Plant flavonols significantly reduce Alzheimer’s risk

A new study published in the journal Neurology in January 2020 concludes that increasing the intake of plant flavonols steeply reduces the risk of Alzheimer’s dementia (AD) by up to a half. In other words, AD could be prevented in many people simply by regularly eating and drinking more foods containing these compounds such as tea, oranges, and broccoli.

Alzheimer’s disease

AD is a progressive brain disorder in which the individual loses cognitive skills, including memory and thinking skills, and the ability to perform simple tasks. It is by far the leading cause of such disorders and affects over 5 million Americans.

One study was carried out on over 900 people, who were part of a community-wide ongoing larger research project called the Rush Memory and Aging (MAP) Project. These participants were assessed yearly for their neurologic health and dietary patterns, for an average of 6 years, but some for as long as 12 years. The average age was 81 years, and 3 out of 4 were female.

The findings

In the first study, 220/921 participants developed AD during the study. The risk of AD fell with a greater intake of flavonols. This finding held good even after the researchers adjusted for other health-associated factors – because those with the highest total flavonol intake were also the best educated, most active and took part in more cognitive activities. They also accounted for genetic factors like the presence of the APOE4 gene, and for cardiovascular risk factors that could influence the risk of AD, such as diabetes mellitus, history of heart attack, or stroke, or hypertension.

When classified into five groups based on decreasing flavonol intake, the participants in the first group (highest intake) consumed over 15 mg of flavonols a day. Compared to those in the lowest fifth (about 5 mg a day), these individuals showed an approximately 50% reduction in AD risk.

In concrete terms, 28 of 186 patients in the highest-intake group developed AD, vs. 54 of 182 in the lowest-intake group.

With respect to individual flavonols, kaempferol intake was linked to a reduction of almost 50%, and both myricetin and isorhamnetin by 40% each. A fourth flavonol, called quercetin, had no noticeable effect on AD risk.

Participants with the highest flavonol intake drank about one cup of black tea a day. Kale, and about a glass of red wine each day, could also supply flavonols.

Sources of flavonols

Kaempferol is richly present in green leafy vegetables, including spinach, broccoli, beans, tea and kale – and also in tea. Isorhamnetin-rich foods include olive oil, red wine, pears and tomato sauce. Myricetin is found in tea, kale, oranges, tomatoes and red wine.

Researcher Thomas Holland says, “More research is needed to confirm these results, but these are promising findings. Eating more fruits and vegetables and drinking more tea could be a fairly inexpensive and easy way for people to help stave off Alzheimer's dementia.”

Implications

Many scientists disagree with the emphasis on flavonols. Though these were thought to have antioxidant activity in the body, this theory was discredited many decades earlier. Antioxidant activity ceases when they are ingested and subjected to the activity of enzymes in the digestive tract.

They point out that flavonols are found in many plants, fruits and vegetables, which have been associated with good health for centuries. Nutritionists say that the AD-delaying effects of such foods are likely due to other plant chemicals which are relatively more abundant. On the other hand, taking flavonol pills or tea extracts is unlikely to produce the same healthful effect, and overdoses could be counterproductive.

This is not to say that eating more flavonol-rich foods or drinking a cup of black tea in the morning would hurt, since any foods containing these chemicals would also contain many more healthful compounds including vitamins, minerals and plant fiber. Holland makes a valid point with his conclusion: “'With the elderly population increasing worldwide, any decrease in the number of people with this devastating disease, or even delaying it for a few years, could have an enormous benefit on public health.”

https://n.neurology.org/content/early/2020/01/29/WNL.0000000000008981

Plant flavonols significantly reduce Alzheimer’s risk

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."

Matcha green tea kills breast cancer stem cells

MATCHA, the Green Tea packed with antioxidants, is often hailed as containing properties which prevent disease.

Scientists in Salford, UK have shed a ray of light on the claim by testing it on cancer stem cells - with surprising results.

In research published in the journal Aging, a team from the Biomedical Research Centre at the University of Salford, used metabolic phenotyping on cell lines of breast cancer stem cells and found that Matcha "shifted cancer cells towards a quiescent metabolic state" and stopped their spread at a relatively low concentration (0.2 mg/ml).

They also found that the signaling pathways that promote cancer stem cells indicated that Matcha "strongly affected mTOR signals, weakening components of the 40S ribosome. This raised the possibility that Matcha could be used in place of chemical drugs such as rapamycin.

Michael Lisanti, professor of translational medicine at the center, explained: "Matcha green tea is a natural product used as a dietary supplement with great potential for a range of treatments. But, the molecular mechanism underpinning all that remains largely unknown.

"By using metabolic phenotyping, we found that the tea is suppressing oxidative mitochondrial metabolism - in other words it is preventing the cells from 're-fuelling' and therefore they become inactive and die.

"The effects on human breast cancer cells were very striking; the active ingredients in matcha having a surgical effect in knocking out certain signaling pathways.

"Our results are consistent with the idea that Matcha may have significant therapeutic potential, mediating the metabolic reprogramming of cancer cells."

The team who specialize in identifying non-toxic methods of killing cancer stem cells recently found that Earl Grey tea ingredient, Bergamot kills cancer cells and works as an anti-cholesterol agent.

Ref : https://www.salford.ac.uk/news/articles/2018/green-tea-prevent-cancer-cells-from-refuelling

Matcha green tea kills breast cancer stem cells

MATCHA, the Green Tea packed with antioxidants, is often hailed as containing properties which prevent disease.

Scientists in Salford, UK have shed a ray of light on the claim by testing it on cancer stem cells - with surprising results.

In research published in the journal Aging, a team from the Biomedical Research Centre at the University of Salford, used metabolic phenotyping on cell lines of breast cancer stem cells and found that Matcha "shifted cancer cells towards a quiescent metabolic state" and stopped their spread at a relatively low concentration (0.2 mg/ml).

They also found that the signaling pathways that promote cancer stem cells indicated that Matcha "strongly affected mTOR signals, weakening components of the 40S ribosome. This raised the possibility that Matcha could be used in place of chemical drugs such as rapamycin.

Michael Lisanti, professor of translational medicine at the center, explained: "Matcha green tea is a natural product used as a dietary supplement with great potential for a range of treatments. But, the molecular mechanism underpinning all that remains largely unknown.

"By using metabolic phenotyping, we found that the tea is suppressing oxidative mitochondrial metabolism - in other words it is preventing the cells from 're-fuelling' and therefore they become inactive and die.

"The effects on human breast cancer cells were very striking; the active ingredients in matcha having a surgical effect in knocking out certain signaling pathways.

"Our results are consistent with the idea that Matcha may have significant therapeutic potential, mediating the metabolic reprogramming of cancer cells."

The team who specialize in identifying non-toxic methods of killing cancer stem cells recently found that Earl Grey tea ingredient, Bergamot kills cancer cells and works as an anti-cholesterol agent.

Ref : https://www.salford.ac.uk/news/articles/2018/green-tea-prevent-cancer-cells-from-refuelling

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."

Is Okra Good for Diabetes?

According to a handful of recent studies, okra may reduce symptoms of diabetes - a group of diseases that includes type 1 diabetes, type 2 diabetes, and gestational diabetes.

 

Diabetes claimed the lives of 75,578 Americans in 2013, according to the United States Centers for Disease Control and Prevention (CDC). In 2014,8.5 percent of adults worldwide had the condition, the World Health Organization (WHO) report. By 2030, diabetes may be the seventh leading cause of death.

A number of factors increase a person's risk of developing diabetes, including a family history of the disease. Lifestyle factors also play a role, so doctors routinely recommend diet changes and increased exercise to reduce blood sugar levels.

Okra may help reduce blood sugar levels in some people with diabetes. Research into the effects of this seedy vegetable is still in the early stages, but the results are promising.

Okra thrives in temperate climates, producing large hibiscus-like flowers that eventually give rise to green seed pods. It is a member of the mallow family, which includes a number of other popular plants, including hibiscus, cocoa, and cotton.

Scientifically known as Abelmoschus esculentus, okra may have been grown as long ago as 2000 BCE in Egypt.

Okra's flavor is mild, and the entire seed pod can be eaten. This vegetable-like fruit also has a long history in traditional medicine.

Kew Royal Botanic Gardens report that in Eastern traditional medicine, okra leaves and fruit were used as pain relievers, moisturizers, and to treat urinary disorders. In Congolese medicine, okra is used to encourage a safe delivery during childbirth.

Can okra help with symptoms of diabetes?

Diabetes can often be well-managed with increasing a hormone called insulin and other medical therapies. However, some people with diabetes wish to avoid regular insulin injections. Others experience blood sugar dips and other unpleasant side effects, and diabetes medications do not work for everyone.

The possibility that a readily available seed pod could help control diabetes is an exciting one. But there is no evidence yet that okra can cure diabetes. So far, the research on okra has only looked at its effects on animals. Human bodies are similar to animals, but not all research on animals has worked out in humans.

Increased absorption of sugar by muscles

A 2005 study published in Planta Medica investigated the effects of okra on rats with diabetes. A substance called myricetin is present in okra and some other foods, including red wine and tea.

Researchers isolated myricetin from okra, then administered it to the rat. The treatment increased absorption of sugar in the rats' muscles, lowering their blood sugar.

A 2012 Food Science and Human Wellness review points to a number of other laboratory and animal studies that have linked myricetin to lower blood sugar. The study argues that myricetin may also reduce other risk factors for diabetes.

Reduction in blood sugar spikes after eating

A 2011 study published in ISRN Pharmaceutics found a link between okra and decreased blood sugar spikes after eating.

Researchers fed rats liquid sugar as well as purified okra through a feeding tube. Rats who consumed the okra experienced a reduction in blood sugar spikes after feeding. The study's authors think this is because the okra blocked the absorption of sugar in the intestines.

The study also explored possible interactions between okra and metformin, a drug that can reduce blood sugar in type 2 diabetes. Okra appeared to also block absorption of metformin. This suggests that okra could reduce the effectiveness of metformin, and should therefore not be eaten at the same time as the drug.

Lower blood sugar levels

A 2011 study published in the Journal of Pharmacy and Bioallied Sciences points to a link between eating okra and lower blood sugar. The researchers allowed the blood sugar of rats with diabetes to stay level for 14 days. They then gave the rats powdered okra peel extracts and seeds dosages of up to 2,000 milligrams per kilogram of body weight.

There were no poisonous effects linked with these relatively high doses of okra. The rats that ate okra had reduced blood sugar levels after up to 28 days of eating okra. The study ended on day 28, so it is unclear if the effects on blood sugar levels would have lasted longer.

Considerations for using okra

Few studies have linked okra to negative side effects, but some negative side effects are possible:

• Okra may make the drug metformin less effective.
• Okra is high in substances known as oxalates. Oxalates may increase the risk of kidney stones in people vulnerable to kidney stones.
• Okra can contain bacteria, pesticides, and other dangerous substances if it is not thoroughly washed. People should never consume rotten okra, frozen okra that is past its expiration date, or okra that has not been thoroughly washed.
• People with an okra allergy should not consume okra. Those with an allergy to other plants in the mallow family, such as hibiscus or cotton, may also be allergic to okra.
• Even if okra proves to be ineffective in fighting diabetes, it remains a safe snack for people with diabetes. A single serving of 100 grams contains just 30 calories, but offers a number of nutritional benefits:
  • Okra contains no saturated fats or cholesterol
  • Okra is rich in fiber, containing 9 percent of the recommended daily value (RDV)
  • Okra contains 8 percent of the RDV of calcium, 43 percent of the RDV of manganese, 10 percent of the RDV of iron and copper, and 44 percent of the RDV of vitamin K
  Okra is rich in protective substances known as antioxidants, including myricetin. According to the National Center for Complementary and Integrative Health, antioxidants may reduce oxidative stress, a process that damages cells in the body. Oxidative stress plays a role in the development of diabetes, as well as diseases such as:
  • Parkinson's disease
  • Alzheimer's disease
  • Cataracts
  • Macular degeneration
  • Heart and blood vessel disease
  • Cancer
  In addition to its antioxidant benefits, okra may also reduce tiredness. A 2015 study published in Nutrients found that substances found in okra seeds known as polyphenols and flavonoids could reduce fatigue.