All Posts tagged researchers

High Fat Diet Can Make Asthma Symptoms Worse

Avoid eating meals high in fat, especially if you suffer from asthma, urges Australian researchers after finding the fat leads to inflamed breathing passages and hinders drug interventions.

Lisa Wood, PhD, research fellow and lecturer in the biomedical sciences and pharmacy department of Hunter Medical Research Institute, at the University of Newcastle, led the study with a team of researchers and presented their findings at ATS 2010, the international meeting of the American Thoracic Society, in New Orleans.

The researchers challenged 14 non-obese asthmatics and 16 obese participants to a high-fat diet (1,000 calories with 52%/60g of fat) of burgers and fried potatoes and another group of 16 non-obese asthmatics to eat a low-fat yogurt diet (200 calories, 13%/3g fat). “Induced sputum samples were collected at baseline and at 4 hours” according to the study's abstract.

“Subjects who had consumed the high-fat meal had an increase in airway neutrophils and TLR4 mRNA gene expression from sputum cells, that didn't occur following the low fat meal, ” said Wood.

She continued, “The high fat meal impaired the asthmatic response to albuterol. In subjects who had consumed a high fat meal, the post-albuterol improvement in lung function at three and four hours was suppressed.”

The researchers were surprised to find that the fatty diet also impacted the effectiveness of asthma medications, like albuterol. Wood added, “This is the first study to show that a high fat meal increases airway inflammation, so this is a very important finding. The observation that a high fat meal changes the asthmatic response to albuterol was unexpected as we hadn't considered the possibility that this would occur.”

It's unclear how and why fat not only inflames the airways but also prevents known asthma therapies from working. The researchers intend to design “more studies to investigate this effect. We are also investigating whether drugs that modify fat metabolism could suppress the negative effects of a high fat meal in the airways. If these results can be confirmed by further research, this suggests that strategies aimed at reducing dietary fat intake may be useful in managing asthma.”

Whether you have asthma or not is becoming increasingly more important for heart and now lung health to avoid the fat.

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Folate Helps Repair Damage Due to Ageing

Since the 1960s, researchers have been studying how the water-soluble vitamin supports the healthy functioning of cells. They discovered that it's essential for cell division and replication, making it especially important for expectant mothers.

It's also important to proper replication of DNA and RNA — a lack of folate has been linked to genetic mutations that can lead to cancer.

Folate is commonly found in leafy green vegetables like spinach and turnip greens. Since 1998, the U.S. Food and Drug Administration has mandated that many foods, such as rice, flour and cornmeal, be enriched with a synthetic folate known as folic acid.

While folate deficiency is no longer a problem in the U.S., it remains widespread in developing nations and much of Europe, where enriching grain products is not widely practiced.

This new research, funded by the National Science Foundation and originally sparked by funding from the U.S. Department of Energy, links folate to the production or repair of compounds called iron-sulfur clusters through a recently discovered intermediary protein called COG0354.

These clusters are part of the mechanism cells use to produce energy and carry out other vital reactions. But they are also sensitive to a byproduct of the energy-producing process: highly reactive oxygen-based molecules, some of which are called free radicals.

The oxidative stress caused when these molecules pollute a cell has been linked to cell death and aging, as well as to conditions such as atherosclerosis, Parkinson's disease, heart disease, Alzheimer's, fragile X syndrome and many more.

Examining the folate-iron-sulfur cluster link required the team to pull experience from not only UF's microbiology and cell science and food science and human nutrition departments, but also the McKnight Brain Institute and the National High Magnetic Field Laboratory.

Expertise from the latter two institutions was needed because the researchers used nuclear magnetic resonance analysis to observe folate interacting with COG0354 protein — molecular-scale activity that could otherwise only have been shown indirectly, said Arthur Edison, the NHMFL's director of chemistry and biology and an associate professor with UF's biochemistry and molecular biology department.

The researchers have found that COG0354 is present in creatures from each of the six kingdoms of life, from mice and plants to one-cell organisms that may predate bacteria.

The findings will open new avenues of study into the overall mechanism of oxidative stress repair, and may someday lead to new medicines. For now, the researchers emphasize that this is another example of the vitamin's importance in one's diet.

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Special Diets and Rheumatoid Arthritis

The new study comprised 366 people with RA from eight separate trials. Fasting followed by eating a vegetarian diet for 13 months or eating a Mediterranean style diet replete with fruits, vegetables, healthy fats, and legumes for 12 weeks may relieve pain, the study showed. These diets did not improve morning joint stiffness or physical function when compared to regular diets.

There was not enough data to draw any conclusions about how vegan and/or elimination diets affect RA symptoms.

The positive changes seen with vegetarian and Mediterranean diets may be a result of simply adapting a healthier way of eating as opposed to any specific diet, the study researchers conclude.

People with RA who were put on special diets were more likely to drop out of the studies, suggesting that some people may have difficulty adhering to the eating plans.

Some special diets also resulted in weight loss which may not always be a good thing people with RA who are already at risk for nutritional shortfalls.

“There is a need for more and better research on dietary interventions for RA,” conclude researchers led by Geir Smedslund, PhD, a senior researcher at the Centre for Rehabilitation in Rheumatology at the Diakonhjemmet Hospital in Oslo, Norway.

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12 Ways Vitamin D Can Help

Vitamin D, the “sunshine” vitamin, does a lot more than help keep bones strong — scientists are finding that it impacts all aspects of our health.

Vitamin D can be obtained from exposure to sunlight, vitamin supplements (vitamin D-3 is recommended by many experts), and foods such as salmon and tuna.

Recent studies show that having high levels of vitamin D in our blood can help protect against many diseases, while low levels are linked with several disorders.

Here are 12 critically important ways vitamin D can help protect your health:

1. Colon cancer. A study by cancer prevention specialists at the Moores Cancer Center at the University of California found that high amounts of vitamin D could slash colorectal cancer rates by two-thirds. A European study found that high levels of vitamin D cut the odds of colon cancer by almost 40 percent.

2. Breast cancer. Research using data from two earlier studies found that women with the highest amounts of vitamin D in their blood lowered their risk of breast cancer by 50 percent when compared to women with the lowest levels. A Canadian study found that women who took a vitamin D pill of least 400 international units every day lowered their risk of developing breast cancer by 24 percent.

3. Heart disease. A British study has found that middle-aged and elderly people with high levels of vitamin D reduce their risk of developing cardiovascular disease by 33 percent. Utah scientists found that patients who raised their blood levels of vitamin D after being diagnosed as deficient lowered their risk of having a heart attack by 33 percent, their risk of heart failure by 20 percent, and their risk of dying from any cause by 30 percent.

4. Brain health. A European study of men between the ages of 40 and 79 found that high levels of vitamin D were associated with high scores on memory tests.

5. Diabetes. Researchers at Warwick Medical School found that adults with the highest blood levels of vitamin D lowered their risk of developing Type 2 diabetes by 55 percent.

6. Asthma. Asthmatics who have high levels of vitamin D have better lung function and respond to treatment better than those who have low levels, according to researchers at National Jewish Health in Denver.

7. Bone health. Vitamin D and calcium reduce the risk of hip fractures in the elderly. Studies show that people who are deficient in vitamin D absorb 65 percent less calcium than those with normal levels. One recent study from the United Kingdom found that 95 percent of patients with hip fractures were deficient in vitamin D, and having adequate levels could reduce hip fractures by up to 50 percent.

8. Depression. University of Toronto researchers found that people who suffer from depression, especially those with seasonal affective disorder, improved as the levels of vitamin D in the blood rose. Researchers in Norway found that high doses of vitamin D helped relieve the symptoms of depression.

9. Multiple sclerosis. Australian scientists discovered that people who live in the state furthest from the equator — and get less sunlight — are seven times more likely to develop multiple sclerosis than those who live in the sunniest state.

10. Colds and flu. Scientists at the University of Colorado found that people with the lowest amounts of vitamin D in their blood had the highest incidence of colds and flu.

11. Rheumatoid arthritis. Researchers from the University of Alabama, Birmingham, found that women with the highest levels of vitamin D in their blood lowered their chances of developing rheumatoid arthritis by 30 percent.

12. Crohn's Disease. Vitamin D switches on genes responsible for fighting Crohn's disease (a chronic inflammatory disease primarily affecting the small and large intestine), according to Canadian researchers. “Our data suggests that vitamin D deficiency can contribute to Crohn's disease,” Dr. John White, endocrinologist at the Research Institute of the McGill University Health Center in Montreal, Canada, said in a statement.

(Source: National Institute of Health UK)

 

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Abdominal Fat in Middle Age Associated with Greater Risk of Dementia

Researchers from Boston University School of Medicine determined that excess abdominal fat places otherwise healthy, middle-aged people at risk for dementia later in life. Preliminary findings suggest a relationship between obesity and dementia that could lead to promising prevention strategies in the future. Results of this study are published early online in Annals of Neurology, a journal of the American Neurological Association.

A 2005 World Health Organization (WHO) report estimated that 24.3 million people have some form of dementia, with 4.6 million new cases annually. Individuals with dementia exhibit a decline in short-term and long-term memory, language processing, problem solving capabilities, and other cognitive function. Clinical diagnosis of dementia is made when two or more brain functions are significantly impaired. Symptoms of dementia can be attributed to irreversible causes such Alzheimer's disease, vascular dementia, and Huntington's disease, or caused by treatable conditions such as brain tumor, medication reaction, or metabolic issues.

For the current study, Sudha Seshadri, M.D. and colleagues recruited participants from the Framingham Heart Study Offspring Cohort. The sample included 733 community participants who had a mean age of 60 years with roughly 70% of the study group comprised of women. Researchers examined the association between Body Mass Index (BMI), waist circumference, waist to hip ratio, CT-based measures of abdominal fat, with MRI measures of total brain volume (TCBV), temporal horn volume (THV), white matter hyperintensity volume (WMHV) and brain infarcts in the middle-aged participants.

“Our results confirm the inverse association of increasing BMI with lower brain volumes in older adults and with younger, middle-aged adults and extends the findings to a much larger study sample,” noted Dr. Seshadri. Prior studies were conducted in cohorts with less than 300 participants and the current study includes over 700 individuals.

“More importantly our data suggests a stronger connection between central obesity, particularly the visceral fat component of abdominal obesity, and risk of dementia and Alzheimer's disease,” Dr. Seshadri added. The research showed the association between VAT and TCBV was most robust and was also independent of BMI and insulin resistance. Researchers did not observe a statistically significant correlation between CT-based abdominal fat measures and THV, WMHV or BI.

“Our findings, while preliminary, provide greater understanding of the mechanisms underlying the link between obesity and dementia,” concluded Dr. Seshadri. “Further studies will add to our knowledge and offer important methods of prevention.”

Source: Stéphanie Debette, Alexa Beiser, Udo Hoffmann, Charles DeCarli, Christopher J. O'Donnell, Joseph M. Massaro, Rhoda Au, Jayandra J. Himali, Philip A. Wolf, Caroline S. Fox, Sudha Seshadri. Visceral Fat is Associated with Lower Brain Volume in Healthy Middle-Aged Adults. Annals of Neurology, 2010

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Omega 3s Show Health Benefits for Non-Fish Eaters

Increased intakes of omega-3 fatty acids may decrease the risk of heart disease and heart attack in people with low fish intakes, says a new study from The Netherlands. Daily intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of about 240 milligrams was associated with a 50 per cent reduction in the risk of coronary heart disease (CHD), compared with intakes of about 40 milligrams, according to findings published in the Journal of Nutrition. Furthermore, the highest average intake of DHA and EPA was associated with a 38 per cent reduction in the heart attack, said researchers from Wageningen University following a study with over 21,000 people with low fish intakes.

The heart health benefits of consuming oily fish, and the omega-3 fatty acids they contain, are well-documented, being first reported in the early 1970s by Jorn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition. To date, the polyunsaturated fatty acids (PUFAs) have been linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.

Omega-3 fatty acids, most notably DHA and EPA, have been linked to a wide-range of health benefits, including reduced risk of cardiovascular disease (CVD) and certain cancers, good development of a baby during pregnancy, joint health, and improved behaviour and mood.

Study details

Intakes of EPA plus DHA, and fish were assessed in 21,342 people aged between 20 and 65. Fish intakes ranged from 1.1 to 17.3 grams per day. Over the course of an average of 11.3 years, the researchers documented 647 deaths, of which 82 were linked to coronary heart disease, with 64 of these being heart attack.

According to the results, the highest average intake of EPA plus DHA (234 milligrams per day) was associated with a 51 per cent reduction in the risk of fatal CHD, compared to the lowest average intake (40 mg per day).

“In conclusion, in populations with a low fish consumption, EPA+DHA and fish may lower fatal CHD and [heart attack] risk in a dose-responsive manner,” wrote the researchers.

Source: Journal of Nutrition
“Marine (n-3) Fatty Acids, Fish Consumption, and the 10-Year Risk of Fatal and Nonfatal Coronary Heart Disease in a Large Population of Dutch Adults with a Low Fish Intake”
Authors: J. de Goede, J.M. Geleijnse, J.M. A. Boer, D. Kromhout, W. M.M. Verschuren

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Vegetarians face increased risk of eating disorders

While vegetarians tend to eat healthier diets and are less likely than non-vegetarians to be overweight or obese, they may be at increased risk for binge eating with loss of control, and former vegetarians may be at increased risk for extreme unhealthful weight-control behaviors, according to researchers at University of Minnesota, University of Texas and St. John's University.

The researchers analyzed vegetarianism, weight, dietary intake and weight-control behaviors data from a population-based study in Minnesota of more than 2,500 males and females between 15 and 23. They found vegetarians ate healthier diets than non-vegetarians when it came to fruits, vegetables and fat intake. Among young adults, current vegetarians were less likely to be overweight or obese.

However, adolescent and young adult vegetarians were also more likely to report binge eating with loss of control compared to non-vegetarians. Among adolescents, former vegetarians were more likely to engage in extreme unhealthful weight-control behaviors. And among young adults, former vegetarians were more likely to engage in extreme unhealthful weight-control behaviors than people who either were currently vegetarians or had never followed a vegetarian eating plan.

Examples of extreme unhealthful weight-control behaviors included “took diet pills,” “made myself vomit,” “used laxatives” and “used diuretics.”

The researchers conclude: “Adolescent and young adult vegetarians may experience the health benefits associated with increased fruit and vegetable intake and young adults attain the added benefit of decreased risk for overweight and obesity. However, vegetarians may be at increased risk for disordered eating behaviors, such as binge eating and unhealthful weight-control behaviors.

“Study results indicate that it would be beneficial for clinicians to ask adolescents and young adults about their current and former vegetarian status when assessing risk for disordered eating behaviors. Furthermore, when guiding adolescent and young adult vegetarians in proper nutrition and meal planning it may also be important to investigate an individual's motives for choosing a vegetarian diet.”

Source: Journal of the American Dietetic Association

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Calcium may help you live longer

All had reported on their diet at the beginning of the study. During follow-up, about 2,358 died.

The top calcium consumers had a 25 percent lower risk of dying from any cause and a 23 percent lower risk of dying from heart disease during follow-up relative to men that had the least amount of calcium in their diet. Calcium intake didn't significantly influence the risk of dying from cancer.

Men in the top third based on their calcium intake were getting nearly 2,000 milligrams a day, on average, compared to about 1,000 milligrams for men in the bottom third. The US Recommended Dietary Allowance (RDA) for calcium intake is 1,000 milligrams for men 19 to 50 years old and 1,200 milligrams for men 50 and over. “Intake of calcium above that recommended daily may reduce all-cause mortality,” Kaluza and her colleagues conclude.

Calcium could influence mortality risk in many ways, they note, for example by reducing blood pressure, cholesterol, or blood sugar levels. For the men in the study, the main sources of calcium in the diet were milk and milk products and cereal products. In contrast to calcium, there was no relationship between magnesium consumption and overall mortality or deaths from cancer or heart disease. Study participants' intakes ranged from around 400 milligrams per day to around 525 milligrams; the RDA for magnesium is 420 milligrams for men 31 and older.

This analysis, the researchers say, may have found no effect for magnesium because all of the men in the study seemed to be getting enough of the mineral in their diet. “Further studies are needed in other populations with lower dietary magnesium intakes to address this issue,” they say. Future research should also look into calcium and magnesium intake from drinking water, they add, which can be a significant source of these minerals.

SOURCE: American Journal of Epidemiology

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Blackcurrants show anti-asthma potential

Study details

Led by Dr Roger Hurst, the New Zealand-based researchers examined the effects of the anthocyanidin-rich blackcurrant extract on cells from lung tissue. The researchers focussed on a compound called eotaxin-3 or CCL26, which is expressed in the lungs after stimulation of the cells by cytokine interleukin-4 (IL-4). According to their findings, epigallocatechin (EGC) worked in conjunction with other natural immune responses to suppress CCl26 expression, and therefore inflammation. Furthermore, these actions were distinct from the inflammation-reducing activity of anthocycanins, said the researchers.

“The bioavailability of plant-derived phytochemicals, although not the focus of this particular study, is an important consideration in the design of a functional food,” wrote Dr Hurst and his co-workers. “In particular, blackcurrant- derived proanthocyanidins mainly (480 per cent) consist of high molecular weight polymers, however, recent findings show that these large proanthocyanidins can be broken down by chemical, enzymatic and/or resident microflora in various regions of the digestive tract to release small oligomers and monomers that are easily absorbed, such as EGC and epicatechin. “Therefore, it is feasible that blackcurrant metabolites, such as EGC, may be able to modulate eotaxin expression in lung tissue,” they added.

Plant & Food Research's Dr Roger Hellens, Genomics Science Group Leader, will be presenting at the upcoming NutraIngredients Antioxidants 2010 Conference in Brussels on the subject of super Vegetables. 

Source: Molecular Nutrition and Food Research
“Blackcurrant proanthocyanidins augment IFN-gamma-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells”
Authors: S.M. Hurst, T.K. McGhie, J.M. Cooney, D.J. Jensen, E.M. Gould, K.A. Lyall, R.D. Hurst

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Vitamin K tied to lower cancer risk

In the current study, vitamin K2 — which study participants most frequently got through cheese — was linked to the odds of developing or dying from cancer, whereas vitamin K1 was not.

The findings are based on data from 24,340 German adults who were between the ages of 35 and 64, and cancer-free at the outset. The researchers estimated the participants' usual vitamin K intake based on a detailed dietary questionnaire. Over the next decade, 1,755 participants were diagnosed with colon, breast, prostate or lung cancers, of whom 458 died during the study period.

In general, the researchers found, the one quarter with the highest intakes of vitamin K2 were 28 percent less likely to have died of any one of the cancers than the one-quarter of men and women with the lowest intakes of the vitamin. That was with factors like age, weight, exercise habits, smoking and consumption of certain other nutrients, like fiber and calcium, taken into account.

Of the one-quarter of study participants who got the least vitamin K2, 156 — or 2.6 percent — died of one of the four cancers. That was true of 1.6 percent of participants with the highest intakes of the vitamin from food.

When Linseisin's team looked at the cancer types individually, there was no clear link between either form of vitamin K and breast cancer or colon cancer. However, greater consumption of vitamin K2 was linked to lower risks of developing or dying from lung cancer — a disease for which smoking is the major risk factor — or of developing prostate cancer.

Of the one-quarter of study participants with the lowest vitamin K2 intakes, 47 — or 0.8 percent — developed lung cancer, versus 0.4 percent of the one-quarter who got the most vitamin K2 in their diets. When it came to prostate cancer, there were 111 cases among the one-quarter of men with the lowest vitamin K2 intakes, and 65 cases in the group with the highest consumption.

In theory, vitamin K itself could offer some protection against cancer. It's often used to counteract too-high doses of blood thinners, although this does not have an obvious link to cancer. In lab research, however, Linseisin and his colleagues point out, the vitamin has been shown to inhibit cancer cell growth and promote apoptosis — a process by which abnormal cells kill themselves off.

But whether vitamin K intake itself is responsible for the lower cancer risks in this study is unclear, according to the researchers. One limitation is that they estimated vitamin K intake based on participants' reported eating habits; most of their vitamin K came from eating cheese, and it's possible, Linseisin and his colleagues note, that some other components of that food are related to cancer risk.

Future studies, the researchers say, should measure people's blood levels of vitamin K and look at the relationship of those levels with cancer risks.

SOURCE: American Journal of Clinical Nutrition

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