Chocolate is Finally Put to the Test

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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:

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Side-Effects of Aspartame on the Brain

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The National Institutes of Health AARP study of hundreds of thousands of Americans followed for years found that frequent consumption of sweetened beverages, especially diet drinks, may increase depression risk among older adults. Whether soda, fruit-flavored drinks, or iced tea, those artificially sweetened drinks appeared to carry higher risk. There was a benefit in coffee drinkers compared to non-drinkers, but if they added sugar, much of the benefits appeared to disappear, and if they added Equal or Sweet-and-Low, the risk appeared to go up.

Various effects of artificial sweeteners, including neurological effects, have been suspected. For example, aspartame--the chemical in Equal and Nutrasweet--may modulate brain neurotransmitters such as dopamine and serotonin, although data have been controversial and inconsistent. Scientific opinions range from "safe under all conditions" to "unsafe at any dose." The controversy started in the 80's soon after aspartame was approved. Researchers at the Mass College of Pharmacy and MIT noted:

"given the very large number of Americans routinely exposed, if only 1% of the 100,000,000 Americans thought to consume aspartame ever exceed the sweetener's acceptable daily intake, and if only 1% of this group happen coincidentally to have an underlying disease that makes their brains vulnerable to the effects, then the number of people who might manifest adverse brain reactions attributable to aspartame could still be about 10,000, a number on the same order as the number of brain and nerve-related consumer complaints already registered with the FDA before they stopped accepting further reports on adverse reactions to the sweetener."

Those with a history of depression might be especially vulnerable. Researchers at Case Western designed a study I highlighted in my video Aspartame and the Brain to ascertain whether individuals with mood disorders are particularly vulnerable to adverse effects of aspartame. Although they had planned on recruiting 40 patients with depression and 40 controls, the project was halted early by the Institutional Review Board for safety reasons because of the severity of reactions to aspartame within the group of patients with a history of depression.

It was decided that it was unethical to continue to expose people to the stuff.

Normally when we study a drug or a food, the company donates the product to the researchers because they're proud of the benefits or safety of their product. But the Nutrasweet company refused to even sell it to these researchers. The researchers managed to get their hands on some, and within a week there were significantly more adverse effects reported in the aspartame group than in the placebo group. They concluded that individuals with mood disorders may be particularly sensitive to aspartame, and therefore its use in this population should be discouraged.

In a review of the direct and indirect cellular effects of aspartame on the brain, it was noted that there are reports of aspartame causing neurological and behavioral disturbances in sensitive individuals, such as headaches, insomnia and seizures. The researchers go even further and propose that excessive aspartame ingestion might be involved in the development of certain mental disorders and also in compromised learning and emotional functioning. They conclude that "due to all the adverse effects caused by aspartame, it is suggested that serious further testing and research be undertaken to eliminate any and all controversies," to which someone responded in the journal that "there really is no controversy," arguing that aspartame was conclusively toxic.

But what do they mean by excessive ingestion? The latest study on the neuro-behavioral effects of aspartame consumption put people on a high aspartame diet compared to a low aspartame diet. But even the high dose at 25 mg/kg was only half the adequate daily intake set by the FDA. The FDA says one can safely consume 50mg a day, but after just eight days on half of that, participants had more irritable mood, exhibited more depression, and performed worse on certain brain function tests. And these weren't people with a pre-existing history of mental illness; these were just regular people. The researchers concluded that "given that the higher intake level tested here was well below the maximum acceptable daily intake level [40mg in Europe, 50mg here] careful consideration is warranted when consuming food products that may affect neurobehavioral health."

Easier said than done, since it's found in more than 6,000 foods, apparently making artificial sweeteners "impossible to completely eradicate from daily exposure." While that may be true for the great majority of Americans, it's only because they elect to eat processed foods. If we stick to whole foods, we don't even have to read the ingredients lists, because the healthiest foods in the supermarket are label-free, they don't even have ingredients lists--produce!

I've previously touched on artificial sweeteners before:

The healthiest caloric sweeteners are blackstrap molasses and date sugar (whole dried powdered dates). The least toxic low-calorie sweetener is probably erythritol (Erythritol May Be a Sweet Antioxidant).

Coffee may decrease suicide and cancer risk (Preventing Liver Cancer with Coffee? and Coffee and Cancer) but may impair blood flow to the heart (Coffee and Artery Function).

Other ways to improve mood 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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Mike Mozart / Flickr

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The Role of Caffeine in Artery Function

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There are dietary guidelines for food, but what about for beverages? A Beverage Guidance Panel was "assembled to provide guidance on the relative health and nutritional benefits and risks of various beverage categories." They ranked them from one to six, and water was ranked number one.

Soda ranked last at number six. Whole milk was grouped with beer, with a recommendation for zero ounces a day, in part out of concern for links between milk and prostate cancer, as well as aggressive ovarian cancer due to IGF-1. Number two on the list, though, after water, was tea and coffee, preferably without creamer or sweetener.

Even without creamer, though, lots of unfiltered coffee can raise cholesterol, but the cholesterol-raising compounds are trapped by the paper filter in brewed coffee, so filtered coffee is probably better.

But about ten years ago, a study was published on the effects of coffee on endothelial function, the function of our arteries. I profile this study in my video Coffee and Artery Function, showing that within 30 minutes of drinking a cup of coffee there was a significant drop in the ability of our arteries to dilate, whereas decaf did not seem to have a significant effect. This was the first study to demonstrate an acute unfavorable effect on arterial function of caffeinated coffee, but one cup of decaf didn't seem to affect performance. And two cups of decaf appeared to have a beneficial effect. So maybe it's a "battle between caffeine and antioxidants." Something in caffeinated coffee appears to be hurting arterial function, whereas something in decaf appears to be helping.

It's similar to red wine. De-alcoholized red wine significantly improves arterial function, as there are grape components trying to help, but the presence of alcohol counteracts and erases the benefit.

Drinking really high antioxidant coffee, by preparing it Greek style for example (where we actually drink the grounds), coffee drinkers may actually be at an advantage

It might not be the caffeine in caffeinated coffee that appears to be harmful, though. In a randomized, double-blind, placebo-controlled, cross-over study, researchers found that caffeine alone--about two and a half cups of coffee worth--significantly improved arterial function in both people with and without heart disease.

Coffee contains more than a thousand different compounds other than caffeine, many of which are also removed by the decaffeination process, so there must be something else in the coffee bean that's causing the problem. In fact, caffeine may even enhance the repair of the fragile inner lining of our arteries by enhancing the migration of our endothelial progenitor cells, the stem cells that patch up potholes in our artery walls.

But how might we get the potential benefit of caffeine without the risky compounds in caffeinated coffee? Tea consumption enhances artery function, and there are substantial beneficial effects of both green tea and black tea. Instead of other components in tea leaves undermining caffeine's potential benefits, they appear to boost the benefit in healthy individuals, as well as heart disease patients, reversing some of their arterial dysfunction, both immediately and long-term.

All the measurements in the studies I've talked about so far were done on the brachial artery, the main artery in the arm (just because it's easier to get to). What we care about, though, is blood flow to the heart. And caffeine appears to impair blood flow to our heart muscle during exercise even in healthy folks, but especially in those with heart disease. Thankfully caffeine in tea form appears to have the opposite effect, significantly improving coronary blood flow, suggesting that tea consumption has a beneficial effect on coronary circulation, though the addition of milk may undermine the protective effects.

I'm fascinated by how complicated such a simple question can get. The take-home is that water is the healthiest beverage, followed by tea.

The effects of coffee on cancer risk are more salutary:

I've previously covered Walnuts and Artery Function and Dark Chocolate and Artery Function. Stay tuned for a few more coming up further exploring the effects of tea, olive oil, and plant-based diets on our lovely endothelium.

Low Carb Diets and Coronary Blood Flow is one of the few other studies I've done that measured blood flow within the coronary arteries themselves. For more background on the brachial artery test, see my video The Power of NO.

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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

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Coffee for Hepatitis C

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Decades ago, researchers in Norway came upon an unexpected finding. Alcohol consumption was associated with liver inflammation (no surprise), but a protective association was found for coffee consumption. These findings were replicated in the U.S. and around the world. Those at risk for liver disease--who drank a lot of alcohol or were overweight--appeared to cut their risk in half if they drank more than two cups of coffee a day.

Liver cancer is one of the most feared complications of liver inflammation. Hepatocellular carcinoma is the third leading cause of cancer death, and the incidence has been rapidly rising in the United States and Europe, largely driven by the burden of hepatitis C infection and fatty liver disease. Putting together all the best studies done to date, those drinking the most coffee had half the risk of liver cancer compared to those that drank the least. Since the meta-analysis was published, a new study found that male smokers may be able to cut their risk of liver cancer more than 90% by drinking four or more cups of coffee a day. (Of course, they could also stop smoking!). It's similar to heavy drinkers of alcohol: drinking more coffee may decrease liver inflammation, but not as much as drinking less alcohol.

Liver cancers are among the most avoidable cancers, through hepatitis B vaccination, control of hepatitis C transmission, and reduction of alcohol drinking. These three measures could, in principle, wipe out 90% of liver cancers worldwide. It remains unclear whether coffee drinking has an additional role on top of that, but in any case such a role would be limited compared to preventing liver damage in the first place. But what if you already have hepatitis C or are among the 30% of Americans with non-alcoholic fatty liver disease due to obesity, which may quadruple one's risk of dying from liver cancer? Coffee seems to help with hepatitis C, reducing liver damage, disease activity, and mortality. It was only the lack of randomized, interventional studies on the topic that prevented us from concluding that coffee has a protective effect.

But in 2013 we got such a study, a randomized controlled trial on the effects of coffee consumption in chronic hepatitis C (highlighted in my video, Preventing Liver Cancer with Coffee). Forty patients with chronic hepatitis C were randomized into two groups: the first consumed four cups of coffee/day for 30 days, while the second remained coffee "abstinent." Then the groups switched for the second month. Two months is too soon to detect changes in cancer rates, but the researchers were able to demonstrate that coffee consumption reduces oxidative DNA damage, increases the death of virus infected cells, stabilizes chromosomes, and reduces fibrosis, all of which could explain the role coffee appears to play in reducing the risk of disease progression and of evolution to cancer.

Is it time to write a prescription for coffee for those at risk for liver disease? Some say no: "[A]lthough the results are promising, additional work is needed to identify which specific component of coffee is the contributing factor in reducing liver disease and related mortality." There are, after all, more than 1000 compounds that could be responsible for its beneficial effects. But that's such a pharmacological worldview. Why do we have to know exactly what it is in the coffee bean before we can start using them to help people? Yes, more studies are needed, but in the interim; moderate, daily, unsweetened coffee ingestion is a reasonable adjunct to therapy for people at high risk such as those with fatty liver disease.

Daily consumption of caffeinated beverages can lead to physical dependence. Caffeine withdrawal symptoms can include days of headache, fatigue, difficulty with concentration, and mood disturbances. But this dependence could be a good thing: "The tendency for coffee to promote habitual consumption may ultimately be advantageous if its myriad potential health benefits are confirmed."

More on coffee in:

Broccoli can boost the liver's detoxifying enzymes (Prolonged Liver Function Enhancement from Broccoli) but one can overdo it (Liver Toxicity Due to Broccoli Juice?).

What other foods might reduce DNA damage? 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: Matthew Wicks / Flickr

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Do Dietary Toxins Contribute to Hand Tremors?

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Essential tremor, affecting 1 in 25 adults over 40 and up to 1 in 5 of those in their 90s, is one of the most common neurological diseases. In addition to the potentially debilitating hand tremor, there can be other neuropsychiatric manifestations, including difficulty walking and various levels of cognitive impairment.

Might beta-carboline neurotoxins play a role in essential tremor? Harmane is one of the most potent of the tremor-producing neurotoxins. Expose people to harmane, and they develop tremors; take it away, and the tremors disappear. What if we're exposed long-term? A recent study at Columbia University, highlighted in my video, Essential Tremor and Diet, found that those with essential tremor have much higher levels of this toxin in their bloodstream compared to those without tremor. Furthermore, the higher the harmane levels, the worse the tremor. The highest levels are found in those who have both essential tremor and cancer, suggesting harmane may be playing a role in both diseases.

How did folks get exposed to these chemicals? Primarily through meat: beef, pork, fish, and especially chicken. So if this potent, tremor-producing neurotoxin is concentrated in cooked muscle foods, is meat consumption associated with a higher risk of essential tremor? Another Columbia University study found that men who ate the most meat had 21 times the odds of essential tremor. To put that in context, if we go back to the original studies on smoking and lung cancer, we see that smoking was only linked to about 14 times the odds, not 21.

Blood levels of this neurotoxin may shoot up within five minutes of eating meat. Five minutes? It's not even digested by then. This rapid uptake is indicative of significant absorption directly through the mouth straight into the bloodstream, bypassing the stomach and, most importantly, bypassing the detoxifying enzymes of the liver. This may lead to higher exposure levels in peripheral organs, like the brain.

Due to its high fat solubility, harmane accumulates in brain tissue, and, using a fancy brain scan called "proton magnetic resonance spectroscopic imaging," higher harmane levels have been linked to greater metabolic dysfunction in the brains of essential tremor sufferers.

Harmane is also found in certain heated plants, like tobacco. A broiled chicken breast has about 13 micrograms of harmane, and cigarettes average about one microgram, so a half pack of cigarettes could expose us to almost as much of this neurotoxin as a serving of chicken. Harman is created when tobacco is burned, and also when coffee beans are roasted. However, coffee intake has not been tied to increased risk (and neither has tobacco for that matter), so it may be something else in meat that's to blame for the 2,000 percent increase in odds for this disabling brain disease.

I also have a few videos about the other major tremor condition, Parkinson's Disease: Preventing Parkinson's Disease with Diet and Treating Parkinson's Disease with Diet

Other compounds created in cooked meats may also have implications for cancer risk:

-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: Gennaro D'Orio / Flickr

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Is Liquid Smoke Safe?

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We know smoke inhalation isn't good for us, but what about smoke ingestion? Decades ago, smoke flavorings were tested to see if they caused DNA mutations in bacteria--the tests came up negative. Even as more and more smoke flavoring was added, the DNA mutation rate remained about the same.

But the fact that something is not mutagenic in bacteria may have little predictive value for its effect on human cells. A group at MIT tested a hickory smoke flavoring they bought at the store against two types of human white blood cells. Unlike the bacteria, the mutation rate shot up as more and more liquid smoke was added. But, "there is no evidence that mutagenic activity in a particular human cell line is more closely related to human health risk than is mutagenic activity in bacteria." In other words: just because liquid smoke causes DNA mutations to human cells in a petri dish, doesn't mean that it does the same thing within the human body.

A good approach may be to just analyze liquid smoke for known carcinogens, chemicals that we know cause cancer.

Damaging DNA is just one of many ways chemicals can be toxic to cells. A decade later researchers tested to see what effect liquid smoke had on overall cell viability. If you drip water on cells, nothing happens, they keep powering away at around 100% survival, but drip on more and more wood fire smoke, and you start killing some of the cells off. Cigarette smoke is more toxic, but three out of four of the brands of liquid smoke they bought at the supermarket killed off even more cells, leading them to conclude that the cytotoxic potential of some commercial smoke flavorings is greater than that of liquid cigarette smoke, a finding they no doubt celebrated given that the researchers were paid employees of the R. J. Reynolds Tobacco Co.

Unfortunately they didn't name names of the offending brands. That's one of the reasons I was so excited about a new study, where they tested--and named--15 different brands of liquid smoke. This maximum "response" they were measuring was p53 activation.

P53 is a protein we make that binds to our DNA, you can see this illustrated in my video, Is Liquid Smoke Flavoring Carcinogenic?. It activates our DNA repair enzymes. So a big p53 response may be indicative of a lot of DNA damage,and a few of the liquid smoke flavorings activated p53 almost as much as a chemotherapy drug like etoposide, whose whole purpose is to break DNA strands.

Other flavorings didn't seem as bad, though there was a hickory smoke powder that ranked pretty high, as did the fish sauce, though smoked paprika didn't register at all.

The p53-activating property in liquid smoke was eliminated by standard baking conditions (350°F for 1h), so if you're baking something with liquid smoke for long enough, it should eliminate this effect, though just boiling--even for an hour, or slow cooking doesn't appear to work.

They conclude "If the DNA-damaging activities of liquid smoke were thought to be deleterious, it might be possible to replace liquid smoke with other safer, smoky substances." Why do they say if thought to be deleterious? That's because they're not really measuring DNA damage, they're measuring p53 activation, and that's not necessarily a bad thing.

P53 is considered "Guardian of our Genome," guardian of our DNA. It's considered a tumor suppressor gene, so if something boosts its activity is that good or bad? It's like the broccoli story. Cruciferous vegetables dramatically boost our liver's detoxifying enzymes. Is this because our body sees broccoli as toxic and is trying to get rid of it quicker? Either way, the end result is good, lower cancer risk.

It's a biological phenomenon known as hormesis - that which doesn't kill us may make us stronger. Like exercise is a stress on the body, but in the right amount can make us healthier in the long run. So, for example, teas and coffees caused p53 activation as well, but their consumption is associated with lower cancer risk. So it's hard to know what to make of this p53 data. Due to the limitations of the available tests it's hard to calculate the genotoxic potential of liquid smoke, or any other food for that matter. A better approach may be to just analyze liquid smoke for known carcinogens, chemicals that we know cause cancer.

This was first attempted back in 1971. One of the seven liquid smoke flavors researchers tested contained one polycyclic aromatic hydrocarbon known to be cancer-causing, but there's a bunch of similar carcinogens researchers didn't test for. A later study, however, tested across the board, looking specifically at five different carcinogens in retail liquid smoke seasonings.

The recommended daily upper safety limit for these carcinogens is 47. Hickory smoke flavoring has only 0.8 per teaspoon, so we'd have to drink three bottles a day to bump up against the limit. And mesquite liquid smoke has only 1.1.

It turns out that most of the carcinogens in smoke are fat soluble, so when we make a water-based solution, like liquid smoke, we capture the smoke flavor compounds without capturing most of the smoke cancer compounds. The only time we need to really worry is when eating smoked foods--foods directly exposed to actual smoke. For example, smoked ham has 21.3 per serving, and smoked turkey breast has 26.7 per serving. One sandwich and we may be halfway to the limit, and one serving of barbequed chicken takes us over the top. Eating less than a single drumstick and we nearly double our daily allotment of these carcinogens. Nothing, however, is as bad as fish. Smoked herring? 140 per serving. And smoked salmon? One bagel with lox could take us ten times over the limit.

I've touched on those cooked meat carcinogens before. In Estrogenic Cooked Meat Carcinogens I explored the role of these cooked meat chemicals in tumor growth. PhIP: The Three Strikes Breast Carcinogen explored their role in cancer invasion. Reducing Cancer Risk In Meateaters offered some mediation strategies. Heterocyclic Amines in Eggs, Cheese, and Creatine? showed how even vegetarians may be at risk and Cancer, Interrupted: Green Tea and Cancer, Interrupted: Garlic & Flavonoids explored some counter measures.

Some smoke compounds may be a concern even if we don't eat them. See Meat Fumes: Dietary Secondhand Smoke. Even the smell of frying bacon may be carcinogenic: Carcinogens in the Smell of Frying Bacon.

Some plant foods exposed to high temperatures may also present a concern. See Is Yerba Mate Tea Bad for You? and Acrylamide in French Fries. What about Carcinogens in Roasted Coffee?

The broccoli liver enzyme boost story is covered in The Best Detox.

-Michael Greger, M.D.

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

Image Credit: eric forsberg / Flickr

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Tea and Flouride Risk

 

 

 

 

 

 

 

 

Childhood Tea Drinking May Increase Fluorosis Risk

If cranberries are so good at keeping bacteria from sticking to the wall of the bladder (see my video Can Cranberry Juice Treat Bladder Infections?), what about keeping bacteria from sticking to other places? There is in vitro research suggesting cranberry phytonutrients may reduce adhesion of H. pylori bacteria in the wall of the stomach, so maybe cranberries should be given along with antibiotics to help eradicate the ulcer-causing bacteria. But hey, what about our teeth?

Dental plaque is bacteria sticking to our teeth, particularly Streptococcus mutans. We’ve known that those with different drinking habits—be they coffee, tea, barley coffee, or wine—have about 10 times less of these plaque bacteria. Since those are all beverages from plants, maybe phytonutrients are fighting back at plaque.

If bacteria cause plaque and cavities, why not just swish with some antibiotic solution? There are downsides to just indiscriminately wiping out bacteria both good and bad, as I detailed in my Don’t Use Antiseptic Mouthwash video. So maybe it would be better if we just stop the bad bugs from sticking to our teeth.

There is some evidence that cranberries might affect the adhesion of bacteria to fake teeth in a petri dish, but nothing yet definitive. Green tea also appears to help prevent cavities, but that may be because of its natural fluoride content in the tea plant. I have a video about a woman who developed fluoride toxicity drinking up to the equivalent of about five dozen cups a day, but what about just regular consumption?

During the tooth development years, up to about age 9, children exposed to too much fluoride can develop dental fluorosis, a mottled discoloration of the teeth. It’s just a cosmetic issue and usually just manifests as faint white spots, but it’s the main reason the EPA is reconsidering current tap water fluoridation levels. If you watch my 3-min video Childhood Tea Drinking May Increase Fluorosis Risk, you’ll see that herbal teas are fine–about 100 fold under the limit–but caffeinated teas exceed the suggested limit, and decaf teas exceed the mandatory limit. Those limits are for tap water, though, so tea drinking would only pose much of a risk if drank all day long as one’s primary beverage. Kids who primarily drink non-herbal tea as a source of hydration would be at risk for dental fluorosis.

What may be the best source of hydration for kids? Might tea also cause dehydration? Find the answers to these beverage-related questions in my videos Does a Drink of Water Make Children Smarter? and Is Caffeinated Tea Dehydrating?

What about all those folks that say fluoride is a poison to be avoided at all costs? I offer my brief two cents in the Q&A The Dangers of Fluoride? There are elements for which there is no safe level of exposure, though. I explore a few in my video Fukushima and Radioactivity in Seafood.

Beyond cosmetic issues, what should we eat and drink to keep our mouth healthy? See my videos Plant-Based Diets: Oral Health and Plant-Based Diets: Dental 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 and More Than an Apple a Day.

Image credit: Josconklin / Wikimedia Commons

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Treating Parkinson’s Disease With Diet

 

 

 

 

 

 

 

 

 

Caffeine consumption appears to help prevent Parkinson’s, but what if you already have the condition? A recent study found that giving folks the equivalent of about two cups of coffee a day worth of caffeine significantly improved symptoms of the disease. Of course, there’s only so much you can charge for coffee, so drug companies took caffeine and added a few side groups so they could patent it into new drugs (Preladenant and Istradefylline). These drugs appear to work no better than plain caffeine, which is dramatically cheaper and probably safer. You can see more of the risks and benefits of coffee and caffeine in Coffee and Cancer and What About the Caffeine?

Similarly, certain plants, such as berries, and plant-based diets in general may help prevent Parkinson’s. See my last post Avoiding Dairy to Prevent Parkinson’s. This may be partially because of pollutants that magnify up the food chain into the meat and dairy supply, but it could also be from the protective phytonutrients in healthy plant foods. For example, as you can see in my 3-min video Treating Parkinson’s Disease With Diet, I profile a case report in which a dietician struck with Parkinson’s was able to successfully clear most of her symptoms with a plant-based diet rich in strawberries, whole wheat, and brown rice. These are rich sources of two particular phytonutrients, N-hexacosanol and fisetin, but there hadn’t been a formal interventional trial published, until now.

At its root, Parkinson’s is a dopamine deficiency disease due to a die-off of dopamine-generating cells in the brain. These cells make dopamine from L-dopa derived from an amino acid in our diet. Just like we saw with the serotonin story I described in my three-part series The Wrong Way to Boost SerotoninA Better Way to Boost Serotonin, and The Best Way to Boost Serotonin, the consumption of animal products blocks the transport of L-dopa into the brain, crowding it out.  With this knowledge, researchers first tried what’s called a “protein redistribution diet.” This is where people could only eat meat for supper so the patients would hopefully be sleeping by the time the negative effects of the animal protein hit.

The researchers didn’t consider cutting out all animal products altogether until it was discovered that fiber consumption naturally boosts L-dopa levels. Thus, a plant-based diet would be expected to raise levodopa bioavailability and bring some advantages in the management of the disease through two mechanisms: reduced animal protein intake and an increased fiber intake. That’s why plant protein is superior, because that’s where fiber is found. So researchers put folks on a strictly vegan diet, saving beans for the end of the day, and indeed found a significant improvement in symptoms.

More on what fiber can do for us in videos such as:

-Michael Greger, M.D.

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

Image credit:  royalconstantinesociety/Flickr

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