|Zinc supplements cut respiratory infection rate
July 7, 1998
The number of respiratory infections -- a serious cause of childhood illness and death in developing countries -- can be reduced by more than 40% simply by supplying children with dietary zinc supplements, according to a study conducted in India.
Pneumonia and other acute lower respiratory infections cause some 4 million deaths each year and account for one third of all deaths among children in developing countries. Poor nutrition has been shown to increase both the rate of these infections and their severity.
Dr. Sunil Sazawal, of the All India Institute of Medical Sciences, New Delhi, and his associates, report their findings in the July issue of the journal Pediatrics.
They studied 609 children, ages 6-35 months, living in a low socioeconomic population of urban India. The children were randomly divided into two groups. Both groups were given vitamins, but in one group, children received additional supplements of zinc.
After six months, the incidence of respiratory illness was 45% lower for the children given supplements. Twenty-four children in the supplemented group contracted acute lower respiratory infections, compared to 44 episodes in the other group.
Zinc may fight pneumonia and other infections by enhancing the body's immune status, preventing the infection from establishing itself or improving the immune system's ability to rid itself of the infecting organism, the researchers write.
Previous studies have shown that zinc reduces the rate of diarrhea in young children and improves growth. "Interventions to improve zinc intake deserve more attention," whether through supplementation, dietary modification, or fortification of commonly consumed foods, they suggest.
SOURCE: Pediatrics 1998;102:1-5.
And Tylenol Don't Mix
The new label on Tylenol, which contains acetaminophen, will contain a warning, reports CBS News Correspondent John Roberts.
People who consume three or more alcoholic drinks per day will be told to consult their doctor before taking the medication, and that chronic heavy drinkers may be at "increased risk of liver damage."
"We know that there are some individuals who have had very serious side effects...liver damage from Tylenol," said Michael Friedman of the U.S. Food and Drug Administration.
Among those who have suffered serious side effects is Antonio Benedi. A former aide to President Bush, he won $8 million from the makers of Tylenol after he combined the medication with wine drinking and ended up with a liver transplant.
Dr. Ron Busutill, a transplant specialist at UCLA medical center, sees many such cases.
"We have seen patients who have chronically ingested alcohol and then taken acetaminophen for a back problem or a chronic pain problem and then that combination results in liver failure," said Dr. Busutill.
Tylenol is not the only drug with new warnings.
Motrin, which contains ibuprofen, now highlights an "increased risk of stomach bleeding" when combined with alcohol. However, the company that makes both medications, says occasional drinkers have no need to worry.
"You need to be consuming heavy amounts of alcohol over a period of time before you increase your risk," said Dr. Anthony Temple of McNeil Home Products.
Tylenol and Motrin have voluntarily changed their labels. But the FDA is so concerned that consumers know the possible side effects of over the counter painkillers that it will soon require all of them to carry warnings about the dangers of alcohol and analgesics.
July 10, 1998
Antibiotic resistant bacteria can be passed from farm animals to humans, according to a report released Thursday by the National Research Council. However, the Council concludes that the use of antibiotics in animal feed "does not appear to (constitute) an immediate public health concern," and calls for more research on the issue.
Low doses of antibiotics such as tetracycline and penicillin are routinely added to animal feed or water because they result in better growth and prevent infections that can occur when animals are raised in close contact.
"Using antibiotics to control and treat disease in animals improves the safety of our food supply by providing healthier sources of meat, cheese, milk and eggs," said James Coffman of Kansas State University in a statement released by the National Research Council. "But there have been a few cases in which resistant bacteria have been passed to people," according to Coffman, chair of the Committee on Drug Use in Food Animals, which developed the report. The panel was formed at the request of the US Department of Agriculture, the Center for Veterinary Medicine and the Food and Drug Administration.
The use of antibiotics in food animals, as well as in human medicine, increases the chances that bacteria will become resistant to such drugs and therefore more difficult to treat when they cause disease, according to a summary of the report.
"This report acknowledges that there is a link between the use of antibiotics in food animals, the development of bacterial resistance to these drugs, and human disease, although the incidence of such disease is very low," the committee concluded. Those at greater risk include infants, the elderly, those with weakened immune systems, farm workers and people exposed to antibiotics in the manufacture of pharmaceuticals or animal feed.
The panel recommends increased monitoring of drug resistance, drug usage and drug residues in farm animals, as well as identifying alternative agricultural methods to using such drugs in farm animals.
In the report, the panel note that a ban on the use of antibiotics in livestock may lead to increased spread of disease among animals, "which could increase public health risks and lead to higher demand for antibiotics to treat sick animals." A ban could also raise the prices of meat, poultry, and fish by as much as an additional $9.72 per person per year.
"The National Research Council report is a landmark, because it is the first authoritative US report that explicitly acknowledges that agricultural uses of antibiotics pose a risk to the public health," according to a statement issued by the Center for Science in the Public Interest, a Washington, DC-based consumer advocacy group.
June 23, 1998
Drinking three cups of coffee a day could increase the risk of thromboembolic stroke in older men who have high blood pressure, a study suggests.
Thromboembolic stroke is where the brain is damaged due to reduced blood flow caused by blockage in an artery supplying blood to the brain. This may be caused by thrombosis, where arterial disease leads to the blockage, or embolism, where a clot is usually the culprit. Stroke may also be caused by hemorrhage, where an artery bleeds, interrupting blood supply to the brain.
Researchers examined the link between coffee intake and the risk of stroke in a group of men between 55 to 68 years with high blood pressure, one of the most common risk factors for cardiovascular disease. Of the sample of 499 men who were enrolled in the Honolulu Heart Program between 1965 and 1968, 76 men experienced a stroke during a 25-year period.
After adjusting for the age of the men, the risk of stroke due to thrombosis or a blood clot rose as coffee consumption increased. When adjusted for other factors, the risk of stroke more than doubled for men who drank three cups of coffee a day compared with men who did not drink coffee.
There was no link found between coffee consumption and hemorrhagic stroke.
"After adjustments were made for age, systolic blood pressure, total cholesterol, triglycerides, diabetes, alcohol use, and the physical activity index, men who consumed 24 ounces of coffee per day experienced twice the risk of stroke as compared to nondrinkers," reported senior investigator Dr. Robert Abbott, of the University of Virginia School of Medicine in Charlottesville and colleagues.
As part of the Honolulu Heart Program, 8,006 Japanese-American men living on the island of Oahu, Hawaii, were enrolled in the study between 1965 to 1968. The authors of the present study limited their analysis to men with high blood pressure who were free of stroke at the time of enrollment, and who were in older middle-age when follow-up began. High blood pressure was defined as having systolic blood pressure at or above 140 mm Hg, or diastolic blood pressure at or above 90 mm Hg. Only men who had never smoked cigarettes were considered for follow-up, and information on coffee intake was recorded by a dietitian based on 24-hour recall at the time of study entry.
While the results suggest a correlation between coffee consumption and stroke in the population studied, the authors caution that further research is needed to validate the results. It is difficult to accurately follow a large group over time and systematically record coffee intake, they note.
"Although in need of further confirmation, consumption of coffee appears to be positively associated with an increased risk of thromboembolic stroke in hypertensive men in older middle-age," they conclude. "Findings suggest that it may be prudent to advise older middle-aged men with hypertension who consume large amounts of coffee to consider reducing their coffee intake."
SOURCE: Journal of Clinical Epidemiology 1998;51:487-494.
July 8, 1998
Regular exercise can lead to improved glucose (blood-sugar) tolerance in older adults -- which can reduce their risk of developing diabetes, according to researchers.
The effects of moderate levels of aerobic exercise are even more important in older people with high blood glucose levels (hyperglycemia) and insulin resistance, they report.
"Moderate-intensity aerobic training has a favorable effect on glucose tolerance," conclude investigators at Yale University School of Medicine in New Haven, Connecticut.
Glucose tolerance -- the ability of the body to regulate blood sugar levels -- decreases with age, but excess weight gain and decreased physical activity also play a role. Decreased glucose tolerance is believed to be a step in the development of type 2 (adult onset) diabetes. Since obesity has been linked to impaired glucose tolerance, many experts have assumed that only those exercise regimens which resulted in weight loss could bring the condition under control.
That may not always be the case, however. In the Yale study, published in the July issue of The Journal of the American Geriatrics Society, researchers placed 16 elderly men and women on a four month regimen of either aerobic exercise or non-aerobic yoga and stretching. Those in the aerobic exercise group were encouraged to walk and run on mini-trampolines equipped with handrails.
Those who participated in the non-aerobic regimen, four months of stretching and yoga, saw no changes in fitness level or glucose metabolism, according to a statement issued by the journal.
The four month aerobic regimen produced no "appreciable weight or fat loss" in elderly participants. However, blood tests revealed that people in the aerobic exercise group who had impaired glucose tolerance at the beginning of the study showed a 25% improvement in the way their body handled glucose.
The researchers also noted that blood levels of free fatty acids fell by 24% in the aerobic exercise group, leading the researchers to suggest that "training-related improvements in glucose regulation... may be modulated by decreases in (free fatty acid) concentrations."
The study team also conclude that "use of the mini-trampoline allows a safe, enjoyable, and effective mode of exercise for older people, who may otherwise be at risk for musculoskeletal injury from more traditional forms of weight-bearing aerobic exercise."
SOURCE: The Journal of the American Geriatrics Society 1998;46:875-879
June 23, 1998
A high sugar intake, as well as a high fat intake can be linked to increased risk for heart disease, according to researcher Dr. William B. Grant of the NASA Langley Research Center in Hampton, Virginia. But sugar appears to be the most important dietary heart risk factor in women, while foods high in animal fat are the primary culprits in men according to his study, which looked at the diet and heart disease mortality rates of men and women aged 35 to 74 from 33 countries.
The data was collected in 1986, according to a report in the June 22nd issue of the Journal of Orthomolecular Medicine.
While animal fats remained the strongest dietary risk factor for heart disease mortality in men, sugar was the primary dietary risk factor in women. Sugar also contributed to heart disease risk in men, but it was less important than animal fat. A link between sugar intake and heart disease is plausible, the researcher argues.
"The likely mechanism linking sweeteners to heart disease is that it raises serum triglycerides and, hence, very low density lipoprotein levels," he wrote. In fact, Grant says, simple sugars are the primary source of both triglycerides, a type of blood fat, and very low density lipoprotein, another risk factor for atherosclerosis.
"An important question raised by the analysis in this paper is why the associations between sweeteners and heart disease are higher for females than for males," the NASA researcher points out. This variation could be because women eat more sugar than men, or possibly because "the female physiology is better able to assimilate animal fat," according to the report.
According to Grant, sugar intake may account for over 150,000 premature deaths from heart disease in the US each year. "Considerable reduction in the 700,000 cases of heart failure and $20 billion of expenditures per year for treatment of heart disease and loss of life and productivity could be achieved by reducing the amount of simple sugars in our diet," said Grant in a press release.
SOURCE: Journal of Orthomolecular Medicine 1998;13:95-104.
Obesity linked to sleep disorders
June 22, 1998
In an apparent vicious circle, sleep problems can contribute to obesity - and obesity can interfere with sleep, according to two related studies.
A sleep disorder called obstructive sleep apnea may contribute to weight gain by depriving people of rapid eye movement (REM) sleep, according to a study presented at the June 21st annual meeting of the Associated Professional Sleep Societies in New Orleans, Louisiana. REM sleep deprivation has been linked to overeating, according to the study.
Conversely, the results of a second study, published in the June 22nd issue of the Archives of Internal Medicine, show that obesity can interfere with sleep even when it does not cause sleep apnea.
After falling asleep, people with sleep apnea frequently stop breathing and awaken briefly. Consequently, they get less restful sleep. Research has shown that weight gain contributes to the risk for apnea.
But apnea also appears to contribute to weight gain, according to Dr. Jennifer Peszka of the University of Southern Mississippi in Hattiesburg and colleagues.
Peszka's team studied 163 patients who were treated for sleep apnea at a sleep lab. The researchers compared patients' weights, and laboratory read-outs showing how much sleep they got before and after treatment. They found that patients who got the least REM sleep were the heaviest. They also found that patients who got more REM sleep after treatment lost weight, and that those who showed the biggest increases in REM sleep lost the most weight.
These findings suggest that apnea contributes to weight gain, at least in part, by disrupting REM sleep. Previous studies, the researchers write, have shown that animals deprived of REM sleep eat more food. Apnea may also contribute to weight gain because it leaves people feeling tired, and people who are tired are less likely to be physically active, the researchers note.
In the related study published in the Archives of Internal Medicine, Dr. Alexandros N. Vgontzas and colleagues at Pennsylvania State University College of Medicine in Hershey, Pennsylvania, report that obese patients get less restful sleep at night and are sleepier during the day even when they do not have apnea.
At a sleep lab, Vgontzas team monitored 45 normal weight "control" subjects, and 73 obese subjects - none of whom had apnea or other sleep-related breathing problems. Compared with the control subjects, obese subjects got less sleep at night, were sleepier during the day, fell asleep faster and slept longer during daytime, the researchers found.
"Daytime sleepiness is a... characteristic of obese patients with a potentially significant impact on their lives and public safety," write Vgontzas and his team.
Obese patients' nighttime sleep problems and daytime sleepiness might be due to a biological clock or metabolic abnormality associated with obesity, Vgontzas and colleagues theorize. The fact that obese patients tend to be sleepier during the day but more wakeful at night might also explain why obese people are more likely to overeat after dark, the researchers report.
SOURCE: Archives of Internal Medicine 1998;158:1333-1337.
US child vaccinations at record level
July 10, 1998
Vaccination of US children hit an all time high in 1997, with a national average of over 90% of children between the ages of 19 and 35 months receiving most recommended vaccines, according to a report from the Centers for Disease Control and Prevention (CDC).
But immunization rates in some states and urban areas still lag behind the national average. And the report also notes that many children are still not receiving particular vaccines, including the chicken pox and hepatitis B vaccines, and the fourth dose of the DTP vaccine.
Analysis of 1997 data shows that vaccinations against polio, measles, DTP3 (diphtheria, tetanus, and whooping cough) and Haemophilus influenzae type b (Hib) -- a bacterial infection that can lead to meningitis -- were at a record high, each reaching or exceeding 90% coverage levels nationwide in children aged 19-35 months.
But hepatitis B vaccination was still below recommended levels, increasing only two percentage points from 1996, to 84% nationwide.
The same goes for the recommended fourth dose of the DTP vaccine, called DTP4; which remained at 1996 vaccination levels (81% of children). Coverage with DTP4 was particularly low among children living below the poverty level, according to the CDC report.
Varicella (chicken pox) vaccination increased from 16% in 1996 to 26% in 1997, but coverage among states ranged widely, from 39% in Pennsylvania to 4% in South Dakota. The varicella vaccine was approved for use in 1995.
Among children, varicella is the leading cause of vaccine-preventable death in the United States, according to the report. "Every year there are approximately 5,000-9,000 hospitalizations and 100 deaths from chickenpox in the United States," according to a CDC statement.
"Achieving the national goal of 90% coverage by 2000 will require states to achieve and maintain high coverage levels for each vaccine," write CDC experts. "Public health efforts must focus on implementing effective strategies that achieve and sustain high vaccination coverage."
SOURCE: Morbidity and Mortality Weekly Report 1998: 47;547-554.
Whole grains protect against cancer
June 24, 1998
Consumption of whole grain foods, particularly breads and pasta, may protect against a variety of cancers, according to a study.
Dr. Liliane Chatenoud from Milan, Italy, and colleagues studied more than 10,000 hospital patients with a variety of cancers and almost 8,000 patients treated for non-cancerous conditions between 1983 and 1996 in northern Italy. The patients filled out questionnaires about their medical history, smoking habits, consumption of alcohol and intake of a variety of foods, especially whole grains.
"High intake of whole grain foods consistently reduced risk of (cancer) at all sites, except thyroid," the researchers write in the International Journal of Cancer.
Specifically, the researchers say a diet with many whole grain foods lowered the risk of various cancers, including those affecting the digestive tract (stomach, colon, rectum, liver, pancreas and gall bladder), and those outside the digestive system, including cancers of the upper respiratory tract, breast, prostate, ovary, bladder, and kidney.
The investigators do not offer any conclusive reason why whole grains reduce cancer risk. But they speculate that because whole grains have more insoluble and soluble fiber, they spend less time in the digestive tract. Whole grains may also have antioxidant effects, reducing the risk of cancer by "mopping up" cancer-causing free radical molecules formed during some cells processes.
"It is also possible that more frequent whole grain consumption simply implies a lower intake of refined grains, which have been associated with elevated risk of colorectal, breast, and perhaps other cancer sites," the researcher write.
SOURCE: International Journal of Cancer 1998;77:24-28.
Workplace smoke is harmful
July 10, 1998
Exposure to second-hand smoke in the workplace increases lung cancer risk just as much as exposure to environmental smoke at home, according to a new analysis of the medical research.
Five other recent analyses have concluded that workplace exposure to side-stream tobacco smoke does not increase lung cancer risk. But these analyses, "conducted by employees of, or consultants to, the tobacco industry," were based in part on flawed research, according to the author of the new analysis, Dr. A. Judson Wells of Kennett Square, Pennsylvania.
Reviewing the 14 studies on which the five previous analyses were based, Wells found that the quality of the research varied "considerably" and that three of the studies had serious errors.
"When relative risks from the better studies are combined via meta-analysis, a statistically significant increase in lung cancer risk is found that is similar to the increased risk from household studies," writes Wells, whose analysis appears in the current issue of the American Journal of Public Health.
People exposed to environmental smoke in the workplace run a 39% higher risk of lung cancer than those who are not exposed to side stream smoke at work, Wells concludes.
"Wells meticulously elucidates how these other meta-analyses obscured the finding of any relationship because they failed to take account of errors in the underlying studies accepted into their databases," Dr. Lester Breslow and Dr. Robert Elashoff of the School of Public Health at the University of California, Los Angeles, write in an accompanying editorial.
"The paper by Wells will contribute significantly to combating what is still the top cause of preventable mortality in the United States," Breslow and Elashoff conclude.
SOURCE: American Journal of Public Health 1998;88:1025-1028, 1011-1012.