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Biomedical subjects

L Marquart

Publications and source records attributed to L Marquart.

10 recordsLinked to original sources
PubMed2001

The role of whole grains in disease prevention.

Despite universal acceptance of the importance of whole grains in the diet, consumer knowledge of the benefits of whole grains and intake of these foods are low. This review summarizes the research supporting whole-grain consumption and gives practical suggestions about how to increase whole-grain intake. Whole-grain foods are valuable sources of nutrients that are lacking in the American diet, including dietary fiber, B vitamins, vitamin E, selenium, zinc, copper, and magnesium. Whole-grain foods also contain phytochemicals, such as phenolic compounds, that together with vitamins and minerals play important roles in disease prevention. The exact mechanisms linking whole grains to disease prevention are not known but may include gastrointestinal effects, antioxidant; protection, and intake of phytoestrogens. Dietary intake studies indicate that consumption of whole grains is far less than the recommended intake of 3 servings a day, with an average daily intake of 1 or fewer servings a day. A new whole-grains health claim, allowed in July 1999 by the Food and Drug Administration, and inclusion of a whole-grain recommendation in the 2000 revision of the US Dietary Guidelines for Americans, should help increase whole-grain consumption.

Blood Glucose↗
PubMed2001

Grain processing and nutrition.

Whole grains provide a wide range of nutrients and phytochemicals that optimize health. Epidemiologic studies support the protectiveness of whole grain consumption for cardiovascular disease and cancer. Dietary guidance endorses increased whole grains in our diet. A crucial question remaining is the effect of processing of whole grains on their content of nutrients and phytochemicals. Although processing is often considered to be a negative attribute in nutrition, and some forms of processing reduce nutritional value, many factors support the importance of processing of grains to enhance grain consumption. First, whole grains as harvested are generally not consumed directly by humans but require some processing prior to consumption. While refining, that is, removal of the bran and the germ, reduces the nutrient content of grain, milling of grains otherwise concentrates desirable grain components and removes poorly digested compounds and contaminants. Cooking of grains generally increases digestibility of nutrients and phytochemicals. Studies in both animal models and humans support the notion that processed grains are often nutritionally superior to unprocessed grains, probably because of enhanced nutrient bioavailability in processed grains. Processing of grains also provides shelf-stable products that are convenient and good tasting for consumers.

Animals↗
PubMed2000

Antioxidant content of whole grain breakfast cereals, fruits and vegetables.

BACKGROUND: Considerable scientific evidence suggests that whole grains, as commonly consumed in the United States and Europe, reduce risk for chronic disease including cancer and heart disease. Whole grains provide a wide range of nutrients and phytochemicals that may work synergistically to optimize human health. Fruits and vegetables provide protection against age related diseases. It is believed their high content of antioxidant compounds is key to such protection. OBJECTIVE: This research compares the antioxidant activity of whole grain, ready-to-eat (RTE) breakfast cereals to that of fruits and vegetables. METHOD: Antioxidant activity was determined by dispersing finely ground samples in a 50% aqueous methanol solution of the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). DPPH, which forms a deep purple solution, reacts with antioxidants and color loss at 515 nm correlates to antioxidant content, which is expressed as Trolox equivalents/100 grams (TE). RESULTS: Whole grain breakfast cereals analyzed in this study contained from 2,200-3,500 TE. By comparison, fruits generally ranged from 600-1,700 TE, with a high of 2,200 TE for red plums. Berries averaged 3,700 TE and. vegetables averaged 450 TE with a high of 1,400 TE for red cabbage. A 41 gram average serving of RTE breakfast cereal provides 1,120 TE, while an average 85 gram serving of vegetables or fruits provides 380 and 1,020 TE, respectively. CONCLUSION: Whole grain breakfast cereals, fruits and vegetables are all important dietary sources of antioxidants.

Antioxidants↗
PubMed2000

Grain processing and nutrition.

Whole grains provide a wide range of nutrients and phytochemicals that optimize health. Epidemiologic studies support the protectiveness of whole grain consumption for cardiovascular disease and cancer. Dietary guidance endorses increased whole grains in our diet. A crucial question remaining is the effect of processing of whole grains on their content of nutrients and phytochemicals. Although processing is often considered to be a negative attribute in nutrition, and some forms of processing reduce nutritional value, many factors support the importance of processing of grains to enhance grain consumption. First, whole grains as harvested are generally not consumed directly by humans but require some processing prior to consumption. While refining, that is, removal of the bran and the germ, reduces the nutrient content of grain, milling of grains otherwise concentrates desirable grain components and removes poorly digested compounds and contaminants. Cooking of grains generally increases digestibility of nutrients and phytochemicals. Studies in both animal models and humans support the notion that processed grains are often nutritionally superior to unprocessed grains, probably because of enhanced nutrient bioavailability in processed grains. Processing of grains also provides shelf-stable products that are convenient and good tasting for consumers.

Animals↗
PubMed1999

Plausible mechanisms for the protectiveness of whole grains.

Dietary guidelines recommend the consumption of whole grains to prevent chronic diseases. Epidemiologic studies support the theory that whole grains are protective against cancer, especially gastrointestinal cancers such as gastric and colon can-cer, and cardiovascular disease. Components in whole grains that may be protective include compounds that affect the gut environment, such as dietary fiber, resistant starch, and oligosaccharides. Whole grains are also rich in compounds that function as antioxidants, such as trace minerals and phenolic compounds, and phytoestrogens, with potential hormonal effects. Other potential mechanisms whereby whole grains may protect against disease include binding of carcinogens and modulation of the glycemic response. Clearly, the range of protective substances in whole grains is impressive and advice to consume additional whole grains is justified. Further study is needed regarding the mechanisms behind this protection so that the most potent protective components of whole grains will be maintained when developing whole grains into acceptable food products for the public.

Cardiovascular Diseases↗
PubMed1998

Whole-grain intake and cancer: an expanded review and meta-analysis.

Whole grains are nutrient rich and may protect against chronic disease. To study this, we previously reviewed 14 case-control studies of colorectal, gastric, and endometrial cancers and found consistently lower risk in those with high than in those with low whole-grain intake. Questions remained concerning other cancers, dietary assessment, quantity consumed, confounding, and differential study quality. Here we expand the review to 40 case-control studies of 20 cancers and colon polyps. Odds ratios are < 1 for 46 of 51 mentions of whole-grain intake and for 43 of 45 after exclusion of 6 mentions with design/reporting flaws or low intake. The pooled odds ratio for high vs. low whole-grain intake among the 45 mentions was 0.66 (95% confidence interval = 0.60-0.72); they range from 0.59 to 0.78 across four types of dietary questionnaires. Odds ratios were < 1 in 9 of 10 mentions of studies of colorectal cancers and polyps, 7 of 7 mentions of gastric and 6 of 6 mentions of other digestive tract cancers, 7 of 7 mentions of hormone-related cancers, 4 of 4 mentions of pancreatic cancer, and 10 of 11 mentions of 8 other cancers. Most pooled odds ratios for specific cancers were in the range of 0.5-0.8, notable exceptions being breast (0.86) and prostate (0.90). The pooled odds ratio was similar in studies that adjusted for few and many covariates. Dose-response associations were stronger in studies using food-frequency questionnaires than in more quantitative questionnaires. The case-control evidence is supportive of the hypothesis that whole-grain intake protects against various cancers.

Adult↗
PubMed1997

Estimated dietary calcium intake and food sources for adolescent females: 1980-92.

PURPOSE: To estimate dietary calcium intake of three groups of adolescent females ages 11-12 years, 13-14 years, and 15-18 years during four separate 2-year time periods from the years 1980-92; and to identify their food sources of calcium. METHODS: Nutrient intake survey based on 14-day food consumption records collected from four national representative samples of 4,000 United States households. RESULTS: Dietary calcium consumption declined significantly (p < .01) over the 10-year period for the 15-18 year olds. Calcium intake was significantly lower for 13-14 year olds compared to the youngest age group, and for 15-18 year olds when compared to the two younger age groups for all four study periods (p < .01). Over 90% of all adolescent females consumed < 100% of the RDA for calcium during all data collection periods. The percentage of adolescent females who consumed less than two-thirds of the RDA increased with age. Seventy-seven percent of 15-18 year olds consumed below this level from 1990-92. Milk and milk products were the best food sources of calcium contributing over one-half of the calcium to the diet. This percentage declined over time and with age to 44% for the 15-18 year old females in 1990. This drop can be attributed to a 7-12% decline in fluid milk consumption for the 11-12 year olds and 15-18 year olds, respectively. CONCLUSIONS: Estimates indicate that dietary calcium intakes fall far short of both the Recommended Dietary Allowance (RDA) and National Institutes of Health (NIH) recommendations. Intakes have declined over time, with age, and appear to be related to a decline in fluid milk consumption. Efforts to increase calcium consumption among adolescent females appear critical. Clear recommendations to consume a minimum of three servings everyday of lowfat or nonfat dairy products such as milk and yogurt are needed to help this population meet daily calcium requirements.

Adolescent↗
PubMed1997

Whole-grain consumption and chronic disease: protective mechanisms.

Dietary guidance recommends consumption of whole grains to reduce the risk of chronic diseases including cancer and cardiovascular disease. Epidemiologic studies support the belief that whole grains are protective against cancers, especially gastrointestinal cancers such as gastric and colonic, and cardiovascular disease. Components in whole grains that may be protective are diverse and include compounds that affect the gut environment, i.e., dietary fiber, resistant starch, and other undigestible compounds in whole grains, compounds that function as antioxidants such as trace minerals and phenolic compounds, and compounds that are phytoestrogens with potential hormonal effects. Many of the protective compounds in whole grains are also in fruits and vegetables, but some plant compounds are more concentrated in whole grains, such as phenolic compounds including ferulic and caffeic acid. Other potential mechanistic effects of whole grains include binding of carcinogens and modulation of glycemic index. Clearly, the range of protective substances in whole grains is impressive, and advice to consume additional whole grains is justifiable.

Acute Disease↗
PubMed1995

Whole grain intake and cancer: a review of the literature.

There has been little research concerning the health effects of whole grain intake in humans. We have synthesized 15 american and European case-control and prospective studies of whole grain intake. Most subjects were middle aged or older. The studies employed disparate dietary methods, and the foods referred to and quantities eaten are ill defined. Nevertheless there is a striking consistency in reduced risk for colorectal and gastric cancers associated with intake of whole grain, also found in isolated studies of endometrial cancer and coronary heart disease. Because reduced risk was not associated with refined grain intake, these findings do not appear to be confounded by participant confusion concerning refined vs. whole grains. The independence of these findings from reduced risk associated with fruit and vegetable intake is not established. There should be further research to establish whether whole grain intake is protective against chronic disease.

Colorectal Neoplasms↗