NutritionFacts.org http://nutritionfacts.org The Latest in Nutrition Research Tue, 31 May 2016 03:16:35 +0000 en-US hourly 1 Preventing Breast Cancer with Flax Seeds http://nutritionfacts.org/2016/05/26/preventing-breast-cancer-with-flax-seeds/?utm_source=rss&utm_medium=rss&utm_campaign=preventing-breast-cancer-with-flax-seeds http://nutritionfacts.org/2016/05/26/preventing-breast-cancer-with-flax-seeds/#comments Thu, 26 May 2016 12:00:37 +0000 http://nutritionfacts.org/?p=29894 I’ve previously discussed the role of dietary lignans in the reduction of breast cancer risk and improvement in breast cancer survival, based on studies that showed that women with breast cancer who ate the most lignans appeared to live longer (Flaxseeds & Breast Cancer Survival: Epidemiological Evidence and Flaxseeds & Breast Cancer Survival: Clinical Evidence). […]]]>

I’ve previously discussed the role of dietary lignans in the reduction of breast cancer risk and improvement in breast cancer survival, based on studies that showed that women with breast cancer who ate the most lignans appeared to live longer (Flaxseeds & Breast Cancer Survival: Epidemiological Evidence and Flaxseeds & Breast Cancer Survival: Clinical Evidence). However, lignans are found throughout the plant kingdom—in seeds, whole grains, vegetables, fruits, berries—so how do we know lignans aren’t merely a marker for the intake of unrefined plant foods? For example, those who eat lots of plants—vegetarians—have about eight times the lignan intake than omnivores.

In a petri dish, lignans have been shown to both have direct anticancer growth activity against human breast cancer cells and to prevent cancer cell migration. But it wasn’t until 2005 that it was put to the test in people. Researchers from the University of Toronto conducted a randomized double-blind placebo-controlled clinical trial (as seen in my video, Can Flax Seeds Help Prevent Breast Cancer?) of flaxseeds, the world’s most concentrated source of lignans, in breast cancer patients. The researchers found that flax appears to have the potential to reduce human breast tumor growth in just a matter of weeks. Therefore, I started recommending ground flax seeds to breast cancer patients.

Can lignans also help prevent breast cancer in the first place? High lignan intake is associated with reduced breast cancer risk, but again lignan intake may just be saying an indicator of high plant food intake in general. So researchers from the University of Kansas gave women at high risk for breast cancer a teaspoon of ground flaxseeds a day for a year, and found on average a drop in precancerous changes in the breast.

What about women who regularly eat flax seeds? Outside of an experimental setting, there just weren’t a lot of women eating flax seeds regularly to study—until now. Matching 3,000 women with breast cancer to 3,000 women without, a study published in Cancer Causes and Control found that consumption of flaxseed (and of flax bread) was associated with a 20–30 percent reduction in breast cancer risk. The researchers note that, as flaxseeds are packed with lignans, only a small daily serving of flaxseed is required to attain the level of lignan intake associated with a reduction in breast cancer risk. Researchers concluded: “As it appears that most women do not consume flaxseed and that small amounts may be associated with reduced breast cancer risk, interventions to increase the prevalence of flaxseed consumption might be considered.”

The latest review summarizes the association between flax and decreased risk of breast cancer, better mental health, and lower mortality among breast cancer patients. The only other study of flax and brain health I’m aware of was an exploration of 100 commonly used drugs and supplements on cognition in older adults, which found that flax is one of the few things that appears to help.

How else may flaxseeds aid in preventing and treating breast cancer? There’s an inflammatory molecule called interleukin-1, which may help tumors feed, grow, and invade. Our bodies therefore produce an interkeukin-1 receptor antagonist, binding to the IL-1 receptor and blocking the action of IL-1. The activity of this protective inhibitor can be boosted with the drug tamoxifen—or by eating flax seed. In premenopausal women, the proinflammatory profile of interleukin-1 can be counteracted by a dietary addition of a few spoonfuls of ground flax. One month of flax may be able to increase the anti-inflammatory inhibitor levels by over 50 percent, better even than the drug.

Yes, having one’s ovaries removed may reduce breast cancer risk as much as 60 percent, but at the cost of severe side-effects. The drug tamoxifen may reduce the incidence of breast cancer by more than 40 percent, but may induce other severe side effects such as uterine cancer and blood clots. That’s why less toxic (even safe!) breast cancer preventive strategies such as dietary modifications need to be developed. These lignan phytoestrogens in flaxseeds may be one successful route given the data showing reduced breast cancer risk and improved overall survival.

Lignans are not a magic bullet to prevent breast cancer—we can’t just sprinkle some flax on your bacon cheeseburger—but as a part of a healthy diet and life-style, they might help to reduce breast cancer risk in the general population.

Flaxseeds may also help fight hormone-mediated cancers in men. See Flaxseed vs. Prostate Cancer and Was It the Flaxseed, Fat Restriction, or Both?

What else can these puppies do? See:

I have another 100+ videos on breast cancer if you want to become an expert and help take care of yourself and/or the women in your life. Here’s a few recent ones to get you started:

In health,
Michael Greger, M.D.

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

Image Credit: Alisha Vargas / Flickr

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Children’s Supplements Found Contaminated With Pollutants http://nutritionfacts.org/2016/05/24/childrens-supplements-found-contaminated-with-pollutants/?utm_source=rss&utm_medium=rss&utm_campaign=childrens-supplements-found-contaminated-with-pollutants http://nutritionfacts.org/2016/05/24/childrens-supplements-found-contaminated-with-pollutants/#comments Tue, 24 May 2016 12:00:10 +0000 http://nutritionfacts.org/?p=29892 A number of case-control studies have found that giving kids cod liver oil supplements may increase their risk of asthma later in life. Case-control studies are done by asking about past behavior in cases (those with asthma) versus controls (those without asthma) to see if certain past behaviors are more likely among the disease group. […]]]>

A number of case-control studies have found that giving kids cod liver oil supplements may increase their risk of asthma later in life. Case-control studies are done by asking about past behavior in cases (those with asthma) versus controls (those without asthma) to see if certain past behaviors are more likely among the disease group. The problem is that asking people to remember what they were doing years ago, when most people can’t remember what they had for breakfast last week, is unreliable. When interpreting the results from case-control studies, we also can’t rule out something called reverse causation. Maybe cod liver oil doesn’t lead to asthma, but asthma led to the use of cod liver oil.

It would therefore be nice to see a cohort study. In a cohort study, researchers would take people without asthma and follow them over time to see if those taking cod liver oil are more likely to develop it. Because people without the disease and their diets are followed over time, cohort studies bypass the problems of recall bias and reverse causation.

In 2013, we finally got one such study. 17,000 people free of asthma were followed over 11 years. Researchers knew who was taking cod liver oil and who wasn’t, and then sat back and watched to see who got asthma over the subsequent 11 years. The researchers  found that cod liver oil intake was indeed significantly associated with the development of asthma. They thought it might be the excessive vitamin A in the cod liver oil that was causing the problem, but there are also a number of substances in fish oil we may not want our children exposed to.

Researchers from Philadelphia University, highlighted in my video PCBs in Children’s Fish Oil Supplements, recently looked at 13 over-the-counter children’s dietary supplements containing fish oil to assess potential exposure to PCBs, toxic industrial pollutants that have contaminated our oceans. PCBs were detected in all products. Could we just stick to the supplements made from small, short-lived fish like anchovies instead of big predator fish like tuna to reduce the impact of biomagnification? Or use purified fish oils?  No, the researchers found no significant difference in PCB levels whether the supplements were labeled as molecularly distilled or how high up the food chain the fish were.

The researchers concluded that while children’s dietary supplements containing the long-chain omega-3’s from fish oils may claim to benefit young consumers, “daily ingestion of these products may provide a vector for contaminant exposure that may off-set the positive health effects.” What positive health benefits are they talking about?

Researchers publishing in the journal, Early Human Development, found that infants given DHA-fortified formula may have better development of their eyes and brains compared to infants getting non DHA-fortified formula. What was the source of the DHA? Not fish, but algae-derived DHA. In that way we can get the benefits of omega 3’s without the contaminant risks. But of course, breast milk is the gold standard, significantly better than either of the formula fed infants. So the best source of omega-3’s is mom.

It’s bad enough when supplement manufacturers exploit adults when they’re sick and vulnerable with pills that are often useless or worse, but taking advantage of our parental drive to do what’s best for our children with contaminated products that may make them sick, makes me sick.

More on supplements in:

And speaking of which, Is Fish Oil Just Snake Oil?

Also check out these videos on fish oil and DHA: Omega-3’s and the Eskimo Fish Tale and Should We Take EPA and DHA Omega-3 For Our Heart?

What about omega 3’s for our child’s growing brain? See my video Mercury vs. Omega-3s for Brain Development

We can also be exposed to PCBs in food. See Food Sources of PCB Chemical Pollutants.

More on the polluted aquatic food chain in:

What can we do to lower the risk of childhood asthma and other allergic-type diseases? See:

In health,
Michael Greger, M.D.

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

Image Credit: Lars Plougmann / Flickr

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No More Than a Quart a Day of Hibiscus Tea http://nutritionfacts.org/2016/05/19/no-more-than-a-quart-a-day-of-hibiscus-tea/?utm_source=rss&utm_medium=rss&utm_campaign=no-more-than-a-quart-a-day-of-hibiscus-tea http://nutritionfacts.org/2016/05/19/no-more-than-a-quart-a-day-of-hibiscus-tea/#comments Thu, 19 May 2016 12:00:37 +0000 http://nutritionfacts.org/?p=29890 Over the counter antacids are probably the most important source for human aluminum exposure in terms of dose. For example, Maalox, taken as directed, can exceed the daily safety limit more than 100-fold, and nowhere on the label does it say to not take it with acidic beverages such as fruit juice. Washing an antacid […]]]>

Over the counter antacids are probably the most important source for human aluminum exposure in terms of dose. For example, Maalox, taken as directed, can exceed the daily safety limit more than 100-fold, and nowhere on the label does it say to not take it with acidic beverages such as fruit juice. Washing an antacid down with orange juice can increase aluminum absorption 8-fold, and citric acid–the acid found naturally concentrated in lemon and limes—is even worse.

Just as sour fruits can enhance the absorption of iron (a good thing), the same mechanism they may enhance the absorption of aluminum (a bad thing). This raises the question of what happens when one adds lemon juice to tea? Previously, I concluded that the amount of aluminum in tea is not a problem for most people because it’s not very absorbable (See Is There Too Much Aluminum in Tea?). What if we add lemon? Researchers publishing in the journal Food and Chemical Toxicology found no difference between tea with lemon, tea without lemon, or no tea at all in terms of the amount of aluminum in the bloodstream, suggesting that tea drinking does not significantly contribute to aluminum getting inside the body.

The researchers used black tea, green tea, white tea, oolong tea, but what about the “red zinger” herbal tea, hibiscus? The reason hibiscus tea is called “sour tea” is because it has natural acids in it like citric acid. Might these acids boost the absorption of any hibiscus’s aluminum? While a greater percentage of aluminum gets from the hibiscus into the tea water than from the other teas, there’s less aluminum overall.

The real question is whether the aluminum then gets from the tea water into our bodies. We don’t have that data, so to be on the safe side we should assume the worst: that hibiscus tea aluminum, unlike green and black tea aluminum, is completely absorbable. In that case, based on this data and the World Health Organization weekly safety limit, we may not want to drink more than 15 cups of hibiscus tea a day, (based on someone who’s about 150 pounds). If you have a 75 pound 10-year-old, a half-gallon a day may theoretically be too much. Recent, more extensive testing highlighted in my video, How Much Hibiscus Tea is Too Much?, suggests that levels may reach level twice as high.  Therefore, to be safe, no more than about two quarts a day for adults, or one quart a day for kids or pregnant women. Hibiscus tea should be completely avoided by infants under six months—who should only be getting breast milk—as well as kids with kidney failure, who can’t efficiently excrete it.

There is also a concern about the impressive manganese level in hibiscus tea. Manganese is an essential trace mineral, a vital component of some of our most important antioxidant enzymes, but we probably only need about two to five milligrams a day. Four cups of hibiscus tea can have as much as 17 milligrams, with an average of about ten. Is that a problem?

One study from the University of Wisconsin found that women given 15 milligrams of manganese a day for four months, saw, if anything, an improvement in their anti-inflammatory, anti-oxidant enzyme activity. Another study using 20 milligrams a day similarly showed no adverse short-term effects, and importantly showed that the retention of dietary manganese is regulated. Our bodies aren’t stupid; if we take in too much manganese, we decrease the absorption and increases the excretion. Even though tea drinkers may get ten times the manganese load (10 or 20 milligrams a day) the levels in their blood are essentially identical. There is little evidence that dietary manganese poses a risk.

These studies were conducted with regular tea, though, so we don’t know about the absorption from hibiscus. To err on the side of caution we should probably not routinely exceed the reference dose of ten milligrams per day, or about a quart a day for adults and a half-quart for a 75 pound child.

I’ve actually changed my consumption. Given the benefits of the stuff, I was using it as a substitute for drinking water, drinking around two quarts a day. I was also blending the hibiscus petals in, not throwing them away, effectively doubling the aluminum content, and increasing manganese concentrations by about 30%. So given this data I’ve cut back to no more than a quart of filtered hibiscus tea a day.

Lemon can actually boost the antioxidant content of green and white tea. See Green Tea vs. White. For a comparison of their cancer-fighting effects in vitro, Antimutagenic Activity of Green Versus White Tea.

Before that I covered another potential downside of sour tea consumption in Protecting Teeth From Hibiscus Tea, and before that a reason we should all consider drinking it in: Hibiscus Tea vs. Plant-Based Diets for Hypertension.

For more on the iron absorption effect, see my video Risks Associated with Iron Supplements.

In health,
Michael Greger, M.D.

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

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Aluminum Levels in Tea http://nutritionfacts.org/2016/05/17/aluminum-levels-in-tea/?utm_source=rss&utm_medium=rss&utm_campaign=aluminum-levels-in-tea http://nutritionfacts.org/2016/05/17/aluminum-levels-in-tea/#comments Tue, 17 May 2016 12:00:53 +0000 http://nutritionfacts.org/?p=29874 While aluminum is the third most abundant element on Earth, it may not be good for our brain, something we learned studying foundry workers exposed to particularly high levels. Although the role of aluminum in the development of brain diseases like Alzheimer’s is controversial, to be prudent, steps should probably be taken to lessen our […]]]>

While aluminum is the third most abundant element on Earth, it may not be good for our brain, something we learned studying foundry workers exposed to particularly high levels. Although the role of aluminum in the development of brain diseases like Alzheimer’s is controversial, to be prudent, steps should probably be taken to lessen our exposure to this metal.

There are a number of aluminum-containing drugs on the market (like antacids, which have the highest levels), though aluminum compounds are also added to processed foods such as anti-caking agents in pancake mix, melting agents in American cheese, meat binders, gravy thickeners, rising agents in some baking powders and dye-binders in candy. Therefore, it’s better to stick to unprocessed, natural foods. Also, if you cook those natural foods in an aluminum pot, a significant amount of aluminum can leach into the food (compared to cooking in stainless steel).

When researchers tried the same experiment with tea, they got a few milligrams of aluminum regardless of what type of pot they used, suggesting that aluminum was in the tea itself. Indeed, back in the 1950’s, researchers noticed that tea plants tended to suck up aluminum from the soil. But it’s the dose that makes the poison. According to the World Health Organization, the provisional tolerable weekly intake—our best guess at a safety limit for aluminum—is two mg per healthy kilogram of body weight per week, which is nearly a milligram per pound. Someone who weighs around 150 pounds probably shouldn’t ingest more than around 20 mg of aluminum per day.

Up to a fifth of aluminum intake may come from beverages; so, what we drink probably shouldn’t contribute more than about four mg a day, the amount found in about five cups of green, black, or oolong tea. So, should we not drink more than five cups of tea a day?

It’s not what you eat or drink, it’s what you absorb. If we just measured how much aluminum was in tea, it would seem as though a couple cups could double aluminum intake for the day. But if we measure the level of aluminum in people’s bodies after they drink tea, it doesn’t go up. This suggests that the bioavailability of aluminum in tea is low, possibly because most of the extractable aluminum in brewed tea is strongly bound to large phytonutrients that are not easily absorbed; so, the aluminum just passes right through us without actually getting into our bodies. Probably more than 90 percent of the aluminum in tea is bound up.

One study out of Singapore, highlighted in my video, Is There Too Much Aluminum in Tea?, did show a large spike in aluminum excretion through the urine after drinking tea compared to water. The only way for something to get from our mouth to our bladder is to first be absorbed into our bloodstream. But the researchers weren’t comparing the same quantity of tea to water. They had the study subject chug down about eight and a half cups of tea, or drink water at their leisure. Therefore, the tea drinkers peed a lot more; so, the aluminum content cup-for-cup was no different for tea versus water. This suggests that gross aluminum absorption from tea is unlikely and that only a little aluminum is potentially available for absorption.

So, although as few as four cups of tea could provide 100 percent of our daily aluminum limit, the percentage available for absorption in the intestine may be less than 10 percent. It is, therefore, unlikely that moderate amounts of tea drinking can have any harmful effects—for people with normal aluminum excretion. Tea may not, however, be a good beverage for children with kidney failure, since they can’t get rid of aluminum as efficiently. For most people, though, tea shouldn’t be a problem.

On a special note, if you drink tea out of a can, buy undented cans. The aluminum in dented cans can leach into the liquid, boosting aluminum levels by a factor of eight while sitting on store shelves for a year.

What about the levels and absorbability of the aluminum in my other favorite type of tea? Find out in my video, How Much Hibiscus Tea is Too Much?

The tea plant also sucks up fluoride. So much so that heavy tea drinking can stain the teeth of children. See my video Childhood Tea Drinking May Increase Fluorosis Risk.

Why should we go out of our way to drink tea? See:

Is Caffeinated Tea Dehydrating? Find out by watching the video!

For more on metals in our food supply, see:

In health,
Michael Greger, M.D.

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

Image Credit: Toshiyuki IMAI / Flickr

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Rinse Your Mouth After Sour Foods and Drinks http://nutritionfacts.org/2016/05/12/rinse-your-mouth-after-sour-foods-and-drinks/?utm_source=rss&utm_medium=rss&utm_campaign=rinse-your-mouth-after-sour-foods-and-drinks http://nutritionfacts.org/2016/05/12/rinse-your-mouth-after-sour-foods-and-drinks/#comments Thu, 12 May 2016 12:00:44 +0000 http://nutritionfacts.org/?p=29871 Hibiscus tea has been found to be as effective at lowering blood pressure as a leading hypertension drug without the potential side-effects (which include everything from lack of strength to impotence, including rare cases of potentially fatal liver damage). Hibiscus, though, may have adverse effects of its own. As I’ve reviewed previously in Plant-Based Diets: […]]]>

Hibiscus tea has been found to be as effective at lowering blood pressure as a leading hypertension drug without the potential side-effects (which include everything from lack of strength to impotence, including rare cases of potentially fatal liver damage). Hibiscus, though, may have adverse effects of its own.

As I’ve reviewed previously in Plant-Based Diets: Oral Health, people who eat plant-based diets appear to have superior periodontal health, including less gum disease and fewer signs of inflammation, like bleeding. However, they also have twice the prevalence of dental erosions, areas on the teeth where the enamel has thinned due to more frequent consumption of acidic fruits and vegetables. Therefore, after we eat something like citrus, we should swish our mouths with water to clear the acid from our teeth.

This includes beverages. I’m a big fan of hibiscus tea, but it’s not called “sour tea” for nothing. In a study highlighted in my video, Protecting Teeth from Hibiscus Tea, researchers at the University of Iowa dental school tested 25 different popular teas and found two with a pH under 3 (as acidic as orange juice or coca cola): Tazo’s passion and Bigelow’s red raspberry, both of which contain hibiscus as their first ingredient.

To see if these teas could actually dissolve teeth, the researchers took 30 extracted molars from people and soaked them in different teas. And indeed, out of the five teas tested, the greatest erosion came from the tea with the most hibiscus. The researchers left the tooth sitting in the tea for 25 hours straight, but this was to simulate a lifetime of exposure. The bottom line is that herbal teas are potentially erosive, particularly fruity and citrusy teas like hibiscus. To minimize the erosive potential, we can use a straw to drink the beverage. And as I mentioned above, after consuming an acidic food or drink we should also rinse our mouth with water to help neutralize the acid.

For more on the effects of hibiscus on blood pressure, see the previous video, Hibiscus Tea vs. Plant-Based Diets for Hypertension.

Are there other potential downsides to tea drinking? That’s the topic of my videos: Is There Too Much Aluminum in Tea? and How Much Hibiscus Tea is Too Much?

For more on avoiding drug side-effects by choosing more natural treatments can be found in videos like:

For more on diet and oral health, see:

In health,
Michael Greger, M.D.

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

Image Credit: T.Kiya / Flickr

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Plant-Based Diets for Hypertension http://nutritionfacts.org/2016/05/10/plant-based-diets-for-hypertension/?utm_source=rss&utm_medium=rss&utm_campaign=plant-based-diets-for-hypertension http://nutritionfacts.org/2016/05/10/plant-based-diets-for-hypertension/#comments Tue, 10 May 2016 12:00:43 +0000 http://nutritionfacts.org/?p=29869 Recently, researchers from Taiwan pitted the herbal tea hibiscus against obesity. They gave hibiscus to overweight individuals and reported that subjects showed reduced body weight. However, after 12 weeks on hibiscus, subjects only lost about three pounds, only one and a half pounds over placebo. Hibiscus is clearly no magic fix for obesity. The purported cholesterol-lowering […]]]>

Recently, researchers from Taiwan pitted the herbal tea hibiscus against obesity. They gave hibiscus to overweight individuals and reported that subjects showed reduced body weight. However, after 12 weeks on hibiscus, subjects only lost about three pounds, only one and a half pounds over placebo. Hibiscus is clearly no magic fix for obesity.

The purported cholesterol-lowering property of hibiscus tea looked a bit more promising. Some older studies suggested as much as an 8% reduction from drinking two cups a day for a month. When all the studies are put together, though, the results are pretty much a wash. This may be because only about 50% of people respond at all to drinking the equivalent of between two to five cups a day, though those that do may get a respectable 12% drop. That’s nothing like the 30% one can get within weeks of eating a healthy, plant-based diet, though.

Hibiscus may really shine in treating high blood pressure, a disease affecting a billion people and killing millions. Up until 2010, there wasn’t sufficient high quality research to support the use of hibiscus tea to treat hypertension, but there are now randomized double-blind, placebo-controlled studies where hibiscus tea is compared to artificially colored and flavored water that looks and tastes like hibiscus tea, and the tea lowers blood pressure significantly better.

We’re still not sure how it works, but hibiscus appears to boost nitric oxide production, which could help our arteries relax and dilate better. Regardless, an updated review acknowledged that the daily consumption of hibiscus tea may indeed significantly lower blood pressures in people with hypertension.

How does hibiscus compare to other blood pressure interventions? The premier clinical trial when it comes to comprehensive lifestyle modification for blood pressure control is the PREMIER Clinical Trial. Realizing that nine out of ten Americans are going to develop hypertension, researchers from John Hopkins randomized 800 men and women with high blood pressure into one of three groups. One was the control group, the so-called “advice only group,” where patients were just told to lose weight, cut down on salt, increase exercise and eat healthier. In the two behavioral intervention groups, the researchers got serious. Eighteen face-to-face sessions, group meetings, food diaries, physical activity records, and calorie and sodium intake monitoring. One intervention group just concentrated on exercise; the other included exercise and diet. Researchers pushed the DASH diet, which is high in fruits and vegetables and low in full-fat dairy products and meat. In six months, subjects achieved a 4.3 point drop in systolic blood pressure, compared to the control, slightly better than the lifestyle intervention without the diet.

A few points might not sound like a lot—that’s like someone going from a blood pressure of 150 over 90 to a blood pressure of 146 over 90—but on a population scale, a five point drop in the total number could result in 14% fewer stroke deaths, 9% fewer fatal heart attacks, and 7% fewer deaths every year overall.

A cup of hibiscus tea with each meal didn’t just lower blood pressure by three, four, or five points, but by seven points, from an average of 129 down to 122. In fact, tested head-to-head against a leading blood-pressure drug, Captopril, two cups of strong hibiscus tea every morning (five tea bags for the two cups) was as effective in lowering blood pressure as a starting dose of 25mg of captopril taken twice a day.

So, hibiscus tea is as good as drugs, without side-effects, and better than diet and exercise? Well, the lifestyle interventions in the PREMIER study were pretty wimpy. As public health experts noted, the PREMIER study was only asking for 30 minutes of exercise a day, whereas the World Health Organization recommends a minimum of an hour a day.

Diet-wise, the lower the animal fat intake, and the more plant sources of protein the PREMIER participants were eating, the better the diet appeared to work. This may explain why vegetarian diets appear to work even better, and the more plant-based, the lower the prevalence of hypertension.

On the DASH diet, subjects cut down on meat, but were still eating it every day, so would qualify as nonvegetarians in the Adventist 2 study (highlighted in my video Hibiscus Tea vs. Plant-Based Diets for Hypertension) which looked at 89,000 Californians. It found that those who only ate meat on a weekly basis had 23% lower rates of high blood pressure. Those who cut out all meat except fish had 38% lower rates. Those eating no meat at all, vegetarians, have less than half the rate. The vegans—cutting out all animal protein and fat—appeared to have thrown three quarters of their risk for this major killer out the window.

One sees the same kind of step-wise drop in diabetes rates as one’s diet gets more and more plant-based, and a drop in excess body weight, such that only those eating completely plant-based diets in the Adventist 2 study fell into the ideal weight category. Could that be why those eating plant-based have such great blood pressure? Maybe it’s just because they’re so skinny. I’ve previously shown how those eating plant-based just have a fraction of the diabetes risk even at the same weight, but what about hypertension?

The average American has what’s called prehypertension, which means the top number of our blood pressure is between 120 and 139. We don’t have hypertension yet, which starts at 140, but we may be well on our way. Compare that to the blood pressure of those eating whole food plant-based diets. In one study, those eating plant-based didn’t have blood pressures three points lower, four points lower, or even seen points lower, but 28 points lower. However, the group eating the standard American diet was, on average, overweight with a BMI over 26, still better than most Americans, while the vegans were a trim 21—that’s 36 pounds lighter.

Maybe the only reason those eating meat, eggs, dairy, and processed junk had such higher blood pressure was because they were overweight. Maybe the diet per se had nothing to do with it?

To solve that riddle we would have to find a group still eating the standard American diet, but as slim as vegans. To find a group that trim, researchers had to use long-distance endurance athletes, who ate the same crappy American diet, but ran an average of 48 miles per week for 21 years. Anyone who runs almost two marathons a week for 20 years can be as slim as a vegan—no matter what they eat!

How did the endurance runners compare to the couch potato vegans? It appears that if we run an average of about a thousand miles every year, our blood pressures can rival some couch potato vegans. That doesn’t mean we can’t do both, but it may be easier to just eat plants.


Those who’ve been following my work for years have seen how my videos have evolved. In the past, the hibiscus results may have been the whole article or video. But thanks to everyone’s support, I’ve been able to delegate the logistics to staff and concentrate more on the content creation. This allows me to do deeper dives into the literature to put new findings into better context. The posts are a bit longer, but hopefully they’re more useful—let me know what you think!

For such a leading killer, hypertension has not gotten the coverage it deserves on NutritionFacts.org. Here’s a few videos, with more to come:

So, should we all be drinking hibiscus tea every day?  This is the first of a four part series on the latest on hibiscus. Stay tuned for the next three:

For another comparison of those running marathons and those eating plants, see: Arteries of Vegans vs. Runners

In health,
Michael Greger, M.D.

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

Image Credit: Amy / Flickr

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How to Treat Prediabetes with Diet http://nutritionfacts.org/2016/05/05/how-to-treat-prediabetes-with-diet/?utm_source=rss&utm_medium=rss&utm_campaign=how-to-treat-prediabetes-with-diet http://nutritionfacts.org/2016/05/05/how-to-treat-prediabetes-with-diet/#comments Thu, 05 May 2016 12:00:39 +0000 http://nutritionfacts.org/?p=29867 For people with prediabetes, lifestyle modification is considered “the cornerstone of diabetes prevention.” Diet-wise, this means individuals with prediabetes or diabetes should aim to reduce their intake of excess calories, saturated fat, and trans fat. Too many of us consume a diet with too many solid fats and added sugars. Thankfully the latest dietary guidelines […]]]>

For people with prediabetes, lifestyle modification is considered “the cornerstone of diabetes prevention.” Diet-wise, this means individuals with prediabetes or diabetes should aim to reduce their intake of excess calories, saturated fat, and trans fat. Too many of us consume a diet with too many solid fats and added sugars. Thankfully the latest dietary guidelines aim to shift consumption towards more plant-based foods.

Lifestyle modification is now the foundation of the American Association of Clinical Endocrinology guidelines, the European Diabetes Association guidelines, and the official standards of care for the American Diabetes Association. Dietary strategies include reducing intake of fat and increasing intake of fiber (meaning unrefined plant foods, including whole grains).

The recommendation to consume more whole grains is based on research showing that eating lots of whole grains is associated with reduced risk of developing type 2 diabetes. New research even suggests that whole grains may protect against prediabetes in the first place.

According to the American Diabetes Association’s official standards of care (which you can see in my video Lifestyle Medicine Is the Standard of Care for Prediabetes), dietary recommendations should focus on reducing saturated fat, cholesterol and trans fat intake (meat, dairy, eggs and junk food). Recommendations should also focus on increasing omega 3’s, soluble fiber and phytosterols, all three of which can be found together in flax seeds; an efficient, but still uncommon, intervention for prediabetes. In one study, about two tablespoons of ground flax seed a day decreased insulin resistance (the hallmark of the disease).

If the standards of care for all the major diabetes groups say that lifestyle is the preferred treatment for prediabetes because it’s safe and highly effective, why don’t more doctors do it? Unfortunately, the opportunity to treat this disease naturally is often unrecognized. Only about one in three patients report ever being told about diet or exercise. Possible reasons for not counseling patients include lack of reimbursement, lack of resources, lack of time, and lack of skill.

It may be because doctors aren’t getting paid to do it. Why haven’t reimbursement policies been modified? One crucial reason may be a failure of leadership in the medical profession and medical education to recognize and respond to the changing nature of disease patterns.

“The inadequacy of clinical education is a consequence of the failure of health care and medical education to adapt to the great transformation of disease from acute to chronic. Chronic disease is now the principal cause of disability, consuming three quarters of our sickness-care system. Why has there been little academic response to the rising prevalence of chronic disease?”

How far behind the times is the medical profession? A report by the Institute of Medicine on medical training concluded that the fundamental approach to medical education “has not changed since 1910.”


 

I hope my work is helping to fill the gap that medical professionals are not getting during training about preventing and treating chronic disease. That’s actually how this all started. I would make trips to Countway at the beginning of every month in medical school to read all the new journal issues. I felt I had a duty to my patients to stay on top of the literature. But hey, since I’m doing so much work, might as well share it! So what started as an email newsletter morphed into a medical school speaking tour into a DVD series and then now all online for everyone.

For more on preventing and treating prediabetes/diabetes, see:

For more on lifestyle medicine:

And for insight into the sad state of nutrition in medical training, Doctors Know Less Than They Think About Nutrition and Medical School Nutrition Training.

In health,
Michael Greger, M.D.

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

Image Credit: Alden Chadwick / Flickr

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Are Sprouted Lentils Healthier Than Canned Lentils? http://nutritionfacts.org/2016/05/03/sprouted-lentils-healthier-canned-lentils/?utm_source=rss&utm_medium=rss&utm_campaign=sprouted-lentils-healthier-canned-lentils http://nutritionfacts.org/2016/05/03/sprouted-lentils-healthier-canned-lentils/#comments Tue, 03 May 2016 12:00:04 +0000 http://nutritionfacts.org/?p=29774 Beans, chickpeas, split peas and lentils are packed with nutrients and play a role in the prevention of chronic disease, but most can’t be eaten raw. Some can be sprouted, though. Boiling is the most common cooking method, which is used for canned beans. Which is healthier, though, cooked or sprouted? The easiest way to […]]]>

Beans, chickpeas, split peas and lentils are packed with nutrients and play a role in the prevention of chronic disease, but most can’t be eaten raw. Some can be sprouted, though. Boiling is the most common cooking method, which is used for canned beans. Which is healthier, though, cooked or sprouted?

The easiest way to compare healthfulness is to measure nutrient levels—such as the anthocyanin pigments that make kidney beans so pretty—thought to account for some of beans’ protective benefits against chronic disease. Sprouted beans have more of some anthocyanins, but less than others. We find this same pattern across the board with the other phenolic phytonutrients: sprouted beans have more of some, less of others. Because the positive effects of these compounds may be related to their antioxidant capacity, we can compare the overall antioxidant power of boiled versus sprouted beans. In that case, boiled appears to have a marginal edge.

Ideally, though, rather than merely comparing concentrations of phytochemicals, we’d measure physiological effects. For example, we might look at the effect of boiled versus sprouted beans against cancer cell growth. That’s exactly what researchers did. In my video Cooked Beans or Sprouted Beans?, you can see the concentrations of bean extract needed to cut the breast cancer growth rate in half in a petri dish. Boiled beans do about 40 times better than raw beans—the same cancer growth inhibition at just a fraction of the concentration. Sprouted beans do about the same.

We can’t eat most beans raw, but I wanted to include them to show you a fascinating phenomenon. No amount of raw bean extract appears to totally stop the growth of breast cancer cells, but just small amounts of cooked or sprouted beans can. We find the same thing with killing off cancer. No amount of raw bean extract can fully kill off breast cancer cells, but both boiled and sprouted beans can.

Similar results were found for melanoma cells, a type of malignant skin cancer. Processing the beans—either cooking or sprouting—boosted anticancer activity in vitro. However, against kidney cancer, raw and boiled worked, but sprouted didn’t at all.

There has also been interest in brain protection. Given that elderly persons who report always eating legumes may be significantly less likely to experience cognitive decline, a group of Chinese researchers decided to compare the protective effects of boiled versus sprouted beans on astrocytes.

Astrocytes are the most abundant type of cell in our brain. They are star-shaped cells that keep our brain running smoothly. Should they become damaged, though, they may play an important role in the development of neurodegenerative disorders such as Lou Gehrig’s disease, Alzheimer’s, or Parkinson’s. So if we’re thinking clearly, we should thank our lucky stars.

To see if beans help protect astrocytes from damage, we’d have to first make sure bean extracts wouldn’t cause any damage. Cooked beans don’t seem to hurt cells at all, and sprouted beans seem to even help them grow a little. If we add an oxidative chemical to the cells, we can kill off about a quarter of them. However, if we add that chemical along with some boiled bean extract, the astrocytes were partially protected at higher doses. Sprouted bean extract didn’t appear to offer significant benefit.

What’s the takeaway? As far as I’m concerned, we should eat beans in whichever way will get us to eat the most of them.

I do love my lentil sprouts, one of the healthiest snacks on the planet (along with kale chips). I can grow my own in just 2 to 3 days. But using canned beans I can get similar nutrition in about 2 to 3 seconds.

Sprouting is so much fun, though! I’ve got a bunch of videos on broccoli sprouts, for example: Biggest Nutrition Bang for Your Buck.

But again, whichever way we like them we should eat them. Why? See:

Mostly I just used canned. See Canned Beans or Cooked Beans?

Other videos on practical prep tips include:

In health,
Michael Greger, M.D.

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

Image Credit: Veganbaking.net / Flickr

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Egg Consumption and LDL Cholesterol Size http://nutritionfacts.org/2016/04/28/egg-consumption-and-ldl-cholesterol-size/?utm_source=rss&utm_medium=rss&utm_campaign=egg-consumption-and-ldl-cholesterol-size http://nutritionfacts.org/2016/04/28/egg-consumption-and-ldl-cholesterol-size/#comments Thu, 28 Apr 2016 12:00:38 +0000 http://nutritionfacts.org/?p=29772 Maria Fernandez has received nearly a half million dollars from the egg industry and writes papers like “Rethinking dietary cholesterol.” She admits that eggs can raise LDL cholesterol, bad cholesterol, but argues that HDL, so-called “good cholesterol,” also rises, thereby maintaining the ratio of bad to good. To support this assertion, she cites one study […]]]>

Maria Fernandez has received nearly a half million dollars from the egg industry and writes papers like “Rethinking dietary cholesterol.” She admits that eggs can raise LDL cholesterol, bad cholesterol, but argues that HDL, so-called “good cholesterol,” also rises, thereby maintaining the ratio of bad to good. To support this assertion, she cites one study that she performed with Egg Board money that involved 42 people.

If we look at a meta-analysis, a measure of the balance of evidence, the rise in bad is much more than the rise in good with increasing cholesterol intake. The analysis of 17 different studies showed that dietary cholesterol increases the ratio of total to HDL cholesterol, suggesting that the favorable rise in HDL fails to compensate for the adverse rise in total and LDL cholesterol. Therefore, increased intake of dietary cholesterol from eggs may indeed raise the risk of coronary heart disease.

The Egg Board responded (as seen in my video, Does Cholesterol Size Matter?) by saying that the increased heart disease risk associated with eating eggs needs to be put in perspective relative to other risk factors, arguing that it’s worse to be overweight than it is to eat eggs, to which the authors of the meta-analysis replied, “Be that as it may, many people do not find it a major hardship to cut back on egg intake, whereas most people find it impossible to lose weight permanently.”

Fine, Fernandez admitted, eggs increase LDL, but she claims that the increase is in large LDL, arguing that large, fluffy LDL particles are not as bad as small, dense particles. Indeed, large LDL only raises heart disease risk of women by 44%, instead of 63% for small LDL. Light large buoyant LDL still significantly increases our risk of dying from our #1 killer. The difference is similar for men: large LDL only increases risk of heart attack or death by 31%, instead of 44%. As the latest review on the subject concluded, LDL cholesterol has “clearly been established as a causal agent in atherosclerosis … Regardless of size, LDL particles are atherogenic.” Yet Egg Board researcher, Fernandez, wrote that the formation of larger LDL from eggs is considered protective against heart disease, relative to small LDL. That’s like saying getting stabbed with a knife is protective–relative to getting shot!

Health practitioners should bear in mind, she writes, that “restricting dietary cholesterol puts a burden on egg intake” and leads to the avoidance of a food that contains dietary components like carotenoids and choline. She wrote this in 2012, before the landmark 2013 study showing that choline from eggs appears to increase the risk of stroke, heart attack, and death, so she can be excused for that. But what about the carotenoids in eggs, like lutein and zeaxanthin, which are so important for protecting vision and reducing cholesterol oxidation? As I explored previously, the amounts of these phytonutrients in eggs are miniscule. One spoonful of spinach contains as much as nine eggs. Comparing the predictable effects on eye health of organic free-range eggs versus corn and spinach, the effect of eggs is tiny.

What about the effects of eggs on cholesterol oxidation? We’ve known for decades that LDL cholesterol is bad, but oxidized LDL is even worse. Therefore, according to Fernandez, since eggs have trace amounts of antioxidants, eggs may prevent cholesterol oxidation. But the science shows the exact opposite. Consumption of eggs increases the susceptibility of LDL cholesterol to oxidation. The researchers found that not only does eating eggs raise LDL levels, but also increases LDL oxidizability, in addition to the oxidizability of our entire bloodstream. This was published 18 years ago, yet Fernandez still tries to insinuate that eggs would reduce oxidation.

She acknowledges receiving funding from the American Egg Board, and then claims she has no conflicts of interest.

This is why a site like NutritionFacts.org can be so useful, because even when a paper is published in the peer-reviewed medical literature, it can misrepresent the science. But who has time to check the primary sources? I do! If you’d like to support this work, please consider making a tax-deductible donation.

Here are some other videos in which I contrast the available science with what the egg industry asserts:

Only the meat industry may be as bold: BOLD Indeed: Beef Lowers Cholesterol?

For more on the role of cholesterol, see:

In health,
Michael Greger, M.D.

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

Image Credit: Kool skatkat / Flickr

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How to Protect Our Telomeres with Diet http://nutritionfacts.org/2016/04/26/how-to-protect-our-telomeres-with-diet/?utm_source=rss&utm_medium=rss&utm_campaign=how-to-protect-our-telomeres-with-diet http://nutritionfacts.org/2016/04/26/how-to-protect-our-telomeres-with-diet/#comments Tue, 26 Apr 2016 12:00:33 +0000 http://nutritionfacts.org/?p=29770 In my video, Does Meditation Affect Cellular Aging?, I discussed how stress reduction through meditation might be able to lengthen telomeres, the protective caps at the tips of our chromosomes that tend to deplete as we age. What about exercise? We can’t always change our situation in life, but we can always go out for […]]]>

In my video, Does Meditation Affect Cellular Aging?, I discussed how stress reduction through meditation might be able to lengthen telomeres, the protective caps at the tips of our chromosomes that tend to deplete as we age.

What about exercise? We can’t always change our situation in life, but we can always go out for a walk. London researchers studied 2,400 twins, and those who exercised more may have pumped up their telomeres along with their muscles. Apparently it doesn’t take much either. The “heavy” exercise group was only averaging about a half-hour a day.

These were mostly folks in their 40’s, but does it still work in your 50’s? Yes. A study out of South Korea found that people in their 50’s who work out three hours a week had longer telomeres.

In my video, Telomeres: Cap It All Off with Diet, you can see the telomere lengths of young healthy regular folk controls at around age 20, and then at age 50. As we’d expect, the older subjects’ telomeres were significantly shorter. What about athletes? The young athletes started out in the same boat, with nice, long, young, healthy telomeres capping all their chromosomes. The older athletes, in contrast to the controls, appeared to still have the chromosomes of 20-year-olds. But these were marathon runners, triathletes running 50 miles a week for 35 years.

What was it about the Ornish intervention that so powerfully protected telomeres after just three months? We saw that stress management seems to help, but what about diet and exercise? Was it the plant-based diet, was it the walking 30 minutes a day, or was it just because of the weight loss? In 2013, a study was published that can help us answer just that question.

The researchers took about 400 women and randomized them into four groups: a portion-controlled diet group, an exercise group, a portion controlled diet and exercise group, and a control group for a full year. In the video, you can see a comparison of the length of each group’s telomeres. After a year of doing nothing, there was essentially no change in the control group, which is what we’d expect. The exercise group was 45 minutes of moderate-to-vigorous exercise like jogging. After a year of that, they did no better. What about just weight loss? Nothing. The same thing for exercise and weight loss, no significant change either.

So, as long as we’re eating the same diet, it doesn’t appear to matter how small our portions are, or how much weight we lose, or how hard we exercise. After a year, the subjects saw no benefit. On the other hand, the Ornish group on the plant-based diet, who lost the same amount of weight after just three months and exercised less than half as hard, saw significant telomere protection.

It wasn’t the weight loss or the exercise: it was the food.

What aspects of a plant-based diet make it so protective? Studies have associated more vegetables and fruit, and less butter, with longer telomeres. From the latest review, foods high in fiber and vitamins are strongly related to longer telomeres. However, the key may be avoiding saturated fat. Swapping just 1%  of saturated fat calories in our diet for anything else can add nearly a whole year of aging’s worth of length onto our telomeres.

Saturated fats like palmitic acid, the primary saturated fat in salmon, and found in meat, eggs, and dairy in general, can be toxic to cells. This has been demonstrated in heart cells, bone marrow cells, pancreatic cells, and brain cells. The toxic effects on cell death rates happen right around what you’d see in the blood stream of people who eat a lot of animal products. It may not be the saturated fat itself, however, as saturated fat may just be a marker for the increased oxidative stress and inflammation associated with those foods.

With this link to saturated fat, it’s no wonder that lifelong low cholesterol levels have been related to longer telomeres and a smaller proportion of short telomeres—in other words, markers of slower biological aging. In fact, there’s a rare congenital birth defect called progeria syndrome, where children age 8-10 times faster than normal. It seems associated with a particular inability to handle animal fats.

The good news is that “despite past accumulated injury leading to shorter telomere lengths, current healthy behaviors might help to decrease a person’s risk of some of the potential consequences like heart disease.” Eating more fruit and vegetables and less meat and having more support from friends and family attenuate the association between shorter telomeres and the ravages of aging.

To summarize: inflammation, oxidation, damage and dysfunction are constantly hacking away at our telomeres. At the same time, our antioxidant defenses, healthy diet, exercise and stress reduction are constantly rebuilding them.


 

I’ve asked this diet versus exercise question in a few other contexts. See:

Though dietary change appears more impactful, I’m a big fan of walking. See Longer Life Within Walking Distance and for my personal favorite exercise, Standing Up for Your Health.

For more on the role saturated fat may play in disease, see, for example, my videos Heart Disease Starts in Childhood and Treating Multiple Sclerosis with the Swank MS Diet.

In health,
Michael Greger, M.D.

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

Image Credit: AJC ajcann.wordpress.com / Flickr

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