F

Fat

Fats are a necessary part of a healthy diet, but both the amount and type of fat makes a significant difference to heart health. High intake of saturated fats and trans fats increases blood cholesterol levels and the risk of coronary heart disease. Saturated fats derive mainly from animal sources, such as meat, cheese and other whole milk dairy products. Trans fats are primarily produced through hydrogenation -- a process that turns liquid vegetable oils into solids, such as the shortening and margarine often used in baked goods and snack foods. Fried food and fast food, in general, tend to be high in trans fats. The Dietary Guidelines for Americans recommends that total fat intake be kept between 20 to 35% of calories, with most fats coming from sources of "heart-healthy" polyunsaturated and monounsaturated fatty acids. These fats have been shown to reduce the risk of heart disease when used in place of saturated and trans fats. A recent study from Iowa State University found mono- and polyunsaturated fats help the body absorb fat-soluble nutrients such as vitamins A, D, E and K. One of the healthiest polyunsaturated fats is omega-3 fatty acids, which may promote a healthy heart and brain, and may reduce the risk of arthritis. Sources of omega-3 polyunsaturated fatty acids include soybean oil, canola oil, walnuts, flaxseed, salmon, and trout. Sources that are rich in monounsaturated fatty acids include olives, olive oil, canola oil, avocado and nuts.

Fiber

The two types of dietary fiber, water-soluble and insoluble, act differently in the body and both are beneficial. All fiber-containing foods contain a combination of both types of fiber. Water-soluble fiber - found in oats, beans, apples, carrots and oranges - helps lower cholesterol, while slowing both the rate at which food leaves the stomach as well as the rate at which sugar is absorbed into the bloodstream, keeping you full longer. Insoluble fiber acts to promote regularity. Best sources of insoluble fiber are whole grains like wheat bran and brown rice, and fruits and vegetables such as figs, raspberries, blackberries, broccoli, artichokes, and green peas. Prebiotic fiber, most commonly as polysaccharides - found in plants such as bananas, onions, leeks, garlic, chicory, and artichokes-selectively feed our intestinal defense team. Resistant starch, an indigestible fiber found in bananas, might boost your body’s ability to metabolize fat. Fiber also plays a role in preventing colorectal, prostate and breast cancers. Higher fiber intake may lessen the inflammation and oxidative stress caused by second-hand smoke. Unfortunately, about 50% of adult men and women do not get enough fiber.

Flavonoids

Flavonoids are a class of phytochemicals which lab research shows may have antioxidant, antiviral, anti-platelet, anti-inflammatory, and anti-cancer properties. Most brightly colored fruits and vegetables supply flavonoids.

Folic acid (or folate) is a vitamin belonging to the B-complex family and is particularly important for pregnant women in protecting against birth defects, including neural tube defects such as spina bifida. Folate deficiency has also been linked to depression, osteoporosis, and increased colorectal caner risk. Folate lowers levels of homocysteine, an amino acid linked to increased risk of fractures - as well as cardiovascular and Alzheimer's disease. However, excessive folate supplementation may actually increase replication of colorectal precancerous cells in lab research. Top natural sources include beans, spinach, broccoli, romaine lettuce, chicory, oranges and papaya.

Free radicals are chemically unstable molecules that have a normal, possibly antimicrobial role, but in excessive amounts, may cause cell damage that lead to heart disease and cancer. Stress, smoking, metabolizing a rich meal and over-exposure to the sun may cause an excess of free radicals. Antioxidants in fruits and vegetables help neutralize free radicals, thereby reducing their oxidative damage .

G

Glucosinolates

Glucosinolates are a group of sulfur-rich phytochemicals found in cruciferous vegetables, such as broccoli, cabbage, Brussels sprouts, and cauliflower. Two of the most researched glucosinolate metabolites include indole-3-carbinol and sulforaphane. Preliminary studies indicate that indole-3-carbinol may be effective in models of estrogen-sensitive cancers, such as breast and ovarian cancer. Researchers from Johns Hopkins University speculated that sulforaphane may prompt the body's own natural enzyme systems and so may act against a variety of cancers, including breast and stomach cancers.

I

Iron

Iron supports the formation of hemoglobin, a blood protein that carries oxygen from the lungs to the rest of the body. Fifteen percent of pre-menopausal women fall short on iron while pregnant women and toddlers are also at high risk of a deficiency, which may manifest in a lack of energy, difficulty in maintaining body temperature, and impaired immune response. Among pregnant women, iron deficiency may result in premature deliveries and low birth weights. A study from the University of Rochester demonstrated significantly higher prevalence of iron deficiency in obese children, demonstrating the link between nutrition deficiencies and obesity. Although many different foods contain iron, animal derived sources are more easily absorbed than plant sources. Because of the low-absorption rate of plant-derived iron, vegetarians have higher iron Recommended Dietary Allowances (RDAs). Vitamin C-rich foods enhance iron absorption when eaten with iron-rich plants. Tannins, found in coffee and tea, interfere with iron absorption. Some of the best animal sources for dietary iron include: cooked clams, lean beef, and dark meat turkey. The best plant-derived sources include: cooked spinach, green peas, dried figs and apricots, and beans (kidney, garbanzo and soy).