News Briefs – September 2015
A HIGH-FIBRE DIET DURING PREGNANCY MAY REDUCE THE RISK OF THE BABY EVENTUALLY DEVELOPING ASTHMA
High-Fibre Diet in Pregnancy Cuts Risk of Childhood Asthma
Scientists have concluded that women who consume a high-fibre diet during pregnancy may be reducing the risk of their baby eventually developing asthma. This suggests a high-fibre diet alters the gut bacteria during pregnancy, producing anti-inflammatory substances that suppress asthma-related genes in offspring. (Previously, researchers found that mice fed a high-fibre diet had reduced reactions to asthma-inducing allergens, compared with mice fed a low-fibre diet.)
In the first phase, the researchers found that offspring of mice whose mothers were fed a high-fibre diet during pregnancy did not develop asthma-like symptoms, while the offspring whose mothers were fed a low-fibre diet did. The pregnant, high-fibre mice also experienced changes in gut bacteria, resulting in microbes that produced anti-inflammatory metabolites when the fibre was digested. These metabolites circulated in the bloodstream and traveled through the uterus to the fetus, suppressing (Foxp3) genes linked to asthma development.
Next, the team tested on humans. They analyzed blood samples and diet data of 40 pregnant women, as well as data detailing the frequency of doctor visits due to respiratory symptoms in their offspring during the first year of life. Women who consumed a high-fibre diet during pregnancy had anti-inflammatory metabolites in their blood, and their offspring were significantly less likely to have visited the doctor two or more times as a result of respiratory complaints in their first year of life.
This study was published June 23, 2015 in the journal Nature Communications. The abstract is free at https://tinyurl.com/ol9g32j, where the full report is also available for a fee.
Zinc Found to Play Role in Regulating Heartbeat
Describing it as a paradigm shift in our understanding of how the heart works, scientists have now discovered that zinc plays an important role in regulating heartbeat. Although more work needs to be done to fully understand the process, zinc apparently affects heartbeat rhythm through its regulation of calcium movements in heart cells. This new information may support improved therapies to fight or help prevent heart failure. This discovery suggests that tight regulation of this metal is crucial to maintaining heart muscle contractility. Zinc plays a key role in controlling the release of calcium from intracellular stores by modulating important calcium channels (known as RyR2 channels).
This is important, because excessive release of calcium is a major cause of heart failure and fatal arrhythmias. Very small and precise shifts in zinc, neither too much nor too little, affect chronic heart failure and these findings appear to explain why. Much more research is required, but understanding heart failure may be that much closer.
This study was published July 10, 2015 in the Journal of Biological Chemistry. The full report can now be downloaded at https://tinyurl.com/opxo38d for a fee.
Landmark Study: Intestinal Problems May Be Origin of Parkinson’s
The finding of a new study strongly suggests the novel possibility that Parkinson’s disease (PD) may originate in the gastrointestinal tract and not in the brain. The route travelled by this neurological disease may be from the gut, triggered by intestinal factors of some sort, through the vagus nerve to the brain, where the typical symptoms begin. If further research confirms this, it could open up a whole new avenue of investigation for both a cure and prevention. (Results show that PD appears to follow longstanding constipation problems. It is conceivable that the originating gut issues are disturbed intestinal bacteria makeup, inadequate dietary fiber, or some other digestive problem. However, this type of study cannot assess the underlying cause. PD affects one out of every 1,000 people.)
Scientists noted that most patients also suffered from gastrointestinal symptoms, primarily constipation, for many years prior to being diagnosed with PD. This suggested that gastroenterological problems were an early marker for neurological disease and the vagus nerve may be involved. So the team tracked over 15,000 patients who had undergone a procedure to have their vagus nerve severed (commonly done between 1970 and 1995 to treat ulcers) and found that these people were half as likely to develop PD over the next 20-year period, compared to people who had never had this procedure. Further weight was provided by the fact that patients who had only a small part of the vagus nerve severed were not protected from PD.
This study was posted online on June 24, 2015 before being published in a future issue of the journal Annals of Neurology. A free summary is available at https://tinyurl.com/nf4zctp and access to full study details is available for a $6 fee.
Order in Which Foods Are Eaten Affects Blood Sugar Levels
A new study shows that eating the different foods in a meal in a specific order significantly impacts glucose and insulin levels, potentially helping diabetics or individuals at high risk for diabetes. (This points to a new way to effectively control post-meal glucose levels in diabetic patients and those at risk. Instead of avoiding certain foods totally, patients may be better off simply changing the order in which they eat them.)
Investigators looked at a whole, typically Western meal, with a good mix of vegetables, protein, carbohydrates and fat. The study enlisted patients who had obesity and Type 2 diabetes and who took an oral drug, called Metformin, to control blood sugar. Patients ate a meal of carbohydrates (ciabatta bread and orange juice), as well as protein, vegetables, and fat (chicken breast, lettuce and tomato salad with low-fat dressing, and steamed broccoli with butter) twice, one week apart. Subjects ate carbohydrates first, followed 15 minutes later by the protein, vegetables and fat. Afterwards, researchers checked glucose levels at 30, 60, and 120-minute intervals.
A week later, participants ate the same meal, but with the order reversed: protein, vegetables and fat first, followed 15 minutes later by carbs. Glucose levels were again collected. When vegetables and protein were eaten first, glucose levels were much lower at the 30, 60 and 120 minute checks, by 29, 37, and 17% respectively. Insulin was lower too.
This study was published in the July 2015 issue of Diabetes Care. The full study can now be accessed at https://tinyurl.com/nzval8f free of charge.
Antidepressants May Boost Risk of Bone Fractures
A very large data review has concluded that a popular class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs), which are often prescribed for non-psychiatric problems such as menopausal symptoms, may increase the risk of bone fractures in middle-aged women. The massive analysis scoured a database containing detailed information on over 61 million patients in more than 98 managed care plans in the U.S. The results showed that the heightened fracture risk from SSRIs seems to last for several years. (SSRIs have become the third most frequently prescribed class of drug in the U.S. They are used as an alternative tohormone replacement therapy for hot flashes and night sweats typically associated with menopause.)
The fracture rate among SSRI-users (compared to women taking only digestion drugs) was 76% higher one year after starting treatment, decreasing only to 67% higher fracture risk after five years. The study authors suggested that this effect may be partially attributed to antidepressant-induced alteration of bone turnover, shifting the balance from bone-strengthening to bone-thinning.
This study was released online first, on June 25, 2015, ahead of publication in a later issue of the journal Injury Prevention. The full study can be accessed online at https://tinyurl.com/oscjl5h free of charge.
Tree Nuts May Lower Cardiovascular Risk Factors and Weight
A new study has found that consumption of tree nuts is significantly associated with reduced weight and waist size and with improved risk factors for cardiovascular disease and metabolic syndrome. (Metabolic syndrome is a collection of factors that boost the risk of both diabetes and cardiovascular disease. Tree nuts are the group that includes almonds, Brazil nuts, cashews, filberts (which are also called hazelnuts), macadamias, pecans, pine nuts, pistachios, and walnuts. In addition to polyunsaturated fatty acids, tree nuts contain phenols, phytosterols, flavonoids, resveratrol, and other bioactive compounds. Previous research found that tree nut consumption was linked to lower risk of death due to heart disease.)
Data were analyzed for adults aged 19 or over. Those who were regular consumers of tree nuts, compared to non-consumers of tree nuts, were found to have a lower body-mass index, 21% smaller waist circumference, lower systolic blood pressure (the upper number in a blood pressure reading), and less insulin resistance. Tree nut consumers were also 25% less likely to be obese or overweight. These differences translate to an improvement in factors relating to cardiovascular disease and metabolic syndrome among those regularly consuming these nuts.
This study was published June 28, 2015 in Nutrition Journal. The full report can be read online at https://tinyurl.com/pca6tmm free of charge.
Olive Leaf Extract Lowers Cardiovascular Risk Factors
A human trial has shown that olive leaf extract (OLE) is associated with positive short-term changes in measures associated with cardiovascular health and function. Remarkably, a single dose of OLE resulted in improvements in blood vessel function and a lower inflammatory marker in the blood, compared to placebo. This effect was associated with the absorption of active phenolic components from the extract. These included hydroxytyrosol and oleuropein. (High levels of pro-inflammatory markers measured in this study and poor blood vessel function are key contributors to the deterioration of cardiovascular health, the number one cause of death globally.)
This was a two-day study showing immediate impact, but longer-term studies are needed to make firm conclusions. A longer and larger study of OLE targeting cardiovascular health has been conducted with publication expected later in 2015. This study has been posted at https://tinyurl.com/pws6unh and will soon be published in an issue of the British Journal of Nutrition. You can read the full report online for a fee.
Orange Juice May Boost Risk of Deadly Skin Cancer
Researchers have found a link between consumption of orange juice or whole grapefruit and greater risk of developing melanoma, the most deadly form of skin cancer. In this study of over 100,000 adult health professionals, researchers analyzed the personal data of participants and had them answer detailed surveys on their health and lifestyle. Over 25 years, more than 1,800 people developed melanoma, and the risk of melanoma was higher among those who regularly drank orange juice or ate whole grapefruit. People who had orange juice at least once a day were about 25% more likely to develop melanoma than those who drank the juice less than weekly. Similarly, people who ate whole grapefruit at least three times a week had a 41% higher melanoma risk, versus those who never ate it. This association remained valid, even when other factors were taken into account, such as overall sun exposure and history of bad sunburns.
The findings alone do not prove that citrus foods cause skin cancer, but suggest that citrus compounds increase ultraviolet light damage. The explanation may lie in the fact that citrus foods contain particular photoactive chemicals known as psoralens and furocoumarins, which make the skin more sensitive to the sun when applied topically. This research suggests the effect may also occur after consumption. The report stressed that citrus consumption itself is not harmful; it is the subsequent exposure to sunlight that appears to cause skin cancer. In other words, the citrus cannot hurt you without the excessive sun exposure, against which experts have long warned. The report recommended that people continue to consume citrus fruits for their health benefits.
This study was posted online at https://tinyurl.com/ohyfw6v on June 29, 2015 by the Journal of Clinical Oncology. The journal will publish the research in a future issue. Meanwhile, the full report can be read online for a fee.
Garlic Extract Effective Against Drug-Resistant UTI Bacteria
Scientists have found that garlic extract may be an effective weapon against multi-drug resistant strains of disease-causing bacteria associated with urinary tract infections (UTI) in cases where antibiotic therapy had limited effect. This provides new hope of developing new treatments that will sidestep the growing problem of antibacterial resistance. (Urinary tract infection is the second most common infectious disease encountered in community practice. Worldwide, about 150 million people are diagnosed each year with UTI, at a total treatment cost in the billions of dollars. Although UTI is usually treated with antibiotics, emerging antimicrobial resistance makes it necessary to find new solutions.)
In this study, the team found that 56% of 166 bacteria strains isolated from the urine of people with UTI showed a high degree of resistance to antibiotics. However, about 82% of the antibiotic-resistant bacteria were susceptible to a crude extract of garlic, also known as Allium sativum. This is the first study to report the antibacterial activity of aqueous garlic extract against multidrug-resistant bacteria from infected urine samples.
This study was recently published in the Pertanika Journal of Tropical Agricultural Science. The full study can be read online now at https://tinyurl.com/ozth54x free of charge.
Leisure-Time Sitting Linked to Higher Risk of Specific Cancers
New research has found that spending more leisure time sitting down is associated with a higher risk in women of cancer generally and of multiple myeloma, breast, and ovarian cancers. These higher risks were present even after taking into account body-mass index (BMI), physical activity, and other factors. The study found no association between sitting time and cancer risk in men, although this may be detected by further research. (While extensive research links physical activity to cancer prevention, very little research has examined the link between sitting time and the risk of specific cancers. Over the past few decades, time spent sitting has increased due to technological advancements, video games, and changes in transportation.)
Investigators compared leisure-time sitting to cancer risk among 69,260 men and 77,462 women who were cancer-free. They found longer leisure-time spent sitting was associated, in women, with a 10% higher risk of cancer, a 65% higher risk of multiple myeloma, a 43% higher risk of ovarian cancer, and a 10% higher risk of breast cancer. Further study is needed to determine whether longer leisure-time sitting affects men differently than women.
This study was released online before being published in a future edition of the journal Cancer Epidemiology, Biomarkers and Prevention. The full study can be downloaded at https://tinyurl.com/ootjxyw for a fee.
Greater Exercise Boosts Brain Function in Older Adults
A study funded by the U.S. National Institute on Aging has concluded that older adults can improve their focus, attention, and visual-spatial processing by raising the duration and especially, the intensity, of their exercise. The six-month trial was conducted with healthy adults aged 65 and older who showed no signs of cognitive decline. This study was an attempt to determine the ideal amount of exercise required to achieve potential brain benefits. Participants were placed into one of four groups: one that moderately exercised for the recommended 150 minutes weekly; a second that exercised for just 75 minutes weekly; a third group that exercised for 225 minutes weekly; and a control group that did not have monitored exercise. All groups that exercised received some brain benefit, and those who exercised more saw more benefits, particularly in improved visual-spatial processing (the ability to perceive where objects are in space and how far apart they are from each other). The exercising groups also showed an increase in overall attention levels and ability to focus.
As for ideal duration, the more exercise received, the more brain benefit achieved. However, the scientific team found that the intensity of the exercise appeared to matter more than the duration. To achieve maximum cognitive benefits, it is not enough simply to exercise more; it has to be done in a way that increases fitness.
The results of the current study were published July 9, 2015 in the journal PLoS ONE. The full report is available at https://tinyurl.com/nfaksyw free of charge.
Trees Lining Streets May Promote Better Health
A new study has found that having a total of ten more trees per city block, on average, improves health perception in ways comparable to being seven years younger. The researchers focused on the large urban population of Toronto. They related the domains of green space and health by combining high-resolution satellite imagery and individual tree data with 31,000 questionnaire-based self-reports of general health perception, cardio-metabolic conditions (such as heart disease or diabetes) and mental illnesses from the Ontario Health Study. Green space was defined as a tree canopy only and not urban grass or bushes. People who lived in neighborhoods with a higher density of trees on their streets reported a significantly higher perception of their own health and significantly fewer cardio-metabolic conditions.
The researchers controlled the results for demographic factors, such as income, age and education. Specifically, having ten more trees in a city block substantially boosted health perception. And eleven more trees boosted health perception equivalent to being 1.4 years younger. Studies like this cannot prove cause and effect, but the team recommended that every block plant ten more trees. The potential connection might be better air quality, more stress relief, or indirect promotion of physical activity.
This study was published online July 9, 2015 by the journal Scientific Reports. The report has now been made available online at https://tinyurl.com/opalsz3 without charge.
Sweetened Beverages Boost Risk of Developing Diabetes
A new study has found that consuming large amounts of sugar-sweetened soda drinks or other sweetened drinks raises the risk of developing Type 2 diabetes. Until now, health experts have thought that sugary drinks and diabetes were linked due to the fact that sugar promotes weight gain, and body fat contributes to insulin resistance, which precedes diabetes. But this new study removed weight as a factor, and still found that, over 10 years, every daily serving of sugar-sweetened beverages increases the risk of Type 2 diabetes by 13%. So, discounting weight, the risk of acquiring diabetes over the next decade may increase by over 50% for those who drink four sugar-sweetened beverages daily. When increased weight is considered, however, the risk of diabetes for those consuming sugary beverages is even higher, about 18% higher over a decade per daily drink instead of 13%. (A 12-ounce, or 355 ml, can of cola contains 39 grams of sugar, the equivalent of 9.75 teaspoons of sugar.) Sudden intake of large amounts of sugar causes a spike in blood sugar, which over time can increase insulin resistance even in people who are at normal weight.
These conclusions are based on data from 17 previous observational studies, which researchers combined to create a pool of just over 38,200 people. Because these were not clinical trials, the findings cannot be read as proving a direct link between sugar-sweetened drinks and Type 2 diabetes. Still, one in five people with Type 2 diabetes has a healthy weight, and these findings could help explain why. Another theory holds that high levels of dietary sugar could affect the healthful microbial colonies in the gut, altering digestion in some way that increases risk of diabetes. The researchers said that they are not able to recommend diet drinks or even natural fruit juices as healthier options than sugar-sweetened sodas.
This study was published online by the journal BMJ on July 21, 2015. The entire study can now be read online at https://tinyurl.com/o4brcd6 without charge.
