenomenon.

We know antioxidant-rich diets have been associated with reduced asthma prevalence. However, direct evidence that altering intake of antioxidant-rich foods actually affects asthma was lacking, until now.

There are two ways to test the effects of fruits and vegetables on asthma. Add fruits and vegetables to people’s diets and see if their asthma improves, or take asthmatics and remove fruits and vegetables from their diets and see if they get worse.

The first such study of its kind, highlighted in my video, Treating Asthma With Fruits and Vegetables, placed subjects with asthma on a low antioxidant diet. After just a matter of days, there was a significant worsening of lung function and asthma control. The researchers conclude that, “This finding is highly significant for subjects with asthma, as it indicates that omitting antioxidant-rich foods from the diet, for even a short time frame, will have a detrimental effect on asthma symptoms.”

Ironically, the low antioxidant diet consumed by subjects, where they were restricted to one serving of fruit and up to two servings of vegetables per day, is typical of Western diets. In other words, the low antioxidant diet they used to worsen people’s asthma, crippling their lung function, was just like the standard American diet.

As about “half the population usually consumes a diet with an intake of fruit and vegetables equivalent to that in the study diet or less, it appears likely that this dietary pattern, which must be considered suboptimal for lung health, may have a significant impact on asthma management, indicating the potential for typical Western dietary patterns to contribute to a worsening of lung function and asthma control.”

Within just days, cutting down fruit and vegetable intake can impair lung function, but does adding fruits and vegetables help with asthma? That was the second phase of the study.

Asthmatics on the standard American diet had about a 40% chance of relapsing into an asthma exacerbation within three months. However, put them on seven servings of fruits and vegetables a day instead of three, and we cut their exacerbation rate in half, down to 20%. Imagine if there were a drug that could work as powerfully as a few fruits and vegetables.

If manipulating antioxidant intake by increasing fruit and vegetable intake can so powerfully reduce asthma exacerbation rates, why not just take antioxidant pills instead? I cover that in my video Treating Asthma With Plants vs. Supplements?

And if a few extra servings of fruits and vegetables can make that kind of difference, what about a whole diet composed of plants? Check out Treating Asthma and Eczema With Plant-Based Diets.

What else might antioxidant-rich diets help with? See:

How many antioxidants should we shoot for? See:

Where are antioxidants found the most?

-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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: Pacific Northwest Agricultural Safety and Health Center / Flickr

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How Fruits and Vegetables Can Prevent Asthmahttp://nutritionfacts.org/2015/06/30/how-fruits-and-vegetables-can-prevent-asthma/?utm_source=rss&utm_medium=rss&utm_campaign=how-fruits-and-vegetables-can-prevent-asthma http://nutritionfacts.org/2015/06/30/how-fruits-and-vegetables-can-prevent-asthma/#comments Tue, 30 Jun 2015 12:00:45 +0000 http://nutritionfacts.org/?p=26714 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 […]]]>

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 is 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 DeathMore Than an Apple a Day, and From Table to Able.

Image Credit: EdTech Stanford University School of Medicine / Flickr

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