“An apple a day keeps the doctor away” is a famous proverb indicating the benefits of apples. Researchers at Edith Cowan University in Perth, Western Australia reconfirmed the rationality of this old saying, and they found flavonoids, plant-derived polyphenolic compounds in food like apples, tea and broccoli, can protect against cancer and heart disease.
Flavonoid intake is associated with lower mortality
The cohort study included 56,048 Danish participants aged 50-65 years who were followed for about 23 years. Scientists collected the diets, cancer and health cohort of the participants from Danish nationwide registries.
The statistical analysis shows that moderate flavonoid intake is inversely associated with all-cause, cardiovascular and cancer-related mortality and that this association is strongest at an intake of about 500 mg/day.
Moreover, It was found that the inverse associations between total flavonoid intake and mortality outcomes were stronger in smokers than in non-smokers, as well as in heavy vs low-moderate alcohol drinkers.
The anti-inflammatory activity of flavonoids may protect against cancer and heart disease
The mechanisms behind the protective benefits in smokers and alcoholic users are still unknown. It is speculated that the anti-inflammatory activity of flavonoids plays an important role in protecting against cancer and heart disease.
Alcohol and tobacco consumption can increase inflammatory response, damage blood vessels, and trigger a range of diseases, and flavonoids are believed to reduce inflammation and activate immune modulation to protect the heart.
Nowadays, flavonoids have already been used in the clinical treatment for cardiovascular diseases, and function as active compounds in some drugs for patients with coronary heart disease and angina. Flavonoids can regulate angiogenic growth factors to reduce the risk of atherosclerosis.
The antioxidant activity of flavonoids
In addition to the brilliant anti-inflammatory property, flavonoids also have remarkable antioxidant activities. They are water-soluble and can function as potential antioxidants in the human body.
Free radicals are derived from metabolic processes in the human body and irregular living habits such as overworking, smoking, alcoholism and physical inactivity can cause the overexpression of free radicals to trigger oxidative stress, which can result in aging, diseases and cancer. Flavonoids are found to inhibit oxidative response and help people prevent a variety of diseases.
In addition, recent studies have found other benefits of flavonoids. Studies have found that long-term tea drinking can reduce the incidence of hypertension and the risk of cognitive impairment, which is related to tea rich in catechins. A study reported that fermented soy products with high levels of soy isoflavones can prevent bone loss in postmenopausal women. Studies have also shown that flavonoids can protect the brain’s nerves.
Fruits and vegetables are good sources of flavonoids
Flavonoids come from food and cannot be synthesized by the body. There are about 4,000 kinds of flavonoids, and some well-known ones include quercetin, anthocyanins, apigenin present in fruits and vegetables, catechins high in tea, and isoflavones rich in soy products.
Fruits and vegetables are main sources of flavonoids, and flavonoids-rich fruits and vegetables are usually high in dietary fiber, vitamin C, polyphenols. etc. Therefore, an easy way to supplement flavonoids is to consume enough fruits and vegetables.
Below are some tips that help you eat fruits and vegetables in a wise manner.
Eat more deeply colored vegetables and fruits. Deeply colored vegetables and fruits usually contain higher flavonoids. It is highly recommended to have a rainbow diet with multi-colored vegetables and fruits. Some deeply colored vegetables and fruits contain broccoli, celery, spinach, tomatoes, apples, cherries, orange, carrots, cabbage, grapes and so on. In addition, tea and soy products are also good sources of flavonoids.
Eat fruits with peels. The peels of fruits are usually the most nutritious part and high in flavonoids, and they are safe to eat after cleaning. You do not have to peel fruit before juicing.
Choose seasonal vegetables and fruits. Flavonoids are more abundant in fresh foods in season. Eating fresh and diversified foods can help obtain enough flavonoids and other nutrients.
A daily recommended intake of flavonoids is about 500 mg. Excessive intake of flavonoids shall be avoided, especially for people who are taking targeted therapy.