News Briefs – March 2011

MEDITERRANEAN DIET LOWERS DIABETES RISK

A study has determined that either of two different versions of the Mediterranean diet (MedDiet) results in a reduced risk of Type 2 diabetes among those at high risk of cardiovascular disease, compared to a low-fat diet. Researchers divided at-risk patients into three groups: those given an education in low-fat diets; those placed on a Mediterranean diet with high virgin olive oil content; and those given a Mediterranean diet with high nut content. Participants were not limited in their calorie intake and there were no significant changes in body shape or weight. After four years, the team found the incidence of Type 2 diabetes was 52% lower among the MedDiet with nuts group, and 51% lower among the MedDiet with olive oil group, compared to the low-fat diet group. The amounts of virgin olive oil, or nuts, in the MedDiets were significant: one litre per week, and 30 grams a day, respectively. The team concluded that increased adherence to a MedDiet produces a reduced risk of Type 2 diabetes in patients at high cardiovascular risk. The January 1, 2011 issue of Diabetes Care published this study, which is available online at https://bit.ly/gvRCUa

DASH DIET LOWERS CARDIOVASCULAR RISK AMONG DIABETICS

A study has shown that Type 2 diabetic patients who follow the DASH diet reduce a host of cardiovascular risk factors. (DASH – Dietary Approaches to Stop Hypertension – is an eating plan designed to combat high blood pressure and involves low salt intake, high consumption of fruits and vegetables, and low-fat or no-fat dairy; it has been shown to reduce high blood pressure within 14 days.) Researchers measured the specific effects of the DASH diet on 31 Type 2 diabetics and found that various metabolic risk factors were altered significantly. In just eight weeks, participants had lower body weights; smaller waist circumferences; lower fasting blood glucose levels; higher HDL (good) cholesterol levels; lower LDL (bad) cholesterol readings; lower systolic (upper) blood pressure readings; and reduced diastolic (lower) blood pressure scores. The journal, Diabetes Care, published this study in its January 1, 2011 issue and it can be read online now at https://bit.ly/g8Se2g with journal subscription.

TRANS FAT-FREE LABELS HIDE HARMFUL AMOUNTS

A study has found substantial amounts of trans fat in many foods labeled trans fat-free. The researchers suggested that the government labelling protocol deceives many consumers who unknowingly exceed the healthy recommended intake of 1.11 grams a day. (Trans fats, even when consumed in small quantities, increase the risks of coronary artery disease, sudden cardiac death and diabetes.) Current FDA regulation requires that fat contents of more than five grams be listed in one gram increments; contents under five grams be listed in 0.5 gram increments; and amounts under 0.5 grams be listed as zero grams of fat. However, zero-fat-labeled foods contain up to 0.49 grams of trans fat. Consumption of just three such food items would total 1.47 grams of trans fat, which is considered a medically harmful daily quantity. While these amounts seem small, research shows that raising daily trans fat consumption from 0.9 to 2.1% will increase the risk of cardiovascular disease by 30%. This study was published in the January/February 2011 issue of the American Journal of Health Promotion.

ALL-NATURAL LABELS

Labels boasting “all-natural” are relatively meaningless and foods carrying such labels may be harmful to your health. To be all-natural, products must be free of artificial colours and ingredients and be minimally processed. But because there are no standards, legal or otherwise, that define “minimally processed,” the all-natural label has no real nutritional meaning. In fact, the term “all-natural” can include mercury, lead or arsenic, all of which are naturally occurring elements.

DIETARY FAT LINKED TO BREAST CANCER

Researchers have found that the elevated levels of dietary fat and cholesterol found in the typical Western diet may contribute to the growth and spread of breast cancer. Similar studies of humans have produced contradictory results, prompting this team to study the relationship between cancer, fat and cholesterol in mice with a predisposition towards developing mammary tumours. The development of breast cancer in mice is considered to be similar in many ways to human breast cancer. Mirroring the human Western diet, the study mice received a diet containing 21.2% fat and 0.2% cholesterol while the control group ate a diet of 4.5% fat and negligible cholesterol. Compared to the control group, the mice fed the typical, Western, high-fat, high-cholesterol diet developed twice as many breast cancer tumours and they were 50% larger, faster-growing and more easily metastasized. Since blood cholesterol dropped substantially in mice with breast tumours, the researchers suggested that measuring blood cholesterol may be an effective means of screening for cancer development. Published in the January, 2011 issue of the American Journal of Pathology, this study is available online now at https://bit.ly/f7SZel

DHA MAY PROTECT AGAINST BRAIN INJURY

Although results are preliminary, a study published in February suggests traumatic brain injury (TBI) might be reduced by pre-treating at-risk individuals, such as military personnel and contact-sport athletes, with docosahexanoic acid (DHA), an omega-3 fatty acid. (TBI is brain damage from a violent blow to the head that launches the brain against the skull, often causing brain bruising, tearing of nerve fibers, and bleeding. According to the CDC, one-third of all injury-related deaths in the US are linked to TBI. So far, science has found no effective way to prevent serious outcomes. The main fatty acid found in the brain, DHA may play several roles protecting the brain.) Researchers induced TBI in rats after 30 days of DHA supplementation in dosages of 3, 12, and 40 mg per kilogram of body weight. Highest-dosage rats experienced less tissue damage, less brain cell death, and reduced memory loss, indicating less behavioural impairment. (Another noteworthy finding was reduced expression of beta amyloid protein – a protein linked to the development of Alzheimer’s disease.) This study will appear in the Feb. 2011 issue of Neurosurgery.

LIVING NEAR BUSY ROADWAYS INCREASES RISKS OF ALLERGIES, ASTHMA

A study conducted by an international team of lung experts has found that living immediately next to a busy roadway increases the risk of developing allergies by 30% and raises the risk of acquiring asthma by 100%. The allergies linked to traffic-related pollution included allergies to dust mites, pet hairs and mould. The risks of developing asthma or allergies were increased most nearest to roads where a steady stream of traffic flowed down several lanes unimpeded all day long. Although previous studies have linked traffic pollution to self-reported asthma symptoms, this is the first study known to establish a connection between traffic pollution and the actual origins of asthma. People who do not outgrow their asthma by their early teens are twice as likely to remain asthmatic throughout adulthood. The study included home visits to measure environmental pollutants and lung function. The team plans to study the biological effect of specific traffic pollutants. This study was released January 18, 2011 but will not appear in print until a future issue of the Journal of Allergy and Clinical Immunology.

VITAMIN E SUPPLEMENTS REDUCE RISK OF COPD

Researchers have found that supplementation with 600 international units (IU) every second day is associated with a 10% lower risk of developing chronic obstructive pulmonary disease (COPD), at least in women. Previous observational studies reported links between higher levels of antioxidants and a lower risk of COPD, leading to this randomized, ten-year study on women only, of supplementation with one of the antioxidant vitamins, vitamin E. This benefit was not reduced or increased by a number of other factors: age, multivitamin use, the taking of 100 mg of aspirin every second day, dietary vitamin E intake, or smoking of cigarettes. Smoking was found to be a strong predictor of COPD. An important aspect of these results is that the reduction in COPD risk was observed with vitamin E supplementation, but not with vitamin E intake from diet. This study was released January 21, 2011, but will not be published until a future issue of the journal Thorax.

LOW VITAMIN D IN PREGNANCY AFFECTS CHILDREN’S INSULIN RESISTANCE

A study has found that low blood levels of vitamin D during pregnancy may result in less muscle mass and higher insulin resistance in children. (An effect on musculoskeletal development had long been suspected but metabolic effect was not known.) Researchers measured vitamin D status at the 28 – 32 week period of pregnancy. Later, they examined various blood, insulin and strength factors in the children born to these mothers at the ages of five and 9.5 years. At both ages measured, children born to mothers who had shown a distinct vitamin D deficiency had smaller arm-muscle area. Also, at 9.5 years of age, children of D-deficient mothers showed higher fasting insulin resistance. (In insulin-resistant individuals, the hormone insulin becomes less effective at lowering blood sugars and raises the risk of diabetes and early heart disease.) The American Journal of Clinical Nutrition released this study on January 12, 2011; it will be published in a future issue.

35% OF AMERICANS HAVE PREDIABETES

A newly released, statistical analysis by the Centers for Disease Control (CDC) has found that 26 million Americans now have diabetes and an estimated 79 million have prediabetes. This means that, among Americans aged 20 and over, 35% have prediabetes. Further, the CDC reports that an estimated 27% of all those with full-blown diabetes do not know they have the disease and therefore, are not being treated. (Diabetes involves the gradual loss of ability to use and produce insulin. Risk factors include lack of exercise, obesity, older age, family history and race or ethnicity.) The CDC cautioned against direct comparisons with previous years’ figures because new diagnostic methods are adding more people to the list of those afflicted and better treatments are resulting in patients living longer with diabetes. However, in 2008, the CDC reported that 23.6 million Americans had prediabetes (26 million now) or 7.8% of the population (8% now). In a study published last year, the CDC projected that one third of the U.S. population could have diabetes by 2050. The report was released January 26, 2011.

SHORT BREAKS FROM SITTING BENEFIT HEART

A study has concluded that it is not merely the length of time spent sitting that increases risk factors for heart disease, but also the number of short breaks taken from sitting. Even one-minute breaks proved beneficial. Prolonged periods spent sitting worsened indicators of cardio-metabolic function and inflammation, such as larger waist circumferences, lower levels of HDL (good) cholesterol, higher levels of C-reactive protein (indicating inflammation), and higher triglycerides. However, those who took more breaks during these sedentary periods had smaller waistlines and lower C-reactive protein (inflammation) levels. Researchers stressed that it is not simply the lack of exercise that negatively affects health; it is also the amount of time spent actually sitting during non-exercise periods; and it is the number of brief breaks from sitting that helps reduce the negative effects of being sedentary. The study team recommended that, to significantly reduce heart-related risks, people break up sitting times, stand up once in a while, take phone calls standing up, or walk over to fellow workers rather than emailing. The European Heart Journal published this study in its January 12, 2011 issue. It is available online now at https://bit.ly/hTOktD with subscription or payment.

BLUEBERRIES REDUCE RISK OF HIGH BLOOD PRESSURE

A study has found that a compound in blueberries and strawberries lowers the risk of hypertension (high blood pressure). Thanks to the anthocyanins (a flavonoid) in blueberries, researchers found, those eating at least one serving a week reduced their risk of developing the condition by 10 percent, compared with those who rarely or never eat blueberries. Those consuming strawberries weekly showed an eight percent lower risk. Over 14 years, researchers studied 134,000 women and 47,000 men who did not have hypertension at the start of the study, assessing their health every two years and their diets every four. Newly diagnosed cases of high blood pressure were analyzed in relation to the dietary intake of anthocyanins and the reduced risk was found. The study team concluded that an anthocyanin intake level that is achievable by diet alone could serve to prevent this condition, which leads to stroke and heart disease. The team suggested raspberries, aubergines and blood orange juice as equivalent alternatives. This study was released recently but will not appear in print until the February, 2011 issue of the American Journal of Clinical Nutrition. It is online now at https://bit.ly/ft6gVu with subscription or fee.

BIRCH BARK INGREDIENT HAS STRONG METABOLIC BENEFITS

A component in the bark of birch trees may lower cholesterol, suppress diet-induced obesity, improve insulin sensitivity and slow the development of atherosclerosis (hardening of the arteries), according to a new study. Although the research was conducted on mice, the benefits would be substantial if further work finds the effects hold for humans. For example, betulin decreased cholesterol in the liver, blood and fat to a greater extent than lovastatin, a widely prescribed drug class for treating high cholesterol. The birch ingredient also made the mice more sensitive to insulin, which may help prevent diabetes; caused them to burn more calories and lose weight; and reduced plaque build-up in the arteries. Betulin works by altering the expression of genes involved in the biosynthesis of cholesterol, triglycerides and fatty acids. Although not sold as a supplement, betulin appears to have low toxicity and is a readily available compound, already in use as a precursor in the manufacture of some drugs. This study was published in the January 5, 2011 issue of the journal, Cell Metabolism. The full study is available online now at https://bit.ly/hYelkF without charge.

HIGHER MORTALITY RISK FROM DEPRESSION AND DIABETES TOGETHER

Both clinical depression and type 2 diabetes are, separately, risk factors for cardiovascular death and all-cause mortality. But a study has determined that the coexistence of serious depression and diabetes 2 poses an even greater risk of death – both from cardiovascular disease and from all other causes – than the combination of the separate risks of each condition alone. The research included information on 78,282 women aged 54 to 79, with a six-year follow-up period and made adjustments to exclude the effects of alcohol consumption, body mass index (BMI), physical activity, age, existing heart disease, and other factors. To be considered depressed, subjects had to report feeling depressed, be taking antidepressants, and show a score on the Mental Health Index indicating severe depression. The risk of death from cardiovascular disease was even greater in cases where the coexistence of depression and diabetes 2 occurred over a longer period. The Archives of General Psychiatry published this study in its January, 2010 issue. It is available online now at https://bit.ly/eSUgdy with subscription or payment of an article access fee.

ROOIBOS TEA REDUCES CARDIOVASCULAR RISK

In South Africa, rooibos or redbush is a plant (Aspalathus linearis), traditionally fermented and consumed like a tea. Despite a medicinal reputation, little data have been available from controlled trials. However, a new study has found that a significant daily intake of rooibos improves the status of various factors relevant to heart disease. Volunteers consumed six cups of traditional, fermented rooibos every day for six weeks, followed by a control period with no rooibos consumption, for comparison. After the rooibos phase, blood markers indicated lower levels of lipid peroxidation. (This is a process in which free radicals damage cells by stealing electrons from the fat in the cell membranes.) Also, the level of one form of glutathione (reduced glutathione) was raised relative to another form of glutathione (the disulfide form), which signifies a reduction in oxidative stress. HDL (good) cholesterol levels were higher and LDL (bad) cholesterol levels were reduced, both significantly. These measurements suggest rooibos reduces factors relevant to developing cardiovascular disease. This study was published in the January 7, 2011 issue of the Journal of Ethnopharmacology. It is available online now at https://bit.ly/fXsjTi with subscription or access fee.

DID YOU KNOW…?

“Low carb,” or “low sodium,” or other front-of-box claims often mislead consumers about a food’s nutritive value. A study by the FDA and the Center for Food Safety and Applied Nutrition found that consumers are less likely to read the standard and comprehensive nutritional panel on the back of a package if there is a prominent health claim on the front. However, health statements on the front, such as low-carb claims, often overshadow the amounts of other ingredients such as sodium or saturated fat, which may be extremely high. For example, pork rinds can be labeled “low carb,” thus disguising their 10 grams of saturated fat per serving.

PEANUT ALLERGIES

Infants born to women who ate peanuts during pregnancy may be at greater risk of developing a peanut allergy. The theory that a mother’s egg, milk or peanut consumption during pregnancy can cause allergies in infants has been controversial. But a recent study of 503 infants found that eating peanuts during pregnancy was a substantial predictor of peanut allergy risk. These results were reported in the November 1, 2011 issue of the Journal of Allergy and Clinical Immunology.

SMALLER BREAKFASTS AID WEIGHT LOSS

People commonly believe that skipping breakfast results in greater calorie consumption later in the day and increased weight gain. However, a study has found that eating smaller breakfasts – or even skipping breakfast altogether – results in an overall reduction in daily calories and improved weight loss. Researchers conducted a 14-day evaluation of breakfast calories and how overall caloric intake was affected each day. They found that those skipping breakfast did not fully compensate for the loss of breakfast calories by increased consumption during the rest of the day; and on days of smaller breakfasts, the overall calorie intake that day was less, resulting in weight loss. The study team concluded that, “overweight and obese subjects should consider the reduction of breakfast calories as a simple option to improve their daily energy balance.” The study was released January 17, 2011 but will not be published until a future issue of Nutrition Journal. It is available online now at https://bit.ly/f0xiYY without fee.

FRAGRANCE ALLERGIES 

People sickened by strong colognes or fragrances may be much more than simply allergic. While those with allergies may be inconvenienced or temporarily ill, people with Multiple Chemical Sensitivity (MCS) or asthma can be at risk of death. MCS is a neurological disease and asthma is thought to be an autoimmune disorder. Sufferers of these disorders can experience serious harm from strong fragrances, including progressive and permanent, organ and brain damage – and yes, even death. Contrary to popular belief, filter masks and oxygen do not prevent most exposures.

CELIAC PATIENTS CAN EAT HYDROLYZED WHEAT FLOUR

Wheat products are generally toxic for celiac disease patients but a new study has concluded that baked goods made from hydrolyzed wheat flour are safe even for these patients and do not produce typical celiac symptoms. (Celiac disease occurs in the digestive system when people cannot tolerate a protein called gluten, which is found primarily in wheat. Gluten is also primarily found in barley and rye, but may be in everyday products such as soy sauce and salad dressing, as well as some medications and vitamins. A hydrolyzed protein is one that has been broken down into its component amino acids, or building blocks.) In this study, doctors evaluated the safety of the daily consumption of baked goods made from a hydrolyzed form of wheat flour by patients with celiac disease. The doctors fermented wheat flour with sourdough lactobacilli and fungal proteases; this process decreases the concentration of gluten. Further study may help provide celiac patients with alternatives to the traditional gluten-free diet. This study appears in the January 2011 issue of the journal, Clinical Gastroenterology and Hepatology. It is available online now at https://bit.ly/dFA4Vr with subscription or fee.

BREASTFEEDING BENEFITS ADULT SURVIVORS OF CHILDHOOD CANCER

Researchers have reported that women who survived childhood cancer may benefit during adulthood, from breastfeeding their infants. (The number of childhood cancer survivors is growing and eighty percent of children and adolescents treated for cancer survive. However, survivors face a number of health challenges, including various effects of both the cancer itself and the treatment.) Breastfeeding appeared to improve bone mineral density, metabolic syndrome risk factors, cardiovascular disease and the risk of secondary tumors, all of which are negatively affected by the treatments for childhood cancer. The scientists advised that – in addition to traditional advice to eat plenty of fruits and vegetables, avoid tobacco smoke, use sun protection, practice sun protection, and get exercise – women who have survived childhood cancer should be encouraged to breastfeed to help protect them from the lasting effects of both the cancer and its treatment. This study was released online on January 20, 2011, but the full study will not be available until a future issue of the Journal of Cancer Survivorship.

MINDFULNESS MEDITATION INCREASES BRAIN REGIONS IN EIGHT WEEKS

A study has found that an eight-week program of mindfulness meditation increases the concentration of grey matter in regions of the brain associated with memory, sense of self, empathy and stress. Researchers found reductions in grey matter in an area linked with stress and anxiety. This is the first study to report meditation-produced changes in the brain’s grey matter. (Previous work showed, in those who meditate, a thickening of the cerebral cortex in areas linked to attention and emotional integration but it could not be determined whether those changes resulted from the meditation.) The new results suggest, according to researchers, that the physical relaxation and sense of peace reported by those who meditate might be caused by structural changes in the brain, and not simply by the immediate benefit of physical relaxation. Magnetic resonance (MR) scans were used on subjects who meditated for an average of 27 minutes daily. This study was released early, but will not appear in print until the January 30, 2011 issue of the journal, Psychiatry Research: Neuroimaging. It is available online now at https://bit.ly/eEDJER without subscription or fee.

MUCUS MYTHS

The notion that green mucus indicates the presence of an infection is false. The relevance of mucus colour is a myth that even many doctors believe, according to Drs. Aaron E. Carroll and Rachel C. Vreeman, coauthors of Don’t Swallow Your Gum, who write, “There is no evidence…that antibiotics shorten the duration of an illness when green snot is a symptom.” (The book’s title refers to the often-heard myth that gum will remain in your stomach for seven years.)

TRAFFIC NOISE INCREASES STROKE RISK

A study has found that exposure to noise from road traffic can increase the risk of stroke, especially among those aged 65 years or older. Researchers studying 51,485 subjects concluded that every ten-decibel increase in noise volume may raise the risk of stroke by 27 percent among those 65 years of age and over. Previous studies have linked traffic noise with higher blood pressure and heart attack risk, but this is the first study to link traffic noise with a greater stroke risk. Epidemiological studies such as this, based on common factors among large populations, cannot prove cause-and-effect; but if this is a causal link, it would mean eight percent of all strokes and 19 per cent of strokes among those aged 65 and over, are attributable to road traffic noise. Traffic noise might be interfering with sleep, acting as a stressor, and elevating stress hormones. The study was released January 26, 2011 but will not appear in print until a future issue of the European Heart Journal. It is available online now at https://bit.ly/hP9XyR without subscription or fee.

DID YOU KNOW…?

Contrary to the often-repeated assertion, men do not think about sex every seven seconds, or anywhere close to it. That is as many times as we breathe everyday. Such frequent thinking about anything would be exhausting. In one of the most comprehensive surveys about sexual habits in the United States, conducted by Edward Laumann and colleagues in 1994, 43 per cent of men reported thinking about sex anywhere from a couple times a week, to a couple times a month.

HIGH-FAT DIET HARMS HEART AND COGNITIVE FUNCTION

A study has concluded that the popular high-fat, low-carbohydrate (HFLC) diet may be detrimental to the both the heart and the brain. Researchers assigned men aged 21 to 23 to a high-fat, low-carbohydrate (HFLC) diet and at a later time, to an alternate diet. They conducted MR scans, echocardiograms, and computerized cognitive tests. The HFLC diet produced 44 per cent higher “plasma free fatty acids” (fats circulating in the blood). This higher level was associated with impaired cognitive function in the areas of attention, speed and mood; and a nine per cent lower ratio of cardiac phosphocreatine-to-ATP (indicating reduced energy available to the heart for maintaining its proper functioning). These results occurred after five days on the high-fat diet and suggest an HFLC diet impairs cognition and heart function, reported the team. Released January 26, 2011, this study will be published in a future issue of the American Journal of Clinical Nutrition. In the meantime, it is available online at https://bit.ly/eJf9Wc with subscription or fee payment.

VITAMIN D DEFICIENCY HARMS LUNG GROWTH AND FUNCTION

A study has found the first, concrete, cause-and-effect evidence linking a deficiency of vitamin D with a deficit in lung function, as well as with altered lung structure itself. (Previous research had shown that a vitamin D deficiency may increase the severity of asthma and chronic obstructive pulmonary disease, or COPD, among people already afflicted; but the new study specifically shows that vitamin D deficiency causes diminished lung function and development among otherwise healthy subjects.) The deficiency was introduced to both pregnant mouse mothers and to their offspring, in whom the lung function and structure later were found to be damaged. Among D-deficient mice, lung volume was found to be lower and airway resistance was determined to be greater. Physical activity did not differ between the study and control groups. However, it was not possible to determine whether impairment of lung function and altered lung structure stemmed from the mothers’ vitamin D deficiencies, or from the deficiencies in the newborn mice. Further study may help identify what population groups may be able to improve lung health by vitamin D supplementation. This study was released January 28, 2011 but will not be available until a future issue of the American Journal of Respiratory and Critical Care Medicine.

CALCIUM STUDY

A sufficient supply of dietary calcium may help lower levels of lead in the blood. A study published online in Environmental Health Perspectives on September 18, 2008, found that pregnant women who take 1,200 mg of calcium supplement a day have up to a 31 per cent chance of reduced lead levels in their blood. If confirmed by further research, this suggests that calcium supplements also would lower fetal exposure to lead.