Links Between Wholefood Antioxidants and Heart Disease Cancer and Vision Loss

Antioxidant deficiencies have well-established links to the promotion of specific diseases. This is discussed more fully in other chapters. Antioxidant compounds are accumulated from the diet or synthesized in the body and prevent the chemical oxidation of proteins, lipids and other essential compounds. Industrialization has led to increased environmental pollutants in our air, food and water. Many of these pollutants have the capacity to deplete the body's antioxidant reserves. Antioxidant deficiencies resulting from dietary deficiencies and/or increased environmental oxidant stress may be linked to the development of many diseases including heart disease, cancer and vision loss.

Red wine is a whole-food product that has been widely associated with antioxidant effects (Renaud and de Lorgeril, 1992; Frankel et al., 1993). It was one of the first whole-food products shown to have measurable antioxidant effects in vivo, including increased resistance of low-density lipoproteins (LDL) to oxidation (Fuhrman et al., 1995; Whitehead et al., 1995; Miyagi et al., 1997). LDL oxidation can also be inhibited in vitro by many other whole-food products including: broccoli (Plumb et al., 1997), grape juice (Lanningham-Foster et al., 1995; Miyagi et al., 1997), soybean isoflavonoids (Tikkanen et al., 1998), garlic (Ide et al., 1997), blueberries (Laplaud et al., 1997) and cranberry extracts (Wilson et al., 1998).

Antioxidants may also promote arterial vasodilation and improve blood flow. In humans, antioxidants such as ascorbate have been suggested to promote arterial vasodilation in vivo (Heitzer et al., 1996; Solzbach et al., 1997). Vasodilation may be promoted by flavonoids from whole foods serving as antioxidants that increase the half-life of endothelially derived relaxing factor (EDRF), or these flavonoids may activate EDRF-activated receptors directly.

Damage to cellular regulatory proteins and DNA is central to the promotion of cancer in humans. Oxidation is a primary means by which this damage occurs and antioxidants from our food may have the ability to protect against cancer promotion. Analysis of antiproliferative effects of whole-food products also suggests that an anticancer role may exist. Genistein and other flavonoids derived from soybean products have been found to have antiproliferative effects on breast cancer cells in vitro (Tikkanen et al., 1998). Flavonoid-rich extracts from two members of the Vaccinium genus, cranberries and blueberries, have also been shown to have potent antiproliferative effects on cancer cells in vitro (Bomser et al., 1996).

Block et al. (1992) evaluated the cancer protection linked to fruit and vegetable consumption. The relative risk ratios of 128 of the 158 studies reviewed suggest that consumption of low amounts of fruits and vegetables is associated with an approximate doubling of the risk for several types of cancer.

Because fruits and vegetables remain the primary source of antioxidants, it is probable that the protective effects are due to the antioxidant activities associated with the fruits and vegetables we consume (Block et al., 1992). Compared with today's diet the Paleolithic diet was relatively rich in fruits and vegetables. That diet was evaluated by Eaton et al. (1997), who estimated that it contained 604 mg ascorbate and 33 mg a-tocopherol; this is much more than the typical American diet, which contains 77-109 mg ascorbate and 7-10 mg a-tocopherol. In the developed nations, the relatively high incidence of oxidation-related diseases such as heart disease and cancer may reflect a deficiency in total dietary antioxidants relative to the diet of our ancestors.

Vision loss can result from oxidative damage to the macula of the eye (Seddon et al., 1994). Consumption of foods rich in antioxidants may slow or prevent the development of age-related macular degeneration (see Chapter 22). By reducing oxidative damage to the macula, antioxidants from red wine apparently delay or prevent vision loss at consumption levels as low as one glass per month (Obisesan et al., 1998). Similar processes may prove to be useful for preventing oxidation of proteins in the lens of the eye. Future studies will certainly yield interesting developments in this field because with increased life expectancies we need to maintain quality vision for longer. If antioxidants from whole foods can be shown to be effective in this regard, the quality of life for millions of the elderly could be improved worldwide.

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Berry Boosters

Acai, Maqui And Many Other Popular Berries That Will Change Your Life And Health. Berries have been demonstrated to be some of the healthiest foods on the planet. Each month or so it seems fresh research is being brought out and new berries are being exposed and analyzed for their health giving attributes.

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