Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Joan G. Fischer is active.

Publication


Featured researches published by Joan G. Fischer.


The American Journal of Clinical Nutrition | 2009

Soy isoflavone supplementation and bone mineral density in menopausal women: a 2-y multicenter clinical trial

William W. Wong; Richard D. Lewis; Francene M. Steinberg; Michael J. Murray; Margaret A. Cramer; Paula Amato; Ronald L. Young; Stephen Barnes; Kenneth J. Ellis; Roman J. Shypailo; J. Kennard Fraley; Karen Konzelmann; Joan G. Fischer; E. O'Brian Smith

BACKGROUND Isoflavones are naturally occurring plant estrogens that are abundant in soy. Although purported to protect against bone loss, the efficacy of soy isoflavone supplementation in the prevention of osteoporosis in postmenopausal women remains controversial. OBJECTIVE Our aim was to test the effect of soy isoflavone supplementation on bone health. DESIGN A multicenter, randomized, double-blind, placebo-controlled 24-mo trial was conducted to assess the effects of daily supplementation with 80 or 120 mg of soy hypocotyl aglycone isoflavones plus calcium and vitamin D on bone changes in 403 postmenopausal women. Study subjects were tested annually and changes in whole-body and regional bone mineral density (BMD), bone mineral content (BMC), and T scores were assessed. Changes in serum biochemical markers of bone metabolism were also assessed. RESULTS After study site, soy intake, and pretreatment values were controlled for, subjects receiving a daily supplement with 120 mg soy isoflavones had a statistically significant smaller reduction in whole-body BMD than did the placebo group both at 1 y (P < 0.03) and at 2 y (P < 0.05) of treatment. Smaller decreases in whole-body BMD T score were observed among this group of women at 1 y (P < 0.03) but not at 2 y of treatment. When compared with the placebo, soy isoflavone supplementation had no effect on changes in regional BMD, BMC, T scores, or biochemical markers of bone metabolism. CONCLUSION Daily supplementation with 120 mg soy hypocotyl isoflavones reduces whole-body bone loss but does not slow bone loss at common fracture sites in healthy postmenopausal women. This trial was registered at clinicaltrials.gov as NCT00665860.


The American Journal of Clinical Nutrition | 2011

Clinical outcomes of a 2-y soy isoflavone supplementation in menopausal women

Francene M. Steinberg; Michael J. Murray; Richard D. Lewis; Margaret A. Cramer; Paula Amato; Ronald L. Young; Stephen Barnes; Karen Konzelmann; Joan G. Fischer; Kenneth J. Ellis; Roman J. Shypailo; J. Kennard Fraley; E. O'Brian Smith; William W. Wong

BACKGROUND Soy isoflavones are naturally occurring phytochemicals with weak estrogenic cellular effects. Despite numerous clinical trials of short-term isoflavone supplementation, there is a paucity of data regarding longer-term outcomes and safety. OBJECTIVE Our aim was to evaluate the clinical outcomes of soy hypocotyl isoflavone supplementation in healthy menopausal women as a secondary outcome of a trial on bone health. DESIGN A multicenter, randomized, double-blind, placebo-controlled 24-mo trial was conducted to assess the effects of daily supplementation with 80 or 120 mg aglycone equivalent soy hypocotyl isoflavones plus calcium and vitamin D on the health of 403 postmenopausal women. At baseline and after 1 and 2 y, clinical blood chemistry values were measured and a well-woman examination was conducted, which included a mammogram and a Papanicolaou test. A cohort also underwent transvaginal ultrasound measurements to assess endometrial thickness and fibroids. RESULTS The baseline characteristics of the groups were similar. After 2 y of daily isoflavone exposure, all clinical chemistry values remained within the normal range. The only variable that changed significantly was blood urea nitrogen, which increased significantly after 2 y (P = 0.048) but not after 1 y (P = 0.343) in the supplementation groups. Isoflavone supplementation did not affect blood lymphocyte or serum free thyroxine concentrations. No significant differences in endometrial thickness or fibroids were observed between the groups. Two serious adverse events were detected (one case of breast cancer and one case of estrogen receptor-negative endometrial cancer), which was less than the expected population rate for these cancers. CONCLUSION Daily supplementation for 2 y with 80-120 mg soy hypocotyl isoflavones has minimal risk in healthy menopausal women. This trial was registered at clinicaltrials.gov as NCT00665860.


The FASEB Journal | 1994

Iron nutriture in elderly individuals.

Mary Ann Johnson; Joan G. Fischer; B A Bowman; E W Gunter

The purpose of this review is to examine current research on the iron status of the elderly and factors that influence the body burden of iron. Studies of noninstitutionalized elderly individuals report mean iron intakes that meet current Recommended Dietary Allowances for iron. Dietary practices that may decrease iron bioavailability, and hence iron stores in the body, include low intakes of ascorbic acid or high intakes of calcium, and decreased consumption of highly available iron from meat, fish, and poultry. Although not well documented, the effect of age on iron absorption and iron excretion appears to be small, and body stores of iron increase with age. It is difficult to estimate the prevalence of iron deficiency in elderly persons, because impaired iron status can be the result of iron deficiency or chronic disease. Further study is necessary to determine whether red blood cell ferritin and serum transferrin receptors may be useful biochemical markers to differentiate the anemia of chronic disease from iron deficiency anemia. Hereditary hemochromatosis is a genetic disease that greatly increases the body burden of iron and the risk of hepatic disease among homozygotes. Because iron deficiency or iron excess may impair health, the role of iron in diseases associated with aging such as depressed immune response, neurological dysfunction, cancer, and heart disease is discussed.—Johnson, M. A., Fischer, J. G., Bowman, B. A., Gunter, E. W. Iron nutriture in elderly individuals. FASEB J. 8: 609‐621; 1994.


Journal of Nutrition for The Elderly | 2005

Nutrition and Health Education Intervention for Whole Grain Foods in the Georgia Older Americans Nutrition Program

Jeanna Ellis; Mary Ann Johnson; Joan G. Fischer; James L. Hargrove

Abstract This study examined the effects of a nutrition education intervention on improving the intake and behaviors related to whole grain foods in congregate meal recipients in senior centers in north Georgia. Participants were a convenience sample and completed a pretest, an educational intervention, and a posttest (N = 84, mean age = 77 years, 88% female, 76% Caucasian, and 24% African American). At the pretest, most participants agreed that eating more whole grain foods would help reduce their risk of cancer (69%), heart disease (76%), type 2 diabetes (65%), and bowel disorders (82%), but consumption of 11 whole grain foods was low (10.5 times/week). Following the intervention, participants were more likely to suggest one or more correct ways to identify whole grain foods (45 vs. 62%, P ⩽0.05), and to report an increased intake of whole grain bread, cereal, and crackers (5.8 vs. 6.9 times/week, P ⩽0.05). While awareness of the health benefits of whole grain foods was high, the intakes were low. As a first step, this intervention improved several aspects of the consumption of whole grain foods; however, additional interventions that target the individual and the congregate meal program are needed to increase intakes to the recommended three servings daily.


American Journal of Public Health | 1998

Milk consumption in older Americans.

S.M. Elbon; Mary Ann Johnson; Joan G. Fischer

OBJECTIVES The purpose of this study was to identify individual characteristics associated with types and frequency of milk consumption in older American adults. METHODS A national probability-based sample (response rate = 91%) completed a telephone survey. Generalized logit and cumulative logit analyses were used to identify predictors of and barriers to fluid milk consumption in 494 elderly people. RESULTS The likelihood of drinking skim or 1% milk rather than whole milk increased with nutrition knowledge, income, trying to reduce cholesterol intake, and being female (P < .05). Frequency of milk consumption was higher with nutrition knowledge, frequency of milk consumption during adolescence, and following a diabetic diet but was lower with milk intolerance. CONCLUSIONS The present results could be used to develop intervention strategies for improving milk consumption rates among older adults. These strategies might focus on increasing elderly peoples awareness of milk intolerance and lactose-reduced milk products and their concern about cholesterol. The relationship between current and adolescent milk consumption suggests that intervention strategies should begin early in life.


Journal of Agricultural and Food Chemistry | 2008

Effects of Blueberry (Vaccinium ashei) on DNA Damage, Lipid Peroxidation, and Phase II Enzyme Activities in Rats

Rachel Dulebohn; Weiguang Yi; Anita Srivastava; Casimir C. Akoh; Gerard Krewer; Joan G. Fischer

Blueberry extracts have high antioxidant potential and increase phase II enzyme activities in vitro. This study tested the hypothesis that blueberries would reduce DNA damage and lipid peroxidation and increase phase II enzyme activities in vivo. Young, healthy male Sprague-Dawley rats (n = 8 per group) were fed control AIN-93 diets or AIN-93 diets supplemented with blueberries or blueberry extracts for 3 weeks. Diets were supplemented with 10% freeze-dried whole blueberries, blueberry polyphenol extract and sugars to match the 10% blueberry diet, or 1 and 0.2% blueberry flavonoids, which were primarily anthocyanins. Liver and colon mucosa glutathione-S-transferase (GST), quinone reductase, and UDP-glucuronosyltransferase activities in colon mucosa and liver were not significantly increased by freeze-dried whole blueberries or blueberry fractions. Liver GST activity, however, was approximately 25% higher than controls for the freeze-dried whole blueberry, blueberry polyphenol, and 1% flavonoid groups. DNA damage was significantly lower than control only in the liver of animals fed the 1% flavonoid diet. The level of urinary F(2)-isoprostanes, a measure of lipid peroxidation, was unaffected. In summary, in healthy rats, short-term supplementation with freeze-dried whole blueberries, blueberry polyphenols, or blueberry flavonoids did not significantly increase phase II enzyme activities. However, supplementation with 1% blueberry flavonoids did decrease oxidative DNA damage in the liver.


Maturitas | 2011

Nutrition in centenarians

Dorothy B. Hausman; Joan G. Fischer; Mary Ann Johnson

The oldest old are among the fastest growing segment of the population and it is important to understand not only the influence of modifiable lifestyle factors such as diet and nutrition on the achievement of exceptional longevity but also the role, if any, of these factors on maintaining optimal cognitive, mental and physical health into advanced age. This review summarizes studies of dietary intake and patterns of long-lived peoples and presents current knowledge of nutritional status of centenarians as determined with nutritionally relevant biomarkers, providing information on comparative levels of the various biomarkers between centenarians and older adult controls and on the prevalence and predictors of nutritional deficiencies in centenarians. The studies indicate that BMI and nutritional status as indicated by circulating levels of antioxidant vitamins, vitamin B12, folate, homocysteine and 25(OH) vitamin D of centenarians are quite heterogeneous and influenced by region of residency and many of the demographic, dietary and lifestyle factors that influence nutritional status in other older adults. While many of the studies have been small, convenience samples of relatively healthy community-dwelling centenarians, a few have population-based or included participants of varying cognitive functioning. These and future studies examining associations between nutritional status and cognitive, mental and physical function should be instrumental in determining the role of nutrition in promoting longevity and improving the quality of life in these exceptional survivors.


Journal of Nutrition for The Elderly | 2006

Improvement in A1C Levels and Diabetes Self-Management Activities Following a Nutrition and Diabetes Education Program in Older Adults

Elizabeth H. Redmond; Sarah M. Burnett; Mary Ann Johnson; Sohyun Park; Joan G. Fischer; Tommy Johnson

Abstract This study examined the effects of a nutrition and diabetes education intervention on improving hemoglobin A1C levels, diabetes self-management activities, and A1C knowledge in congregate meal recipients in senior centers in north Georgia. Participants were a convenience sample and completed a pre-test, an educational intervention, and a post-test (N = 91, mean age = 73 years, 60% Caucasian, and 40% African American). Following the intervention, (1) A1C levels significantly decreased by 0.66 and 1.46% among those with pretest A1C of > 6.5% and > 8%, respectively (P ≤ 0.01); (2) compliance significantly increased following a healthful diet, following an eating plan, avoiding high fat foods, spacing carbohydrates, testing blood sugar as recommended by health care provider and inspecting shoes (P ≤ 0.05); (3) the number of A1C knowledge questions answered correctly increased from 42% to 65% (P < 0.0001); and (4) decreases in A1C among those with an initial A1C > 6.5% were correlated with increases in physical activity (P ≤ 0.05). This nutrition and diabetes intervention improved several aspects of the diabetes self-management activities and A1C knowledge, with concurrent decreases in A1C levels in older adults; however, additional interventions are needed to improve A1C levels, diabetes self-management activities, and A1C awareness in older adults.


Journal of Nutrition for The Elderly | 2008

Vitamin D deficiency and insufficiency in the Georgia Older Americans Nutrition Program.

Mary Ann Johnson; Joan G. Fischer; Sohyun Park

ABSTRACT Serum 25-hydroxyvitamin D (25(OH)D) status in older adults enrolled in community-based meal programs is not well characterized. The objective was to identify predictors of poor serum 25(OH)D status and the response to vitamin D supplementation in a convenience sample from the Older Americans Act Nutrition Program (OAANP) in northeast Georgia (N = 158, mean age = 77 years, 81% women, 69% Caucasian, 31% African American). Mean serum 25(OH)D was 55 nmol/l, and intakes of vitamin D and calcium from foods were very low. Vitamin D insufficiency (25(OH)D 25- < 50 nmol/l) occurred in 36.7%. Vitamin D deficiency occurred in 8.2% (25(OH)D < 25 nmol/l) and was associated with low milk intake, low sunlight exposure, receiving meals at home, tobacco use, depression, dementia, antianxiety medication, poor instrumental activities of daily living, and low calf circumference (p ≤ 0.05). When non-supplement users (n = 28) were given a multivitamin with vitamin D (10 µg/d) and calcium (450 mg/d) for 4 months, 25(OH)D increased from 50 to 78 nmol/l, the prevalence of poor vitamin D status (25(OH)D < 50 nmol/l) decreased from 61% to 14%, and serum alkaline phosphatase decreased by 10% (p < 0.01). High body weight appeared to attenuate the increase in 25(OH)D in response to the multivitamin supplement (p ≤ 0.05). In conclusion, OAANP services did not prevent poor vitamin D and calcium status, but a supplement with vitamin D and calcium was beneficial.


Journal of Nutrition for The Elderly | 2008

Vitamin and Mineral Supplements: Barriers and Challenges for Older Adults

Sohyun Park; Mary Ann Johnson; Joan G. Fischer

ABSTRACT Older adults are particularly vulnerable to deficiencies of calcium, vitamin D, and vitamin B12. Despite the availability of fortified foods in the United States, intakes of these nutrients among the elderly remain inadequate. Dietary supplements may be a convenient way to improve nutritional status within this population group. This article provides practical and evidence-based recommendations regarding the use of single vitamin/mineral and multivitamin/mineral (MVM) supplements in older adults and provides details on calcium and vitamin D, B12, E, and K. Some single-nutrient supplements have shown benefits for preventing or reducing risks for chronic diseases. Although MVM supplements have not been shown to prevent several major chronic diseases, they do substantially increase vitamin and mineral intakes and blood concentrations, thus improving overall micronutrient status. Older adults who use MVM and/or vitamin/mineral supplements to foster better nutritional and health status should read labels carefully and consult their health care provider to ensure appropriate dietary supplement use.

Collaboration


Dive into the Joan G. Fischer's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ronald L. Young

Baylor College of Medicine

View shared research outputs
Top Co-Authors

Avatar

Stephen Barnes

University of Alabama at Birmingham

View shared research outputs
Top Co-Authors

Avatar

William W. Wong

Baylor College of Medicine

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge