“Protective effect” of flavonoids more prominent in smokers, Australian study says

14 Aug 2019 --- Consuming flavonoid-rich items such as apples and tea, protects against cancer and cardiovascular heart disease (CVD), particularly for smokers and heavy drinkers, according to new research from Edith Cowan University (ECU), Perth, Australia. The protective effect appeared to be strongest for those at high risk of chronic diseases due to cigarette smoking and those who drank more than two standard alcoholic drinks a day. The findings underscore flavonoids’ potential in preventing cancer and heart disease. The researchers suggest an increased consumption of flavonoid rich foods, while also encouraging people to quit smoking and reduce alcohol intake.

Flavonoids are compounds found in plant-based foods and drinks such as fruits, vegetables, tea, dark chocolate, red wine and soy. The researchers from ECU’s School of Medical and Health Sciences analyzed data from the Danish Diet, Cancer and Health cohort that assessed the diets of 53,048 Danes over 23 years. They found that people who habitually consumed moderate to high amounts of foods rich in flavonoids were less likely to die from cancer or heart disease.

The study
The researchers divided the participants into two groups: smokers and non-smokers. After running an analysis, researchers found the association between flavonoid intake and mortality was stronger in smokers. After analyzing smokers, the researchers split the population into two groups based on their alcohol consumption and reran the numbers to arrive at their conclusions.

“The higher flavonoid impact among smokers and drinkers suggests that flavonoids are having a protective effect and that this group requires a higher intake,” lead researcher Dr. Nicola Bondonno tells NutritionInsight.

How do flavonoids promote health?
The exact nature of the protective effect was unclear, but likely to be multifaceted. “Alcohol consumption and smoking both increase inflammation and damage blood vessels, which can increase the risk of a range of diseases,” Dr. Bondonno says.

“Flavonoids have been shown to be anti-inflammatory and improve blood vessel function, which may explain why they are associated with a lower risk of death from heart disease and cancer. These findings are important as they highlight the potential to prevent cancer and heart disease by encouraging the consumption of flavonoid-rich foods, particularly in people at high risk of these chronic diseases,” she says.

Previous research on flavonoids, such as cannflavin A and cannflavin B which are found in cannabis, has also demonstrated their anti-inflammatory effects. Professor Tariq Akhtar, Department of Molecular and Cellular Biology, notes, “These molecules are non-psychoactive and they target the inflammation at the source, making them ideal painkillers.” When flavonoids in cannabis were first identified in 1985, research verified they provide anti-inflammatory benefits that were nearly 30 times more effective gram-for-gram than acetylsalicylic acid (sold as Aspirin).

Taking the right amount
In the study, participants consuming about 500mg of total flavonoids each day had the lowest risk of death related to cancer or heart disease.

“It’s important to consume a variety of different flavonoid compounds found in different plant-based food and drink. This is easily achievable through the diet: one cup of tea, one apple, one orange, 100g of blueberries and 100g of broccoli would provide a wide range of flavonoid compounds and over 500mg of total flavonoids,” Dr. Bondonno notes. 

Apart from your daily diet, several exotic flavonoid sources are now on the market. For example, Mankai duckweed shows promise to help with glycemic control.

Eriomin is a flavonoid-derived ingredient which also has been shown to have medicinal purposes. “Flavonoids in Eriomin play an important role in prediabetes management, prompting us to begin a second clinical trial with results expected by the end of the year,” says Dr. Thais Cesar, Associate Professor of Nutrition at São Paulo State University.” 

Not a cure-all
“It’s important to note that flavonoid consumption does not counteract all of the increased risks of death caused by smoking and high alcohol consumption. By far, the best thing to do for your health is to quit smoking and cut down on alcohol,” heeds Dr. Bondonno.

“We know these kinds of lifestyle changes can be very challenging, so encouraging flavonoid consumption might be a novel way to alleviate the increased risk, while also encouraging people to quit smoking and reduce their alcohol intake.”

The next step for the research team is to look more closely at which types of heart disease cancers were most protected by flavonoids. “These findings have important clinical and public health implications as they suggest that diet may play an even more crucial role in mitigating mortality risk in people who are at high risk,” she adds.

“Flavonoid intake is associated with lower mortality in the Danish Diet Cancer and Health Cohort” was published in Nature Communications. 

By Missy Green