Thursday, February 5, 2015

Health Benefits of Chocolate - Diabetes, Cardiovascular Disease, and Cancer Benefits


19 randomized controlled trials: Dark chocolate could benefit cardiovascular health


To the tantalizing delight of chocolate lovers everywhere, a number of recent studies employing various methods have suggested that compounds in cocoa called flavanols could benefit cardiovascular health. Now a systematic review and meta-analysis of 19 randomized controlled trials (RCTs) of cocoa consumption reveals some further pieces of supporting evidence.

The meta-analysis in the Journal of Nutrition, an assessment of the combined evidence from all 19 RCTs, focused on whether consumption of flavanol-rich cocoa products was associated with improvements in specific circulating biomarkers of cardiometabolic health as compared to consuming placebos with negligible cocoa flavanol content. In all, 1,139 volunteers were involved in these trials.

"Our meta-analysis of RCTs characterizes how cocoa flavanols affect cardiometabolic biomarkers, providing guidance in designing large, definitive prevention trials against diabetes and cardiovascular disease in future work," said corresponding author Dr. Simin Liu, professor and director of the Center for Global Cardiometabolic Health at Brown University who worked with epidemiology graduate student and lead author Xiaochen Lin. "We found that cocoa flavanol intake may reduce dyslipidemia (elevated triglycerides), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases."

Liu noted some limitations in the trials. All studies were small and of short duration, not all of the biomarkers tracked in these studies changed for the better, and none of the studies were designed to test directly whether cocoa flavanol consumption leads to reduced cases of heart attacks or type 2 diabetes.

But taking into account some of these heterogeneities across studies, the team's meta-analysis summarizing data from 19 trials found potential beneficial effects of flavanol-rich cocoa on cardiometabolic health. There were small-to-modest but statistically significant improvements among those who ate flavanol-rich cocoa product vs. those who did not.

The greatest effects were seen among trial volunteers who ate between 200 and 600 milligrams of flavanols a day (based on their cocoa consumption). They saw significant declines in blood glucose and insulin, as well as another indicator of insulin resistance called HOMA-IR. They also saw an increase in HDL, or "good," cholesterol. Those consuming higher doses saw some of the insulin resistance benefits and a drop in triglycerides, but not a significant increase in HDL. Those with lower doses of flavanols only saw a significant HDL benefit.

In general, Lin said, where there were benefits they were evident for both women and men and didn't depend on what physical form the flavanol-rich cocoa product was consumed in -- dark chocolate vs. a beverage, for example.

"The treatment groups of the trials included in our meta-analysis are primarily dark chocolate -- a few were using cocoa powder-based beverages," Lin said. "Therefore, the findings from the current study apparently shouldn't be generalized to different sorts of chocolate candies or white chocolates, of which the content of sugar/food additives could be substantially higher than that of the dark chocolate."

The authors therefore concluded, "Our study highlights the urgent need for large, long-term RCTs that improve our understanding of how the short-term benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes."

Eating chocolate daily linked to lowered heart disease and stroke risk

Cocoa compound linked to some cardiovascular biomarker improvements

To the tantalizing delight of chocolate lovers everywhere, a number of recent studies employing various methods have suggested that compounds in cocoa called flavanols could benefit cardiovascular health. Now a systematic review and meta-analysis of 19 randomized controlled trials (RCTs) of cocoa consumption reveals some further pieces of supporting evidence.

The meta-analysis in the Journal of Nutrition, an assessment of the combined evidence from all 19 RCTs, focused on whether consumption of flavanol-rich cocoa products was associated with improvements in specific circulating biomarkers of cardiometabolic health as compared to consuming placebos with negligible cocoa flavanol content. In all, 1,139 volunteers were involved in these trials.

"Our meta-analysis of RCTs characterizes how cocoa flavanols affect cardiometabolic biomarkers, providing guidance in designing large, definitive prevention trials against diabetes and cardiovascular disease in future work," said corresponding author Dr. Simin Liu, professor and director of the Center for Global Cardiometabolic Health at Brown University who worked with epidemiology graduate student and lead author Xiaochen Lin. "We found that cocoa flavanol intake may reduce dyslipidemia (elevated triglycerides), insulin resistance and systemic inflammation, which are all major subclinical risk factors for cardiometabolic diseases."

Liu noted some limitations in the trials. All studies were small and of short duration, not all of the biomarkers tracked in these studies changed for the better, and none of the studies were designed to test directly whether cocoa flavanol consumption leads to reduced cases of heart attacks or type 2 diabetes.



But taking into account some of these heterogeneities across studies, the team's meta-analysis summarizing data from 19 trials found potential beneficial effects of flavanol-rich cocoa on cardiometabolic health. There were small-to-modest but statistically significant improvements among those who ate flavanol-rich cocoa product vs. those who did not.

The greatest effects were seen among trial volunteers who ate between 200 and 600 milligrams of flavanols a day (based on their cocoa consumption). They saw significant declines in blood glucose and insulin, as well as another indicator of insulin resistance called HOMA-IR. They also saw an increase in HDL, or "good," cholesterol. Those consuming higher doses saw some of the insulin resistance benefits and a drop in triglycerides, but not a significant increase in HDL. Those with lower doses of flavanols only saw a significant HDL benefit.

In general, Lin said, where there were benefits they were evident for both women and men and didn't depend on what physical form the flavanol-rich cocoa product was consumed in --dark chocolate vs. a beverage, for example.

"The treatment groups of the trials included in our meta-analysis are primarily dark chocolate -- a few were using cocoa powder-based beverages," Lin said. "Therefore, the findings from the current study apparently shouldn't be generalized to different sorts of chocolate candies or white chocolates, of which the content of sugar/food additives could be substantially higher than that of the dark chocolate."

The authors therefore concluded, "Our study highlights the urgent need for large, long-term RCTs that improve our understanding of how the short-term benefits of cocoa flavanol intake on cardiometabolic biomarkers may be translated into clinical outcomes."

Eating chocolate daily linked to lowered heart disease and stroke risk


Eating up to 100 g of chocolate every day is linked to lowered heart disease and stroke risk, finds research published online in the journal Heart.
 
They base their findings on almost 21,000 adults taking part in the EPIC-Norfolk study, which is tracking the impact of diet on the long term health of 25,000 men and women in Norfolk, England, using food frequency and lifestyle questionnaires.

The researchers also carried out a systematic review of the available international published evidence on the links between chocolate and cardiovascular disease, involving almost 158,000 people--including the EPIC study participants.

The EPIC-Norfolk participants (9214 men and 11 737 women) were monitored for an average of almost 12 years, during which time 3013 (14%) people experienced either an episode of fatal or non-fatal coronary heart disease or stroke.

Around one in five (20%) participants said they did not eat any chocolate, but among the others, daily consumption averaged 7 g, with some eating up to 100 g.

Higher levels of consumption were associated with younger age and lower weight (BMI), waist: hip ratio, systolic blood pressure, inflammatory proteins, diabetes and more regular physical activity --all of which add up to a favourable cardiovascular disease risk profile.

Eating more chocolate was also associated with higher energy intake and a diet containing more fat and carbs and less protein and alcohol.

The calculations showed that compared with those who ate no chocolate higher intake was linked to an 11% lower risk of cardiovascular disease and a 25% lower risk of associated death.

It was also associated with a 9% lower risk of hospital admission or death as a result of coronary heart disease, after taking account of dietary factors.

And among the 16,000 people whose inflammatory protein (CRP) level had been measured, those eating the most chocolate seemed to have an 18% lower risk than those who ate the least.
The highest chocolate intake was similarly associated with a 23% lower risk of stroke, even after taking account of other potential risk factors.

Of nine relevant studies included in the systematic review, five studies each assessed coronary heart disease and stroke outcome, and they found a significantly lower risk of both conditions associated with regular chocolate consumption.

And it was linked to a 25% lower risk of any episode of cardiovascular disease and a 45% lower risk of associated death.

This is an observational study so no definitive conclusions about cause and effect can be drawn. And the researchers point out that food frequency questionnaires do involve a certain amount of recall bias and underestimation of items eaten.

Reverse causation--whereby those with a higher cardiovascular disease risk profile eat less chocolate and foods containing it than those who are healthier--may also help to explain the results, they say.
Nevertheless, they add: "Cumulative evidence suggests that higher chocolate intake is associated with a lower risk of future cardiovascular events."

And they point out that as milk chocolate, which is considered to be less 'healthy' than dark chocolate, was more frequently eaten by the EPIC-Norfolk participants, the beneficial health effects may extend to this type of chocolate too.

"This may indicate that not only flavonoids, but also other compounds, possibly related to milk constituents, such as calcium and fatty acids, may provide an explanation for the observed association," they suggest.



Chocolate fights diabetes, obesity, cardiovascular disease, and cancer

Eating high levels of flavonoids including anthocyanins and other compounds (found in berries, tea, and chocolate) could offer protection from type 2 diabetes - according to research from the University of East Anglia (UEA) and King's College London.

Findings published January 2014 in the Journal of Nutrition reveal that high intakes of these dietary compounds are associated with lower insulin resistance and better blood glucose regulation.

A study of almost 2,000 people also found that these food groups lower inflammation which, when chronic, is associated with diabetes, obesity, cardiovascular disease, and cancer.

Prof Aedin Cassidy from UEA's Norwich Medical School led the research. She said: "Our research looked at the benefits of eating certain sub-groups of flavanoids. We focused on flavones, which are found in herbs and vegetables such as parsley, thyme, and celery, and anthocyanins, found in berries, red grapes, wine and other red or blue-coloured fruits and vegetables.

"This is one of the first large-scale human studies to look at how these powerful bioactive compounds might reduce the risk of diabetes. Laboratory studies have shown these types of foods might modulate blood glucose regulation – affecting the risk of type 2 diabetes. But until now little has been know about how habitual intakes might affect insulin resistance, blood glucose regulation and inflammation in humans."

Researchers studied almost 2,000 healthy women volunteers from TwinsUK who had completed a food questionnaire designed to estimate total dietary flavonoid intake as well as intakes from six flavonoid subclasses. Blood samples were analysed for evidence of both glucose regulation and inflammation. Insulin resistance, a hallmark of type 2 diabetes, was assessed using an equation that considered both fasting insulin and glucose levels.

"We found that those who consumed plenty of anthocyanins and flavones had lower insulin resistance. High insulin resistance is associated with Type 2 diabetes, so what we are seeing is that people who eat foods rich in these two compounds – such as berries, herbs, red grapes, wine– are less likely to develop the disease.

"We also found that those who ate the most anthocyanins were least likely to suffer chronic inflammation – which is associated with many of today's most pressing health concerns including diabetes, obesity, cardiovascular disease, and cancer.

"And those who consumed the most flavone compounds had improved levels of a protein (adiponectin) which helps regulate a number of metabolic processes including glucose levels.

"What we don't yet know is exactly how much of these compounds are necessary to potentially reduce the risk of type 2 diabetes," she added.

Prof Tim Spector, research collaborator and director of the TwinsUK study from King's College London, said: "This is an exciting finding that shows that some components of foods that we consider unhealthy like chocolate or wine may contain some beneficial substances. If we can start to identify and separate these substances we can potentially improve healthy eating. There are many reasons including genetics why people prefer certain foods so we should be cautious until we test them properly in randomised trials and in people developing early diabetes."


A Serving a Day of Dark Chocolate Might Keep the Doctor Away

Chocolate, considered by some to be the “food of the gods,” has been part of the human diet for at least 4,000 years; its origin thought to be in the region surrounding the Amazon basin. Introduced to the Western world by Christopher Columbus after his fourth voyage to the New World in 1502, chocolate is now enjoyed worldwide. Researchers estimate that the typical American consumes over 10 pounds of chocolate annually, with those living on the west coast eating the most. Wouldn’t it be great if only chocolate were considered healthy?

In fact, chocolate is a great source of myriad substances that scientists think might impart important health benefits. For instance, it contains compounds called “flavanols” that appear to play a variety of bodily roles including those related to their potent antioxidant and anti-inflammatory actions. Many large-scale human studies have documented a statistical correlation between flavanol intake and risk for cardiovascular disease. And animal studies suggest that this relationship may be due to the physiologic effects that flavanols have on chronic inflammation, blood vessel health, and circulating lipid levels. However, few controlled human intervention studies have been conducted to test the direct effect of chocolate consumption on these variables.

To help fill this knowledge gap, researchers at San Diego State University tested their hypothesis that chocolate, in particular dark chocolate which contains higher levels of flavanols than milk chocolate, may protect against the risk of cardiovascular disease by lowering blood pressure, blood flow, and improving blood lipid levels. In this prospective, controlled human intervention study, 31 fortunate subjects were assigned randomly to consume either a daily serving (50 grams) of either regular dark chocolate (70% cocoa), dark chocolate (70% cocoa) that had been overheated or “bloomed,” or white chocolate (0% cocoa). The subjects were asked to consume the chocolate for 15 days. Blood pressure, forearm skin blood flow, circulating lipid profiles, and blood glucose levels were recorded at the beginning and end of the study.

When compared to participants assigned to the white chocolate group, those consuming either form of dark chocolate had lower blood glucose and low-density lipoprotein cholesterol (LDL, the “bad” form) levels coupled with higher high-density lipoprotein cholesterol (HDL, the “good” form).

The researchers concluded that dark chocolate may reduce the risk of cardiovascular disease by improving glucose levels and lipid profiles. However, they cautioned that—although habitual dark chocolate consumption may benefit one’s health by reducing the risk of cardiovascular disease—it must be eaten in moderation because it can easily increase daily amounts of saturated fat and calories. Indeed, the authors commented, "We had great compliance with our study subjects because everybody wanted to eat chocolate. We actually had to tell them not to eat more than 50 grams a day.


Cocoa Health Benefits

Norman Hollenberg, professor of medicine at Harvard Medical School has spent years studying the benefits of cocoa drinking on the Kuna people in Panama. He found that the risk of 4 of the 5 most common killer diseases: stroke, heart failure, cancer and diabetes, is reduced to less then 10% in the Kuna. They can drink up to 40 cups of cocoa a week. Natural cocoa has high levels of epicatechin.

'If these observations predict the future, then we can say without blushing that they are among the most important observations in the history of medicine,' Hollenberg says. ‘We all agree that penicillin and anaesthesia are enormously important. But epicatechin could potentially get rid of 4 of the 5 most common diseases in the western world, how important does that make epicatechin?... I would say very important’

Nutrition expert Daniel Fabricant says that Hollenberg’s results, although observational, are so impressive that they may even warrant a rethink of how vitamins are defined. Epicatechin does not currently meet the criteria. Vitamins are defined as essential to the normal functioning, metabolism, regulation and growth of cells and deficiency is usually linked to disease. At the moment, the science does not support epicatechin having an essential role. But, Fabricant, who is vice president scientific affairs at the Natural Products Association, says: 'the link between high epicatechin consumption and a decreased risk of killer disease is so striking, it should be investigated further. It may be that these diseases are the result of epicatechin deficiency,' he says.


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Eating chocolate daily linked to lowered heart disease and stroke risk



Eating up to 100 g of chocolate every day is linked to lowered heart disease and stroke risk, finds research published online in the journal Heart.
 
They base their findings on almost 21,000 adults taking part in the EPIC-Norfolk study, which is tracking the impact of diet on the long term health of 25,000 men and women in Norfolk, England, using food frequency and lifestyle questionnaires.

The researchers also carried out a systematic review of the available international published evidence on the links between chocolate and cardiovascular disease, involving almost 158,000 people--including the EPIC study participants.

The EPIC-Norfolk participants (9214 men and 11 737 women) were monitored for an average of almost 12 years, during which time 3013 (14%) people experienced either an episode of fatal or non-fatal coronary heart disease or stroke.

Around one in five (20%) participants said they did not eat any chocolate, but among the others, daily consumption averaged 7 g, with some eating up to 100 g.

Higher levels of consumption were associated with younger age and lower weight (BMI), waist: hip ratio, systolic blood pressure, inflammatory proteins, diabetes and more regular physical activity --all of which add up to a favourable cardiovascular disease risk profile.

Eating more chocolate was also associated with higher energy intake and a diet containing more fat and carbs and less protein and alcohol.

The calculations showed that compared with those who ate no chocolate higher intake was linked to an 11% lower risk of cardiovascular disease and a 25% lower risk of associated death.

It was also associated with a 9% lower risk of hospital admission or death as a result of coronary heart disease, after taking account of dietary factors.

And among the 16,000 people whose inflammatory protein (CRP) level had been measured, those eating the most chocolate seemed to have an 18% lower risk than those who ate the least.
The highest chocolate intake was similarly associated with a 23% lower risk of stroke, even after taking account of other potential risk factors.

Of nine relevant studies included in the systematic review, five studies each assessed coronary heart disease and stroke outcome, and they found a significantly lower risk of both conditions associated with regular chocolate consumption.

And it was linked to a 25% lower risk of any episode of cardiovascular disease and a 45% lower risk of associated death.

This is an observational study so no definitive conclusions about cause and effect can be drawn. And the researchers point out that food frequency questionnaires do involve a certain amount of recall bias and underestimation of items eaten.

Reverse causation--whereby those with a higher cardiovascular disease risk profile eat less chocolate and foods containing it than those who are healthier--may also help to explain the results, they say.

Nevertheless, they add: "Cumulative evidence suggests that higher chocolate intake is associated with a lower risk of future cardiovascular events."

And they point out that as milk chocolate, which is considered to be less 'healthy' than dark chocolate, was more frequently eaten by the EPIC-Norfolk participants, the beneficial health effects may extend to this type of chocolate too.

"This may indicate that not only flavonoids, but also other compounds, possibly related to milk constituents, such as calcium and fatty acids, may provide an explanation for the observed association," they suggest.

 



Bacteria in the stomach gobble the chocolate and ferment it into anti-inflammatory compounds

The health benefits of eating dark chocolate have been extolled for centuries, but the exact reason has remained a mystery –– until now. Researchers report that certain bacteria in the stomach gobble the chocolate and ferment it into anti-inflammatory compounds that are good for the heart.

Their findings were unveiled at the 247th National Meeting & Exposition of the American Chemical Society (ACS) in March 2014.

"We found that there are two kinds of microbes in the gut: the 'good' ones and the 'bad' ones," explained Maria Moore, an undergraduate student and one of the study's researchers.

"The good microbes, such as Bifidobacterium and lactic acid bacteria, feast on chocolate," she said. "When you eat dark chocolate, they grow and ferment it, producing compounds that are anti-inflammatory." The other bacteria in the gut are associated with inflammation and can cause gas, bloating, diarrhea and constipation. These include some Clostridia and some E. coli.

"When these compounds are absorbed by the body, they lessen the inflammation of cardiovascular tissue, reducing the long-term risk of stroke," said John Finley, Ph.D., who led the work. He said that this study is the first to look at the effects of dark chocolate on the various types of bacteria in the stomach. The researchers are with Louisiana State University.

The team tested three cocoa powders using a model digestive tract, comprised of a series of modified test tubes, to simulate normal digestion. They then subjected the non-digestible materials to anaerobic fermentation using human fecal bacteria, according to Finley.

He explained that cocoa powder, an ingredient in chocolate, contains several polyphenolic, or antioxidant, compounds such as catechin and epicatechin, and a small amount of dietary fiber. Both components are poorly digested and absorbed, but when they reach the colon, the desirable microbes take over. "In our study we found that the fiber is fermented and the large polyphenolic polymers are metabolized to smaller molecules, which are more easily absorbed. These smaller polymers exhibit anti-inflammatory activity," he said.


Dark chocolate helps restore flexibility to arteries

Dark chocolate helps restore flexibility to arteries while also preventing white blood cells from sticking to the walls of blood vessels. Both arterial stiffness and white blood cell adhesion are known factors that play a significant role in atherosclerosis. What's more, the scientists also found that increasing the flavanol content of dark chocolate did not change this effect. This discovery was published in the March 2014 issue of The FASEB Journal.

"We provide a more complete picture of the impact of chocolate consumption in vascular health and show that increasing flavanol content has no added beneficial effect on vascular health," said Diederik Esser, Ph.D., a researcher involved in the work from the Top Institute Food and Nutrition and Wageningen University, Division of Human Nutrition in Wageningen, The Netherlands. "However, this increased flavanol content clearly affected taste and thereby the motivation to eat these chocolates. So the dark side of chocolate is a healthy one."

To make this discovery, Esser and colleagues analyzed 44 middle-aged overweight men over two periods of four weeks as they consumed 70 grams of chocolate per day. Study participants received either specially produced dark chocolate with high flavanol content or chocolate that was regularly produced. Both chocolates had a similar cocoa mass content. Before and after both intervention periods, researchers performed a variety of measurements that are important indicators of vascular health. During the study, participants were advised to refrain from certain energy dense food products to prevent weight gain. Scientists also evaluated the sensory properties of the high flavanol chocolate and the regular chocolate and collected the motivation scores of the participants to eat these chocolates during the intervention.

"The effect that dark chocolate has on our bodies is encouraging not only because it allows us to indulge with less guilt, but also because it could lead the way to therapies that do the same thing as dark chocolate but with better and more consistent results," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Until the 'dark chocolate drug' is developed, however, we'll just have to make do with what nature has given us!"


Chocolate: A sweet method for stroke prevention in men?

Eating a moderate amount of chocolate each week may be associated with a lower risk of stroke in men, according to a new study published in the August 29, 2012, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"While other studies have looked at how chocolate may help cardiovascular health, this is the first of its kind study to find that chocolate, may be beneficial for reducing stroke in men," said study author Susanna C. Larsson, PhD, with the Karolinska Institute in Stockholm, Sweden.

For the study, 37,103 Swedish men ages 49 to 75 were given a food questionnaire that assessed how often they consumed various foods and drinks and were asked how often they had chocolate. Researchers then identified stroke cases through a hospital discharge registry. Over 10 years, there were 1,995 cases of first stroke.

Men in the study who ate the largest amount of chocolate, about one-third of a cup of chocolate chips (63 grams), had a lower risk of stroke compared to those who did not consume any chocolate. Those eating the highest amount of chocolate had a 17-percent lower risk of stroke, or 12 fewer strokes per 100,000 person-years compared to those who ate no chocolate. Person-years is the total number of years that each participant was under observation.

In a larger analysis of five studies that included 4,260 stroke cases, the risk of stroke for individuals in the highest category of chocolate consumption was 19 percent lower compared to non-chocolate consumers. For every increase in chocolate consumption of 50 grams per week, or about a quarter cup of chocolate chips, the risk of stroke decreased by about 14 percent.

"The beneficial effect of chocolate consumption on stroke may be related to the flavonoids in chocolate. Flavonoids appear to be protective against cardiovascular disease through antioxidant, anti-clotting and anti-inflammatory properties. It's also possible that flavonoids in chocolate may decrease blood concentrations of bad cholesterol and reduce blood pressure," said Larsson.

"Interestingly, dark chocolate has previously been associated with heart health benefits, but about 90 percent of the chocolate intake in Sweden, including what was consumed during our study, is milk chocolate," Larsson added.


Dark Chocolate, Cocoa Compounds, May Reduce Blood Pressure


Compounds in cocoa may help to reduce blood pressure, according to a new systematic review in The Cochrane Library. The researchers reviewed evidence from short-term trials in which participants were given dark chocolate or cocoa powder daily and found that their blood pressure dropped slightly compared to a control group.

Cocoa contains compounds called flavanols, thought to be responsible for the formation of nitric oxide in the body. Nitric oxide causes blood vessel walls to relax and open wider, thereby reducing blood pressure. The link between cocoa and blood pressure stems from the discovery that the indigenous people of San Blas Island in Central American, who drink flavanol-rich cocoa drinks every day, have normal blood pressure regardless of age. However, flavanol concentrations in cocoa and chocolate products vary according to cocoa processing procedures and types of chocolate, so it is difficult to establish the optimal dosage for an effect.

To investigate the effect of flavanols on blood pressure, the researchers reviewed data from trials in which people consumed dark chocolate or cocoa powder containing between 30-1080 mg of flavanols in 3-100 g of chocolate each day. Altogether, 856 people were involved in 20 trials lasting 2-8 weeks, or in one case, 18 weeks. Flavanol-rich chocolate or cocoa powder reduced blood pressure on average by 2-3 mm Hg.

“Although we don’t yet have evidence for any sustained decrease in blood pressure, the small reduction we saw over the short term might complement other treatment options and might contribute to reducing the risk of cardiovascular disease,” said lead researcher Karin Ried of the National Institute of Integrative Medicine in Melbourne, Australia, who worked with colleagues at the University of Adelaide.

In a subset of trials, when chocolate or cocoa powder was compared to flavanol-free-products as controls, the beneficial effects were more pronounced (3-4 mm Hg), whereas the researchers found no significant effect on blood pressure in the second subset with low-flavanol products as control. It is possible that low-flavanol products also have a small effect on blood pressure, so that it was harder to observe differences between high and low-flavanol products in these trials. However, results of these subsets of trials may have been influenced by trial length and blinding of participants, as trials using flavanol-free control products tended to be of shorter duration with participants knowing their allocated group.

“We’ll also need to see long term trials, including effects on the risk of stroke and cardiovascular disease, before we can come to conclusions regarding clinical outcomes and potential side effects of long-term consumption,” said Ried. “These trials should use flavanol-free products in the control groups to eliminate any potential effects of low-dose flavanol on blood pressure.”


 Dark Chocolate May Reduce Cardiovascular Events

Good news for chocolate lovers! Eating dark chocolate on a daily basis can reduce cardiovascular events, including heart attacks and strokes in people with metabolic syndrome, i.e. a combination of factors that increase the risk of developing heart disease and diabetes.

The study was published in British Medical Journal (BMJ) June 1, 2012.

Worldwide, cardiovascular disease is the highest cause of mortality. Dark chocolate with a cocoa solid content of at least 60% is rich in flavonoids that are known to protect the heart. However, the protecting effects have so far only been assessed in short-term studies. To predict the long-term effects, Australian researchers from Melbourne used a mathematical model to predict the long-term health effects and economic effectiveness of eating dark chocolate on a daily basis. For their study, the researchers recruited 2,013 people who were high-risk candidates for heart disease. 



All participants were hypertensive and met the criteria for metabolic syndrome, yet they had no previous history of heart disease or diabetes and did not take medication to lower their blood pressure. The best-case scenario, i.e. a compliance of 100% meant that eating dark chocolate on a daily basis would be able to prevent 70 non-fatal and 15 fatal cardiovascular events per 10,000 people over a 10-year duration.

By reducing the compliance rate to 80%, they could potentially prevent 55 non-fatal and 10 fatal events respectively, which is still a substantial reduction and effective intervention.

According to the model, governments would be able to spend $A40 (£25; €31; $42) per person per year cost effectively on dark chocolate prevention strategies. This saving could be used for advertising, educational campaigns, or subsidizing dark chocolate in this high-risk population.

The researchers point out that their study only assessed non-fatal stroke and non-fatal heart attacks, and that further tests are required to evaluate the potential impact on other cardiovascular events like heart failure.

They also stress that these protective effects only apply to dark chocolate with a cocoa content of at least 60-70% cocoa, an not to milk or white chocolate. This could be because of the fact that dark chocolate has a much higher level of flavonoids.


Chocolate Consumption Reduces Risk of Stroke in Women


Ample evidence indicates that chocolate may have beneficial effects on the cardiovascular system. Chocolate consumption has been shown to reduce systolic and diastolic blood pressure in short-term randomized feeding trials (1), and has been demonstrated to improve endothelial and platelet function and to ameliorate insulin resistance (2). Moreover, flavonoids in chocolate possess strong antioxidant activity and can suppress oxidation of low-density lipoprotein cholesterol (3).

In the autumn of 1997, 39,227 women completed a questionnaire that included approximately 350 items concerning diet and other lifestyle factors (4). We excluded women with a missing national identification number, those with implausible values for total energy intake, and those with a history of cancer, stroke, coronary heart disease, or diabetes mellitus before baseline. That left 33,372 women, age 49 to 83 years, for analysis. The study was approved by the Ethical Review Board at the Karolinska Institutet (Stockholm, Sweden). Chocolate consumption was assessed using a self-administered food-frequency questionnaire. Women were asked to indicate how often on average they had consumed chocolate and 95 other foods during the previous year. There were 8 pre-defined consumption categories ranging from never to ≥3 times a day. In the 1990s, approximately 90% of chocolate consumption in Sweden was milk chocolate, containing approximately 30% cocoa solids (5).

Our findings are broadly consistent with those from previous smaller studies, which observed either a statistically significant (136 stroke cases) (6) or a nonsignificant (111 or 469 stroke cases) (5,7) inverse association between chocolate consumption and total stroke. In the present study, only women in the highest quartile of chocolate consumption (median 66.5 g/week) had a significantly reduced risk of stroke, suggesting that higher intakes are necessary for a potential protective effect. The reason for the stronger association observed for hemorrhagic stroke than for cerebral infarction is unclear.

In summary, results from this cohort of women suggest that a high chocolate consumption is associated with a lower risk of stroke.


Chocolate reduces the risk of cardiovascular disease and stroke

A number of recent studies have shown that eating chocolate has a positive influence on human health due to its antioxidant and anti-inflammatory properties. This includes reducing blood pressure and improving insulin sensitivity (a stage in the development of diabetes).

However, the evidence about how eating chocolate affects your heart still remains unclear. So, Dr Oscar Franco and colleagues from the University of Cambridge carried out a large scale review of the existing evidence to evaluate the effects of eating chocolate on cardiovascular events like heart attack and stroke.

They analysed the results of seven studies, involving over 100,000 participants with and without existing heart disease. For each study, they compared the group with the highest chocolate consumption against the group with the lowest consumption. Differences in study design and quality were also taken into account to minimise bias.

Five studies reported a beneficial link between higher levels of chocolate consumption and the risk of cardiovascular events and they found that the "highest levels of chocolate consumption were associated with a 37% reduction in cardiovascular disease and a 29% reduction in stroke compared with lowest levels." No significant reduction was found in relation to heart failure.

The studies did not differentiate between dark or milk chocolate and included consumption of chocolate bars, drinks, biscuits and desserts.

The authors say the findings need to be interpreted with caution, in particular because commercially available chocolate is very calorific (around 500 calories for every 100 grams) and eating too much of it could in itself lead to weight gain, risk of diabetes and heart disease.


Moderate chocolate consumption linked to lower risks of heart failure

Study highlights:

• Eating moderate amounts of chocolate is linked to lower risks of heart failure among middle-aged and older women, compared to eating no chocolate at all.
• Experts warn Americans that the potential for heart health benefits from chocolate must be carefully weighed against the negative risks including excess calories and fat.
• This is the first study to examine long-term effects of eating chocolate on heart failure rates.

Middle-aged and elderly Swedish women who regularly ate a small amount of chocolate had lower risks of heart failure risks, in a study reported in Circulation: Heart Failure, a journal of the American Heart Association.

The nine-year study, conducted among 31,823 middle-aged and elderly Swedish women, looked at the relationship of the amount of high-quality chocolate the women ate, compared to their risk for heart failure. The quality of chocolate consumed by the women had a higher density cocoa content somewhat like dark chocolate by American standards. In this study, researchers found:

- Women who ate an average of one to two servings of the high-quality chocolate per week had a 32 percent lower risk of developing heart failure.
- Those who had one to three servings per month had a 26 percent lower risk.
- Those who consumed at least one serving daily or more didn’t appear to benefit from a protective effect against heart failure.

The lack of a protective effect among women eating chocolate every day is probably due to the additional calories gained from eating chocolate instead of more nutritious foods, said Murrray Mittleman, M.D., Dr.P.H., lead researcher of the study.

“You can’t ignore that chocolate is a relatively calorie-dense food and large amounts of habitual consumption is going to raise your risks for weight gain,” said Mittleman, director of the Cardiovascular Epidemiology Research Unit at Harvard Medical School’s Beth Israel Deaconess Medical Center in Boston. “But if you’re going to have a treat, dark chocolate is probably a good choice, as long as it’s in moderation.”

High concentration of compounds called “flavonoids” in chocolate may lower blood pressure, among other benefits, according to mostly short-term studies. However, this is the first study to show long-term outcomes related specifically to heart failure, which can result from ongoing untreated high blood pressure.

In the observational study, researchers analyzed self-reported food-frequency questionnaire responses from participants 48-to-83-years-old in the Swedish Mammography Cohort. Combining the results with data from national Swedish hospitalization and death registries between 1998 through 2006, the researchers used multiple forms of statistical modeling to reach their conclusions on heart failure and chocolate consumption.

Mittleman said differences in chocolate quality affect the study’s implications for Americans. Higher cocoa content is associated with greater heart benefits. In Sweden, even milk chocolate has a higher cocoa concentration than dark chocolate sold in the United States.

Although 90 percent of all chocolate eaten across Sweden during the study period was milk chocolate, it contained about 30 percent cocoa solids. U.S. standards only require 15 percent cocoa solids to qualify as dark chocolate. So, by comparison, American chocolate may have fewer heart benefits and more calories and fat per equivalent amounts of cocoa content compared to the chocolate eaten by the Swedish women in the study.

Also, the average serving size for Swedish women in the study ranged from 19 grams among those 62 and older, to 30 grams among those 61 and younger. In contrast, the standard American portion size is 20 grams.

“Those tempted to use these data as their rationale for eating large amounts of chocolate or engaging in more frequent chocolate consumption are not interpreting this study appropriately,” said Linda Van Horn, Ph.D., R.D., immediate past chair of the American Heart Association Nutrition Committee and professor in the Department of Preventive Medicine at Northwestern University’s Feinberg School of Medicine in Chicago. “This is not an ‘eat all you want’ take-home message, rather it’s that eating a little dark chocolate can be healthful, as long as other adverse behaviors do not occur, such as weight gain or excessive intake of non-nutrient dense ‘empty’ calories.”


Dark chocolate lowers blood pressure

For people with hypertension, eating dark chocolate can significantly reduce blood pressure. Researchers writing in the open access journal BMC Medicine combined the results of 15 studies into the effects of flavanols, the compounds in chocolate which cause dilation of blood vessels, on blood pressure.

Dr Karin Ried worked with a team of researchers from the University of Adelaide, Australia, to conduct the analysis. She said, "Flavanols have been shown to increase the formation of endothelial nitric oxide, which promotes vasodilation and consequently may lower blood pressure. There have, however, been conflicting results as to the real-life effects of eating chocolate. We've found that consumption can significantly, albeit modestly, reduce blood pressure for people with high blood pressure but not for people with normal blood pressure".

The pressure reduction seen in the combined results for people with hypertension, 5mm Hg systolic, may be clinically relevant – it is comparable to the known effects of 30 daily minutes of physical activity (4-9mm Hg) and could theoretically reduce the risk of a cardiovascular event by about 20% over five years. The researchers are cautious, however, "The practicability of chocolate or cocoa drinks as long-term treatment is questionable", said Dr Ried.

Does chocolate reduce blood pressure? A meta-analysis
Karin Ried, Thomas Sullivan, Peter Fakler, Oliver R Frank and Nigel P Stocks
BMC Medicine 2010, 8:39 doi:10.1186/1741-7015-8-39


Dark Chocolate May Guard Against Brain Injury From Stroke

Researchers at Johns Hopkins have discovered that a compound in dark chocolate may protect the brain after a stroke by increasing cellular signals already known to shield nerve cells from damage.

Ninety minutes after feeding mice a single modest dose of epicatechin, a compound found naturally in dark chocolate, the scientists induced an ischemic stroke by essentially cutting off blood supply to the animals' brains. They found that the animals that had preventively ingested the epicatechin suffered significantly less brain damage than the ones that had not been given the compound.

While most treatments against stroke in humans have to be given within a two- to three-hour time window to be effective, epicatechin appeared to limit further neuronal damage when given to mice 3.5 hours after a stroke. Given six hours after a stroke, however, the compound offered no protection to brain cells.

Sylvain Dore, Ph.D., associate professor of anesthesiology and critical care medicine and pharmacology and molecular sciences at the Johns Hopkins University School of Medicine, says his study suggests that epicatechin stimulates two previously well-established pathways known to shield nerve cells in the brain from damage. When the stroke hits, the brain is ready to protect itself because these pathways - Nrf2 and heme oxygenase 1 - are activated. In mice that selectively lacked activity in those pathways, the study found, epicatechin had no significant protective effect and their brain cells died after a stroke.

The study appeared online in the Journal of Cerebral Blood Flow and Metabolism.

Eventually, Dore says, he hopes his research into these pathways could lead to insights into limiting acute stroke damage and possibly protecting against chronic neurological degenerative conditions, such as Alzheimer's disease and other age-related cognitive disorders.

The amount of dark chocolate people would need to consume to benefit from its protective effects remains unclear, since Dore has not studied it in clinical trials. People shouldn't take this research as a free pass to go out and consume large amounts of chocolate, which is high in calories and fat. In fact, people should be reminded to eat a healthy diet with a variety of fruits and vegetables.

Scientists have been intrigued by the potential health benefits of epicatechin by studying the Kuna Indians, a remote population living on islands off the coast of Panama. The islands' residents had a low incidence of cardiovascular disease.

Scientists who studied them found nothing striking in the genes and realized that when they moved away from Kuna, they were no longer protected from heart problems. Researchers soon discovered the reason was likely environmental: The residents of Kuna regularly drank a very bitter cocoa drink, with a consistency like molasses, instead of coffee or soda. The drink was high in the compound epicatechin, which is a flavanol, a flavanoid-related compound.

But Dore says his research suggests the amount needed could end up being quite small because the suspected beneficial mechanism is indirect. "Epicatechin itself may not be shielding brain cells from free radical damage directly, but instead, epicatechin, and its metabolites, may be prompting the cells to defend themselves," he suggests. The epicatechin is needed to jump-start the protective pathway that is already present within the cells. "Even a small amount may be sufficient," Dore says.

Not all dark chocolates are created equally, he cautions. Some have more bioactive epicatechin than others.

"The epicatechin found in dark chocolate is extremely sensitive to changes in heat and light" he says. "In the process of making chocolate, you have to make sure you don't destroy it. Only few chocolates have the active ingredient. The fact that it says 'dark chocolate' is not sufficient."


Chocolate reduces blood pressure and risk of heart disease

Chocolate may be good for you – at least in small quantities and preferably if it's dark chocolate – according to research that shows just one small square of chocolate a day can lower your blood pressure and reduce your risk of heart disease. The study was published online Wednesday 31 March 2010 in the European Heart Journal [1].

Researchers in Germany followed 19,357 people, aged between 35 and 65, for at least ten years and found that those who ate the most amount of chocolate – an average of 7.5 grams a day – had lower blood pressure and a 39% lower risk of having a heart attack or stroke compared to those who ate the least amount of chocolate – an average of 1.7 grams a day. The difference between the two groups amounts to six grams of chocolate: the equivalent of less than one small square of a 100g bar.

Dr Brian Buijsse, a nutritional epidemiologist at the German Institute of Human Nutrition, Nuthetal, Germany, who led the research said: "People who ate the most amount of chocolate were at a 39% lower risk than those with the lowest chocolate intakes. To put it in terms of absolute risk, if people in the group eating the least amount of chocolate (of whom 219 per 10,000 had a heart attack or stroke) increased their chocolate intake by six grams a day, 85 fewer heart attacks and strokes per 10,000 people could be expected to occur over a period of about ten years. If the 39% lower risk is generalised to the general population, the number of avoidable heart attacks and strokes could be higher because the absolute risk in the general population is higher."[2]

However, he warned that it was important people ensured that eating chocolate did not increase their overall intake of calories or reduce their consumption of healthy foods. "Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense food, such as snacks, in order to keep body weight stable," he said.

The people in the study were participants in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC). They received medical checks, including blood pressure, height and weight measurements at the start of the study between 1994-1998, and they also answered questions about their diet, lifestyle and health. They were asked how frequently they ate a 50g bar of chocolate, and they could say whether they ate half a bar, or one, two or three bars. They were not asked about whether the chocolate was white, milk or dark chocolate; however, the researchers asked a sub-set of 1,568 participants to recall their chocolate intake over a 24-hour period and to indicate which type of chocolate they ate. This gave an indication of the proportions that might be expected in the whole study. In this sub-set, 57% ate milk chocolate, 24% dark chocolate and 2% white chocolate.

In follow-up questionnaires, sent out every two or three years until December 2006, the study participants were asked whether they had had a heart attack or stroke, information which was subsequently verified by medical records from general physicians or hospitals. Death certificates from those who had died were also used to identify heart attacks and strokes.

The researchers allocated the participants to four groups (quartiles) according to their level of chocolate consumption. Those in the top quartile, eating around 7.5g of chocolate a day, had blood pressure that was about 1mm Hg (systolic) and 0.9mm Hg (diastolic) lower than those in the bottom quartile. [3]

"Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, therefore chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke," explained Dr Buijsse.

This is, in fact, what the study found. During the eight years there were 166 heart attacks (24 fatal) and 136 strokes (12 fatal); people in the top quartile had a 27% reduced risk of heart attacks and nearly half the risk (48%) of strokes, compared with those in the lowest quartile.

The researchers found lower blood pressure due to chocolate consumption at the start of the study explained 12% of the reduced risk of heart attacks and strokes, but even after taking this into account, those in the top quartile still had their risk reduced by a third (32%) compared to those in the bottom quartile over the duration of the study.

Although more research needs to be carried out, the researchers believe that flavanols in cocoa may be the reason why chocolate seems to be good for people's blood pressure and heart health; and since there is more cocoa in dark chocolate, dark chocolate may have a greater effect.

"Flavanols appear to be the substances in cocoa that are responsible for improving the bioavailability of nitric oxide from the cells that line the inner wall of blood vessels – vascular endothelial cells," said Dr Buijsse. "Nitric oxide is a gas that, once released, causes the smooth muscle cells of the blood vessels to relax and widen; this may contribute to lower blood pressure. Nitric oxide also improves platelet function, making the blood less sticky, and makes the vascular endothelium less attractive for white blood cells to attach and stick around."

The authors of the study conclude: "Given these and other promising health effects of cocoa, it is tempting to indulge more in chocolate. Small amounts of chocolate, however, may become part of a diet aimed to prevent CVD [cardiovascular disease] only after confirmation by other observational studies and particularly by randomized trials."

Commenting on the research on behalf of the European Society of Cardiology (ESC), Frank Ruschitzka, Professor of Cardiology, Director of Heart Failure/Transplantation at the University Hospital Zurich, Switzerland, and a Fellow of the ESC, said: "Basic science has demonstrated quite convincingly that dark chocolate particularly, with a cocoa content of at least 70%, reduces oxidative stress and improves vascular and platelet function. However, before you rush to add dark chocolate to your diet, be aware that 100g of dark chocolate contains roughly 500 calories. As such, you may want to subtract an equivalent amount of calories, by cutting back on other foods, to avoid weight gain."


Notes:

[1] "Chocolate consumption in relation to blood pressure and risk of cardiovascular disease in German adults." European Heart Journal. doi:10.1093/eurheartj/ehq068.

[2] Examples of absolute risk are given here to help with understanding the findings; however, the study itself only reports relative risk.

[3] mm Hg = millimetres of mercury (the measure for blood pressure).

Systolic = when the heart's ventricles contract.

Diastolic = when the ventricles relax.

The normal blood pressure for a healthy adult is around 120/80.


Chocolate could lower risk of stroke

Giving chocolates to your Valentine may help lower their risk of stroke based on a preliminary study from researchers at St. Michael's Hospital. The study, presented at the American Academy of Neurology in April, 2010, also found that eating chocolate may lower the risk of death after suffering a stroke.

"Though more research is needed to determine whether chocolate is the contributing factor to lowering stroke risk, it is rich in anti-oxidants and that may have a protective effect against stroke," explains Dr. Gustavo Saposnik, a neurologist at St. Michael's Hospital.

Chocolate is rich in antioxidants called flavonoids which may help lower the risk of strokes.

Authored by Sarah Sahib, the research analyzed three studies involving chocolate consumption and stroke risk. One showed there was no association between flavonoid intake and risk of stroke or death. In contrast, a second study found an association with stroke for chocolate consumption once a week as opposed to none per week. The third study suggested flavonoid intake from eating chocolate weekly lowered death caused by a stroke.

"We are continuing to investigate the correlation between chocolate and the risk of stroke," says Dr. Saposnik. "The preliminary data is interesting but we need to determine whether consumption truly lowers the risk of a stroke or whether the benefit is biased based on those who are on average healthier than the general population when enrolling in a clinical trial."


 A little dark chocolate = less blood pressure

Consumption of small amounts of dark chocolate associated with reduction in blood pressure

Eating about 30 calories a day of dark chocolate was associated with a lowering of blood pressure, without weight gain or other adverse effects, according to a study in JAMA.

Previous research has indicated that consumption of high amounts of cocoa-containing foods can lower blood pressure (BP), believed to be due to the action of the cocoa polyphenols (a group of chemical substances found in plants, some of which, such as the flavanols, are believed to be beneficial to health). “A particular concern is that the potential BP reduction contributed by the flavanols could be offset by the high sugar, fat and calorie intake with the cocoa products,” the authors write. The effect of low cocoa intake on BP is unclear.

Dirk Taubert, M.D., Ph.D., of University Hospital of Cologne, Germany, and colleagues assessed the effects of low regular amounts of cocoa on BP. The trial, conducted between January 2005 and December 2006, included 44 adults (age 56 through 73 years; 24 women, 20 men) with untreated upper-range prehypertension (BP 130/85 – 139/89) or stage 1 hypertension (BP 140/90 – 160/100). Participants were randomly assigned to receive for 18 weeks either 6.3 g (30 calories) per day of dark chocolate containing 30 mg polyphenols or matching polyphenol-free white chocolate.

The researchers found that from baseline to 18 weeks, dark chocolate intake reduced average systolic BP by −2.9 (1.6) mm Hg and diastolic BP by −1.9 (1.0) mm Hg without changes in body weight, plasma levels of lipids or glucose. Hypertension prevalence declined from 86 percent to 68 percent. Systolic and diastolic BP remained unchanged throughout the treatment period among those in the white chocolate group. Dark chocolate consumption resulted in the short-term appearance of cocoa phenols in plasma and increased vasodilatory S-nitrosoglutathione. There was no change in plasma biomarkers in the white chocolate group.

“Although the magnitude of the BP reduction was small, the effects are clinically noteworthy. On a population basis, it has been estimated that a 3-mm Hg reduction in systolic BP would reduce the relative risk of stroke mortality by 8 percent, of coronary artery disease mortality by 5 percent, and of all-cause mortality by 4 percent,” the authors write.

“The most intriguing finding of this study is that small amounts of commercial cocoa confectionary convey a similar BP-lowering potential compared with comprehensive dietary modifications that have proven efficacy to reduce cardiovascular event rate. Whereas long-term adherence to complex behavioral changes is often low and requires continuous counseling, adoption of small amounts of flavanol-rich cocoa into the habitual diet is a dietary modification that is easy to adhere to and therefore may be a promising behavioral approach to lower blood pressure in individuals with above-optimal blood pressure. Future studies should evaluate the effects of dark chocolate in other populations and evaluate long-term outcomes,” the authors conclude. 


Dark chocolate: Half a bar per week to keep at bay the risk of heart attack

An Italian study, the first outcome of a large epidemiological investigation, finds new beneficial effects of chocolate in the prevention of cardiovascular disease

6.7 grams of chocolate per day represent the ideal amount for a protective effect against inflammation and subsequent cardiovascular disease.

The findings, published in the Journal of Nutrition, official journal of the American Society of Nutrition, come from one of the largest epidemiological studies ever conducted in Europe, the Moli-sani Project, which has enrolled 20,000 inhabitants of the Molise region so far. By studying the participants recruited, researchers focused on the complex mechanism of inflammation. It is known how a chronic inflammatory state represents a risk factor for the development of cardiovascular disease, from myocardial infarction to stroke, just to mention the major diseases. Keeping the inflammation process under control has become a major issue for prevention programs and C reactive protein turned out to be one of the most promising markers, detectable by a simple blood test.

"We started from the hypothesis- says Romina di Giuseppe, 33, lead author of the study- that high amounts of antioxidants contained in the cocoa seeds, in particular flavonoids and other kinds of poly-phenols, might have beneficial effects on the inflammatory state. Our results have been absolutely encouraging: people having moderate amounts of dark chocolate regularly have significantly lower levels of C-reactive protein in their blood. In other words, their inflammatory state is considerably reduced." The 17% average reduction observed may appear quite small, but it is enough to decrease the risk of cardiovascular disease for one third in women and one fourth in men. It is undoubtedly a remarkable outcome".

Chocolate amounts are critical. "We are talking of a moderate consumption. The best effect is obtained by consuming an average amount of 6.7 grams of chocolate per day, corresponding to a small square of chocolate twice or three times a week. Beyond these amounts the beneficial effect tends to disappear".

From a practical point of view, as the common chocolate bar is 100 grams, the study states that less than half a bar of dark chocolate consumed during the week may become a healthy habit. What about the milk chocolate? "Previous studies- the young investigator continues- have demonstrated that milk interferes with the absorption of polyphenols. That is why our study considered just the dark chocolate".

Researchers wanted to sweep all the doubts away. They took into account that chocolate lovers might consume other healthy food too, as wine, fruits and vegetables. Or they might exercise more than others people do. So the observed positive effect might be ascribed to other factors but not to cocoa itself. "In order to avoid this - researcher says - we "adjusted" for all possible "confounding" parameters. But the beneficial effect of chocolate still remained and we do believe it is real".


Cocoa could prevent intestinal pathologies such as colon cancer


A new study on living animals has shown for the first time that eating cocoa (the raw material in chocolate) can help to prevent intestinal complaints linked to oxidative stress, including colon carcinogenesis onset caused by chemical substances.

The growing interest amongst the scientific community to identify those foods capable of preventing diseases has now categorized cocoa as a 'superfood'. It has been recognised as an excellent source of phytochemical compounds, which offer potential health benefits.

Headed by scientists from the Institute of Food Science and Technology and Nutrition (ICTAN) and recently (January, 2012) published in the Molecular Nutrition & Food Research journal, the new study supports this idea and upholds that cacao consumption helps to prevent intestinal complaints linked to oxidative stress, such as the onset of chemically induced colon carcinogenesis.

"Being exposed to different poisons in the diet like toxins, mutagens and procarcinogens, the intestinal mucus is very susceptible to pathologies," explains María Ángeles Martín Arribas, lead author of the study and researcher at ICTAN. She adds that "foods like cocoa, which is rich in polyphenols, seems to play an important role in protecting against disease."

The study on live animals (rats) has for the first time confirmed the potential protection effect that flavonoids in cocoa have against colon cancer onset. For eight weeks the authors of the study fed the rats with a cocoa-rich (12%) diet and carcinogenesis was induced.

Doctor Martín Arribas outlines that "four weeks after being administered with the chemical compound azoxymethane (AOM), intestinal mucus from premalignant neoplastic lesions appeared. These lesions are called 'aberrant crypt foci' and are considered to be good markers of colon cancer pathogenesis.

The results of the study showed that the rats fed a cocoa-rich diet had a significantly reduced number of aberrant crypts in the colon induced by the carcinogen. Likewise, this sample saw an improvement in their endogenous antioxidant defences and a decrease in the markers of oxidative damage induced by the toxic compound in this cell.

The researchers conclude that the protection effect of cocoa can stop cell-signalling pathways involved in cell proliferation and, therefore, subsequent neoplasty and tumour formation. Lastly, the animals fed with the cocoa-rich diet showed an increase in apoptosis or programmed cell death as a chemoprevention mechanism against the development of the carcinogenesis.

Although more research is required to determine what bioactive compounds in cocoa are responsible for such effects, the authors conclude that a cocoa-rich diet seems capable of reducing induced oxidative stress. It could also have protection properties in the initial stages of colon cancer as it reduces premalignant neoplastic lesion formation.

Cocoa is one of the ingredients in chocolate. It is one of the richest foods in phenolic compounds, mainly in flavonoids like procyanidins, catechins and epicatechins, which have numerous beneficial biological activities in the prevention of cardiovascular diseases and cancer (mainly colorectal cancer).

In fact, compared to other foods with a high flavonoid content, cocoa has a high level of procyanidins with limited bioavailability. These flavonoids are therefore found in their highest concentrations in the intestine where they neutralise many oxidants.



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