Nutrition Newsletter

Winter, 2000

Prepared by: Linda B. Bobroff, Ph.D., R.D., LD/N and Amarat (Amy) Simonne, Ph.D.

Colleagues,

I'm pleased to welcome to the Nutrition Newsletter staff Dr. Amy Simonne, our Food Safety Specialist. Dr. Simonne has already "hit the ground running" in her position and is very excited about the many opportunities in Florida Extension programming. She will be contributing to the Food Safety Section of this newsletter beginning with this edition. Please join me in welcoming Amy to the FYCS/IFAS/UF family.

Best regards, Linda

UF Scientist Maps Brain Reactions to Food: Most of us have experienced eating and eating until suddenly we're so stuffed we can hardly waddle from the table to the couch.

Now for the first time, scientists at the University of Florida and the University of Texas have pinpointed the time it takes for the human brain to signal it's full and which areas of the brain are involved in eating. As it turns out, 10 minutes is generally all that separates nutritiously satisfied from excessively gorged.

"The hypothalamus has been known for many years as being related to the regulation of eating, but this is the first study in humans able to directly demonstrate that it undergoes dynamic and physiologic changes as a result," said primary investigator Hijun Liu, Ph.D., an assistant professor in the University of Florida College of Medicine's department of psychiatry.

"Most importantly, using a noninvasive technique, this study determined there was a connection between the changes that occur in the human brain after eating and the traditional biochemical indicators in the body, which are increases in the levels of glucose and insulin in the blood," said Liu, who also is affiliated with the University of Florida Brain Institute.

The findings could help scientists further comprehend how the brain responds to eating and food. That has important implications in better understanding the brain mechanisms involved in the development of obesity and obesity-related diabetes, and for devising and testing medications to treat the disorders down the road. Source: The Friday Evening Post, Newsletter of the UF Health Science Center, July 21, 2000.

BLOOD PRESSURE-LOWERING "DASH" DIET ALSO REDUCES HOMOCYSTEINE: The blood pressure-lowering DASH diet also reduces levels of the amino acid homocysteine, according to a National Heart, Lung, and Blood Institute (NHLBI)-funded study. A high level of homocysteine appears to increase the risk of heart disease, stroke, and peripheral vascular disease. The study appears in the August 22 issue of The Journal of the American Heart Association."

DASH stands for Dietary Approaches to Stop Hypertension. This new report is based on data from the DASH trial, which found that a diet rich in fruits, vegetables, and low-fat dairy foods and low in saturated fat, total fat, and cholesterol significantly and quickly lowers blood pressure. The diet also included whole grains, poultry, fish, and nuts.

The DASH trial involved four sites and a coordinating center. The homocysteine results come from the Johns Hopkins University site in Baltimore, MD.

Homocysteine levels are affected by various factors, including intake of folic acid (or folate) and vitamins B6 and B12. In the trial, participants followed one of three diets -- a control diet similar to what most Americans eat, a diet rich in fruits and vegetables, and the DASH diet. Compared with homocysteine levels of those on the control diet, homocysteine levels of those on the DASH diet were significantly lower, with levels of those on the fruits and vegetables diet being intermediate. Changes in the homocysteine levels were significantly associated with changes in folate levels. Source: NIH News Advisory.

PEANUTS AND PEANUT BUTTER FOUND TO SUPPRESS HUNGER A new study shows that snacking on peanuts and peanut butter is an effective way to control hunger without leading to weight gain. Subjects who snacked on peanuts and peanut butter self-adjusted their caloric intake spontaneously and did not add extra calories to their daily diets. These findings are published in this month's International Journal of Obesity (Vol. 24, p. 1167-75). Source: The Peanut Institute

FRUITS AND VEGETABLES GOOD FOR STRONG BONES, TOO A group of British researchers has found that several vitamins and minerals other than calcium may contribute to bone health and reduce risk of osteoporosis. In a small study of 62 Scottish women, those who consumed the most zinc, magnesium, potassium, fiber, and vitamin C had the highest bone mineral densities. They also showed less evidence of bone loss.

Bone mineral density, a measure of bone health, was assessed at the thigh bone and the lower spine area. Dietary intake was reported by completing a dietary food frequency questionnaire. The micronutrients found to be positively correlated to better bone health included zinc, magnesium, potassium, fiber, and vitamin C. These nutrients are abundant in fruits, vegetables, and whole grain products, including peas, bananas, potatoes, and enriched cereals. The results of this study show that a diet rich in fruits, vegetables, and whole grains may reduce risk of osteoporosis. Ref:erence: Am J Clin Nutr 2000:71:142-51.

LOWER FAT DIETS FOR CHILDREN DID NOT INCREASE FOOD COSTS: High food costs may be perceived as a barrier to the adoption of a low-fat diet. A recent study examined the food costs in diets of children who were eating to a low-fat diet.

Dietary intakes were evaluated from three 24-hour recalls collected by telephone at baseline and at 3 and 12 months following the intervention. The Nutritionist IV diet analysis software was used to estimate food cost. Two groups of children were compared: a treatment group consisting of children with elevated plasma total cholesterol who received the nutrition education intervention, and a control group of children with normal plasma total cholesterol who received no intervention.

The researchers found no significant food cost differences between groups, and there were no differences within groups across time periods. These data suggest that among children eating a low-fat diet, there was no increase in food costs. The authors suggest that "Nutrition education programs may benefit by providing educational strategies to reduce or eliminate perceived food cost barriers." Source: J Nutr Educ, (3)2, March-April 2000, Research Briefs.

CDC AND FDA STATEMENT ON VIBRIO PARAHAEMOLYTICUS: The September 27, 2000 issue of the Journal of the American Medical Association included an article entitled, "Emergence of a new Vibrio parahaemolyticus serotype in raw oysters. A prevention quandary." This article reported on a 1998 outbreak of acute gastroenteritis in the United States caused by oysters that contained the bacteria V. parahaemolyticus. The article did not provide information on subsequent actions taken by the Food and Drug Administration (FDA) and the Interstate Shellfish Sanitation Conference (ISSC) to help prevent outbreaks of V. parahaemolyticus associated with consumption of raw oysters.

Following the outbreak in 1998, FDA provided guidance and recommendations to ISSC which prescribed monitoring for this pathogen. In 1999, a new interim control plan for preventing outbreaks caused by V. parahaemolyticus was unanimously approved as guidance for the states at the annual ISSC meeting. The plan prescribes monitoring oysters specifically during periods of the year known to be associated with the occurrence of V. parahaemolyticus in those states where outbreaks and sporadic cases have been found to occur. Detection of pathogenic V. parahaemolyticus results in closure of waters to harvesting shellfish until monitoring indicates the pathogen is no longer detectable or until environmental temperatures become unfavorable for the proliferation of this organism. These requirements are intended to prevent shellfish-borne outbreaks caused by this organism.

It is important for health professionals and consumers to be assured that CDC, FDA, and ISSC understand that V. parahaemolyticus is a public health problem and are committed to addressing this problem associated with molluscan shellfish. This is a mirror of the page at: http://www.fda.gov/bbs/topics/NEWS/NEW00738.html

What is Vibrio parahaemolyticus anyway? Should Florida citizens be concerned? Vibrio parahaemolyticus is a salt-requiring gram-negative bacterium naturally and commonly found in warm marine and estuary environments. Infection is caused by eating raw or undercooked shellfish, particularly oysters. Less commonly, infections may occur when the wound or soft tissue is exposed to warm seawater. An average of 30 culture-confirmed cases, 10-20 hospitalizations, and 1-3 deaths are reported each year from the Gulf Coast region (reporting states are Alabama, Florida, Louisiana, and Texas). Nationwide, it is estimated that there are as many as 3000 cases (most not culture confirmed), 40 hospitalizations and 7 deaths. Symptoms of infection include watery diarrhea, often with abdominal cramping, nausea, vomiting, and fever. Less common are wound or soft tissue infections, and occasionally, bloodstream infections. Most persons recover after three days and suffer no long-term consequences. Bloodstream infections and death are uncommon and usually occur in persons with underlying medical conditions. Infections are seasonal; approximately 70% occur between May and October. Three outbreaks linked to the consumption of raw oysters occurred in 1997 and 1998. Environmental factors such as warm water and moderate salinity, can increase the number of V. parahaemolyticus organisms in shellfish. More information can be found at: http://www.cdc.gov/ncidod/dbmd/ Source: Press Office, FDA, U.S. Department of Human Service, September 28, 2000.

FDA APPROVES IRRADIATION OF FRESH SHELL EGGS The United States Food and Drug Administration (FDA) published a final rule in the July 21, 2000 Federal Register that approves the use of ionizing radiation to reduce the level of Salmonella in shell eggs. A radiation dose of up to 3 kiloGray (kGy) will be allowed.

Edward Josephson of the University of Rhode Island Food Science and Nutrition Research Center had petitioned for the rule in 1998. FDA took into account three studies from Josephson that demonstrated irradiation of eggs with doses even higher than 3 kGY had no negative effects in mice or rats that were fed irradiated eggs. FDA also considered data gathered previously on irradiation of meat.

Results from Josephson's studies indicated that the structure and digestibility of the eggs, amounts of fatty acids and the quality of protein were not altered in any substantial way by irradiation. While some vitamin levels could be reduced, the data did not indicate any adverse affect on nutrition. No evidence of toxicity was noted either.

At a radiation dose near 3 kGy, color of the yolk and viscosity of the egg might be changed. But FDA determined that this was not a safety concern. "While, based on current knowledge, one cannot guarantee elimination of Salmonella in all eggs, the total level of Salmonella in eggs will decrease substantially and the fraction of eggs that contain viable Salmonella should also decrease," FDA said. Source: Electronic Food Rap, Vol. 10, No. 16, August 18, 2000. Provided through e-mail by William Evers, Purdue University Extension.

ORGANIC OR NOT ORGANIC...SHOULD YOU BE CONCERNED? A new national standard for organic foods is being developed by the U.S. Department of Agriculture (USDA). Currently, there are no federal rules to govern organically grown or organically produced foods. Many states have certification programs for organic products, but definitions and requirements vary.

Here are some facts about organic products:

1. Organic foods can be contaminated like other foods. Consumers should treat organic products just like conventional products during cooking, preparation, and handling.
2. Organic products are not guaranteed to be absolutely free of pesticide and fertilizer residues.
3. Organic products are not always more nutritious than conventional products because nutritional content depends on many factors such as growing conditions and handling practices.
4. Organic foods usually cost more than traditional products.

You can get more information from the National Organic Program Web site: www.ams.usda.gov/nop Source: University of California, Berkeley Wellness Letter(17), 1, October 2000.

NEW TECHNOLOGY KILLS BACTERIA ON FRUITS, VEGETABLES Research at the University of Georgia may provide a better means of destroying harmful bacteria on fresh produce. Reporting at the 220th national meeting of the American Chemical Society in Washington, D.C., Yen-Con Hung, a food scientist at the University's Center for Food Safety and Quality Enhancement and a professor in the Department of Food Science and presented evidence that electrolyzed water can work better than water/chlorine solutions on some fresh produce, meats, cutting boards, and utensils. It appears that the process is better able to reach the uneven surfaces of fruits and vegetables.

The procedure involves applying current to a diluted saltwater solution. This forms "electrolyzed water" throughout the solution. According to Hung, the electrolyzed water works against E. coli 0157:H7, Salmonella and Listeria.

"We've tested the technology on apples and lettuce. It's very effective at killing bacteria and does not affect quality, appearance or taste," said Hung. Tests on strawberries, cantaloupe and alfalfa sprouts are currently underway. The pathogen-killing effect of the electrolyzed water may be due to several changes: chlorine is formed, the water becomes highly acidic and the level of oxygen in the water appears to go down. According to Hung, the increased acidity kills bacteria by destroying the cell wall of the organism.

A real plus for the process is its simplicity of use. Starting the current through the solution involves pushing a button, Hung said. No solutions have to be mixed or prepared. Source: Summarized from Food Chemical News, September 11, 2000, pp. 3-4.

ZINC CURBS COLD SYMPTOMS IN CONTROLLED TRIAL A recent clinical placebo-controlled trial has found that zinc lozenges reduce duration and severity of common cold symptoms. Participants in the randomized, double-blind trial were 50 volunteers who were recruited within 24 hours of developing common cold symptoms. They received one lozenge of 12.8 mg of zinc acetate or a placebo every two to three hours while awake until their symptoms subsided. The participants recorded their subjective symptom scores daily for 12 days. The measures included sore throat, nasal discharge and congestion, sneezing, cough, scratchy throat, hoarseness, muscle and headache and fever.

Of the 48 people who completed the study, 25 took the zinc and 23 were on the placebo. The zinc group had shorter mean overall duration of cold symptoms, cough and nasal discharge. They also had lower total severity scores for all symptoms.

This is the first report of a placebo-controlled trial that show a consistent and significant effect of zinc lozenges on cold symptoms. Source: http://www.docguide.com Reference: Annals of Internal Medicine 133(4):245-252, 2000

SCOOP ON Bt CORN The Food and Drug Administration (FDA) confirmed the presence of unapproved genetically engineered corn in some grocery taco shells and announced plans to begin testing other corn-based products to see if they have been contaminated, too.

"We plan to test other processed corn products though there has been no determination yet exactly which products," an FDA official said." "It's a logical follow-up to the whole incident. We didn't expect to find unapproved pesticide in the taco shells, but we did. So now we'll look to see if it is anywhere else."

In addition, the FDA plans to issue an official recall of the Taco Bell taco shells, marking the first recall of a bioengineered product by the agency. The recall was based on the FDA's determination that the shells posed a potential but limited threat to human health.

The move will be a technicality since the taco shells were already recalled last month by their distributor, Kraft Foods, which found the corn in its own tests. But the recall underscores the seriousness of the incident for the biotechnology industry, which has been trying to reassure the public that its products are safe and well regulated.

The corn, known as Starlink, is produced by Aventis CropScience of Research Triangle Park, N.C. The corn won federal approval as an animal feed in 1988, but was not approved for human use because of concerns it may cause allergic reactions in people. The corn is engineered to contain a form of pesticide that combats the destructive European corn borer. For more information: Foodsafe archives are available at: http://www.nal.usda.gov/foodborne Source: J Food Protection, 63(9) 1277-1281.

Star Link corn has been approved for use in animal feed but not yet for human consumption. It was detected in Taco Bell taco shells in mid-September (Chemical and Engineering News, September 25, page 13). A coalition of environmental, consumer, and health groups had commissioned Genetic ID, an independent testing firm in Fairfield Iowa, to test the taco shells. Genetic ID found that 1% of the corn in the samples is StarLink. A few days later, Kraft Foods, the distributor of the taco shells, reported similar results from separate tests of the shells and promptly recalled the product from grocery store shelves.

StarLink, which is engineered with a gene from Bacillus thuringiensis (Bt) to produce an insecticidal protein, has not yet been approved for human consumption because of concerns that the protein might provoke allergic reactions. That protein, called Cry9C, is heat stable and resists digestion, two characteristics associated with food allergens. In StarLink corn kernels, the insecticidal protein is expressed at levels that are 10- to 100-fold higher than levels of insecticidal proteins in other varieties of Bt corn. Source: Chemical and Engineering News, October 2000.  More information on genetically modified organisms can be obtained at WHO Web site at: http://www.who.int/fsf/GMfood/index.htm http://www.acsh.org/publications/booklets/biotechnology2000.pdf http://www.acsh.org/publications/booklets/biotechnology2000.html

GEORGIA TEAM GETS THE DIRT ON E.coli 0157:H7

What happens to E. coli 0157:H7 when it is inadvertently introduced to soils by the addition of manure? The answer may help to reveal the cause of outbreaks such as that linked to contaminated water in Walkerton, Ontario, and other outbreaks associated with contaminated produce. Researchers at the University of Georgia conducted a study to find out. Based on their findings so far, they believe it may be necessary to pre-treat manure to kill pathogens to reduce the risk of contamination of produce in soil fertilized with cow manure.  In the study, at the University's Center for Food Safety and Quality Enhancement, researchers inoculated fresh cow manure with five strains of E. coli 0157:H7 at 10 6 colony forming units per gram. The inoculated manure was held at 23 C for 20 hours, then mixed with autoclaved and unheated soil at manure-to-soil ratios of 1:100, 1:50, 1:25, and 1:10. The amended soil was held at 5 C in a closed plastic container and periodically analyzed for the pathogen.

The researchers found that populations of E. coli 0157:H7 were reduced to 10 2 CFU/g (cell of bacteria/g) within 63 days in the unheated soil and within approximately 77 days in autoclaved manure-amended soil. The pH of the soil went from approximately one to three pH units within 70 days and moisture content gradually decreased from 10-16 percent to 1 percent, the team found. The pathogen survived best in soil with a manure ratio of 1:10. Inactivation of the pathogen was correlated with dehydration of the soil. The results showed that E. coli 0157:H7 at an initial population of 106CFU/g can survive at 5 C in manure-treated soil for more than two months. Many vegetable growth cycles from planting to harvesting are within that time frame, so such treated soil could be a source of E. coli 0157:H7 if vegetables come in contact with contaminated soil in the field, the researchers noted. The team is now involved in further studies to find out what effect higher temperatures have on the pathogen's survival in manure-amended soil.

Source: Food Protection Report, 16(10), October 2000. Food Protection Inside Report.

UPDATED ESTIMATES OF FOLATE INTAKE A recent study found that an estimated 68% to 87% of women of childbearing age have folic acid intakes below the recommended 400 g/day. This increases their risk of having a neural tube defect affected pregnancy. Source: J American Dietetic Association, January 2000.

FOLATE IN DIET OF PREGNANT WOMEN The richest sources of food folate in the United States diet are liver, ready-to-eat cereals, legumes, and dark green leafy vegetables. Few women of childbearing age (11-50 years) consume these foods, except cereals, according to recently reported data from the Continuing Survey of Food Intakes by Individuals (CSF11). Mean intake of dietary folate was 215 mg, compared to the recommendations of 400 mg. One in four of the women took a daily supplement containing folic acid. These women were more likely to be white, older, more educated, and to have higher incomes. Folate education programs need to target non-white, young women with limited resources, to decrease risk of neural tube defects in these communities  Source: Family Economics and Nutrition Review (Vol. 12(1), 1999).

PROMOTING DAIRY The US dairy industry spends $225 million each year promoting dairy products. To date they have not focused on promotion of low-fat products. [Editors Note: This is the job of nutrition educators.] Source: Family Economics and Nutrition Review (Vol. 12(1), 1999.

EFFECTS OF MENTAL STRESS AND CIRCADIAN CYCLE ON LIPEMIA AFTER MEALS Mental stress is associated with increased plasma concentrations of triglyceride rich lipoproteins after meals; this may contribute to the positive association between mental stress and risk of ischemic heart disease. Source: J American Dietetic Association, January 2000.

COLON CANCER IN THE SOUTH Incidence of colon cancer is about 33% lower in Southern states, compared with other parts of the U.S. Source: ADA, October 1999.

SUN SCREEN AND VITAMIN D Sun screen reduces vitamin D synthesis by about 50%. It's important to get adequate vitamin D from foods (mostly milk) or a multivitamin supplement even when living in warm, sunny climates Source: ADA, October 1999.

OBESITY RATES CLIMB Obesity rose six percent in the United States in 1999, according to the Behavioral Risk Factor Surveillance System (BRFSS). The largest increase was among whites. The Centers for Disease Control and Prevention (CDC) estimates that 300,000 premature deaths are related to overweight and physical inactivity. CDC recommends several approaches to control what they call an "epidemic." A few of these are consistent with the healthy living, non-diet approach that we have been focusing on in Florida Cooperative Extension Services:

• Worksites should offer healthy food choices.
• Worksites should provide opportunities for physical activity.
• Schools should offer physical education that encourages lifelong physical activity.
• Urban Planners should provide more sidewalks, bike paths, etc.
• Parents should reduce their children's TV and computer time and encourage outdoor play.

Source: Press release CDC, October 2, 2000.

COMING SOON TO A COMPUTER SCREEN NEAR YOU! A brand new consumer Web site focused entirely on fruits and vegetables began on September 10. Surf to www.aboutproduce.com for everything you want to know about any variety of fruit or vegetable. This new Web site is brought to you by the Produce for Better Health Foundation and the Produce Marketing Association. Look for recipes, health facts, nutrition information, fruit and vegetable trivia, and more. The aboutproduce.com Web site arrived during National 5 A Day Week September 10-16.

FROM THE PRACTITIONER'S BOOK-SHELF All About Herbs: The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines (Boston, Mass: Integrative Medicine Communications; 1999. Price: $189 (ISBN 0-9655555-0-X).

Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies (4th ed. New York; NY: Haworth Herbal Press; 1999. Price $49.95 (ISBN 07890-0705-3) by Steven Foster and Varro E. Tyler, PhD.

Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals (2nd ed. Baltimore, MD: Haworth Herbal Press;
1999. Price $39.95 (ISBN 0-7890-0159-4) by James E. Robbers, PhD, and Varro E. Tyler, PhD.

1% OR LESS YES 1% or less is a new approach to reduce the burden of diet-related diseases in this country. Rather than encouraging people to overall their entire diet or lifestyle all at once, it has one targeted, simple, and important message: switch from whole or 2% milk to 1% or skim milk. Additional information can be obtained from: 1% OR Less, c/o CSPI, 1975 Connecticut Ave., NW, Suite 300, Washington, DC 2009-5728. Phone: (202) 332-9110 x 352 Fax: (202) 265-4954

FROM THE NATIONAL CANCER INSTITUTE

• Pamphlet: Energizing Tips for a Healthier Family
• Pamphlet: Eat 5 Fruits and Vegetables Every Day
• Pamphlet: Coma menos grasa
• Pamphlet: ¡Su familia se merece los majores alimentos!

For more information call the National Institute's Cancer Information Services at: 1-800-422-6237

FROM THE NATIONAL INSTITUTES OF HEALTH

• Booklet: Milk Matters (English and Spanish)
• Booklet: Your Best Body
• For more information contact NCHD/Milk Matters Clearinghouse at: 1-800-370-2943.

FROM THE WHEAT FOODS COUNCIL

• Brochure: Bread: A great choice, any way you slice it!
• Brochure: Nutrition: Fact vs. Fad...Setting the Record Straight
• For more information contact the Wheat Foods Council at: (303) 840-8787 or visit them on the web at: www.wheatfoods.org

FROM THE NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES

• Booklet: Why Does Milk Bother Me?
• For information call the National Digestive Diseases Information Clearinghouse at: (301) 654-3810

IRON DEFICIENCY IN TEENAGED GIRLS LINKED WITH DECLINE IN COGNITIVE FUNCTION

In a study of 595 teenaged girls, UK researchers have found a significant correlation between low hemoglobin levels and poor cognitive function. The study group surveyed girls aged 11 to 18 years who were attending three comprehensive schools in North London. Subjects included a cross-section of racial groups. The girls provided finger-prick capillary blood samples that were assessed for hemoglobin and packed cell volume. One hundred fifty-two girls also provided venous blood samples and were evaluated for diet and cognitive functioning.

The researchers found "a highly statistically significant difference in IQ between iron-deficient anaemic girls and iron-deficient and iron-replete girls." The current study was prepared for The Nutrition Society's summer meeting and will be published in the Spring issue of "The Nutrition Society 2001." It was funded by the UK Department of Health. Source: Provided by Josefine Wendel through e-mail.

PHYTOSTEROLS: ANTICANCER DIETARY COMPONENTS Phytosterols (PS) are sterols found in plants. They are structurally similar to cholesterol. The most common PS are -sitosterol, campesterol and stigmasterol. Epidemiologic (population) studies, as well as experimental studies in animals suggest that dietary PS may be protective against cancers that are common in Western societies, such as colon, breast and prostate cancer. Possible mechanisms by which PS offer this protection include effects on: (a) membrane structure and function of tumor and host tissue, (b) regulation of tumor growth and apoptosis (a process believed to be important in limiting tumor growth), (c) immune function, and (d) cholesterol metabolism. Source: J. Nutr. 130: 2127-2130, 2000.