Os fitonutrientes, igualmente denominados de fitoquímicos ou fitocomponentes, são compostos bioactivos, considerados não nutrientes, presentes apenas em alimentos de origem vegetal em quantidades muito pequenas (na ordem dos miligramas ou microgramas), muitos deles responsáveis pela cor, aroma e sabor dos próprios alimentos. Entre eles, é de salientar na maçã a quercitina, as catequinas, a floridizina e o ácido clorogénico.
Existem evidências científicas em vários estudos que os fitonutrientes ajudam a reduzir os efeitos do colesterol LDL, evitando a sua oxidação e fixação nas paredes das artérias.
Fiber and coronary heart disease: U.S. researchers report that for every 10 grams of fiber consumed per day the risk of developing heart disease may decrease 14 percent, and the risk of dying from heart disease may decrease 27 percent. Fiber from fruits appeared to be slightly more protective than cereal fiber, lowering the risk of coronary disease death by 30 percent. (Apples are one of the best fruit sources of fiber; one medium-tennis ball-sized apple (154 grams) contains 5 grams of fiber.) Findings were based on researchers' pooled analysis of data from 10 recent prospective cohort studies in the United States and Europe involving 91,058 men and 2345,186 women that measured the amount of fiber in participants’ diets over a period of 6-10 years. Findings challenge the potential long-term health costs of low-/nocarbohydrate diets that discourage consumption of high-fiber carbohydrates in the process. (Source: Arch Int Med, vol. 164, no. 4, Feb. 23, 2004; pp 370-376).
LDL Oxidation: Researchers at the University of California-Davis report that 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 that 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).
LDL Oxidation: Researchers at the University of California-Davis reported that 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 that important phytonutrients from apples are also 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).
Coronary Mortality: Finnish epidemiologists concluded that high consumption of flavonoids from apples and onions was directly associated with the lowest risk for coronary mortality. This conclusion was based on their analysis of diet and health outcomes of a study of 5,133 Finnish men and women aged 30-69 who were initially free of heart disease when the study began in 1967. (Source: British Medical Journal, 1996, 312: 478-481).
Thrombotic Stroke: Finnish researchers report that 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).