Tag: flavonols

Categories : NeurologyTags :

Why do Some People get a ‘Red Wine’ Headache?

On By ModernMedia
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For some people, drinking red wine even in small amounts causes a headache, which typically occurs within 30 minutes to three hours after drinking as little as a small glass of wine. Researchers have examined why this happens – even to people who don’t get headaches when drinking small amounts of other alcoholic beverages. In their work, published in the journal Scientific Reports, the researchers posit that a flavanol found naturally in red wines can interfere with the proper metabolism of alcohol and can lead to a headache.

The headache culprit: Quercetin, a flavanol

This flavanol is called quercetin and it is naturally present in all kinds of fruits and vegetables, including grapes. It’s considered a healthy antioxidant and is even available in supplement form. But when metabolized with alcohol, it can be problematic.

“When it gets in your bloodstream, your body converts it to a different form called quercetin glucuronide,” said wine chemist and corresponding author Andrew Waterhouse, professor emeritus with the UC Davis Department of Viticulture and Enology. “In that form, it blocks the metabolism of alcohol.”

Acetaldehyde toxin buildup leads to flushing, headache, nausea

As a result, people can end up accumulating the toxin acetaldehyde, explains lead author Apramita Devi, postdoctoral researcher with the UC Davis Department of Viticulture and Enology.

“Acetaldehyde is a well-known toxin, irritant and inflammatory substance,” said Devi. “Researchers know that high levels of acetaldehyde can cause facial flushing, headache and nausea.”

The medication disulfiram prescribed to alcoholics to prevent them from drinking causes these same symptoms. Waterhouse said that’s because the drug also causes the toxin to build up in the body when normally an enzyme in the body would break it down. About 40% of the East Asian population also has an enzyme that doesn’t work very well, allowing acetaldehyde to build up in their system.

“We postulate that when susceptible people consume wine with even modest amounts of quercetin, they develop headaches, particularly if they have a preexisting migraine or another primary headache condition,” said co-author Morris Levin, professor of neurology and director of the Headache Center at the University of California, San Francisco. “We think we are finally on the right track toward explaining this millennia-old mystery. The next step is to test it scientifically on people who develop these headaches, so stay tuned.”

Sunlight increases headache-causing flavanol in grapes

Waterhouse said levels of this flavanol can vary dramatically in red wine.

“Quercetin is produced by the grapes in response to sunlight,” Waterhouse said. “If you grow grapes with the clusters exposed, such as they do in the Napa Valley for their cabernets, you get much higher levels of quercetin. In some cases, it can be four to five times higher.”

Levels of quercetin can also differ depending on how the wine is made, including skin contact during fermentation, fining processes and aging.

Clinical trial on wine headaches

Scientists will next compare red wines that contain a lot of quercetin with those that have very little to test their theory about red wine headaches on people. This small human clinical trial, funded by the Wine Spectator Scholarship Foundation, will be led by UCSF.

Researchers said there are still many unknowns about the causes of red wine headaches. It’s unclear why some people seem more susceptible to them than others. Researchers don’t know if the enzymes of people who suffer from red wine headaches are more easily inhibited by quercetin or if this population is just more easily affected by the buildup of the toxin acetaldehyde.

“If our hypothesis pans out, then we will have the tools to start addressing these important questions,” Waterhouse said.

Source: University of California – Davis

Categories : Diet and NutritionTags :

‘Berry’ Good for You? Adding a Banana Reduces Flavanol Levels in Smoothies

On By ModernMedia
Photo by Denis Tuksar on Unsplash

Smoothies can be a tasty and convenient way to get the important fruits and vegetables needed for a healthy diet. But is a banana and blueberry smoothie the best combo? Researchers at the University of California, Davis, suggest that blending certain ingredients in smoothies can influence whether your body is getting a nutritional boost.

The study, published today in the journal Food and Function, used smoothies to test how various levels of polyphenol oxidase (PPO), an enzyme in many fruits and vegetables, affects the levels of flavanols in food to be absorbed by the body. Flavanols are a group of bioactive compounds that are good for your heart and cognitive health and are naturally found in apples, pears, blueberries, blackberries, grapes and cocoa – common smoothie ingredients.

“We sought to understand, on a very practical level, how a common food and food preparation like a banana-based smoothie could affect the availability of flavanols to be absorbed after intake,” said lead author Javier Ottaviani, director of the Core Laboratory of Mars Edge, which is part of Mars, Inc., and an adjunct researcher with the UC Davis Department of Nutrition. Mars Inc. provided the grant for this study as part of its research into flavonols in cocoa.

When peeled or sliced, PPO causes banana or apple to turn brown, The browning occurs when food with PPO is exposed to air, cut or bruised. The researchers wanted to know whether consuming freshly prepared smoothies made with different PPO-containing fruits impacted the amount of flavanols available to the body.

Bananas versus berries

The researchers had participants drink a smoothie made with banana, which has naturally high PPO activity, and a smoothie made with mixed berries, which have naturally low PPO activity. Participants also took a flavanol capsule as a control. Blood and urine samples were analysed to measure how much flavanols were present in the body after ingesting the smoothie samples and capsule. The researchers found that those who drank the banana smoothie had 84% lower levels of flavanols in their body compared to the control.

“We were really surprised to see how quickly adding a single banana decreased the level of flavanols in the smoothie and the levels of flavanol absorbed in the body,” Ottaviani said. “This highlights how food preparation and combinations can affect the absorption of dietary compounds in foods.”

Last year, the Academy of Nutrition and Dietetics issued a dietary recommendation, advising people to consume 400 to 600 milligrams of flavanols daily for cardiometabolic health. Ottaviani said for people who are trying to consume those flavanols, they should consider preparing smoothies by combining flavanol-rich fruits like berries with other ingredients that also have a low PPO activity like pineapple, oranges, mango or yogurt.

He also said bananas remain a great fruit to be eaten or consumed in smoothies. For those who want to consume smoothies with bananas, or other high PPO activity fruits and vegetables such as beet greens, the suggestion is to not combine them with flavanol-rich fruits such as berries, grapes and cocoa.

The findings of this study could spur future research into how other foods are prepared and the effects on flavanols, for example, Ottaviani said tea is a major dietary source of flavanols and depending on how it is prepared, a different amount of flavanols would be available for absorption.

“This is certainly an area that deserves more attention in the field of polyphenols and bioactive compounds in general,” said Ottaviani.

Jodi Ensunsa, Reedmond Fong, Jennifer Kimball and Alan Crozier, all affiliated with the UC Davis Department of Nutrition and researchers affiliated with the UC Davis Department of Internal Medicine, University of Reading, King Saud University and Mars, Inc. contributed to the research.

The study was funded by a research grant from Mars, Inc., which collaborates with researchers to study potential benefits of cocoa flavanols for human health.

Source: University of California – Davis