Chocolate on My Mind

April 10, 2015

By Medical Discovery News


Peanuts creator Charles Schulz once said, “All you need is love. But a little chocolate now and then doesn’t hurt.” New research shows he might be right. In one study, certain compounds in cocoa called flavanols reversed age-related memory problems.

Flavanols, found in a variety of plants, are potent antioxidants that help cells in the body deal with free radicals. Free radicals arise from normal cellular processes as well as from exposure to environmental contaminants, especially cigarette smoke. Unless your body gets rid of free radicals, they can damage proteins, lipids, and even your genetic information. You can get flavanols from tea, red wine, berries, cocoa, and chocolate. Flavanols are what give cocoa that strong, bitter, and pungent taste. Cocoa is processed through fermentation, alkalization, and roasting among other methods, which can influence how much of the good flavanols are lost. Among the products made from cocoa, those with the highest levels of flavanol are cocoa powders not processed by the Dutch method, followed by unsweetened baking chocolate, dark chocolate and semi-sweet chips, then milk chocolate, and finally chocolate syrup contained the least.

In the latest study, a cocoa drink specially formulated by the Mars food company to retain flavanols was compared with another drink that contained very little flavanols. The study asked 37 randomly selected adults aged 50 to 69 to take one of the drinks. One group consumed 900 milligrams per day of flavanols and the others consumed only 10 milligrams per day for three months. Brain imaging and memory tests were administered before and after the trial.

Those who consumed the high levels of cocoa flavanols had better brain function and improved memories. Before the study, the subjects on average demonstrated the memory of a typical 60-year-old person. At the end, those who consumed more flavanols exhibited the memory capabilities more closely resembling a 30- to 40-year-old. Unfortunately, the average candy bar contains only about 40 milligrams of flavanol, so you would have to eat 23 of them a day to equal the amount of flavanol used in the study, which would lead to other health problems like obesity and diabetes.

Other studies have similarly revealed that high-flavanol cocoa beverages cause regional changes in the brain’s blood flow, suggesting that it could be used to treat vascular impairments within the brain. Flavanols have also been reported to reduce blood pressure and other factors that lead to cardiovascular disease, improve insulin sensitivity, modulate platelet activity thereby reducing the risk of blood clots, and improve the activities of the endothelial cells that line our blood vessels. The Kuna indians living on the San Blas Islands near Panama, who consume a type of cocoa rich in flavanol on a daily basis, have unusually low rates of hypertension, cardiovascular disease, cancer, and diabetes.

These studies need to be repeated with larger groups to confirm the benefits of consuming flavanols and to ensure that there are no negative effects. Still, if a cocoa beverage high in flavanols could be mass produced and marketed, we could improve human health in a very tasty way.

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Beer: It’s the Yeast that Counts

March 13, 2015

By Medical Discovery News

Beer - It's the Yeast That Counts

Humans have been drinking fermented beverages such as beer for thousands of years. Long before microbrews were invented, men relied on wild yeast to produce their ale. But we aren’t the only ones who found something so appealing in yeast – fruit flies do as well.

A beer’s aroma and flavor are due to it ingredients, which usually include malted grains, commonly barley and wheat, then hops for bitterness. However, a key determinant of a beer’s flavor is the yeast. During fermentation, yeast introduces a variety of aromatic molecules called acetate esters. The question of why yeast produces these aromatic compounds has been a mystery, until now.

Fifteen years ago, a scientist in Belgium named Kevin Verstrepen rushed out of the lab to get to a bar one Friday evening, leaving three flasks of yeast sitting open on his lab bench. Upon returning on Monday, he discovered that fruit flies from a neighboring genetics lab had invaded his own. Fifty flies were floating in the flask of yeast that had been engineered to make 100 times more of the aromatic molecules that a standard strain. Two flies were in the flask of normal yeast, and none were in the flask of yeast that did not produce those aromatic molecules. He deduced that yeast produces aromatic molecules with aromas similar to ripening fruit to attract flies, but wondered why.

Years later, Verstrepen teamed up with other scientists to repeat the experiment, and once again the amount of aromatic molecules produced by a strain of yeast correlated with the number of flies attracted to it. To be sure the aroma was responsible for attracting the flies, they synthesized the aromatic molecules and added them to a flask of yeast that did not produce them. Sure enough, the flies returned. They then used flies whose brains had been modified to express a fluorescent protein, which would light up when there was neural activity. They discovered that a compound called isoamyl nitrate, which has a smell similar to overripe bananas, causes intense brain activity in flies. Fruit flies apparently can use such aromatic molecules to find yeast, an important part of their diet.

They then wondered whether the yeast that attract flies have an advantage by spreading further into their environment. Using normal yeast and scentless yeast that had been colored differently showed that the aromatic yeast spread four times more into the environment. Basically, yeast emit signals in the form of molecules that flies are attracted to as a food source, but the yeast benefits by being spread by the flies. Yeasts do not have any means of propulsion, so hitching a ride to a new food source on the tiny hairs of a fruit fly’s legs solves their travel problems.

While not reported in a scientific publication, they collected fruit flies from their homes, crushed them up, and analyzed them for yeast. Sure enough, the flies harbored yeast that produced the aromatic compounds. For the final experiment, Verstrepen cultured the yeast and guess what he did with them?  Made beer, of course.  It was reportedly delicious.

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Bring on the Milk

June 20, 2014

By Medical Discovery News


Drinking milk might seem perfectly natural, but it’s actually anything but. Humans are the only species who retain the ability to digest milk after childhood, or at least some of us do. Up to half of adults worldwide don’t have the ability to break down lactose, the main sugar in milk, because their bodies stop producing the enzyme lactase after the age of five.

About 65-75 percent of the population has some degree of lactose intolerance, the most common cause for digestive issues with dairy. Lactase breaks down lactose into simpler forms of sugar that can be absorbed by the bloodstream. Without this enzyme, lactose is fermented by bacteria, causing symptoms like abdominal pain, bloating, flatulence, nausea, and diarrhea 30 minutes to two hours after eating. Populations that have long relied on unfermented milk have the lowest rate of lactose intolerance – only five percent among the Swiss.

Humans’ ability to drink milk actually began as a genetic mutation, like the superheroes of X-Men comics. According to the leading theory, 7,800 years ago humans began to move northward. Since the sun is not out as long in northern latitudes, they could not absorb enough vitamin D from sunlight and needed another source to thrive. Milk is high in vitamin D, which aids in calcium absorption. Humans adapted to this change in their diets and developed a variant of the lactase gene that allowed them to continue synthesizing the enzyme throughout their lifetimes. Since humans with the gene variant had the advantage of consuming more vitamin D, they were successful in passing that gene on to future generations.

But new research suggests that this theory is either wrong or other factors were involved. Scientists in northeastern Spain discovered well-preserved skeletons of people who lived 5,000 years ago. DNA testing revealed that none of these eight skeletons carried the genetic mutation for lactase production. Further testing also showed that these ancient humans are indeed related to modern Spaniards. Next, computer simulations determined that over 5,000 years, chance alone would not have allowed one-third their descendants to digest milk. Strong selection for this trait would have been necessary.

These scientists developed a theory that early farmers began eating fermented dairy products such as cheeses, which have lower levels of lactose. But when food was scarce, they ran out of fermented dairy products and began to consume unfermented milk as a food source. Then, those who acquired the mutated gene for lactose production would have thrived. Those without the mutation would have suffered from diarrhea, making their situation worse, perhaps even life-threatening if they were already starving.

While the need for vitamin D from milk may have been a factor in the spread of lactase persistence, these new findings show that other factors may have also been a part of the selection process that drove this mutation into the population. Now if we could only figure out a way to turn on lactase genes again during adulthood, everyone with lactose intolerance could enjoy a pain-free ice cream cone.

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