Dear doctor: What are flavonoids? All of a sudden they’re making the headlines, and it looks like if you get enough of them you’ll have normal blood pressure. Can you get them in regular food?

Dear reader: Flavonoids definitely have a moment, and not for the first time. Two new studies join a larger body of existing research that links flavonoids to a wide range of health benefits. They exhibit anti-inflammatory, antiviral, and anti-tumor properties, which have been linked to a reduced risk of certain chronic diseases, including cancer, cardiovascular disease, and neurodegenerative disorders.

As you have noticed, one of the two more recent studies links the consumption of foods rich in flavonoids to improved blood pressure. Results from a separate study link nutrients to a lower incidence of cognitive decline in older people. It is important to note that these are observational studies. This means that although the data point to some conclusions, the methodology is unable to prove cause and effect.

Let’s start with the flavonoids themselves. These are chemical compounds which, in addition to giving fruits and vegetables their bright colors, directly participate in the development and growth of plants. They are also called phytonutrients. These are chemical compounds produced by plants that, while often beneficial to humans, are not essential for sustaining life. The main food sources of flavonoids are fruits, vegetables, certain herbs, tea, wine and dark chocolate. Citrus fruits, blueberries, blackberries, cherries, red cabbage, kale, onions, apples, pears, peppers, oregano, and parsley are great sources.

Flavonoids, which are broken down by the trillions of microbes that live in our gut, are divided into six groups. These are based on their chemical structure. Each subgroup offers unique health benefits, making it important to eat from a wide and varied range of fresh fruits and vegetables.

In the study you heard about, published in Hypertension, a journal of the American Heart Association, researchers from Northern Ireland analyzed a year of health and diet data from 900 study participants. . They also sequenced the genetic makeup of bacteria in their intestines. They found that consuming foods rich in flavonoids influenced the composition of the gut microbiome in a way that was beneficial for blood pressure. The effect appeared to be particularly pronounced in people who ate at least 1 1/2 servings per day of foods rich in the flavonoids subcategory associated with blue and red colored foods, such as blueberries, blackberries, and berries. Red grapes.

In the other study, published online in the journal Neurology, researchers at Harvard University analyzed 20 years of health and nutrition data collected from 100,000 women and men. They found that people with a diet rich in flavonoids reduced their risk of cognitive decline by up to 20%. In this study, scientists said they suspected that the antioxidant properties of flavonoids had a protective effect on blood supply to the brain.

There is no specific recommendation for the amount of flavonoids a person should eat each day. Instead, the takeaway here is to make a wide array of fresh fruits, vegetables, and leafy greens a centerpiece of your diet.