A common English saying goes, ‘an apple a day keeps the doctor away’, this in general sense means that eating healthy will keep you from seeing a doctor often.

With their crunchy, tart or sweet taste and various shapes and colours such as, pale yellow, green and deep red, apples are nutritious fruits with numerous benefits.

Experts say that apples have been around for thousands of years, and they are different in their own way. It is believed that there are more than 7,500 varieties of apples worldwide, and some of these have recognisable names like Granny Smith, yet others are not that known, for instance Pink Pearl and Roxbury Russet.

Apples are cultivated worldwide as a fruit tree, and are the most widely grown species in the genus Malus. They can be eaten in diverse ways, for example, as a sauce, slices, or juice and are favoured for pastries, cakes, and pies. Experts explain that a typical apple serving weighs 242 grams and provides 126 calories with a moderate content of dietary fibre.

Emmy Ntamanga, a Kigali-based nutrition consultant, notes that apples contain nutrients such as vitamins A, C, E, K, B, and some minerals like potassium, manganese, and copper. They are also low in calories and high in fibre. He adds that apples promote healthier bones due to the antioxidants the fruits contain.

According to Medical News Today, the rich presence of fibre, vitamins, and minerals in apples, all of which benefit human health, also provide an array of antioxidants. These substances help neutralise free radicals.

"Free radicals are reactive molecules that can build up as a result of natural processes and environmental pressures. If too many free radicals accumulate in the body, they can cause oxidative stress. This can lead to cell damage. Cell damage can contribute to a range of conditions, including cancer and diabetes,” Medical News Today reports.

Ntamanga says that eating an apple at least every day may help keep the lungs healthy—being so rich in antioxidants, apples may help protect the lungs against free radicals and the oxidative damage they can cause.

Additionally, he says that apples can boost gut health, this is because they contain a type of fibre called pectin. This acts as a prebiotic, meaning that it feeds the good bacteria in the gut.

The body doesn’t absorb fibre during digestion. Instead, it goes to the colon where it can promote the health of good bacteria. It also turns into other beneficial compounds that can circulate through the body, he explains.

The nutrition expert explains that apples support healthy blood sugar levels, for instance, eating an apple a day is linked to healthier blood sugar levels and a 28 per cent lower risk of developing health issues that may arise from poor blood sugar.

He adds that it’s possible that the polyphenols in apples help prevent tissue damage to beta cells (cells that make insulin, a hormone that controls the level of glucose—a type of sugar—in the blood) in the pancreas, which produce insulin in the body.

Ntamanga says that apples have been found to help you feel full, as they can assist with portion control. This is thought to probably be due to their water and fibre content.

The American Diabetes Association recommends eating fresh fruits, such as apples, to satisfy a sweet tooth and provide nutrition. However, the organisation informs people to take note of the carbohydrate content in the fruit.

Ntamanga also highlights that consuming fibre-rich foods like apples can help keep acid reflux under control. Acid reflux, also known as gastroesophageal reflux disease, is a chronic condition that occurs when stomach acid or bile flows into the food pipe and irritates the lining.

Acid reflux can cause an uncomfortable burning feeling in one’s chest, which can move up into the neck and throat. This feeling is often referred to as heartburn.

As stated by the Healthline, a study has linked eating white-fleshed fruits and vegetables, like apples and pears, to a reduced risk of stroke. For every (25 grams) of apple slices consumed per day, the risk of stroke decreased by nine per cent.

"Quercetin in apples may protect your brain against oxidative stress. However, further research is needed to validate the effect of eating the whole fruit. Eat whole, unpeeled apples instead of apple juice to get the best out of the fruit,” Healthline suggests.