These are a broad class of antioxidants grouped according to their chemical structure. Polyphenols may or may not be pigmented. They can be divided into flavonoids (found in many fruits and vegetables), tannins (found in tea), diferuloylmethanes (found in some spices like turmeric), stilbenes (found in blueberries and grapes) and phenolic acids (found in coffee).
These are plant-based water-soluble nutritional compounds with an ability to reduce free radical damage in your body. Reducing free radical damage means reduced inflammation and cellular damage, both of which have been linked to a variety of illnesses. They may be commonly found in fruits and vegetables. Plants produce flavonoids to defend themselves against parasites and oxidative injury. There are many types of flavonoids. Anthocyanins are flavonoids with red pigments. Proanthocyanins are colourless flavonoids that have a tendency to become red. Other subclasses include flavonols, isoflavones, etc.
So now that we understand this, we can go on to discuss why apples are becoming the most sought-after health tool. Simply put, apples are loaded with polyphenols! To be more specific, it contains flavonols called quercetin, myricetin, catechin and phloridzin. Chlorogenic acid is the main phenolic acid found in apples and, if the apple is red, you know it’s packed with anthocyanins.
It is this strong antioxidant property of apples that is related to its ability to lower the risk of cancer, diabetes and heart disease.
Antioxidants have long been proven to reduce cancer risk. Apples, in particular, lower the risk of colon and breast cancer. Another surprising discovery is its ability to reduce lung cancer. Apples clearly have some positive effect on the respiratory system because new research has also linked it with reducing asthma. Scientists are not exactly sure yet of the mechanism but we look forward to more research in this area.
Bureau and Martinoli from the University of Quebec concluded that cellular death due to oxidation and inflammation of neurons was reduced by quercetin and could reduce the risk of developing neurodegenerative disorders such as Alzheimer’s disease.
Quercetin inhibits carbohydrate-digesting enzymes like alpha-glucosidase and alpha-amylase. This means that when you eat, less carbohydrate is broken down into simple sugars. Less simple sugars absorbed into the bloodstream means less workload on our pancreas to produce insulin. The polyphenols found in apples therefore help to regulate our blood sugar level.
Apples are closely linked to cardiovascular protection due to their pectin content. Apples contain about 2-3 g of fibre for every 3.5 ounces. Although less than 50% of this soluble fibre is made of pectins, when the pectins combine with the polyphenols, it prevents oxidation of fats that are found in the bloodstream and in the lining of our blood vessels. This leads to an overall reduction in LDL cholesterol. Florida State University researchers found that older women who ate apples everyday had 23% less bad cholesterol and 4% more good cholesterol after 6 months. Pectins given alone, without the combination with other polyphenols, did not have such a dramatic effect on overall cholesterol in laboratory studies. Quercetin, in particular, also has strong anti-inflammatory properties and recent research has shown that quercetin caused a drop in C-reactive protein (an inflammatory marker in heart disease). In addition, chlorogenic acid has been shown to aid in weight loss. While green coffee bean extract has the highest concentrations of chlorogenic acid, an apple a day can certainly help.
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Storage and Consumption
When an apple gets bruised, polyphenol oxidase enzymes in the apple start eating up the polyphenols. That gives the apple its brown discolouration. It also starts releasing ethylene gas, which can pose a risk to other undamaged apples. It is therefore very important to handle the apples with care and to remove damaged ones from the group. Research again has proven the old proverb correct - One bad apple can spoil the whole bunch!
Polyphenols are what apples use to protect themselves against the sun’s harmful UV-B rays. They are the apple’s natural sunscreen, and most of them are in the apple skin or just below it. Therefore, apple skin should not be removed before consumption. As much as possible, buy organic apples. They will not look as shiny as regular apples but this will avoid the problem of contaminants and pesticides on the apple skin, where most of its goodness and fibre is stored.
If you cannot find organic apples, then the trade-off between the nutrients and contaminants on the apple skin still warrants keeping the skin intact. Dieticians from the University of California Davis have found that apples have consistently low levels of pesticides. In this case, it is advised that you thoroughly rinse the entire apple in pure water while gently scrubbing the skin for about 15 seconds. Alternatively, you can fill a bowl with warm water and splash of vinegar and let the apples soak for about 30 seconds to 2 minutes. White vinegar and water can kill about 98% of pesticides and bacteria on fruits and vegetables. Rinse them under the tap and they are ready to eat!
Note, however, that these benefits are only found when consuming the apple as a fruit and not as applesauce or apple juice.
Besides being loaded with antioxidants, apples also contain vitamin C, B-complex vitamins and dietary fiber. The table above shows the other trace minerals that can be found in apples. Apples are truly the new “miracle fruit” in medical research. Seems like an apple a day, CAN keep the doctor away!