An apple a day has long been considered a simple component of a balanced diet. However, not all apples are the same. Depending on the variety, the amounts of certain plant compounds can vary significantly.

Particularly interesting are the so-called polyphenols. These are secondary plant compounds that are being studied for their potential antioxidant and anti-inflammatory properties. One variety consistently ranks high in comparisons: the Boskoop.

The extent of the differences is shown by a German study that compared ten traditional apple varieties with five widely spread varieties today.

The traditional varieties included Red Boskoop, Berlepsch, Goldparmäne, and Gravensteiner. Also examined were Braeburn, Elstar, Golden Delicious, Granny Smith, and Jonagold.

In the flesh, the average polyphenol content of the traditional varieties was around 29 milligrams per 100 grams. For the five widespread varieties, it was an average of 13 milligrams.

Particularly high values were found in Red Boskoop and Dülmener Rosenapfel. Golden Delicious, on the other hand, was at the lower end of the comparison for both the peel and the flesh.

Other studies also show significantly different values. In an analysis of seven varieties available in Germany, around 90 milligrams of polyphenols per 100 grams were measured for the whole cored Boskoop. Braeburn reached about 41 milligrams. Even higher values were achieved by Goldparmäne with 123 and Gewürzluiken with 158 milligrams.

Thus, the Boskoop is not automatically the variety with the highest polyphenol content. However, among the well-known and locally available apples, it is one of the varieties that achieve notably high values in studies.

The fact that traditional varieties often perform well could be related to their breeding history.

Polyphenols not only influence potential health properties but also the taste and appearance of an apple. They can, for example, contribute to a more tart flavor and be involved in the browning of the flesh after cutting.

For many modern table apples, other characteristics were therefore prioritized – such as sweetness, appearance, good storability, or a lower tendency to brown. The authors of the German study see this as a possible explanation for the higher polyphenol content in some traditional varieties.

However, a simple rule like „old variety = healthier“ cannot be derived from this. The differences within the individual groups are considerable. Ultimately, the specific variety is decisive.

There are differences not only between the varieties. Polyphenols are also distributed differently within a single apple.

In a study of apples from the German market, between 68 and 285 milligrams of polyphenols per 100 grams were found in the peel, depending on the variety and apple. In the flesh, the values ranged from 17 to 127 milligrams.

The peel makes up only a small part of the entire apple. Nevertheless, it can be worthwhile to eat a well-washed apple with the peel.

One should not infer too much from the color. Red apple skins do contain anthocyanins, which are responsible for the coloring. However, other polyphenols are also present in green or yellow apples. Therefore, red does not automatically mean healthier.

This is where it gets more difficult. It is well documented that the ingredients of different varieties can be measured. However, whether a particularly polyphenol-rich apple therefore also brings a greater health benefit cannot be deduced from this alone.

A systematic review published in 2026 evaluated 38 human studies on apples and apple products. Among other things, positive effects on blood sugar, vascular function, and gut flora were described.

However, the studies examined differed significantly from each other. Therefore, it remains unclear which ingredients are responsible for individual effects and how significant the long-term impact actually is.

A small study with 25 healthy adults also provides interesting insights. A particularly polyphenol-rich red-fleshed apple and a white-fleshed apple were compared. After consuming the red-fleshed apple, changes were observed in certain gut bacteria and in genes of the immune system.

However, such a small study is not sufficient for far-reaching statements about long-term health.

(VIENNA.AT)

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