Posts tagged with "Polyphenols"

Above, viral videos claim that green tea aids in weight loss. (Photo source: Joyce Lee for The New York Times)

Is green tea really ‘Nature’s Ozempic’?

September 25, 2024

Green tea has been bandied about as a diet hack for centuries: In ancient China 2,000 years ago, people touted the beverage as a weight loss tool. In modern times, the drink if often mentioned in diet books and meal plans, reports The New York Times.

Now, green tea has followed the inevitable trajectory of any weight loss trick: It’s getting big on TikTok. Viral videos claim the drink aids with shedding pounds, going so far as to call it “nature’s Ozempic.” Some posts suggest drinking as many as five cups a day.

While there is some research into green tea and weight, the evidence on whether a mug (or several) can melt away pounds is unclear, said Dr. Jyotsna Ghosh, an obesity medicine doctor at Johns Hopkins University.

Many of the TikTok videos claim that green tea boosts the production of glucagon-like peptide-1 (GLP-1), a gut hormone that prompts the pancreas to release insulin after a meal. That insulin, in turn, lowers blood sugar. GLP-1 also slows down the rate at which food leaves the stomach, and it affects areas of the brain that regulate hunger.

Ozempic and drugs like it deliver a compound that mimics GLP-1, making people feel fuller faster. Many stop experiencing strong cravings for food.

Some researchers have theorized that green tea might stimulate GLP-1, in part because studies have found green tea extract can lower blood sugar in diabetic mice. But there have been only a few small studies in humans, and the results are inconclusive. One of the few clinical trials on the subject—which looked at 92 people with Type 2 diabetes—suggested there was not a notable difference in GLP-1 production between people who took green tea extract and those who took a placebo pill.

Any effect green tea might have on GLP-1 is likely to be small, experts said. Any food or drink can increase GLP-1 levels slightly, Dr. Ghosh says. But GLP-1 levels in the bloodstream dip minutes after you eat or drink something; that’s one of the reasons we get hungry again—and why temporarily boosting the hormone does not guarantee weight loss.

Ozempic and similar drugs, by contrast, linger in the body for days, and are far more potent than the natural hormone; which makes them uniquely good at suppressing appetite.

Many of the claims about green tea and weight loss mention two components of the drink: caffeine and antioxidants. Caffeine might, in theory, slightly speed up someone’s metabolism. But it is unlikely that effect would translate directly into substantial weight loss, Dr. Ghosh notes.

Green tea also contains compounds called polyphenols, antioxidants that can help protect cells from damage and reduce inflammation. Studies in animals and in human cells have suggested that these compounds could improve metabolism and reduce fat absorption from the gut. But trials in humans have had mixed results.

People turning to green tea to lose weight “can’t expect a big effect, and certainly nothing close to medications like Ozempic,” says Rob van Dam, a professor of exercise and nutrition sciences at the Milken Institute School of Public Health at George Washington University.

Julia Zumpano, a registered dietitian at the Cleveland Clinic, says that focusing on a single food or drink ignored the many other factors that played a role in weight loss. Those include a person’s broader diet, exercise habits, genetics, stress, metabolic health and even the quality of sleep an individual gets.

“Look at how you can improve lifestyle, if weight loss is your goal,” she said. “Not just specifically one food, drug, supplement, whatever it might be.”

Research contact: @nytimes

Above, eating apples can lead to better overall health, say dietiticians. (Photo source: Johnny Miller/The New York Times; food stylist/Susan Spungen)

How healthy are apples?

September 23, 2024

“An apple a day” might seem like overkill, but America’s most popular fruit—currently weighing down branches in orchards everywhere—is packed with health benefits, reports The New York Times.

They’re good for your gut

Apples are rich in dietary fiber, a type of complex carbohydrate that our bodies aren’t capable of digesting on their own. That fiber acts as food for many of the bacteria species that reside in our guts. These bacteria have a powerful impact on our health, affecting everything from cancer risk, to weight, to mood.

A diet high in fruits and vegetables, including apples, has been shown to increase the number of beneficial bacteria and decrease the number of harmful bacteria in peoples’ guts, says Marie van der Merwe, a nutrition scientist at the University of Memphis. That could lead to better overall health, Dr. van der Merwe believes.

In addition, apples themselves contain a host of beneficial bacteria. (While this is true for all fruits and vegetables, one study found that apples have a greater variety of bacteria than most.) When you eat an apple, some of those bacteria may become part of your microbiome. The apple is “acting like a probiotic in addition to acting like a prebiotic,” Dr. van der Merwe explains.

They’re heart healthy

Apples have high amounts of pectin, a dietary fiber that can help you maintain healthy cholesterol levels.

In a 2012 study, 160 postmenopausal women ate either 75 grams of dried apples (equal to about two medium sized apples) or prunes every day for one year. After six months, the women who consumed apples experienced a 13% drop in their total cholesterol and a 24% drop in “bad” LDL cholesterol, while the women who ate prunes experienced a 3.5 percent drop in total cholesterol and an 8 percent drop in LDL cholesterol.

Apples are also one of the biggest dietary sources of polyphenols—tiny, health-promoting molecules that plants produce to defend themselves from the elements. Certain polyphenols in apples, called flavonoids, are particularly good at stimulating the production of nitric oxide, a gas that flows through our blood vessels, causing them to dilate. That’s good for blood pressure, says e who has coauthored several studies on apples.

They can reduce chronic inflammation

Polyphenols in apples can reduce inflammation— and, in turn, possibly help reduce disease risk. Researchers published a study in August that analyzed health data from more than 119,000 people collected over nearly 20 years—including records of everything they ate over a 24-hour period on five separate occasions.

The study found that those who reported eating more than two apples a day in the meal logs had a 30% lower chance of developing chronic obstructive pulmonary disease later on.

“We saw benefits even at just half a serving a day,” says Aedin Cassidy, the chair of nutrition and preventive medicine at Queen’s University Belfast and a study co-author. The study found that the association between apples and C.O.P.D. risk was also linked to a reduction in inflammatory markers.

Apples are most nutritious when you leave the skin on, Dr. Bondonno says: After all, it’s the skin that contains those powerful polyphenols (and much of the fiber). She added that you should wash apples thoroughly before eating them to avoid pesticide exposure.

In general, a darker color apple will have a richer variety of polyphenols, Dr. van der Merwe notes. But more important than selecting the deepest red apple you can find is eating different apple varieties, so you can absorb as many different polyphenols as possible, she said.

Research contact: @nytimes

Photo source: Green Tea Guide

Study: Green tea extract supplements improve gut health, help lower blood sugar levels

July 27, 2022

Green tea has long been viewed as a healthful drink—and now, an Ohio State University study has demonstrated that four-week green tea extract consumption can improve gut health and reduce blood sugar levels by decreasing inflammation, reports Gut News.

The research team conducted this work to build off a 2019 study that established that fewer health risks and incidences of  obesity  are associated with consumption of green tea.

“There is much evidence that greater consumption of green tea is associated with good levels of cholesterol, glucose, and triglycerides, but no studies have linked its  benefits to the gut  to those health factors,” says Richard Bruno, senior study author and professor of Human Nutrition at the school.

This latest clinical trial included 40 adults—21 with metabolic syndrome; and 19, healthy. They consumed gummy green tea extract supplements for 28 days daily. The dosage equates to five cups of tea. In the randomized double-blind crossover trial, all participants consumed a placebo for an additional 28 days, taking a month off entirely between treatments.

Researchers also advised participants to follow a diet low in polyphenols, which are antioxidants found naturally in fruits, vegetables, teas, and spices. This is so that during the placebo and green tea extract supplement phases, the results could be attributed to just the green tea and not anything confounding.

Results show that fasting blood glucose levels in all participants were significantly lower after taking the green tea extract supplement compared to post-placebo.

Also, upon analysis of fecal samples, a reduction in pro-inflammatory proteins was see in all participants—meaning that the gut saw a significant decrease in inflammation.

Further, the team used a technique to assess sugar ratios in urine samples. Findings show participants’ small intestine permeability decreased after the green tea consumption, meaning that  leaky gut syndrome  conditions were alleviated.

“That absorption of gut-derived products is thought to be an initiating factor for obesity and  insulin resistance, which are central to all cardiometabolic disorders,” Bruno notes. “If we can improve gut integrity and reduce leaky gut, the thought is we’ll be able to not only alleviate low-grade inflammation that initiates cardiometabolic disorders, but potentially reverse them.”

Metabolic syndrome wasn’t cured over the month, but the study does show that green tea has lots of potential to notably lessen the risk for developing the condition and even reversing it, due to its supportive effects on the gut. Bruno’s lab is confident that their team produced findings that will positively impact chronic conditions through gut health. They plan to continue analyzing the gut microbiome, identifying any toxins that can increase susceptibility to poor health.

This study is published in the journal, Current Developments in Nutrition.

For those who are interested in trying green tea extract, a high dosage is considered to range from 10 to 29 milligrams per kilogram (or 4.54 to 13.15 milligrams per pound) of body weight per day.

And experts warn enthusiasts no to overdo it. The National Institute of Health  says green tea extract supplements have been linked to several cases of liver damage and can accelerate liver disease.

Research contact: @gutnews