A major review study published in the Nutrition Journal provides dozens of reasons to enjoy an apple every day. A review study is one that looks at the results of many other studies. This one included an analysis of 85 studies. Apples were found to be most consistently associated with a reduced risk of cancer, heart disease, asthma, and type 2 diabetes when compared to other fruits and vegetables. In addition, eating apples was also associated with increased lung function and increased weight loss.
Here are some of the reasons why:
Apples are a rich and very important source of phytonutrients, including flavonoids and phenols, in the American diet and in Europe. In the United States, 22% of the phenolic compounds consumed from fruits come from apples, making them the largest source of phenols in the American diet. When compared to other fruits, apples ranked second in total concentration of phenolic compounds, and perhaps more importantly, had the highest portion of free phenols. Since free phenols are not bound to other compounds in the fruit, they may be more available for absorption into the bloodstream. Apples are also an excellent source of antioxidants, and when compared to many other commonly consumed fruits in the United States, were found to have the second highest level of antioxidant activity. Many of the phytonutrients found in apples, including quercetin, catechin, phloridzin and chlorogenic acid, are strong antioxidants.
The total antioxidant activity of 100 grams of whole apple (with the peel) was found to be equivalent to the antioxidant effect of about 1500 mg of vitamin C. (However, the amount of vitamin C in 100 g of apples is only about 5.7 mg. Nearly all of the antioxidant activity from apples comes from a variety of other compounds.) Whole apples, especially their peels, have been found to have a number of powerful antioxidant effects, one of which is to protect VLDL and LDL (“bad”) cholesterol from oxidation. Yet when quercitin, one of the most important antioxidant flavonoids in apples, was tested by itself in laboratory animals, it had no protective effect. And when apple flesh and apple juice were tested, they provided less than a tenth the benefit of whole apple. Apples’ protective effects against free radical damage to cholesterol reach their peak at three hours following apple consumption and drop off after 24 hours, providing yet another good reason to eat a whole fresh apple a day. In animal studies, apples have also been shown to lower LDL (“bad”) cholesterol while raising beneficial HDL cholesterol.
Not only did the laboratory animals in these studies produce less cholesterol, but they also excreted more in their feces when fed apples, pears and peaches-but apples had the greatest cholesterol-lowering effect. In the most recent studies, investigators found that the combination of apple pectin and apple phenols lowered cholesterol and triglycerides to a much greater extent than either apple pectin or phenols alone.
This again suggests a beneficial synergy between the many healthful compounds found in apples and supports eating the whole fruit instead of simply drinking apple juice, eating peel-free applesauce or taking fiber supplements. ~~~Apples have also been shown to greatly inhibit the growth of liver and colon cancer cells in several studies. In one study, at a dose of 50 mg/mL, liver cancer cell proliferation was inhibited by 39% by extracts of whole Fuji apple and 57% by whole Red Delicious extracts. In another study in which colon cancer cells were treated with apple extracts, cell proliferation was inhibited 43% at a dose of 50 mg/mL.
Eating an apple a day may also offer significant protection against breast cancer, suggests an animal study published in the Journal of Agricultural and Food Chemistry . When ~~~laboratory animals with breast cancer were fed the human equivalent of 1, 3 or 6 apples a day for 6 months, their tumors shrank by 25%, 25%, and 61%, respectively. Researchers credit apples’ strong protective action to the synergistic interactions among the wide variety of potent antioxidant and antiproliferative phytonutrients, including phenolics and flavonoids, they contain. In several large epidemiological (population) studies conducted in the United Kingdom, Finland and the Netherlands, apple consumption (a minimum of 2 apples per week) was found to be inversely linked with asthma and type 2 diabetes, and positively associated with general lung health. Researchers attribute apples’ protective effects in these conditions to apples’ high concentration of anti-inflammatory flavonoids, such as quercitin and catechin. In addition to their beneficial effects against chronic diseases ~~~including cancer, cardiovascular disease, asthma and diabetes, apples may also help combat cholera. Recently, crude extracts from immature apples were found to inhibit cholera toxin in a dose dependent manner by up to 98%.Variation in Antioxidant Phytonutrients Among Different Types of Apples
Researchers have found distinct differences in total phenolic and flavonoid content among different apple varieties: Of the four common varieties used for applesauce (Rome Beauty, Idared, Cortland, and Golden Delicious), Rome Beauty had the highest phenolic content. Out of 10 varieties commonly consumed in the U.S., Fuji apples had the highest total phenolic and total flavonoid compounds, but Red Delicious apples were also quite high. These apple varieties also tended to have higher antioxidant activity. Apple phytonutrient content is not greatly affected by storage. After 100 days, the amount of phenolic compounds in the skin begins to decrease slightly, but even after 200 hundred days in cold storage, the total amount of these compounds remains close to the level at the time of harvest. However, processing apples into juice greatly lowers their phytonutrient content. Apple juice obtained from Jonagold apples by pulping and straight pressing had only 10% of the antioxidant activity of fresh apples, while juice obtained after pulp enzyming had only 3% of fresh apples’ antioxidant activity. The take home message: store apples in the refrigerator and enjoy a sweet, crunchy, whole apple at least 2-3 times each week.
A Flavonoid Unique to Apples May Help Prevent Menopausal Bone Loss
~~~A flavonoid found only in apples called phloridzin may help prevent bone loss associated with menopause, suggests a study published in Calcified Tissue International.. A side effect of the sex hormone changes that occur during a woman’s transition through menopause is a tendency towards increased inflammation and free radical production, which in turn, promotes bone loss. Because of their anti-inflammatory actions, polyphenols have been suggested as one means of protecting against bone loss during this pro-inflammatory time in women’s lives. To test this theory, French researchers ovariectomized lab animals (to simulate menopause) and divided them into two groups, which were given either a control diet or a diet supplemented with phloridzin for 80 days. Three weeks before the animals were sacrificed, 10 animals in each group were put into an inflammatory state. While all the animals on the control diet lost bone, and those in the inflammatory state lost even more bone, the rats receiving phloridzin not only did not lose bone, but actually increased bone mineral density-even if they were experiencing a high inflammatory state! If you’re moving through menopause, eating an apple a day may help you keep bone loss at bay.