Dietary fruit

Hassimotto NMA, Genovese MI and Lajolo FM. 2005. Antioxidant activity of dietary fruits, vegetables, and commercial frozen fruit pulps. J Agric Food Chem 53(8) 2928-2935. 

Folic acid (or folate) deficiency, one of the most common vitamin deficiencies in the population consuming few dietary fruits and vegetables, causes chromosome breaks in humans,34 analogous to those caused by radiation. Folate supplementation above... 

Nyberg E, Hou SM, Perdhagen G, Lambert B. Dietary fruit and vegetables protect against somatic mutation in vivo, but low or high intake of carotenoids does not. Carcinogenesis 2003 24 689-696. 

Berry GT, Palmieri M, Gross KC, Acosta PB, Hestenburg JA, Mazur A, Reynolds R, Segal S. The effect of dietary fruits and vegetables on urinary galactitol excretion in galactose-1-phosphate uridyltransferase deficiency. J Inherit Metab Dis 1993 16 91-100. 

In the following sections each vegetable will be discussed briefly. Particular phytochemicals will be highlighted, but this should not be taken as an indication that these are the only phytochemicals associated with the foodstuff as it is evident that the phytochemical content of some dietary fruits and vegetables have been investigated in detail while others have received very little, if any, attention. 

Several studies have investigated the role of dietary factors in prostate cancer risk, but results appear inconsistent. Significant effects have not been detected for dietary soya products certain vegetables, beans, fruit, rice and seaweed appear to be protective in some studies, while another has shown no protective effect from seaweed or vegetable consumption. In addition, a number of other risk factors have been shown to be associated with an increased risk of this cancer, including meat and dairy products and carotenoids. 

Scurvy results from a dietary vitamin C deficiency and involves the inability to form collagen fibrils properly. This is the result of reduced activity of prolyl hydroxylase, which is vitamin C-dependent, as previously noted. Scurvy leads to lesions in the skin and blood vessels, and, in its advanced stages, it can lead to grotesque disfiguration and eventual death. Although rare in the modern world, it was a disease well known to sea-faring explorers in earlier times who did not appreciate the importance of fresh fruits and vegetables in the diet. 

An alkene, sometimes caJled an olefin, is a hydrocarbon that contains a carbon-carbon double bond. Alkenes occur abundantly in nature. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and o-pinene is the major component of turpentine. Life itself would be impossible without such alkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, /3-carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

In Hsinchu, Taiwan, the dietary intake of a- and P-endosulfan was studied from June 1996 to April 1997 (Doong and Lee 1999). p-Endosulfan was not detected in any of the 14 different foods studied, including fruits, meats, seafood, and cereal, and a-endosulfan, by contrast, was found in 78 of 149 samples at an average concentration of 2.76 ng/g wet weight. Based on the average Taiwanese diet, the estimated daily intake of a-endosulfan was 6.24x10 " mg body weight/day. 

Vitamin C occurs as L-ascorbic acid and dihydroascorbic acid in fruits, vegetables and potatoes, as well as in processed foods to which it has been added as an antioxidant. The only wholly undisputed function of vitamin C is the prevention of scurvy. Although this is the physiological rationale for the currently recommended intake levels, there is growing evidence that vitamin C may provide additional protective effects against other diseases including cancer, and the recommended dietary allowance (RDA) may be increased in the near future. Scurvy develops in adults whose habitual intake of vitamin C falls below 1 mg/d, and under experimental conditions 10 mg/d is sufficient to prevent or alleviate symptoms (Bartley et al., 1953). The RDA is 60 mg per day in the USA, but plasma levels of ascorbate do not achieve saturation until daily intakes reach around 100 mg (Bates et al., 1979). Most of the ascorbate in human diets is derived from natural sources, and consumers who eat five portions, or about 400-500 g, of fruits and vegetables per day could obtain as much as 200 mg of ascorbate. 

The antioxidant activities of carotenoids and other phytochemicals in the human body can be measured, or at least estimated, by a variety of techniques, in vitro, in vivo or ex vivo (Krinsky, 2001). Many studies describe the use of ex vivo methods to measure the oxidisability of low-density lipoprotein (LDL) particles after dietary intervention with carotene-rich foods. However, the difficulty with this approach is that complex plant foods usually also contain other carotenoids, ascorbate, flavonoids, and other compounds that have antioxidant activity, and it is difficult to attribute the results to any particular class of compounds. One study, in which subjects were given additional fruits and vegetables, demonstrated an increase in the resistance of LDL to oxidation (Hininger et al., 1997), but two other showed no effect (Chopra et al, 1996 van het Hof et al., 1999). These differing outcomes may have been due to systematic differences in the experimental protocols or in the populations studied (Krinsky, 2001), but the results do indicate the complexity of the problem, and the hazards of generalising too readily about the putative benefits of dietary antioxidants. 

Table 7.1 shows the common dietary sources of carotenoids in regular vegetable foods, p,g/100 fresh weight. Although the greatest amount of the hydrocarbon carotenoids is present as the all-trans isomer, there is always a proportion of cis isomers present. This table represents only a small number of the fruits and vegetables that contribute carotenoids in the European diet. For more comprehensive information readers are directed to A European Carotenoid Database O Neill et al, 2001, which lists the carotenoid composition of over 100 food items. 

TERRY p, GIOVANNUCCI E, MICHELS K, BERGKVIST L, HANSEN H, HOLMBERG L and WOLK A (2001) Fruit, Vegetables, dietary fibres, and risk of colorectal cancer. JNatl Cancer Inst, 93, 525-33. 

Lycopene is a bright red pigment that colors several ripe fruits, vegetables, and flowers. Tomato and tomato products are the main dietary sources of this carotenoid, although it is also found in watermelons, guavas, pink grapefruits, and in small quantities in at least 40 plants. - The absorption of lycopene in the human gut is increased by heat treatment, probably because the breakdown of the plant cells makes the pigment more accessible. ... 

Daily consumption of various fruits, vegetables, and derived juices contributes to human intake of carotenoids. The estimation of carotenoid intakes has been made possible throngh publication of the qnalitative and qnantitative carotenoid contents of commonly consnmed foods. Average intake estimates in the United States are around 6.5 mg/day. In seven conntries in Enrope, the average total carotenoid intake based on the snm of the five carotenoids was approximately 14 mg/day. When dietary source of carotenoids were analyzed, carrots appeared as the major sonrces of p-carotene in all conntries except Spain, where spinach was the main contribntor. 

Carotenoids and prostate cancer — Numerous epidemiological studies including prospective cohort and case-control studies have demonstrated the protective roles of lycopene, tomatoes, and tomato-derived products on prostate cancer risk other carotenoids showed no effects. " In two studies based on correlations between plasma levels or dietary intake of various carotenoids and prostate cancer risk, lycopene appeared inversely associated with prostate cancer but no association was reported for a-carotene, P-carotene, lutein, zeaxanthin, or p-cryptoxanthin. - Nevertheless, a protective role of all these carotenoids (provided by tomatoes, pumpkin, spinach, watermelon, and citrus fruits) against prostate cancer was recently reported by Jian et al. ... 

Specific uses bitter soda and wine (100 mg/1), jam, jellies, marmalades, similar fruit preparations including low-caloric products (100 mg/kg), sobrasada (135 mg/kg) all foodstuffs and amounts mentioned for Allura red general use FDA can be safely used generally for coloring foods (including dietary supplements) in amounts consistent with GMP JECFA can be used up to 300 mg/kg in various foods2 ... 

One common objective of an LSMBS is to refine the estimates of actual exposure of consumers to ingredients or impurities in one or more products. For example, study results might be intended to determine a realistic human dietary exposure to pesticide residues in fresh fruits and vegetables. The advent of the Food Quality Protection Act of 1996 (FQPA) has produced an enhanced focus on the exposure of children to pesticides. A well-designed and implemented LSMBS would afford the opportunity to delineate better the exposure and risk to children and other population subgroups. The LSMBS would provide consumer-level data at or near the point of consumption, allowing the refined, relevant, and realistic assessments of dietary exposure. 

OPMBS data were intended to support a valid estimate of the dietary exposure of populations and sub-populations to organophosphate residues in fresh fmits and vegetables. The results of the study were presented to the EPA in a report, with appropriate summaries. All of the study results, i.e., residue levels of each compound determined in each sample of each commodity, were also provided to the EPA in a database. EPA has recently notified the task force that the OPMBS study on the frequency and magnitude of organophosphate residues in fruits and vegetables is acceptable. The EPA is expected to utilize the data in a new assessment of potential dietary risk from organophosphate residues. 

O The single most important risk factor for the development of lung cancer is smoking, and the most effective way for high-risk patients to reduce their risk is to stop smoking. Additional recommendations should include an increase in dietary intake of fruits and vegetables. 

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