STUDY: Amino acid, when heated, helps form possible carcinogen
ABSTRACT: Scientists have found a clue to the chemical reaction that may cause potato chips, french fries and other fried or baked starchy foods to build up high levels of a possible cancer-causing substance.
COMMENTARY: The suspect is asparagine, a naturally occurring amino acid that, when heated with certain sugars such as glucose, leads to the formation of the worrisome substance acrylamide.
The Food and Drug Administration has made studying acrylamide’s risk and determining how to lower its levels in food one of its highest research priorities, according to a plan that agency officials were to discuss Monday with consumer groups and food manufacturers.
Canada’s government made the discovery about the suspect chemical reaction, and has ordered food manufacturers to look for ways to alter it and thus lower levels of acrylamide in food. Cincinnati-based manufacturer Procter & Gamble Co. says its scientists also have found the asparagine connection. And Swiss and British scientists report in this week’s edition of the journal Nature that they, too, found the link.
It is the first clue to emerge in the mystery of acrylamide since Swedish scientists made the surprise announcement in the spring that high levels of the possible carcinogen are in numerous everyday foods: french fries, potato chips, some types of breakfast cereals and breads — plenty of high-carbohydrate foods that are fried or baked at high temperatures. The chemical was not found in boiled foods, which are cooked at lower temperatures.
Acrylamide is used to produce plastics and dyes and to purify drinking water. Although traces have been found in water, no one expected high levels to be in basic foods.
It causes cancer in test animals, but it has not been proved to do so in people. Still, Swedish scientists have said the levels are high enough that foodborne acrylamide might be responsible for several hundred cases of cancer in that country each year.
The food industry stresses that while fried potato products are getting most of the bad publicity — most testing so far shows the highest levels in them — acrylamide is in a wide variety of foods. Procter & Gamble said Friday that its testing found acrylamide in such previously unimplicated foods as roasted asparagus and banana chips.
Everyone should be eating a healthy whole food diet. By doing so you will limit the quantity of this and other potentially harmful substances. Remember fruits and veggies and whole grains will promote your health. Try to eat things as they occur in nature with the least amount of processing.
JOURNAL: Journal of the American Medical Association
AUTHORS: Christine Velicer
ABSTRACT: Women who use antibiotics to treat infections may be increasing their risk of breast cancer, a US study has suggested.
COMMENTARY: Researchers found that women who used the drugs for up to 500 days were about 1.5 times as likely to develop cancer. Among higher users, the risk of death from the disease was nearly 3.5 times as great.
The association between disease and death was even stronger among those who used antibiotics for longer, although the authors of a report in the Journal of the American Medical Association stressed that more research was needed to establish whether the apparent association was causal or if other factors needed to be considered.
These included the possibility that immune systems were already undermined by conditions for which antibiotics were being taken or that inflammation of tissues linked to some conditions made them more suitable breeding grounds for tumours.
Scientists are already concerned about the excessive use of antibiotics to treat infections, blaming it for growing bacterial resistance to drugs.
The study, led by Christine Velicer of Washington University, Seattle, compared medical data for 2,266 women who had breast cancer with 7,953 women who did not.
In the report on their work, the researchers said: "While the implications for clinical practice will not be clear until additional studies are conducted, the results of this study support the continued need for prudent long-term use of antibiotics."
STUDY: Vitamin-rich foods, not supplements, appear best
JOURNAL: Journal of the American Medical Association
AUTHORS: Martha Clare Morris
ABSTRACT: In the latest work to show that vitamins may protect against dementia, new studies suggest that eating nuts, leafy green vegetables and other foods rich in antioxidants such as vitamin E may reduce the risk of Alzheimer’s.
COMMENTARY: The connection, at least, is considered plausible: Antioxidant vitamins have been shown to block the effects of oxygen molecules called free radicals, which can damage cells and are thought to contribute to cancer and heart disease. And lesions typically associated with exposure to free radicals have been found in the brains of Alzheimer’s patients.
One of the studies found strong effects from vitamins E and C. In the other, results from vitamin E foods were more conclusive.
There was no protective effect in participants with a gene variation called apoplipoprotein E-4, which has been linked to the development of Alzheimer’s.
Other work has hinted that high levels of the amino acid known as homocysteine may also be associated with Alzheimer’s disease, suggesting that folic acid and other B vitamins may offer some protection.
There’s no question, experts say, that folic acid and B vitamins break down homocysteine in the body, thereby reducing blood levels. But the link between homocysteine and dementia still needs to be confirmed.
STUDY: Plant-based, edible compounds are one answer
JOURNAL: Diabetes Week
AUTHORS: Sam J. Bhathena
ABSTRACT: Obesity and diabetes mellitus are two nutritional disorders that have become major public health concerns in industrialized countries because of their epidemic proportions and association with major cardiovascular risk factors that are responsible for excess morbidity and mortality. Researchers are looking for ways to combat these diseases.
COMMENTARY: Phytoestrogens are a group of biologically active plant-based compounds.
Phytoestrogens are present in edible plants that can be classified as isoflavones, lignans and coumestaus. Soybean is an abundant source of isoflavones in the human diet, while flaxseed is the richest source of lignans.
Earlier studies in obese animals and humans have suggested that soy, as a source of dietary protein, has significant antiobesity effects.
A study conducted in genetically obese mice found that soy protein and its hydrolsate were more effective than whey protein in weight reduction. This effect may be due to an active tetrapeptide present in soy. Several studies reported increased insulin sensitivity in rats fed isolated soy proteins compared with rats fed casein. A 37-kDa protein in soy appears to modulate insulin action on fat decomposition. Studies on the role of flaxseed and its components in obesity and diabetes in humans are limited.
Lean and obese rats were fed diets containing either 20% casein or 20% isolated soybean protein or 20% flaxseed meal for 26 weeks. The lean rats were hypertensive while the obese rats showed symptoms of type II diabetes. Obese rats had significantly higher levels of plasma glucose, triglycerides, total cholesterol, (high-density lipoprotein cholesterol [HDL-C] and low-density lipoprotein cholesterol [LDL-C]).
Soybean significantly decreased total cholesterol and LDL in both lean and obese rats but had no significant effect on glucose.
Flaxseed decreased total cholesterol and triglycerids in both lean and obese rats, but it significantly decreased HDL-C and LDL-C only in obese rats. Flaxseed also decreased glucose in lean but not in obese rats and it had greater effect on various parameters than did soybean.
Soybean and flaxseed affected plasma lipids and a number of enzymes. They also had varying effects on tissue weights in lean and obese rats. Obese rats compared with lean rats had significantly lower plasma creatinine but higher total bilirubin, blood urea nitrogen, alanine aminotransferase and lactate dehydrogenase.
Both soy and flaxseed meal decreased total bilirubin, protein and uric acid in the lean rats, but the effects in obese rats were mixed.
STUDY: Ailment affects 1 in 133
JOURNAL: Archives of Internal Medicine
AUTHORS: Alessio Fasano
ABSTRACT: New research is revealing that celiac disease may be one of the most common genetic diseases, affecting perhaps as many as 2 million Americans. A national survey published today, for example, estimates that 1 in 133 Americans has it.
COMMENTARY: Most doctors miss the diagnosis of celiac disease. It’s now clear that the textbook description of this once-obscure ailment is woefully incomplete and describes only a minority of cases.
Below the tip of the so-called celiac iceberg is a diverse world of illness that may include thousands of people suffering from various, seemingly unrelated conditions, such as anemia, osteoporosis, infertility, irritable bowel syndrome and chronic fatigue.
“We were taught in another way. We were looking in the wrong direction. We were not putting our face under the water to see the iceberg,” said Alessio Fasano, a gastroenterologist at the University of Maryland School of Medicine in Baltimore.
It is Fasano and his colleagues who are publishing the survey that estimates 1 in 133 Americans has celiac disease. About 40 percent of the afflicted report no symptoms, although the disease may be having inapparent effects, such as the loss of bone mass, subtle changes in mood and infertility. In close relatives of people with celiac disease, the ailment was especially common, with a prevalence of 1 in 22, according to the paper, which is appearing in the Archives of Internal Medicine.
Celiac disease is characterized by a chronic inflammation of the upper portion of the small intestine. This occurs in response to gluten and similar proteins found in wheat, rye and barley. In classical cases, this leads to vomiting and diarrhea in young children soon after cereals are introduced in the diet.
What’s now clear is that people can develop celiac disease throughout life and that they often have few, if any, intestinal symptoms.
The symptoms they do have often arise from deficiencies of nutrients absorbed in the affected part of the intestine, such as iron, calcium and fat-soluble vitamins.
Iron-deficiency anemia is the most common “clinical presentation” of adults with celiac disease. In Fasano’s survey, 30 percent of people in which the disease was newly diagnosed had joint pain. One quarter had fatigue. Six percent had osteoporosis.
Celiac disease is diagnosed by testing for three antibodies — anti-gliadin, anti-endomysial and anti-tissue transglutaminase — that are present when an affected person is exposed to gluten but disappear when the offending grains are no longer consumed.