Caffeine can prevent memory loss in diabetes

Caffeine can prevent memory loss in diabetes: Badly controlled diabetes are known to affect the brain causing memory and learning problems and even increased incidence of dementia, although how this occurs is not clear. But now a study in mice with type 2 diabetes has discovered how diabetes affects a brain area called hippocampus causing memory loss, and also how caffeine can prevent this. 

Coffee helps teams work together, study suggests

In continuation of my update on coffee

Good teamwork begins with a cup of coffee for everyone, a new study suggests.

Researchers found that people gave more positive reviews for their group's performance on a task—and their own contribution—if they drank caffeinated coffee beforehand.

A second study showed that people talked more in a group setting under the influence of caffeinated coffee—but they also were more on-topic than those who drank decaf.

Coffee seems to work its magic in teams by making people more alert, said Amit Singh, co-author of the study and a doctoral student in marketing at The Ohio State University's Fisher College of Business.

"We found that increased alertness was what led to the positive results for team performance," Singh said.

"Not surprisingly, people who drank caffeinated coffee tended to be more alert."

Singh conducted the study with Vasu Unnava and H. Rao Unnava, both formerly at Ohio State and now with the Graduate School of Management at the University of California, Davis. The study appears online in the Journal of Psychopharmacology.

While many studies have looked at how caffeine affects individual performance, this is the first to examine the impact it has on teams, Singh said.

The first study involved 72 undergraduate students who said they were coffee drinkers. They were instructed not to drink coffee before the experiment.

Half of them first participated in what they were told was a coffee-tasting task. They were split into groups of five. After drinking a cup of coffee and rating its flavor, they were given 30 minutes of filler tasks to give the caffeine a chance to kick in. The other half of the participants did the coffee tasting at the end of the experiment.

Each group then read about and were asked to discuss a controversial topic—the Occupy movement, a liberal movement that highlighted social and economic inequality. After a 15-minute discussion, group members evaluated themselves and the other group members.

Results showed that those who drank the coffee before the discussion rated themselves and their fellow team members more positively than did those who drank coffee after the discussion, Singh said.

The second study was similar, except that 61 students all drank coffee at the beginning of the study. However, half drank decaf and the others drank caffeinated brew.

http://journals.sagepub.com/loi/jop

What Does the Research Say About Coffee and Your Health?

In continuation of my update on coffee...

Coffee-Cup of joe. Java. No matter what you call it, millions of people worldwide wake up and fuel their day with it. And though consumers might be jittery about the recent court battle in California over cancer warnings, experts say most of the science actually indicates coffee could have health benefits.

"The overall picture is quite clear," said Dr. Frank Hu, chair of nutrition at Harvard University's T.H. Chan School of Public Health. "There is no long-term increased risk of major chronic disease, including diabetes, cardiovascular disease or even cancer."

The java confusion stems over an eight-year court case. A Los Angeles-based judge's preliminary decision last month requires cancer warning labels because of concerns about acrylamide, a chemical produced during the roasting process. Acrylamide also is present in some fried or roasted starchy foods, including french fries, potato chips, breakfast cereals and toast. It's also found in cigarette smoke. The judge gave the coffee industry a few weeks to file appeals and could issue a final ruling late this month.

But there's little evidence acrylamide levels in food cause cancer in humans. Studies have found no consistent evidence acrylamide exposure in food is associated with cancer risk, according to the U.S. National Cancer Institute. The World Health Organization's International Agency for Research on Cancer reviewed more than 1,000 human and animal studies and issued a statement in 2016 that "found no conclusive evidence for a carcinogenic effect of drinking coffee."

"The California judge's decision to label coffee as a cancer risk is really inconsistent with the scientific literature," Hu said. "It's very misleading and has already caused a huge amount of confusion in the general public. The health outcomes have been remarkably consistent."

Hu was senior author of a 2015 study in the journal Circulation that concluded people who regularly drink moderate amounts of coffee daily -- fewer than five cups -- experienced a lower risk of death from heart and neurological diseases.

About four years ago, the U.S. government gave coffee its OK, too. The Department of Agriculture's dietary guidelines for all Americans, published every five years as a go-to source for nutrition advice, said three to five cups a day, which can be up to 400 milligrams a day of caffeine, can be part of a healthy diet. The American Heart Association suggests that people who have an arrhythmia, an abnormal heart rhythm, talk to their health care provider about caffeine intake.

"This guidance on coffee is informed by strong and consistent evidence showing that, in healthy adults, moderate coffee consumption is not associated with an increased risk of major chronic diseases (e.g., cancer) or premature death, especially from cardiovascular disease," the federal guidelines say. "However, individuals who do not consume caffeinated coffee or other caffeinated beverages are not encouraged to incorporate them into their eating pattern."

More recently, a review of more than 200 studies published last fall in the BMJ concluded three to four cups a day may be "more likely to benefit health than harm." It found a lower risk of liver disease and some cancers in coffee drinkers, and a lower risk of dying from stroke.

All of that should be good news to the people around the world who drink more than 1.1 billion cups of coffee each day.

But it's still easy to be confused. A quick search for coffee and health online yields hundreds, even thousands, of results.

Studies abound -- some funded by the coffee industry. For example, a European Journal of Nutritionstudy investigated the effects of coffee and its antioxidant properties and found no effect. Researchers took blood samples of 160 volunteers who drank up to three to five cups of coffee or water each day for eight weeks.

"Up to five cups of coffee per day had no detectable effect, either beneficial or harmful, on human health," that study concluded. It was funded by Kraft Foods, which makes Maxwell House coffees.

Of course, "no one is talking about coffee as a magic bullet," Hu said. He and other experts say it's important to keep track of the bigger picture, with the focus on moderation and dietary patterns.

"You can't pin anything on any one specific lifestyle behavior, particularly with diet," said Alice Lichtenstein, a senior scientist and director of the Cardiovascular Nutrition Laboratory at Tufts University in Boston.

"When we talk about diet, it should really be about the whole package, not single items. Right now, the majority of the evidence suggests there may be a health benefit from drinking coffee and there doesn't seem to be any disadvantage. Of course, with a caveat that you don't want to add a lot of cream and sugar, or to use it as an excuse to have a few cookies or a pastry. Then, there is a downside," said Lichtenstein, a professor of nutrition science and policy who also was an advisor on the federal dietary guidelines.

"We have a tendency to focus on one or two specific foods or beverages, and that's when the whole floor falls out from under us."

Tea could help lower high blood pressure: Study

In continuation of my update on tea and its effect....

A new study suggests that taking tea daily could help in lowering blood pressure.The study shows that people who drank three cups of black tea a day were able to lower their blood pressure. This was seen when compared to those who drank a placebo similar in taste and caffeine content. Those who drank the tea saw a slight drop in both systolic and diastolic blood pressure over six months.

Experts however warned that drinking tea is not a substitute for blood pressure-lowering medication, but researchers said the findings show tea could still provide a benefit.

Researchers note that although the study cannot identify specific components of the tea that might lead to a drop in blood pressure, past studies have shown flavonoids, compounds found in many plants such as tea, are good for heart health.

“The message really isn't for an individual to go out and drink a lot of tea,” said Jonathan Hodgson,

More...

Can Green Tea, Coffee Reduce Stroke Risk? - Drugs.com MedNews

In continuation of my update on green tea...

This study of about 83,000 people suggests that drinking green tea or coffee daily might lower stroke risk by about 20 percent, with even more protection against a specific type of stroke.

"The regular action of daily drinking [of] green tea and coffee is a benefit in preventing stroke," said lead researcher Dr. Yoshihiro Kokubo, chief doctor in the department of preventive cardiology at the National Cerebral and Cardiovascular Center, in Osaka.

"If you cannot readily improve your lifestyle, try to prevent stroke by drinking green tea every day," he said.

Although it isn't certain why coffee and tea may have this effect, Kokubo thinks it might be due to certain properties in these drinks that keep blood from clotting.

In addition, green tea contains catechins, which have an antioxidant, anti-inflammatory effect. Some chemicals in coffee, such as chlorogenic acid, may cut the risk of stroke by lowering the chances of developing type 2 diabetes, he explained.

Coffee also contains caffeine, which may have an impact on cholesterol levels and blood pressure, and may cause changes in insulin sensitivity, which affects blood sugar, he added.

One expert, Dr. Ralph Sacco, past president of the American Heart Association, cautioned that this type of study cannot say for sure that the lower risk of stroke is really the result of drinking coffee or tea.

"Such association studies are still limited in [the] ability to tell whether it is some ingredients in the coffee or tea or some other behavior common to coffee and tea drinkers that is driving the protective effects," said Sacco, chairman of neurology at the University of Miami Miller School of Medicine.

Can Green Tea, Coffee Reduce Stroke Risk? - Drugs.com MedNews

Is Green Tea a Fad or a Real Health Boost?

In continuation of my updates on Green tea

Green tea is a popular health trend, with many people sipping in hopes of deriving benefits from the brew.

There's nothing wrong with that, dietitians say -- green tea is a healthy drink loaded with antioxidants. But the jury's still out on many of its purported health benefits.

"Clinical trials related to green tea are still in their early stages," said Nancy Farrell Allen, a registered dietitian nutritionist in Fredericksburg, Va. "I say drink it, enjoy it. It's not going to hurt, and it might have worthy benefits to it. But nutrition is a science, and it takes time for our understanding to evolve."

Green tea's potential health benefits derive from catechins, which are powerful antioxidant compounds known as flavonoids, said Chelsey Schneider, clinical nutrition supervisor at Mount Sinai Beth Israel Cancer Center in New York City.

One catechin in particular, known as EGCG, is found at higher levels in green tea than in either white or black tea, she said.

"This compound can be even stronger than vitamin C and E, which are very, very strong antioxidants," Schneider said. Antioxidants help prevent damage to cells.

Green, black and white tea all come from the same plant, said Allen, who is a spokeswoman for the Academy of Dietetics and Nutrition.

Green tea is made from the leaves of the mature plant, while white tea is made of leaves plucked early in development. Black tea is made from green tea leaves that are laid out and covered with a damp cloth, she said.

"They dry and blacken and ferment a little, giving black tea that darker, richer flavor," Allen said. But this process also reduces levels of catechins in black tea.

Weight loss has been associated with green tea, with experts suggesting that its mixture of caffeine and catechins can enhance a person's metabolism and processing of fat, according to the University of California-Davis Department of Nutrition.

But it appears that folks have to drink a lot of green tea to get substantial weight loss benefits and carefully watch the rest of their diet, UC-Davis says.

Green tea also has been tied to heart health.

For example, green tea was shown to reduce "bad" LDL cholesterol in a 2018 study of more than 80,000 Chinese published in the Journal of the American Heart Association.

Evidence suggests catechins in green tea also could lower risk of heart attacks, help blood vessels relax and reduce inflammation, UC-Davis says.

Green tea even has been associated with a lower risk of some cancers.

The American Cancer Society says studies have linked green tea to a reduction in ovarian cancer risk. And UC-Davis said experimental models have shown that green tea might reduce risk of a variety of other cancers.

But a 2016 evidence review by the Cochrane Library concluded that there is "insufficient and conflicting evidence to give any firm recommendations regarding green tea consumption for cancer prevention."

Schneider said the research is limited. "Some small studies say green tea can maybe be preventative for certain cancers, like breast, ovarian, endometrial, pancreatic and oral cancers, but there aren't so many conclusive human trials that support that," she said.

Green tea also might help keep your brain younger. A 2014 study in the journal PLOS One found that Japanese who drank more green tea had significantly less decline in brain function, although researchers couldn't rule out the possibility that these folks might have other healthy habits that helped keep them mentally sharp.

One caveat with all of this research is that it tends to take place in Asian countries, where people drink much more green tea. There might be significant differences for Americans.

And the way you take your green tea could diminish any potential positive effects, Schneider added.

"A lot of people are adding processed white sugar to their green tea, which really makes something beautiful and healthy into something unhealthy," she said.

Adding milk or cream to your tea also might not be a good idea.

"There are some studies that say having milk in green tea can actually block the effects of you absorbing the antioxidant," Schneider said. "If it was me, I'd drink it straight up."

Maillard reaction is the principle contributor to the antioxidant capacity of coffee brews ......

Food scientists at the University of British Columbia have been able to pinpoint more of the complex chemistry behind coffee's much touted antioxidant benefits, tracing valuable compounds to the roasting process.  Yazheng Liu and Prof. David Kitts found that the prevailing antioxidants present in dark roasted coffee brew extracts result from the green beans being browned under high temperatures.

Liu and Kitts analyzed the complex mixture of chemical compounds produced during the bean's browning process, called the "Maillard reaction (a chemical reaction between an amino acid and a reducing sugar, usually requiring heat). The term refers to the work by French chemist Louis-Camille Maillard who in the 1900s looked at how heat affects the carbohydrates, sugars and proteins in food, such as when grilling steaks or toasting bread. Previous studies suggested that antioxidants in coffee could be traced to caffeine or the chlorogenic acid (see structures above and below respectively)  found in green coffee beans, but the present results clearly show that the Maillard reaction is the main source of antioxidants claims the researchers.  Researchers conclude that that coffee beans lose 90 per cent of their chlorogenic acid during the roasting process, LFS food science professor and director of the Food, Nutrition and Health program.

Ref : Yazheng Liu and David D. Kitt, Food Research International.

Daily dose of coffee could help reverse non-alcoholic fatty liver disease

Adding coffee to the diet of people with non-alcoholic fatty liver disease (NAFLD) could help reverse the condition, according to a new study conducted in mice presented at The International Liver Congress 2016 in Barcelona, Spain.

The study found that a daily dose of coffee (equivalent to six cups of espresso coffee for a 70kg person) improved several key markers of NAFLD in mice that were fed a high fat diet. These mice also gained less weight than others fed the same diet without the dose of caffeine.

The scientists also showed how coffee protects against NAFLD by raising levels of a protein called Zonulin (ZO)-1, which lessens the permeability of the gut. Experts believe that increased gut permeability contributes to liver injury and worsens NAFLD. People suffering from NAFLD can develop scaring of the liver, also known as fibrosis, which can progress to a potentially life-threatening condition known as cirrhosis.

"Previous studies have confirmed how coffee can reverse the damage of NAFLD but this is the first to demonstrate that it can influence the permeability of the intestine," said Vincenzo Lembo, at the University of Napoli, Italy and study author. "The results also show that coffee can reverse NAFLD-related problems such as ballooning degeneration, a form of liver cell degeneration."

Researchers analysed three different groups of mice over a 12 week period. Group one received a standard diet, group two had a high fat diet and group three was given a high fat diet plus a decaffeinated coffee solution.

Coffee supplementation to a high fat diet significantly reversed levels of cholesterol (p<0.001), alanine aminotransferase (an enzyme which levels increase in the blood when the liver is damaged) (p<0.05), amount of fat in the liver cells (steatosis) (p<0.001) and ballooning degeneration (p<0.05). The combination of coffee and a high fat diet also reduced weight gain over time (p=0.028) in the mice. The study results suggest that coffee supplementation could cause variations in the intestinal tight junctions, which regulate the permeability of the intestine.

Daily dose of coffee could help reverse non-alcoholic fatty liver disease: Adding coffee to the diet of people with non-alcoholic fatty liver disease (NAFLD) could help reverse the condition, according to a new study conducted in mice presented at The International Liver Congress 2016 in Barcelona, Spain.

Seeds of tropical shrub guarana contain ten times more amount of catechins than green tea

 

In continuation of my update on catechins. 

The millions of people who consume green tea all over the world benefit from the catechins it contains. Catechins are a class of chemical compounds with anti-oxidant and anti-inflammatory properties, among other healthy ingredients. Researchers at the University of São Paulo's Public Health School (FSP-USP) have discovered that guarana (Paullinia cupana) is a worthy competitor, at least as far as catechins are concerned: the seeds of the tropical shrub, used in fizzy drinks that are among the most popular in Brazil, as well as in over-the-counter supplements, contain more than ten times the amount of catechins found in green tea.

 Catechins

A clinical trial with healthy human volunteers has demonstrated that guarana is a rich source of catechins, which, when properly absorbed, reduce the oxidative stress associated with the development of neurodegenerative and cardiovascular disorders, as well as diabetes, cancer, inflammation and premature aging due to cell death, among other conditions harmful to health and wellbeing.

"Guarana has always been seen above all as a stimulant, especially by the international scientific community, because of its high caffeine content. We also found few Brazilian scientific studies that seek to identify other biological effects of guarana," said Lina Yonekura, the principal investigator for this research and currently an assistant professor at Kagawa University's School of Agriculture in Japan. "This pioneering assessment of the absorption and biological effects of its catechins in human volunteers should foster interest in guarana as a functional food on the part of scientists, the market, and society in general."

The paper with the results of the study is featured on the cover of the latest issue ofFood & Function, published by the Royal Society of Chemistry in the United Kingdom as one of the "Hot Articles in Food & Function 2016.

The month-long study was conducted in two stages. After selecting volunteers who were healthy but slightly overweight and with a moderately elevated risk of cardiovascular disease, the researchers measured baseline parameters on the first day and evaluated the same items again on day 15 after a the implementation of a controlled diet.

The participants were then asked to take guarana at home every morning before breakfast for the next fortnight. They were given bottles containing guarana seed powder and instructed to prepare a daily drink with the contents of one bottle (3 g of guarana powder) in 300 mL of water.

This procedure ensured that each participant acted as his or her own control. The researchers compared the same volunteers' blood tests at different times to avoid the influence of variability between individuals. The acute effect of guarana was measured one hour after the participants drank the solution on day 1 and day 15. The prolonged effect was assessed after overnight fasting on the same days.

The researchers assessed the extent to which guarana affected oxidative stress markers during the two-week intervention period. They also performed a detailed study to evaluate the subjects' absorption of catechins and their metabolites, as they had found no information in the scientific literature on the bioavailability of these compounds in guarana.

The oxidative stress markers included oxidation of low-density lipoprotein (LDL), popularly known as bad cholesterol. LDL is essential to an organism's proper functioning because it is the main particle that carries cholesterol to cells. Cholesterol is a structural component of all cell membranes and is used to manufacture steroid hormones (estrogen and testosterone). When oxidized, however, LDL causes atherosclerosis and increases the risk of cardiovascular disease. The tests performed by Yonekura's team showed an increase in oxidation resistance of the LDL in the blood samples taken from the volunteers after they drank guarana.

They also performed a comet assay, also called single cell gel electrophoresis (SCGE), a technique for quantifying and analyzing DNA damage in individual cells due to various factors, including oxidative stress. In this case, lymphocyte DNA in blood samples taken one hour after guarana intake was less damaged than expected when submitted to an oxidizing environment, indicating the presence of anti-oxidant substances or enhanced performance of the lymphocytes' enzymatic anti-oxidant system.

"All these markers depend on the presence of catechins in the bloodstream," Yonekura said. "The improvement in the parameters we assessed was associated with a rise in the concentration of plasma catechins after guarana intake, showing that guarana was indeed responsible for this effect."

Moreover, she went on, the guarana catechins strengthened the cells' native anti-oxidant enzymes, especially glutathione peroxidase, catalase, and superoxide dismutase, which combine to convert superoxide into peroxide and finally into water, protecting cells from the oxidative damage caused by their own metabolism of outside factors.

The tests showed increased glutathione peroxidase and catalase activity both shortly after guarana ingestion and on the following day.

"These results are exciting, suggesting that the bioavailability of guarana catechins is equal to or greater than that of green tea, cocoa and chocolate catechins," Yonekura said. "In fact, their bioavailability was sufficient to have a positive effect on plasma anti-oxidant activity, protect erythrocyte DNA, reduce plasma lipid oxidation, and increase anti-oxidant enzyme activity. We hope the results lead to heightened interest in guarana as the species is native to the Amazon, and Brazil is practically the only country that produces it on a commercial scale."