Scientists already know much about the more than 200 bones that make up your body. But mysteries remain regarding the exact role that many natural compounds in foods might play in strengthening our skeletons. Those compounds include estrogen-like substances known as soybean isoflavones.
Agricultural Research Service (ARS) physiologist Marta D. Van Loan and other researchers learned more about these compounds in a 3-year study—the longest of its kind—reported earlier this year in the American Journal of Clinical Nutrition. Van Loan is with the ARS Western Human Nutrition Research Center at the University of California-Davis.
Because of its potential as a possible substitute for conventional steroid hormone replacement therapy for postmenopausal women, soy has been the subject of more than two dozen studies conducted here and abroad during the past decade. According to Van Loan, some of those investigations suggest that soy enhances bone health.
Van Loan teamed up with Iowa State University researcher D. Lee Alekel and others for the 3-year investigation to determine whether isoflavones extracted from soy protein would protect postmenopausal volunteers against bone loss. Participants in the study took either a placebo tablet or a tablet containing one of two moderate amounts of the isoflavones—80 milligrams (mg) or 120 mg—for the duration of the investigation.
Overall, the isoflavones had no significant positive effect on preventing bone loss. However, the 120-mg treatment showed a modest benefit when evaluated in conjunction with lifestyle factors.
The researchers suggest that the body's response to isoflavones extracted from soy proteins may be different from responses to isoflavones in their natural matrix of soy protein or soy foods, or in a soy-protein supplement. Or, some soy-protein compound other than the extracted isoflavones may have been responsible for the bone-protecting effects seen in some previous studies. Finally, the isoflavone doses used in the 2010 study may not have been high enough to produce a bone-sparing effect.
Read more about this and other bone-health research in the July 2010 issue of Agricultural Research magazine.
ARS is the principal intramural scientific research agency of the U.S. Department of Agriculture.
Saturday, July 31, 2010
Friday, July 30, 2010
Calcium supplements boost myocardial infarction risk
Myocardial infarction or heart attack was more commonly found in patients with osteoporosis who used calcium supplements,a meta-analysis of 16 studies reported in the British Medical Journal or BMJ revealed.
Doctors whose training on nutrition received from medical school is generally limited if any may advise their patients with bone disease to take calcium supplements with or without supplementation of vitamin D.
But the current study led by Ian Reid, MD, of the University of Auckland in New Zealand, and colleagues showed patients who had osteoporosis and took calcium supplements were 30 percent more likely to suffer myocardial infarction or heart attack.
The study was based on data from 11 previous clinical trials of 11,921 participants who were followed for a mean period of four years and five observational studies of 8151 participants who were followed for 3.6 years on average.
Patients in none of the studies were using vitamin D along with calcium supplements.
In the current study, separate analyses of data from both types of studies showed similar results, using calcium supplements was associated with 30 percent increased risk of myocardial infarction.
Suzanne Steinbaum, DO, cardiologist at Lenox Hill Hospital in New York City, was quoted by MedPage Today as commenting that "For patients who are at risk for heart disease, with multiple risk factors, or a strong family history, perhaps calcium supplementation should not be considered."
In the analysis of data from studies which were reported by patients, calcium supplementation was linked with an increased risk of myocardial infarction in those who had a dietary calcium intake above an average 805 mg per day, but not in those with a lower dietary intake.
The authors noted that calcium supplements may increase the risk of myocardial infarction by increasing serum calcium levels which have been found linked with higher heart attack risk in some epidemiological studies.
How could calcium supplements increase risk of myocardial infarction?
A myocardial infarction or heart attack occurs when blood flow to an area of the heart muscle is completely blocked, according to the National Heart Lung and Blood Institute.
The blockage results from coronary artery disease - a condition in which plaque builds up inside the coronary arteries. The plaque consists of fat, cholesterol, calcium and other substances in the blood.
Healingdaily.com suggests on its website that it is part of a terrible campaign that convinces patients that cholesterol is the major cause for heart disease and suppresses the fact that calcium plays a potentially even more important role in heart disease.
It should not be news that calcium supplements increase risk of cardiovascular disease such as heart attack as many studies have demonstrated the association.
In fact, a class of drugs called calcium channel blockers have been found at least as effective in reducing risk of cardiovascular disease including heart attack as other anti-hypertensive medications, according to Alcocer L and colleagues from Universidad Nacional Autónoma de México.
The drugs of this class are known to reduce risk of coronary calcification and retard progression of atherosclerosis, Alcocer et al. said in their report published this year in American Journal of Cardiovascular Drugs.
The current study even though there are some limitations suggests that too much calcium can be a risk for myocardial infarction or heart attack.
High concentrations of calcium are found in both animal-based foods such as milk, yogurt and cheddar cheese and plant-based foods such as pinto beans, red beans, white beans, tofu, bok choy, kale, Chinese cabbage, broccoli, rhubarb and spinach.
Doctors whose training on nutrition received from medical school is generally limited if any may advise their patients with bone disease to take calcium supplements with or without supplementation of vitamin D.
But the current study led by Ian Reid, MD, of the University of Auckland in New Zealand, and colleagues showed patients who had osteoporosis and took calcium supplements were 30 percent more likely to suffer myocardial infarction or heart attack.
The study was based on data from 11 previous clinical trials of 11,921 participants who were followed for a mean period of four years and five observational studies of 8151 participants who were followed for 3.6 years on average.
Patients in none of the studies were using vitamin D along with calcium supplements.
In the current study, separate analyses of data from both types of studies showed similar results, using calcium supplements was associated with 30 percent increased risk of myocardial infarction.
Suzanne Steinbaum, DO, cardiologist at Lenox Hill Hospital in New York City, was quoted by MedPage Today as commenting that "For patients who are at risk for heart disease, with multiple risk factors, or a strong family history, perhaps calcium supplementation should not be considered."
In the analysis of data from studies which were reported by patients, calcium supplementation was linked with an increased risk of myocardial infarction in those who had a dietary calcium intake above an average 805 mg per day, but not in those with a lower dietary intake.
The authors noted that calcium supplements may increase the risk of myocardial infarction by increasing serum calcium levels which have been found linked with higher heart attack risk in some epidemiological studies.
How could calcium supplements increase risk of myocardial infarction?
A myocardial infarction or heart attack occurs when blood flow to an area of the heart muscle is completely blocked, according to the National Heart Lung and Blood Institute.
The blockage results from coronary artery disease - a condition in which plaque builds up inside the coronary arteries. The plaque consists of fat, cholesterol, calcium and other substances in the blood.
Healingdaily.com suggests on its website that it is part of a terrible campaign that convinces patients that cholesterol is the major cause for heart disease and suppresses the fact that calcium plays a potentially even more important role in heart disease.
It should not be news that calcium supplements increase risk of cardiovascular disease such as heart attack as many studies have demonstrated the association.
In fact, a class of drugs called calcium channel blockers have been found at least as effective in reducing risk of cardiovascular disease including heart attack as other anti-hypertensive medications, according to Alcocer L and colleagues from Universidad Nacional Autónoma de México.
The drugs of this class are known to reduce risk of coronary calcification and retard progression of atherosclerosis, Alcocer et al. said in their report published this year in American Journal of Cardiovascular Drugs.
The current study even though there are some limitations suggests that too much calcium can be a risk for myocardial infarction or heart attack.
High concentrations of calcium are found in both animal-based foods such as milk, yogurt and cheddar cheese and plant-based foods such as pinto beans, red beans, white beans, tofu, bok choy, kale, Chinese cabbage, broccoli, rhubarb and spinach.
Branding and labeling have the most significant impact on consumers' buying decisions
Branding and labelling have the most impact on consumers’ buying decisions, followed by blind tasting, concludes a study that used wine tasting as a model to determine the relative influence of different cues on purchasing intent.
When a consumer is making up their mind whether or not to buy a product they are not guided by its taste alone. A number of extrinsic factors also vie for their attention, such as awareness of the brand, labelling, price and origin. For a marketers, it is vital to understand how the different triggers that can lead target consumers towards the check out.
Authors of the new study Simone Mueller and Gergely Szolnoki said that little is know about the relative impact of the various extrinsic cues on informed product evaluation. They set out to investigate this, and how strongly consumers differ in their responsiveness. Their findings could help marketers develop more targeted strategies for product launches.
For the study, which has been accepted for publication in the journal Food Quality and Preference, Mueller and Sziolnoki recruited 521 wine drinkers in three German cities. The participants first ranked their liking of white wines in a blind tasting, then evaluated different elements of product: region of origin, grape variety, brand, and packaging style.
Wine was chosen as a good model because there is a keen interplay between intrinsic sensory characteristics and extrinsic attributes.
Overall label style and brand evaluation were seen to be the most important elements, followed by liking in the blind tests.
However not all consumer groups responded to the cues in the same way.
Younger consumers, deemed to be less experienced, used a mix of cues, whereas consumers more experienced with drinking wine tended to base their decisions on grape variety and liking.
The oldest consumers tended to be most swayed by brand and packaging. The researchers suggest that this may have been because they have had longer to form evaluation heuristics.
Price matters
The researchers introduced the issue of price only after the tasting and other cues had been evaluated. They found that product quality and taste preferences swayed purchase intent on one hand, economic constraints on the other.
The model might be applied to other products.
Mueller and Szolnoki concluded: “Our approach could be useful for products with less sensory fatigue for which a larger number of samples can be evaluated in blind and informed conditions, also reducing the potential bias from presenting identical stimuli.
“A larger test design also reduces the risk that respondents might become aware of the manipulation of evaluating the same sensory stimulus in different informed conditions.”
Some drawbacks to the design were also flagged.
“Although we aimed to include a large number of the most important extrinsic wine attributes into the experimental design, the relative effect of other cues such as closure, health claims or alcohol level still has to be explored in future research.”
Source
Food Quality and Preference
DOI: 10.1016/j.foodqual.2010.07.011
"The relative influence of packaging, labelling, branding and sensory attributes on liking and purchase intent: consumers differ in their responsiveness"
When a consumer is making up their mind whether or not to buy a product they are not guided by its taste alone. A number of extrinsic factors also vie for their attention, such as awareness of the brand, labelling, price and origin. For a marketers, it is vital to understand how the different triggers that can lead target consumers towards the check out.
Authors of the new study Simone Mueller and Gergely Szolnoki said that little is know about the relative impact of the various extrinsic cues on informed product evaluation. They set out to investigate this, and how strongly consumers differ in their responsiveness. Their findings could help marketers develop more targeted strategies for product launches.
For the study, which has been accepted for publication in the journal Food Quality and Preference, Mueller and Sziolnoki recruited 521 wine drinkers in three German cities. The participants first ranked their liking of white wines in a blind tasting, then evaluated different elements of product: region of origin, grape variety, brand, and packaging style.
Wine was chosen as a good model because there is a keen interplay between intrinsic sensory characteristics and extrinsic attributes.
Overall label style and brand evaluation were seen to be the most important elements, followed by liking in the blind tests.
However not all consumer groups responded to the cues in the same way.
Younger consumers, deemed to be less experienced, used a mix of cues, whereas consumers more experienced with drinking wine tended to base their decisions on grape variety and liking.
The oldest consumers tended to be most swayed by brand and packaging. The researchers suggest that this may have been because they have had longer to form evaluation heuristics.
Price matters
The researchers introduced the issue of price only after the tasting and other cues had been evaluated. They found that product quality and taste preferences swayed purchase intent on one hand, economic constraints on the other.
The model might be applied to other products.
Mueller and Szolnoki concluded: “Our approach could be useful for products with less sensory fatigue for which a larger number of samples can be evaluated in blind and informed conditions, also reducing the potential bias from presenting identical stimuli.
“A larger test design also reduces the risk that respondents might become aware of the manipulation of evaluating the same sensory stimulus in different informed conditions.”
Some drawbacks to the design were also flagged.
“Although we aimed to include a large number of the most important extrinsic wine attributes into the experimental design, the relative effect of other cues such as closure, health claims or alcohol level still has to be explored in future research.”
Source
Food Quality and Preference
DOI: 10.1016/j.foodqual.2010.07.011
"The relative influence of packaging, labelling, branding and sensory attributes on liking and purchase intent: consumers differ in their responsiveness"
Thursday, July 29, 2010
Study Says Media Misrepresents Organic
A new study published in the British Food Journal finds U.S. media coverage of organic agriculture and organic food are more likely to be positive than negative and inaccurately claim organic food is safer.
Researchers from Kansas State University explored how topics of organic food and agriculture were discussed in five North American newspapers. Using the content analysis technique, the 618 articles collected were analyzed for topic, tone and theme regarding food safety, environmental concerns and human health. The prominent topics of the articles were genetic engineering, pesticides and organic farming.
The researchers found 41.4 percent of the articles had a neutral tone toward organic agriculture and food; 36.9 percent had a positive tone; 15.5 percent were mixed; and 6.1 percent were negative.
"We concluded that articles about organic production in the selected time period were seldom negative," said lead author Doug Powell. "Organic agriculture was often portrayed in the media as an alternative to allegedly unsafe and environmentally damaging modern agriculture practices. That means organic was being defined by what it isn't, rather than what it is."
The U.S. Department of Agriculture has repeatedly stated that the organic standard is a verification of production methods and not a food-safety claim, Powell said.
"Food safety was the least important in the media discussion of organic agriculture," he said. "The finding that 50 percent of food safety-themed statements in news articles were positive with respect to organic agriculture, while 81 percent of health-themed statements and 90 percent of environment-themed statements were positive toward organic food, indicates an uncritical press."
Sources:
* Kansas State University: STUDY FINDS MEDIA MAY BE OVERHYPING BENEFITS OF ORGANIC FOOD, AGRICULTURE
Researchers from Kansas State University explored how topics of organic food and agriculture were discussed in five North American newspapers. Using the content analysis technique, the 618 articles collected were analyzed for topic, tone and theme regarding food safety, environmental concerns and human health. The prominent topics of the articles were genetic engineering, pesticides and organic farming.
The researchers found 41.4 percent of the articles had a neutral tone toward organic agriculture and food; 36.9 percent had a positive tone; 15.5 percent were mixed; and 6.1 percent were negative.
"We concluded that articles about organic production in the selected time period were seldom negative," said lead author Doug Powell. "Organic agriculture was often portrayed in the media as an alternative to allegedly unsafe and environmentally damaging modern agriculture practices. That means organic was being defined by what it isn't, rather than what it is."
The U.S. Department of Agriculture has repeatedly stated that the organic standard is a verification of production methods and not a food-safety claim, Powell said.
"Food safety was the least important in the media discussion of organic agriculture," he said. "The finding that 50 percent of food safety-themed statements in news articles were positive with respect to organic agriculture, while 81 percent of health-themed statements and 90 percent of environment-themed statements were positive toward organic food, indicates an uncritical press."
Sources:
* Kansas State University: STUDY FINDS MEDIA MAY BE OVERHYPING BENEFITS OF ORGANIC FOOD, AGRICULTURE
Subscribe to:
Posts (Atom)
Posts
