An apple a day...

Apples are widely consumed across the population and are generally regarded as being healthy. However, what is less known is that apples are a potent source of powerful antioxidants plus other protective plant compounds with epidemiological studies linking their consumption with a reduced risk of some cancers, cardiovascular disease, asthma and diabetes.

In recent studies, apples have been found to have very strong antioxidant activity, inhibit cancer cell proliferation, decrease lipid oxidation and lower cholesterol. Apples contain a variety of phytochemical compounds, including quercetin, catechin, phloridzin and chlorogenic acid, all of which are strong antioxidants.

Due to a combination of a highly oxidative environment and poor diet the body's antioxidant defenses can be overwhelmed and oxidative stress results. Oxidative stress has been linked to the development of a variety of diseases including cancer, heart disease, neuronal degeneration such as Alzheimer's and Parkinson's disease as well as the process of ageing. This type of damage may be prevented or limited by dietary antioxidants in fruits and vegetables such as apples.

The table below shows the total antioxidant capacity for some common fruits as measured using ORAC - oxygen radical absorbance capacity. It has been found that apples contain almost 5 times the antioxidant capacity of bananas and more than twice that of an orange. Just 100g of apple has the equivalent antioxidant power of a 1740mg megadose of Vitamin C.

Fruit	Approx ORAC value (per 100 grams)
apple	4200
pear	2900
avocado	1900
orange	1800
mandarin	1650
grapes	1100
banana	800
rockmelon	250
watermelon	200

Apples and cancer

Apples are one of the very few individual foods specifically identified in population studies as having the capacity to reduce cancer risk and more specifically lung cancer. In a Finnish study involving 10 000 men and women and a 24 year follow up, a strong inverse association was seen between flavonoids intake and cancer development. Apples were the only specific foods that were inversely related to lung cancer risk. Since apples were the main source of flavonoids in the Finnish population, it was concluded that the flavonoids from apples were most likely responsible for the decreased risk in lung cancer.

A more recent study to specifically investigate apple intake and cancer risk was conducted in Europe where the researchers analysed data from thousands of individuals who participated in multi-centre case controlled studies over 11 years. Dietary patterns (including consumption of apples) were compared with patients who did not have any type of cancer. Individuals, who consumed an apple a day or more, had a reduced incidence of different cancers: oral, eosophageal, larynx, breast, ovary, prosdtate and colorectal. After allowing for consumption of other fruits and vegetables, "the association with apples did not change, and became even stronger for some cancer sites" revealed the authors.

Other apple benefits

Apples also have benefits on other common afflictions such as asthma and diabetes. In one study, whole apples were found to protect against asthma, current asthma as well as bronchial hyperreactivity while total fruit and vegetable intake was not associated with asthma risk or severity. Pears were also found to be protective. The ability for apples to help prevent asthma has recently been expanded to consider the impact of the maternal diet. New research suggests that mothers who eat apples during pregnancy may protect their children from developing asthma later in life. While the association is not yet full understood, the protective benefits appear to be apple specific, possibly because the apple's flavonoids content has positive effects on airway and immune development.

An apple intake of one per day or more resulted in a significant 28 per cent reduction in risk of Type 2 diabetes compared to those who did not consume apples in a study of more than 38 000 women, published in the journal of the American College of Nutrition. The previously mentioned Finnish study of 10 000 people also considered apple intake and Type 2 diabetes risk and found apple intake was associated with decreased risk. Higher quercetin intake, a major component of apple peels, was also associated with a decreased risk in type 2 diabetes.

Apple facts: