Who Should Avoid Coffee?

Oct 19 Coffee copy.jpeg

Do coffee drinkers live longer than non-coffee drinkers? Is it "wake up and smell the coffee" or don't wake up at all? I discuss these questions in my video, Coffee and Mortality.

The largest study ever conducted on diet and health put that question to the test, examining the association between coffee drinking and subsequent mortality among hundreds of thousands of older men and women in the United States. Coffee drinkers won, though the effect was modest, a 10-15% lower risk of death for those drinking six or more cups a day. This was due specifically to lower risk of dying from heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections.

However, another study that amount of coffee was found to increase the death rate of younger people under age 55. It may be appropriate, then, to recommend that you avoid drinking more than four cups a day. But if you review all the studies, the bottom line is that coffee consumption is associated with no change or a small reduction in mortality starting around one or two cups a day, for both men and women. The risk of dying was 3% lower for each cup of coffee consumed daily, which provides reassurance for the concern that coffee drinking might adversely affect health, or at least longevity.

A recent population study found no link between coffee consumption and symptoms of GERD, reflux diseases such as heartburn and regurgitation. If you actually stick a tube down people's throats and measure pH, though, coffee induces significant acid reflux, whereas tea does not. Is this just because tea has less caffeine? No. If you reduce the caffeine content of the coffee down to that of tea, coffee still causes significantly more acid reflux. Decaf causes even less, so GERD patients might want to choose decaffeinated coffee or, even better, opt for tea.

Coffee intake is also associated with urinary incontinence, so a decrease in caffeine intake should be discussed with patients who have the condition. About two cups of coffee a day worth of caffeine may worsen urinary leakage.

A 2014 meta-analysis suggested that daily coffee consumption was associated with a slightly increased risk of bone fractures in women, but a decreased risk of fractures in men. However, no significant association was found between coffee consumption and the risk of hip fracture specifically. Tea consumption may actually protect against hip fracture, though it appears to have no apparent relationship with fracture risk in general.

Certain populations, in particular, may want to stay away from caffeine, including those with glaucoma or a family history of glaucoma, individuals with epilepsy, and, not surprisingly, people who have trouble sleeping. Even a single cup at night can cause a significant deterioration in sleep quality.

We used to think caffeine might increase the risk of an irregular heart rhythm called atrial fibrillation, but that was based on anecdotal case reports like one of a young woman who suffered atrial fibrillation after "chocolate intake abuse." These cases invariably involved the acute ingestion of very large quantities of caffeine. As a result, the notion that caffeine ingestion may trigger abnormal heart rhythms had become "common knowledge," and this assumption led to changes in medical practice.

We now have evidence that caffeine does not increase the risk of atrial fibrillation. Low-dose caffeine--defined as less than about five cups of coffee a day--may even have a protective effect. Tea consumption also appears to lower cardiovascular disease risk, especially when it comes to stroke. But given the proliferation of energy drinks that contain massive quantities of caffeine, one might temper any message that suggests that caffeine is beneficial. Indeed, 12 highly caffeinated energy drinks within a few hours could be lethal.


To learn more about various health aspects of coffee, see my videos Coffee and Cancer, What About the Caffeine?, Preventing Liver Cancer with Coffee?, and Coffee and Artery Function.

What else can we consume to live longer? Check out Nuts May Help Prevent Death, Increased Lifespan from Beans, Fruits and Longevity: How Many Minutes per Mouthful?, and Finger on the Pulse of Longevity.

And, for more on controlling acid reflux, see Diet and GERD Acid Reflux Heartburn and Diet and Hiatal Hernia.

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:

Original Link

Who Should Avoid Coffee?

Oct 19 Coffee copy.jpeg

Do coffee drinkers live longer than non-coffee drinkers? Is it "wake up and smell the coffee" or don't wake up at all? I discuss these questions in my video, Coffee and Mortality.

The largest study ever conducted on diet and health put that question to the test, examining the association between coffee drinking and subsequent mortality among hundreds of thousands of older men and women in the United States. Coffee drinkers won, though the effect was modest, a 10-15% lower risk of death for those drinking six or more cups a day. This was due specifically to lower risk of dying from heart disease, respiratory disease, stroke, injuries and accidents, diabetes, and infections.

However, another study that amount of coffee was found to increase the death rate of younger people under age 55. It may be appropriate, then, to recommend that you avoid drinking more than four cups a day. But if you review all the studies, the bottom line is that coffee consumption is associated with no change or a small reduction in mortality starting around one or two cups a day, for both men and women. The risk of dying was 3% lower for each cup of coffee consumed daily, which provides reassurance for the concern that coffee drinking might adversely affect health, or at least longevity.

A recent population study found no link between coffee consumption and symptoms of GERD, reflux diseases such as heartburn and regurgitation. If you actually stick a tube down people's throats and measure pH, though, coffee induces significant acid reflux, whereas tea does not. Is this just because tea has less caffeine? No. If you reduce the caffeine content of the coffee down to that of tea, coffee still causes significantly more acid reflux. Decaf causes even less, so GERD patients might want to choose decaffeinated coffee or, even better, opt for tea.

Coffee intake is also associated with urinary incontinence, so a decrease in caffeine intake should be discussed with patients who have the condition. About two cups of coffee a day worth of caffeine may worsen urinary leakage.

A 2014 meta-analysis suggested that daily coffee consumption was associated with a slightly increased risk of bone fractures in women, but a decreased risk of fractures in men. However, no significant association was found between coffee consumption and the risk of hip fracture specifically. Tea consumption may actually protect against hip fracture, though it appears to have no apparent relationship with fracture risk in general.

Certain populations, in particular, may want to stay away from caffeine, including those with glaucoma or a family history of glaucoma, individuals with epilepsy, and, not surprisingly, people who have trouble sleeping. Even a single cup at night can cause a significant deterioration in sleep quality.

We used to think caffeine might increase the risk of an irregular heart rhythm called atrial fibrillation, but that was based on anecdotal case reports like one of a young woman who suffered atrial fibrillation after "chocolate intake abuse." These cases invariably involved the acute ingestion of very large quantities of caffeine. As a result, the notion that caffeine ingestion may trigger abnormal heart rhythms had become "common knowledge," and this assumption led to changes in medical practice.

We now have evidence that caffeine does not increase the risk of atrial fibrillation. Low-dose caffeine--defined as less than about five cups of coffee a day--may even have a protective effect. Tea consumption also appears to lower cardiovascular disease risk, especially when it comes to stroke. But given the proliferation of energy drinks that contain massive quantities of caffeine, one might temper any message that suggests that caffeine is beneficial. Indeed, 12 highly caffeinated energy drinks within a few hours could be lethal.


To learn more about various health aspects of coffee, see my videos Coffee and Cancer, What About the Caffeine?, Preventing Liver Cancer with Coffee?, and Coffee and Artery Function.

What else can we consume to live longer? Check out Nuts May Help Prevent Death, Increased Lifespan from Beans, Fruits and Longevity: How Many Minutes per Mouthful?, and Finger on the Pulse of Longevity.

And, for more on controlling acid reflux, see Diet and GERD Acid Reflux Heartburn and Diet and Hiatal Hernia.

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:

Original Link

Chocolate is Finally Put to the Test

Oct 10 Chocolate copy.jpeg

Botanically speaking, seeds are small embryonic plants--the whole plant stuffed into a tiny seed and surrounded by an outer layer packed with vitamins, minerals, and phytochemicals to protect the seedling plant's DNA from free radicals. No wonder they're so healthy. By seeds, using the formal definition, we're talking all whole grains; grains are seeds--you plant them and they grow. Nuts are just dry fruits with one or two seeds. Legumes (beans, peas, and lentils) are seeds, too, as are cocoa and coffee beans. So, finding health-promoting effects in something like cocoa or coffee should not be all that surprising. There is substantial evidence that increased consumption of all these little plants is associated with lower risk of cardiovascular disease.

Of course, much of chocolate research is just on how to get consumers to eat more. While it didn't seem to matter what kind of music people were listening to when it came to the flavor intensity, pleasantness, or texture of a bell pepper, people liked chocolate more when listening to jazz than classical, rock, or hip hop. Why is this important? So food industries can "integrate specific musical stimuli" in order to maximize their profits. For example, purveyors may play jazz in the background to increase consumers' acceptance of their chocolates. Along these lines, another study demonstrated that people rated the oyster eaten "more pleasant in the presence of the 'sound of the sea' than in the presence of 'farmyard noises.'"

You'd think chocolate would just sell itself, given that it's considered the most commonly craved food in the world. The same degree of interest doesn't seem to exist as to whether or not Brussels sprouts might provide similar cardiovascular protection. So, it's understandable to hope chocolate provides health benefits. Meanwhile, despite their known benefits, Brussels sprouts don't get the love they deserve.

One of the potential downsides of chocolate is weight gain, which is the subject of my Does Chocolate Cause Weight Gain? video. Though cocoa hardly has any calories, chocolate is one of the most calorie-dense foods. For example: A hundred calories of chocolate is less than a quarter of a bar, compared to a hundred calories of strawberries, which is more than two cups..

A few years ago, a study funded by the National Confectioners Association--an organization that, among other things, runs the website voteforcandy.com--reported that Americans who eat chocolate weigh, on average, four pounds less than those who don't. But maybe chocolate-eaters exercise more or eat more fruits and vegetables. The researchers didn't control for any of that.

The findings of a more recent study published in the Archives of Internal Medicine were less easy to dismiss and there were no apparent ties to Big Chocolate. The researchers reported that out of a thousand men and women they studied in San Diego, those who frequently consumed chocolate had a lower BMI--actually weighed less--than those who ate chocolate less often. And this was even after adjusting for physical activity and diet quality. But, it was a cross-sectional study, meaning a snapshot in time, so you can't prove cause and effect. Maybe not eating chocolate leads to being fatter, or maybe being fatter leads to not eating chocolate. Maybe people who are overweight are trying to cut down on sweets. What we need is a study in which people are followed over time.

There was no such prospective study, until now. More than 10,000 people were followed for six years, and a chocolate habit was associated with long-term weight gain in a dose-response manner. This means the greatest weight gain over time was seen in those with the highest frequency of chocolate intake. It appears the reason the cross-sectional studies found the opposite is that subjects diagnosed with obesity-related illnesses tended to reduce their intake of things like chocolate in an attempt to improve their prognosis. This explains why heavier people may, on average, eat less chocolate.

To bolster this finding came the strongest type of evidence--an interventional trial--in which you split people up into two groups and change half their diets. Indeed, adding four squares of chocolate to peoples' daily diets does appear to add a few pounds.

So, what do we tell our patients? In 2013, researchers wrote in the American Family Physician journal that "because many cocoa products are high in sugar and saturated fat, family physicians should refrain from recommending cocoa...." That's a little patronizing, though. You can get the benefits of chocolate without any sugar or fat by adding cocoa powder to a smoothie, for example. Too often, doctors think patients can't handle the truth. Case in point: If your patients inquire, one medical journal editorial suggest, ask them what type of chocolate they prefer. If they respond with milk chocolate, then it is best to answer that it is not good for them. If the answer is dark chocolate, then you can lay out the evidence.


Even better than dark chocolate would be cocoa powder, which contains the phytonutrients without the saturated fat. I've happily (and deliciously) created other videos on cocoa and chocolate, so check out Update on Chocolate, Healthiest Chocolate Fix, A Treatment for Chronic Fatigue Syndrome, and Dark Chocolate and Artery Function.

Whether with Big Candy, Big Chocolate, or some other player, you always have to be careful about conflict of interest. For more information, watch my Food Industry Funded Research Bias video.

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:

Original Link

Chocolate is Finally Put to the Test

Oct 10 Chocolate copy.jpeg

Botanically speaking, seeds are small embryonic plants--the whole plant stuffed into a tiny seed and surrounded by an outer layer packed with vitamins, minerals, and phytochemicals to protect the seedling plant's DNA from free radicals. No wonder they're so healthy. By seeds, using the formal definition, we're talking all whole grains; grains are seeds--you plant them and they grow. Nuts are just dry fruits with one or two seeds. Legumes (beans, peas, and lentils) are seeds, too, as are cocoa and coffee beans. So, finding health-promoting effects in something like cocoa or coffee should not be all that surprising. There is substantial evidence that increased consumption of all these little plants is associated with lower risk of cardiovascular disease.

Of course, much of chocolate research is just on how to get consumers to eat more. While it didn't seem to matter what kind of music people were listening to when it came to the flavor intensity, pleasantness, or texture of a bell pepper, people liked chocolate more when listening to jazz than classical, rock, or hip hop. Why is this important? So food industries can "integrate specific musical stimuli" in order to maximize their profits. For example, purveyors may play jazz in the background to increase consumers' acceptance of their chocolates. Along these lines, another study demonstrated that people rated the oyster eaten "more pleasant in the presence of the 'sound of the sea' than in the presence of 'farmyard noises.'"

You'd think chocolate would just sell itself, given that it's considered the most commonly craved food in the world. The same degree of interest doesn't seem to exist as to whether or not Brussels sprouts might provide similar cardiovascular protection. So, it's understandable to hope chocolate provides health benefits. Meanwhile, despite their known benefits, Brussels sprouts don't get the love they deserve.

One of the potential downsides of chocolate is weight gain, which is the subject of my Does Chocolate Cause Weight Gain? video. Though cocoa hardly has any calories, chocolate is one of the most calorie-dense foods. For example: A hundred calories of chocolate is less than a quarter of a bar, compared to a hundred calories of strawberries, which is more than two cups..

A few years ago, a study funded by the National Confectioners Association--an organization that, among other things, runs the website voteforcandy.com--reported that Americans who eat chocolate weigh, on average, four pounds less than those who don't. But maybe chocolate-eaters exercise more or eat more fruits and vegetables. The researchers didn't control for any of that.

The findings of a more recent study published in the Archives of Internal Medicine were less easy to dismiss and there were no apparent ties to Big Chocolate. The researchers reported that out of a thousand men and women they studied in San Diego, those who frequently consumed chocolate had a lower BMI--actually weighed less--than those who ate chocolate less often. And this was even after adjusting for physical activity and diet quality. But, it was a cross-sectional study, meaning a snapshot in time, so you can't prove cause and effect. Maybe not eating chocolate leads to being fatter, or maybe being fatter leads to not eating chocolate. Maybe people who are overweight are trying to cut down on sweets. What we need is a study in which people are followed over time.

There was no such prospective study, until now. More than 10,000 people were followed for six years, and a chocolate habit was associated with long-term weight gain in a dose-response manner. This means the greatest weight gain over time was seen in those with the highest frequency of chocolate intake. It appears the reason the cross-sectional studies found the opposite is that subjects diagnosed with obesity-related illnesses tended to reduce their intake of things like chocolate in an attempt to improve their prognosis. This explains why heavier people may, on average, eat less chocolate.

To bolster this finding came the strongest type of evidence--an interventional trial--in which you split people up into two groups and change half their diets. Indeed, adding four squares of chocolate to peoples' daily diets does appear to add a few pounds.

So, what do we tell our patients? In 2013, researchers wrote in the American Family Physician journal that "because many cocoa products are high in sugar and saturated fat, family physicians should refrain from recommending cocoa...." That's a little patronizing, though. You can get the benefits of chocolate without any sugar or fat by adding cocoa powder to a smoothie, for example. Too often, doctors think patients can't handle the truth. Case in point: If your patients inquire, one medical journal editorial suggest, ask them what type of chocolate they prefer. If they respond with milk chocolate, then it is best to answer that it is not good for them. If the answer is dark chocolate, then you can lay out the evidence.


Even better than dark chocolate would be cocoa powder, which contains the phytonutrients without the saturated fat. I've happily (and deliciously) created other videos on cocoa and chocolate, so check out Update on Chocolate, Healthiest Chocolate Fix, A Treatment for Chronic Fatigue Syndrome, and Dark Chocolate and Artery Function.

Whether with Big Candy, Big Chocolate, or some other player, you always have to be careful about conflict of interest. For more information, watch my Food Industry Funded Research Bias video.

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:

Original Link

40 Whole Food Vegan Delicious Desserts

Dessert can be decadent without damaging your health goals. Opting for whole grain flours, whole food sweeteners, and oil-free options enables infinite versatility for wholesome, healthy deliciousness! *Notes: Opt for 100% pure maple syrup, date paste, or date syrup when applicable instead of agave, coconut nectar, or honey and (mineral-rich) blackstrap molasses if the strong taste works in a …

Original Link

What To Do if You Suspect Gluten Problems

NF-Mar1 How to Diagnose Gluten Intolerance.jpeg

Symptoms of gluten sensitivity include irritable bowel type symptoms such as bloating, abdominal pain, and changes in bowel habits, as well as systemic manifestations such as brain fog, headache, fatigue, depression, joint and muscle aches, numbness in the extremities, skin rash, or anemia. I previously discussed why people who suspect they might be gluten sensitive should not go on a gluten-free diet. But if that's true, what should they do?

The first thing is a formal evaluation for celiac disease, which currently involves blood tests and a small intestinal biopsy. If the evaluation is positive, then a gluten-free diet is necessary. If it's negative, it's best to try a healthier diet with more fruits, vegetables, whole grains and beans while avoiding processed junk. In the past, a gluten-free diet had many benefits over the traditional American diet because it required increasing fruit and vegetable intake--so no wonder people felt better eating gluten-free: no more unhealthy bread products, no more fast food restaurants. Now, there is just as much gluten-free junk out there.

If a healthy diet doesn't help, then the next step is to try ruling out other causes of chronic gastrointestinal distress. In a study of 84 people who claim gluten causes them adverse reactions (they're referred to in the literature as"PWAWGs," People Who Avoid Wheat and/or Gluten), highlighted in my video, How to Diagnose Gluten Intolerance, about a third didn't appear to have gluten sensitivity at all. Instead, they either had an overgrowth of bacteria in their small intestine, were fructose or lactose intolerant, or had a neuromuscular disorder like gastroparesis or pelvic floor dysfunction. Only if those are also ruled out, would I suggest people suffering from chronic suspicious symptoms try a gluten-free diet. If symptoms improve, stick with it and maybe re-challenge with gluten periodically.

Unlike the treatment for celiac disease, a gluten-free diet for gluten sensitivity is ideal not only to prevent serious complications from an autoimmune reaction, but to resolve symptoms and try to improve a patient's quality of life. However, a gluten-free diet itself can also reduce quality of life, so it's a matter of trying to continually strike the balance. For example, gluten-free foods can be expensive, averaging about triple the cost. Most people would benefit from buying an extra bunch of kale or blueberries instead.

No current data suggests that that general population should maintain a gluten-free lifestyle, but for those with celiac disease, a wheat allergy, or a sensitivity diagnosis, gluten-free diets can be a lifesaver.

For more on gluten, check out Is Gluten Sensitivity Real? and Gluten-Free Diets: Separating the Wheat from the Chat.

Some food strategies that may help with irritable bowel symptoms are covered in a few of my previous videos, such as Kiwifruit for Irritable Bowel Syndrome and Cayenne Pepper for Irritable Bowel Syndrome and Chronic Indigestion.

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: Jeremy Segrott/ Flickr

Original Link

Coca-Cola Stopped Sponsoring the Academy of Nutrition and Dietetics

NF-Nov10 Academy of Nutrition and Dietetics Conflicts of Interest.jpg

The American Dietetic Association (ADA) is the world's largest association of nutrition professionals. They claim to be devoted to "improving the nation's health." They promote a series of Nutrition Fact Sheets. Who writes them? Industry sources pay $20,000 per fact sheet to the ADA and explicitly take part in writing the documents. The ADA then promotes them through its journal and on its website.

Some of these fact sheets are "What's a Mom to Do: Healthy Eating Tips for Families" sponsored by Wendy's; "Lamb: The Essence of Nutrient Rich Flavor," sponsored by the Tri-Lamb Group; "Cocoa and Chocolate: Sweet News" sponsored by the Hershey Center for Health and Nutrition; "Eggs: A Good Choice for Moms-to-Be" sponsored by the American Egg Board's Egg Nutrition Center; "Adult Beverage Consumption: Making Responsible Drinking Choices" in connection with the Distilled Spirits Council; and "The Benefits of Chewing Gum" sponsored by the Wrigley Science Institute. For visuals, see Academy of Nutrition and Dietetics Conflicts of Interest.

Did you know there was a Wrigley Science Institute?

In 2008, the ADA announced that the Coca-Cola Company had become an "ADA Partner" through its corporate relations sponsorship program. The ADA "provides partners a national platform via ADA events and programs with prominent access to key influencers, thought leaders and decision makers in the nutrition marketplace." The ADA's press release also pointed out that "the Coca-Cola Company will share their research findings with ADA members in forums such as professional meetings and scientific publications." For example, did you know there are "No Harmful Effects of Different Coca-Cola Beverages on Rat Testicles?" Was that even a concern? Thou doth protest too much methinks...

When the American Academy of Pediatrics was called out on their proud new corporate relationship with Coke to support patient education on healthy eating, an executive vice-president of the Academy tried to quell protest by explaining that this alliance was not without precedent. The American Academy of Pediatrics has had relationships with Pepsi and McDonald's for some time. This is reminiscent of similar types of relationships in the past, like doctors promoting cigarette smoking.

The fact that the Academy of Pediatrics was also collaborating with Pepsi and McDonald's didn't seem to placate the critics. So the executive continued, noting that the American Dietetic Association has made a policy statement that "There are no good or bad foods." Indeed, that's the ADA's official position, "classification of specific foods as good or bad is overly simplistic."

One commentator asks, "Is this what [family doctors] have been reduced to...? To justify an unholy financial alliance we hide behind what others say and do and deny that there are actually unhealthy, 'bad' foods. I wonder how much money the ADA receives from the Coca-Cola Company and other food and beverage companies to have come up with this counter-intuitive 'no good or bad foods' philosophy?"

In 2012, the American Dietetic Association changed their name to the Academy of Nutrition and Dietetics. Did their policies change at all? A landmark report from one of my favorite industry watchdogs, Michele Simon, found that they continue to take millions of dollars in corporate sponsorship money every year from meat, processed junk, dairy, soda, and candy bar companies, and in return offer official educational seminars to teach dietitians what to say to their clients. So when you hear the title "registered dietitian," this is the group they're forced to be registered through. Thankfully there are also Dietitians for Professional Integrity.

After giving millions of dollars to the Academy of Nutrition and Dietetics, Coca Cola has apparently withdrawn sponsorship. It's not enought o disclose conflicts of interest; we should strive to eliminate them in medical and nutrition research.

For more on the corrosive effect of money and politics in nutrition, see:

There are lots of evidence-based dietitians, such as Brenda Davis, Jeff Novick, and Julieanna Hever--not to mention our very own Joseph Gonzales!

-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: Piotr Drabik / Flickr

Original Link

How Dark Chocolate Affects Our Arteries

NF-Nov5 Dark Chocolate and Artery Function.jpg

Chocolate: delicious beauty or harmful beast? Or both?

Although chocolate products can contain high levels of fat and sugar, the cocoa powder itself may have beneficial effects in a number of chronic disease conditions including heart disease.

Flow-mediated dilation, measured in the main artery of the arm, is considered one of the best measures of arterial function, a predictor of cardiovascular mortality. Researchers found that a little cocoa can give one a significant boost in arterial function within hours of consumption. It doesn't take much--just about a teaspoon of natural cocoa powder (or about a tablespoon or more of Dutched cocoa). For a graph of this, check out my video, Dark Chocolate and Artery Function.

Now, it might make us a little suspicious that the author of this study works in Hershey, Pennsylvania, at the Hershey Medical center, and has accepted money from our largest chocolate manufacturer's Center for Health and Nutrition, conveniently located near the intersection of Chocolate and Cocoa Avenue (seriously!).

However, putting together all of the best available evidence, dozens of randomized controlled trials, arterial function was significantly improved within hours, and after weeks and months of chronic cocoa consumption. It's always difficult to tease fact from fiction when such powerful financial interests are involved though. Many of the other studies were funded by industry as well, and as in all areas of research, evidence suggests that industry funding is associated with pro-industry conclusions. But even after removing studies funded by industry, reviewers found the same protective effect.

The reason researchers often measure arterial function in the arm rather than where we really need it--in the coronary arteries of the heart--is that it would require an angiogram, which is a much more invasive procedure. But what if we were able to find people already scheduled for an angiogram anyway? A double-blind, randomized trial of people already scheduled for an angiogram found that dark chocolate actually opens up coronary arteries. When researchers did what's called a "cold pressor test," where they plunge subjects' hands into buckets of ice water, they found that after dark chocolate consumption arteries actually dilated when they're normally supposed to constrict.

Because chocolate also contains fat and sugar, we have to be careful. Furthermore, most chocolate products are manufactured with milk, an ingredient known to influence the antioxidant capacity in our blood. Even if milk chocolate had the same flavonoid phytonutrient content as dark chocolate, the antioxidant effect of cocoa is potentially weakened in the blood when milk is consumed.

So not only are there triple the antioxidants in dark compared to milk chocolate, but the milk actively works against the effects in the human body. Eat dark chocolate, and we get a nice spike in the antioxidant power of our bloodstreams within an hour. Eat milk chocolate, and we get nothing. If we eat that same dark chocolate with a cup of milk, the benefit is suppressed. The addition of milk, either in your stomach or in the chocolate, inhibits the within-body antioxidant activity of chocolate and the absorption into the bloodstream of one of the target phytonutrients.

Sugar isn't good for us either. Sugar impairs arterial function. One bottle of soda's worth of sugar can cripple arterial function. That's why sugar-free cocoa improves arterial function better than the same amount of cocoa with sugar added. So, eliminating sugar appears to amplify the beneficial effects of cocoa.

The bottom line is that although the positive effects of chocolate and cocoa products seem apparent, precautions exist when we're talking about the calories, fat, and sugar in chocolate. Cocoa powder, then, offers the best of both worlds. Although not as tasty, cocoa-based products with little or no sugar or fat are certainly preferred. And we can make them tasty as I note in my Healthy Chocolate Milkshake recipe, and my healthy chocolate ice cream video.

More on the corrupting effect of money in nutrition research in Academy of Nutrition and Dietetics Conflicts of Interest.

I've covered chocolate before, coming to basically the same conclusion:

What effects do other foods have on arterial function? See:

-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: Kyknoord / Flickr

Original Link

How to Boost the Benefits of Exercise

NF-Aug28 What Happens to Our Bodies After We Exercise & How to Boost the Health Benefits.jpg

We all know exercise is beneficial to our health. Then why is it that ultramarathon runners may generate so many free radicals during a race that they can damage the DNA of a significant percentage of their cells? Researchers have looked at the exercise-induced increase in free radical production as a paradox: why would an apparently healthy act--exercise--lead to detrimental effects through damage to various molecules and tissues? This arises out of somewhat of a misunderstanding: exercise in and of itself is not necessarily the healthy act--it's the recovery after exercise that is so healthy, the whole "that-which-doesn't-kill-us-makes-us-stronger" notion. For example, exercise training has been shown to enhance antioxidant defenses by increasing the activities of our antioxidant enzymes. So, during the race ultra-marathoners may be taking hits to their DNA, but a week later they can experience great benefits, as shown in my video, Enhanced Athletic Recovery Without Undermining Adaptation.

In a recent study, researchers from Oregon State University looked at the level of DNA damage in athletes. Six days after a race, athletes didn't just go back to the baseline level of DNA damage, but had significantly less, presumably because they had revved up their antioxidant defenses. So, maybe exercise-induced oxidative damage is beneficial, similar to vaccination. By freaking out the body a little, we might induce a response that's favorable in the long run.

This concept, that low levels of a damaging entity can up-regulate protective mechanisms, is known as hormesis. For example, herbicides kill plants, but in tiny doses may actually boost plant growth, presumably by stressing the plant into rallying its resources to successfully fight back.

Wait a second, though. Could eating anti-inflammatory and anti-oxidant rich plant foods undermine this adaptation response? We know that berries may reduce inflammatory muscle damage (See Reducing Muscle Soreness with Berries), and greens may reduce free radical DNA damage (See Preventing Exercise Induced Oxidative Stress with Watercress). Dark chocolate and tomato juice appear to have similar effects. How it works is that flavonoid phytonutrients in fruits, vegetables, and beans seem to inhibit the activity of xanthine oxidase, considered the main contributor of free radicals during exercise. And the carbs in plant foods may also decrease stress hormone levels.

So in 1999, a theoretical concern was raised. Maybe all that free radical stress from exercise is a good thing, and increased consumption of some antioxidant nutrients might interfere with these necessary adaptive processes. If we decrease free radical tissue damage, maybe we won't get that increase in activity of those antioxidant enzymes.

A group of researchers who performed a study on tart cherry juice and recovery following a marathon responded to this antioxidant concern by suggesting that, although it is likely that muscle damage, inflammation, and oxidative stress are important factors in the adaptation process, minimizing these factors may improve recovery so we can train more and perform better. So, there are theories on both sides, but what happens when we actually put it to the test?

While antioxidant or anti-inflammatory supplements may prevent these adaptive events, researchers found that blackcurrant extract - although packed with antioxidant and anti-inflammatory properties - actually boosted the health benefits of regular exercise.

If we take antioxidant pills--vitamin C and vitamin E supplements-- we can also reduce the stress levels induced by exercise, but in doing so we block that boost in antioxidant enzyme activity caused by exercise. Now maybe we don't need that boost if we don't have as much damage, but vitamin C supplements seem to impair physical performance in the first place. With plant foods, though, we appear to get the best of both worlds.

For example, lemon verbena, an antioxidant-rich herbal tea, protects against oxidative damage and decreases the signs of muscular damage and inflammation, without blocking the cellular adaptation to exercise. In a recent study, researchers showed that lemon verbena does not affect the increase of the antioxidant enzyme response promoted by exercise. On the contrary: antioxidant enzyme activity was even higher in the lemon verbena group. In my video, Enhanced Athletic Recovery Without Undermining Adaptation, you can see the level of antioxidant enzyme activity before and after 21 days of intense running exercises in the control group. With all that free radical damage, the body started cranking up its antioxidant defenses. But give a dark green leafy tea, and not only do we put a kabosh on the damage due to all the phytonutrients and antioxidants, but we still get the boost in defenses--in fact, in this case, the boost was even greater.

Find out more on enhancing athletic recovery in this three-part video series:

1. Reducing Muscle Fatigue with Citrus
2. Reducing Muscle Soreness with Berries
3. Preventing Exercise-Induced Oxidative Stress With Watercress

Then there's my 15-video series on using nitrate-rich vegetables to boost athletic performance starting with Doping With Beet Juice and ending with So Should We Drink Beet Juice or Not?

-Michael Greger, M.D.

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

Original Link

How To Get Our Kids to Eat Their Vegetables

Tricks to Get Kids to Eat Healthier at Home.jpg

When researchers offered kids broccoli or a chocolate bar, which do you think they picked? Four out of five picked the chocolate (though how proud are the parents of the one in five kids that chose the broccoli?!).

But what if we put an Elmo sticker on the broccoli? When an Elmo sticker was placed on the broccoli, it was half and half. Fifty percent chose the broccoli.

It works in schools, too. A picture of SpongeBob saying, "Got beans?" and 37% more boys and 17% more girls chose green beans. One little sign and kids were eating significantly more vegetables.

We saw how we should cut up (or cut out) cookies to minimize consumption in my video Tricks to Get Kids to Eat Healthier at School. How should we cut up vegetables to maximize consumption? Which do you think 9 to 12 year olds ate more of, whole slices, sticks or stars? And do they like them bigger, or smaller? The results were strikingly clear. Turns out "Shape was very influential; children clearly preferred having their vegetables cut." Stars were liked the most. What about whole slices versus sticks? No difference. It turns out that size only mattered for the whole chunk: the ordinary size was preferred to the miniature versions.

If they're still not biting, we can apply the same trick I use to get our dog to eat stuff she doesn't like: dip it in peanut butter. "Pairing vegetables with peanut butter may successfully increase intake, even in vegetable-resistant children." Offering a salad dressing dip may help, too.

Then there's always the hidden vegetables strategy. In one study, "broccoli, cauliflower, tomatoes, squash, and zucchini were covertly added to familiar entrees so that the appearance, flavor, and texture of the original recipes were maintained," like pureeing vegetables into a pasta sauce, and families weren't any wiser. Covertly incorporating vegetables into foods can "have a beneficial effect on children's vegetable intake, but it should not be the only way that vegetables are served to children." Since the appetite for an initially unappetizing vegetable can be increased through repeated exposure, it is important to use several strategies to ensure that children experience different forms of vegetables, especially whole vegetables, because they're not always going to be at home.

Worse comes to worst, public health advocates can make a video game. There's a public/private partnership, "The Quest to Lava Mountain," where you can apparently harvest kale and gain "knowledge about the health benefits of eating healthy foods such as fruits, vegetables, and whole-grain foods" as well as the detrimental effects of eating junk. Where were the kale video games when I was growing up?

What may be the best way, though, to get kids to eat more fruits and vegetables? One study, featured in my video Tricks to Get Kids to Eat Healthier at Home, looked at all sorts of parenting styles--should we pressure them or should we lay off? What was the most important factor? The most important predictor of children's fruit consumption was... the parent's consumption. That was pretty much the case with vegetables, too. If we want our kids to eat healthy, we have to model healthy behavior. The researchers concluded that in order to try to increase children's fruit and vegetable consumption, parents should be guided to improve their own diets first.

For a smattering of other videos on children's health, check out:

I cover grown-ups in Tricks to Get Adults to Eat Healthier.

-Michael Greger, M.D.

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

Image Credit: U.S. Department of Agriculture / Flickr

Original Link