The 'super' powers of apples against tumors, cardiovascular diseases and diabetes

Autumn is also the season for apples, which have always been attributed with beneficial powers. Just think of the famous ancient saying: "An apple a day keeps the doctor away." But what is true about the proverb according to the latest scientific evidence?

Apples, in addition to being well-stored throughout the year (therefore always available), are undoubtedly one of the fruits richest in phytochemicals with protective potential.

Oxidative damage

These substances, present above all in the skin, "are concentrated in the outer layer to protect the fruit from damage by solar radiation, - specifies Ettore Corradi, director of the Complex Structure of Dietetics and Clinical Nutrition of the Asst Grande Ospedale Metropolitano Niguarda in Milan. - Therefore, they are phytochemical substances that can act against oxidative damage and inflammation and this, applied to human health, translates into protective effects against some types of cancer, against cardiovascular and metabolic diseases (such as diabetes)".

This is shown by several epidemiological studies conducted on apple consumption (often associated with pears): for example, the EPIK study (“European Prospective Investigation Into Cancer and Nutrition 2006-2007”), which links high apple consumption to a low incidence of lung and bladder cancer, or the American NHS study (Nurses' Health Study), which analyzes apple consumption in relation to a low incidence of lung cancer.

Phenolic compounds

The most studied substances in relation to these effects are in fact phenolic compounds, which can be divided into two main groups: flavonoids and phenolic acids, which are abundant in apples.

"It is necessary to make a clarification," Corradi specifies for "Corriere della Sera", "it is one thing to study the action of flavonoids in vitro, which has been found to be very powerful, and another thing is their bioavailability when eating the fruit: for example, eating a whole apple has completely different metabolic effects compared to enjoying the pulp without the skin or the juice, because inside they lack the fibers, which have a strong prebiotic effect and allow the beneficial ingredients to be absorbed much better."

Some types of flavonoids are found mainly in the skin, in fact, their bioavailability also varies in relation to the color of the apple and its type, which indicates the concentration of polyphenols in its interior and in the pulp of the six types of apples on the market.

From this, it can be concluded that the general rule to obtain as much as possible of all the precious nutrients with the consumption of an apple remains that of eating the whole fruit, but without focusing on just one type: "Eating as many types of fruit as possible guarantees better coverage of the needs of all nutrients, - notes Corradi. - In general, from a nutritional point of view, what we currently know is that we should not focus too much on a single nutrient or a single food, but more on a healthy lifestyle, with a diet rich in vegetables and fruits, in which fruit portions should be at least two or three per day".

Organic option

Other tips for healthy apple consumption are to choose the organic option, which, with current regulations, must nevertheless be certified, and to prefer local products: this is not the case with apples in particular, but some substances (such as vitamin C) are unstable and a product that has to travel a long way dissipates the substances during the journey.

When is it best to eat fruit? "There is not enough scientific evidence to recommend eating an apple at a specific time of day, but I would suggest using it as a snack. It would make us arrive at the next meal less hungry and would be a high-quality 'snack' compared to ultra-processed foods," the expert continues.

Is an apple a day really good for everyone? "Chronic degenerative diseases have a common matrix, namely a diet that goes from a caloric surplus to a poverty of protective antioxidant and anti-inflammatory substances. Therefore, a diet rich in protective products (like apples) may be suitable for heart patients, diabetics and obese people."

Diabetics

Can diabetics also eat an apple? "If the subject has diabetes compensated with medication and if we are talking about a whole fruit, it is absolutely indicated, because pectin (the fiber in which apples are rich) helps in the bioavailability of protective nutrients and slows the entry of simple sugars into the blood, helping to maintain glycemic peaks", - emphasizes Ettore Corradi.

The portions that should be respected, according to the guidelines (developed by CREA), are 2-3 per day (150 g of leftovers and 100 g for more sugary fruits such as bananas, figs, grapes, dates).

The first rule for diabetics is not to consume fruit on an empty stomach.

In fact, to minimize the impact of fructose, it is best to pair it with other foods, especially those that help reduce the glycemic peak (i.e. foods rich in fiber, protein, or good fats).