After adjusting for health and sociodemographic factors, the analysis revealed significant associations between total and specific flavonol intake and mortality risks from various causes.

The highest intake of dietary flavonols reduced the risk of cancer-related mortality by 55%, cardiovascular disease mortality by 33%, and risk of death from other causes by 36%.

Comprehensive findings also highlighted specific flavonols, each contributing to substantial reductions in all-cause and disease-specific mortality risks.

Of note, the highest myricetin consumption exhibited a staggering 66% decrease in Alzheimer’s disease-specific mortality risk.

The researchers observed no significant correlation between dietary flavonol intake and mortality risk from diabetes.

The study results also revealed that the consumption of flavonols had a greater protective effect against all-cause mortality in those over 40 years old than in younger individuals.

These findings suggest diets rich in flavonols could significantly lower the risks of death from cancer, heart disease, Alzheimer’s disease, and other causes among U.S. adults, particularly in mature or aging populations.

The study’s findings on flavonol intake and mortality are limited by a partial dataset from the NHANES database and an estimation of flavonol intake that might not accurately reflect consumption over the study period.

Further research is needed to confirm the results, considering additional dietary factors such as total calorie intake and micronutrient supplement usage, which could influence the observed flavonol effects.

Medical News Today discussed this study with Dr. Thomas M. Holland, a physician-scientist at the RUSH Insitute for Healthy Aging, Rush University System for Health, not involved in the study.

He said: “[I]t is a little challenging to establish the dietary intake of flavonoids from 24-hour recalls instead of food frequency questionnaires that would provide a bit more robust data on typical food intake habits or behavior.”

However, he suggested that 24-hour recalls provide adequate data and that the study design and sample size were strengths.

The health benefits of flavonoids are well established, but this study is the first to thoroughly explore the relationship between dietary flavonol intake and cause-specific mortality in humans.

So, while it has its limitations, Dr. Holland explained, “[t]his study really moves the research that has been done over the last 15 years — particularly in the last 4 years —forward in a great way.”

“One notable aspect of the study is its detailed analysis of various types of flavonols, including total flavonol, isorhamnetin, kaempferol, myricetin, and quercetin,” added Michelle Routhenstein, RD, a registered dietitian who specializes in preventative cardiology nutrition at Entirely Nourished, and who was not involved in this study.

“By considering these specific flavonoid compounds, the study provides a nuanced understanding of how different components of flavonoid-rich diets may influence mortality risks,” she said.

Dr. Holland emphasized:

“The primary aspect here is that the data shows a reiteration that consumption of nutrient and [bioactive] rich foods in a healthier diet is associated with decreased risk of some of the most detrimental non-[communicable] diseaseTrusted Source processes that plague the world.”

To incorporate more health-promoting, flavonol-rich foodsTrusted Source, Dr. Holland suggested an overall shift to a healthier diet, such as the MIND diet or the Green Mediterranean diet.

“These diets stand as one of the preeminent ways we can safeguard cognitive health while also mitigating risks for Alzheimer’s dementia, all-cause mortality, cancer, and cardiovascular disease, given their robust flavonoid concentrations,” he explained.

Kiran Campbell, RDN, registered dietitian and owner of Kiran Campbell Nutrition, not involved in the study, agreed that a broader focus on diet is essential.

“StudiesTrusted Source suggest that the overall intake of fruits and vegetables provides more health benefits than focusing on a single plant compound like flavonoids,” she said.

According to Routhenstein and Campbell, for those looking to incorporate more flavonols into a healthy diet, some of the richest sources include:

• tea: green and black tea
• chocolate: dark chocolate or cocoa
• legumes: chickpeas and soybeans
• fruit: apples, grapes, cherries, citrus fruits
• vegetables: red onion, artichokes, bell peppers
• berries: black currants, cranberries, and other berries
• herbs: dill, parsley, and oregano
• dark leafy greens: spinach and kale
• grains/pseudo-grains: buckwheat and quinoa

Are food sources of flavonols better than supplements?

In short, yes. Obtaining flavonols from whole foods is preferable to supplements.

While flavonoid levels are not concerning in the amounts found in foods, high-potency supplements can lead to excessive consumption and flavonoid toxicityTrusted Source.

FlavonoidsTrusted Source are often considered safe because they are natural, but supplements may exceed safe intake levels or interact with medications, leading to potential risks, warned Campbell.

Dr. Holland further suggested:

“[C]onsider incorporating whole fruits and vegetables into your diet and enjoying a cup of tea. If you decide to use supplements, it’s recommended to do so under the guidance of your primary care physician to help address any nutritional gaps you may have. This approach allows you to benefit from the diversity of quantity and quality of nutrients found in whole foods, including valuable bioactives like flavonols.”