Color yourself healthy
As if great taste was not enough to make an apple a day worthwhile, it turns out an apple a day really might keep the doctor away. With obesity at an all-time high in the United States, the good news is apples are full of flavor without high calories or fat. If you’re looking to downsize your waistline and give your health a boost, apples are your answer. The health benefits of apples continue to be revealed in studies around the world.

Several recently released books are promoting the link between color pigments found in foods and their health benefits, including apples. In The Color Code: A Revolutionary Eating Plan for Optimum Health, Harvard’s James A. Joseph, Ph.D., and Daniel A. Nadeau, M.D., and Newsweek’s Anne Underwood, report the level of phytonutrients in fruits and vegetables is directly related to the food’s color pigmentation. The good news for apple eaters is that apples in all their colors – red, yellow, green, and in between – are great sources of health-promoting phytonutrients. Take note: much of an apple’s phytonutrients, not to mention the fiber, can be found in its colorful skin. So, put the peeler away and keep the color in your diet.

Studies show apples provide a wide range of health benefits that make eating apples even more delicious. While the study of apples’ health benefits is still in very early stages, research to date suggests apples and apple nutrients may play a role in promoting human health in a number of ways, providing a whole-body range of health benefits. Following are summaries of recent studies of apples’ health benefits.

Apples and cancer
Prostate cancer: Researchers at Rochester, Minnesota’s Mayo Clinic report that quercetin, a plant-based nutrient found most abundantly in apples, may provide a new method for preventing or treating prostate cancer. Researchers found quercetin reduced or prevented the growth of human prostate cancer cells by blocking activity of androgen hormones, in an in vitro (laboratory) study. Previous studies had linked androgens to prostate cancer’s growth and development. This is the first known study to link apples with a major men’s health issue. (Source: Carcinogenesis, 2001, 22: 409-414)

Colon and liver cancer: Researchers at Cornell University report phytonutrients in apples inhibited the growth of colon cancer and liver cancer cells in vitro. While the beneficial phytonutrients were most strongly concentrated in the apple skin, the apple flesh also contained significant levels of phytonutrients. According to the Cornell researchers, 100 grams of unpeeled fresh apple – about two-thirds of a medium-sized apple – provides the total antioxidant activity of 1,500 milligrams of vitamin C. (Source: Nature, 2000, 405: 903-904)

Lung cancer: Researchers at the University of Hawaii found increased consumption of quercetin was associated with a reduced risk of lung cancer in their population-based, case-control study involving 600 lung cancer patients and 600 cancer-free persons. Researchers investigating a possible relationship between the consumption of flavonoids and lung cancer risk found a statistically significant inverse association between lung cancer risk and intake of the flavonoid quercetin, found primarily in apples and onions, and the flavonoid naringin, found in white grapefruit. No association was found for important food sources of other flavonoids. This study validated similar findings published in 1997 (see the American Journal of Epidemiology study referenced below). (Source: Journal of the National Cancer Institute, 2000, 92: 154-160)

Cancer and lung cancer: Epidemiologists from Finland’s National Public Health Institute report consumption of a flavonoids-rich diet – and particularly flavonoid-rich apples – was associated with a reduced risk of developing cancer. Their study of 9,959 cancer-free Finnish men and women, begun in 1965, revealed that people who regularly consumed the most flavonoid-rich foods – apples, onions, fruits, juices, vegetables, and jams – during the 24-year study period were about 20 percent less likely to develop cancer. Researchers found lung cancer was 46 percent lower among those whose diets contained the highest amount of flavonoids, particularly from apples. Of the major dietary flavonoid sources, apples showed the greatest inverse association with lung cancer incidence. (Source: American Journal of Epidemiology, 1997, 146: 223-230)

Lung health
Asthma: Researchers from London’s King’s College and the University of Southampton report people who ate at least two apples per week had a 22 percent to 32 percent lower risk of developing asthma than people who ate fewer apples. Their conclusions were based on a population-based, case-control study of 1,471 adults in the United Kingdom that sought to examine how dietary antioxidants might affect asthma risk and severity. (Source: American Journal of Respiratory and Critical Care Medicine, November 2001, volume 164, number 10: 1823-1828)

Lung disease: Eating fruits and vegetables, in particular an apple a day, may reduce smokers’ risk of developing chronic obstructive pulmonary disease (COPD), based on a University of Groningen, Netherlands, study of long-term, heavy smokers. It is the first known study to suggest smokers could benefit from increased apple consumption. (Source: American Thoracic Society, unpublished findings presented at the society’s Annual Meeting, May 2001, poster 617)

Lung function:

• Researchers from the University of Nottingham in the United Kingdom report apple eaters have better lung function and lower risk of respiratory disease, such as asthma, than non-apple eaters, based on a nine-year population study of 2,633 adults. This study’s findings are similar to previous findings (see the Journal of the National Cancer Institute and Thorax studies referenced herein). (Source: American Thoracic Society, unpublished findings presented at the society’s Annual Meeting, May 2001, poster 618)

• British researchers report apple eaters have better lung function than non-apple eaters, as measured by forced expiratory volume. Investigating an hypothesized association between diet and lung function, researchers at London’s St. George’s Hospital found a strong positive association between lung function and the number of apples eaten each week, after analyzing dietary records and health outcomes of a group of 2,512 men studied for five years. Although it had been suggested by other researchers that vitamin C from fresh fruit was responsible for improving lung function, this research found to the contrary. Researchers postulated the healthful effect may be due to antioxidants in apples (e.g., flavonoids like quercetin). (Source: Thorax, 2000, 55:102-108)

Heart health
LDL oxidation:

• Researchers at the University of California-Davis report daily consumption of apples and apple juice may help reduce the damage caused by the “bad” type of cholesterol and protect against heart disease, based on the first human study of its kind. Researchers demonstrated apples and apple juice may help to slow the oxidation process that is involved in the buildup of plaque that leads to heart disease. Clinical study participants added only two apples, or 12 ounces of apple juice, to their diet. This study validated earlier in vitro findings (see the Life Sciences study referenced below). (Source: Journal of Medicinal Food, 2000, 3: 159-165)

• Researchers at the University of California-Davis reported phytonutrients in apples and apple juice prevent oxidation in vitro of the “bad” (LDL) cholesterol, and thus may help protect against cardiovascular disease. They also confirmed important phytonutrients from apples also are found in apple juice. While both foods varied in the levels of phytonutrient concentrations, both inhibited oxidation of LDL cholesterol, which can lead to unwanted build-up of harmful plaque in arteries. (Source: Life Sciences, 1999, 64: 1913-1920)

Stroke
Thrombotic stroke: Finnish researchers report persons who ate the most apples had the lowest risk of thrombotic stroke, possibly due to the phytonutrients found in the apples. This conclusion was based on evaluation of dietary records and health outcomes of 9,208 men followed for 28 years. Unlike findings from other epidemiological studies, the researchers attributed this positive association to phytonutrients other than quercetin found in apples (e.g., catechins), demonstrating apples’ broad phytonutrient content. (Source: European Journal of Clinical Nutrition, 2000, 54: 415-417)