Linking flavonoid consumption to the development of type 2 diabetes
From 2006 to 2010, more than half a million individuals in the United Kingdom were enrolled in the massive UK Biobank project, which provided the participants for the new research. The sample size was 113,097. Two or more 24-hour dietary questionnaires were used to measure the individuals’ flavonoid consumption, which was then analyzed using the United States Department of Agriculture databases.
Ten foods were selected for their daily flavonoid content. By adding together the servings of these 10 items, a Flavodiet Score (FDS) was determined. To evaluate the association between flavonoid consumption in the diet and the onset of type 2 diabetes, statistical analyses were conducted, taking into consideration possible confounders.
Those who were older, more physically active, more educated, and female tended to eat more foods rich in flavonoids than younger, less educated, or younger participants. An average of 805.7 mg of flavonoids were taken each day. With 67% and 22% of the total intake of the flavonoid subclasses, the most important components were polymers (including proanthocyanidins) and flavan-3-ols. These categories were mostly derived from tea. The consumption of flavones, mostly found in peppers, was the lowest among all flavonoids. Researchers controlled for demographic and lifestyle variables in their analysis of the flavonoid intake type 2 diabetes risk connection.
The study indicated that the risk of acquiring type 2 diabetes was 28% lower in those with a higher Flavodiet Score (FDS), which is the same as eating six servings of foods rich in flavonoids per day, compared to those with a lower FDS, which is the same as eating one serving of flavonoids per day. According to the study, a 6% reduction in diabetes risk was found for every serving of flavonoid-rich foods consumed daily; a 21% reduction in risk was associated with 4 servings of black or green tea daily; a 15% reduction in risk was associated with 1 serving of berries daily; and a 12% reduction in risk was associated with 1 serving of apples daily.
The anti-inflammatory and blood sugar-regulating properties of flavonoids
The probable mediators discovered in the investigation were insulin-like growth factor 1 (IGF-1), urate, cystatin C, body mass index (BMI), GGT, and ALT. According to the results, a diet high in flavonoids may help with weight loss, inflammation, glucose metabolism, and kidney and liver health, all of which lead to a lower chance of developing type 2 diabetes. The most common types of flavonoids are anthocyanins, flavan-3-ols, and flavonols; they improve glucose transport and metabolism and increase insulin production and signaling.
This study lends credence to many of our hypotheses on the etiology of type 2 diabetes, according to Megan Hilbert, RDN, a registered dietitian who focuses on nutrition for gut health and the gut-brain axis, who spoke with MNT. Flavonoids have anti-inflammatory and weight-maintenance properties, and “this study confirms flavonoids’ impact on this,” she said. “These findings demonstrate that consuming flavonoids can lead to a decrease in excess adipose tissue, which can have pro-inflammatory effects, and in the adipose tissue surrounding smooth muscle tissue, which allows for increased absorption of blood glucose by these muscle cells,” Hilbert noted. These changes enhance the body’s ability to absorb blood glucose more efficiently, lowering the chance of developing type 2 diabetes.
According to Kelsey Costa, MS, RDN, creator of Dietitian Insights and a registered dietitian nutritionist, “the results of the present study are not surprising given flavonoids’ well-documented anti-diabetic effects” (Trusted Source). Costa posits that the association between flavonoids and a reduced risk of diabetes could be due to their function in blood sugar regulation. She did warn that there was more data to suggest that flavonoids may have a preventive function in warding off type 2 diabetes, thanks to the big UK Biobank cohort and extensive follow-up.
Reasons why alcohol usage must be controlled
Further, she brought attention to the fact that “researchers are finding more and more evidence of the negative consequences of alcohol use, such as its link to obesity, insulin resistance, and other metabolic disorders that can lead to type 2 diabetes.” Costa informed us that the study considered the participants’ total alcohol intake when examining the link between flavonoid consumption and type 2 diabetes risk. They then reanalyzed the data by removing red wine from the flavonoid diet score to see if the results would differ. Overall, they made a good call. Aside from that, she said, “[t]his approach allowed them to isolate the effects of flavonoids without the influence of alcohol and show that the protective association between flavonoid intake and type 2 diabetes risk remained significant without any red wine consumption.”
Serious consequences for people’s health and the general population
Costa said people may improve their health and reduce their risk of chronic diseases without drinking too much alcohol if they eat a diet high in naturally occurring flavonoids from foods like fruits, vegetables, and teas. Patients are encouraged to eat more foods high in flavonoids, as this may greatly lower their chance of developing type 2 diabetes. Consuming six servings of a mix of flavonoid-rich foods, including grapes, oranges, grapefruit, sweet peppers, onions, at least 70% dark chocolate, and notably black and green tea, apples, and berries, are among the attainable targets identified by the research, according to Costa. The significance of incorporating flavonoid-rich foods into a well-rounded, health-promoting lifestyle is highlighted in these guidelines, which provide practical measures for enhancing health, even though further study is needed, she noted. “Although further research is required to determine which foods are best for preventing diabetes or how much of them to eat, there is little doubt that eating foods that are high in flavonoids on a regular basis can have important positive effects on health.”
“Even as the science continues to evolve,” Costa said, “this approach allows individuals to take proactive steps to enhance their well-being.”
Link between a high flavonoid diet and type 2 diabetes
A recent research study published in the Nutrition & Diabetes journal investigated the relationship between a diet high in flavonoids and the development of type 2 diabetes in a large British population. Current evidence suggests that individuals who consume a plant-based diet have a reduced risk of type 2 diabetes. However, plants contain various polyphenolic chemicals, and these compounds have different levels of bioavailability and bioactivity.
Flavonoids are a class of polyphenolic chemicals that can be categorized into six primary subclasses: isoflavones, flavanones, flavones, anthocyanins, and flavan-3-ols. Some research suggests that increasing flavonoid consumption may improve insulin sensitivity and blood lipid profiles.
The study utilized data from the UK Biobank project, which included over half a million individuals from the United Kingdom. The researchers analyzed the dietary questionnaires completed by the participants and calculated their flavonoid consumption using USDA databases.
Based on the analysis, individuals who were older, more physically active, more educated, and female tended to consume more flavonoid-rich foods. On average, the participants consumed 805.7 mg of flavonoids per day, with the main sources being polymers and flavan-3-ols derived from tea. Flavones, found in peppers, were consumed in the lowest quantities.
The statistical analysis revealed that individuals with a higher Flavodiet Score (FDS), indicating a higher intake of flavonoid-rich foods, had a 28% lower risk of developing type 2 diabetes compared to those with a lower FDS. The study also found that consuming one serving of flavonoid-rich foods daily was associated with a 6% reduction in diabetes risk. Specific foods like black or green tea, berries, and apples were linked to even greater risk reductions.
The investigation identified potential mediators, such as insulin-like growth factor 1 (IGF-1), urate, cystatin C, body mass index (BMI), GGT, and ALT, that may explain the beneficial effects of flavonoids on weight loss, inflammation, glucose metabolism, and kidney and liver health.
Registered dietitians Megan Hilbert and Kelsey Costa commented on the findings. Hilbert highlighted the anti-inflammatory and weight-maintenance properties of flavonoids and their ability to decrease excess adipose tissue and improve glucose absorption by muscle cells. Costa emphasized the well-documented anti-diabetic effects of flavonoids and their potential role in blood sugar regulation.
Costa also noted the negative consequences of excessive alcohol consumption, including its link to obesity, insulin resistance, and metabolic disorders associated with type 2 diabetes. However, the study demonstrated that the protective association between flavonoid intake and type 2 diabetes risk remained significant even when alcohol was excluded from the analysis.
To reduce the risk of chronic diseases like type 2 diabetes, Costa recommended consuming a diet high in naturally occurring flavonoids from fruits, vegetables, and teas. The study suggested consuming six servings of flavonoid-rich foods per day, including grapes, oranges, grapefruit, peppers, onions, dark chocolate, black and green tea, apples, and berries.
While further research is needed to determine the optimal foods and quantities for diabetes prevention, incorporating flavonoid-rich foods into a well-rounded lifestyle can have significant positive effects on health. By following these guidelines, individuals can take proactive steps to enhance their well-being.