Health News Briefs – May 2012
Participants with low levels of omega-3 showed lower brain volumes, equalling 2 years of brain aging
LOW LEVELS OF OMEGA-3 FATTY ACIDS LINKED TO MEMORY PROBLEMS
Scientists have determined that lower levels of docosahexaenoic acid (DHA) are associated with smaller brain volume; and lower levels of omega-3 fatty acids generally are associated with reduced visual memory and executive functions such as problem solving, multi-tasking and abstract thinking.
For the study, 1,575 people with an average age of 67 – and free of dementia – underwent MRI brain scans. They were also given tests that measured mental function, body mass and the omega-3 fatty acid levels in their red blood cells.
People whose DHA levels were among the bottom 25 percent of the participants had lower brain volume compared to people who had higher DHA levels. In fact, people with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging.
Also, compared to those subjects with blood levels of all omega-3 fatty acids in the upper 25 percent, those in the bottom 25 percent also scored lower in visual memory and cognitive function.
This study was published in the February 28, 2012 issue of the journal Neurology. It is available online at https://bit.ly/wmxPt0 with subscription or fee.
DIETARY VITAMIN D MAY REDUCE BONE FRACTURE RISK IN GIRLS
Researchers have found an association between a higher intake of vitamin D from food sources and a reduced risk of stress fractures, at least in adolescent and pre-adolescent girls, and especially among girls involved in at least one hour a day of high-impact activity. (Stress fractures, a relatively common sports-related injury, occur when stresses on a bone exceed its capacity to withstand and heal from those forces.)
Scientists studied 6,712 girls aged 9 to 15 at the start of the project and followed up over seven years. Dairy and calcium intakes were not found to lower stress fracture risk; in fact, high calcium intakes were linked to higher fracture risk, although further study is needed for clarification. However, vitamin D intakes from food sources were found to correlate to a lower risk of stress fracture. Further study would be necessary to determine whether supplemental vitamin D would have a similar preventive effect against stress fractures. This study was released March 5, 2012 and will be published in a future issue of the Archives of Pediatrics and Adolescent Medicine. It has been made available online now at https://bit.ly/JCSe6H with subscription or access fee.
CURED MEAT LINKED TO HOSPITAL READMISSIONS FOR LUNG PATIENTS
Scientists have completed research showing that consumption of cured meat, such as salami, sliced ham, sausages, hot dogs or bacon, increases the risk of hospital readmission for COPD patients. (COPD, or chronic obstructive pulmonary disease, is a narrowing of the airways as a result of the co-occurrence of chronic bronchitis and emphysema, which leads to limitation of airflow into and out of the lungs and shortness of breath. It is caused by an abnormal inflammatory response to toxic gases, usually tobacco smoke.)
The study showed that those who regularly eat substantial amounts of cured meats, defined as the equivalent of more than one slice of ham per day, were more likely to suffer exacerbated symptoms that led to admission to hospital. However, the study advised that avoiding smoke would be more protective than avoiding cured meat. Negative effects of cured meats may result from the nitrites used as preservatives and from anti-bacterial agents in the meat. This study was released March 8, 2012, but will not be published until a future issue of the European Respiratory Journal. It is not yet available online.
MAGNESIUM PROMOTES REDUCTIONS IN BLOOD PRESSURE
A research review that investigated previous studies on the subject has found that supplemental magnesium intake is linked to a small but significant reduction in both systolic and diastolic blood pressure readings; and greater intake of magnesium was associated with a greater blood pressure reduction. (Cardiovascular disease is the number one cause of death. Elevated blood pressure or hypertension is a major risk factor for mortality from cardiovascular and renal disease. Causes of hypertension can include smoking, sedentary lifestyle, a diet high in sodium and an inadequate intake of other minerals such as potassium, calcium and magnesium.)
Until now, there has been inconclusive evidence on the effect of magnesium on blood pressure, with some studies showing no association. But when all evidence from previous studies was combined, including data from 1173 persons in total, the link was discovered. The dosages of magnesium supplements in the various studies ranged from 120 mg to 973 mg. This recently released review will be published in the July 2012 issue of the European Journal of Clinical Nutrition. It can be accessed online now at the journal site at https://bit.ly/yDfYru%20 with subscription or access fee.
MATERNAL OBESITY MAY AFFECT BRAINS OF PREMATURE INFANTS
A study has concluded that the obesity of a mother may contribute to cognitive impairment in an infant child who is born very premature. (Mental developmental delay is one of the main remaining risks for babies born at less than seven months. Over 30,000 babies are born extremely prematurely in the U.S. every year.)
Researchers evaluated the cognitive skills of babies at the age of two, who had been born before 28 weeks of gestation, using the Mental Development Index (MDI) portion of the Bayley Scales of Infant Develop-ment, a commonly used measure of cognitive function. Maternal obesity correlated with impaired early cognitive performance. Obesity has been linked to inflammation, and inflammation can damage the developing brain. It is still not known whether the obesity-related inflammation in the mother is transmitted to the fetus.
Scientists are conducting a study that follows these same babies into mid-childhood to determine long-term cognitive problems. This study was published in the March 2012 issue of the journal Pediatrics. It is available online now at https://bit.ly/xTNNab
DID YOU KNOW…?
Women use an average of 12 personal care products to start each day, reports the Canadian Breast Cancer Society. The ingredients, including paraben, phthalates and placenta extracts, may be absorbed by the body and the long-term effects are not yet clear.
BETTER DIET, EXERCISE COULD PREVENT 25% OF ALL CANCERS
Researchers have concluded that improved eating habits and more exercise could prevent 25% of cancers of all types, and a better lifestyle would have the greatest impact on the incidence of colorectal cancer and breast cancer. The researchers reported that this substantial reduction in cancer cases would occur if there were greater consumption of vegetables, less sedentary lifestyles, lower rates of obesity and overweight, higher dietary fiber, more moderate alcohol consumption, avoidance of first- and second-hand cigarette smoke, and a reduction in the consumption of red meat, especially processed meat.
The research was conducted in Australia, where cancer represents about 19% of the overall disease burden, as measured by financial cost, mortality and a range of other factors. The research is expected to have similar implications for other Western countries. The research team stressed that all of these cancer-prevention factors are within individual control. This study was published March 19, 2012 in the Medical Journal of Australia. It is available online now at https://bit.ly/FQQhRO without cost.
WHITE RICE RAISES RISK OF DEVELOPING TYPE II DIABETES
Researchers have found that greater consumption of white rice raises the risk of developing Type II diabetes. Among Asians, those consuming the greatest amount of white rice show a 55% higher risk of diabetes than those consuming the least. In any population, every additional 158 grams of white rice per day increases the risk of Type II diabetes by a further 11%; and women from any population showed a stronger association between white rice consumption and diabetes risk. White rice is a simple carbohydrate that ranks high on the glycemic index (GI); foods with a higher GI rank are linked to a higher risk of diabetes. Brown rice contains more nutrients than white rice, including vitamins, fiber, and magnesium, some of which are linked to a lower risk of Type II diabetes. The researchers suggested that Asian populations, known to eat more white rice, are at greater risk of diabetes, and advised that people in all populations consume more whole grains. This study was posted online March 15, 2012 by the British Medical Journal. It is available now at https://bit.ly/w2izry without cost.
DID YOU KNOW…?
Poisoning deaths now exceed deaths by car accident, according to a recent report from the National Center for Health Statistics. Over the past three decades, car crash deaths dropped by half, while poisoning deaths tripled, driven largely by pain medications and illegal drug use.
FURTHER EVIDENCE OF ALZHEIMER’S-LINKED DIABETES TYPE 3
Two studies have added to the considerable evidence that a form of diabetes, known as diabetes type 3, is involved in the development of Alzheimer’s disease (AD); and that treating insulin resistance can improve the cognitive dysfunction of, and may even prevent, AD. (Brains of AD patients have low insulin levels; and diabetics have a higher risk of developing AD.) The first study examined insulin signaling in human brain tissue, postmortem, finding that low activation of insulin signaling molecules was closely related to poor memory and cognitive function; also, insulin resistance was found to be a common, early feature of AD. The second study also found impaired insulin signaling in Alzheimer-brain tissue of animals and primates; and treating insulin resistance in mice with a form of AD (using an anti-diabetic drug) did more than simply normalize insulin signaling: it triggered remarkable cognitive and memory improvement. Research has not proved a causal link; however, these studies suggest that one type of diabetes triggers AD. Both studies are published in the April 2, 2012 issue of the Journal of Clinical Investigation. The first study is now online at https://bit.ly/GETy7X; the second study is online at https://bit.ly/GBvtNZ. Both are available without cost.
DID YOU KNOW…?
A study in the journal Ophthalmology found that certain nutrients lower the odds of getting age-related macular degeneration (AMD), the most common form of blindness among the elderly: vitamins C and E, zinc, lutein, zeaxanthin, and the omega-3 fatty acids known as DHA and EPA.
HIGHER ABDOMINAL FAT LINKED TO GREATER MENTAL DECLINE
A study has found that older adults with a high body mass index (BMI) are more likely to suffer from decreased cognitive function; and the prevention of obesity, particularly central obesity, may be important for the prevention of cognitive decline or dementia. There was a direct association between the amount of fat around the abdomen and cognitive decline. A total of 250 people over age 60 were included in the five-year research project. The relationship between BMI and abdominal fat on one hand, and mental decline on the other, was found among those between 60 and 70 years of age, but did not appear to hold true for those over 70. In addition, those with higher BMI showed a greater risk of high blood pressure. This study was released March 22, 2012 by the journal Age and Ageing. It is now accessible online at https://bit.ly/KHUFpu without cost.
LIFESTYLE SHORTENS TELOMERES, WHICH RAISES HEART DISEASE RISK
Researchers have discovered that the shortening of telomeres at the ends of chromosomes causes a 50% increased risk of heart attack and a 25% increased risk of early death, regardless of whether the telomeres become shortened by the process of aging or by poor lifestyle choices at any age. (Telomeres are caps at the ends of chromosomes that keep DNA from unraveling; as our chromosomes generate new chromosomes over time, the telomeres on the ends become clipped, getting shorter and shorter; and this shortening is related to aging and early death. Whether telomere shortening is related to lifestyle has been speculated, although smoking and obesity are related to heart disease.)
This research establishes that, aside from the aging process, smoking and obesity separately cause telomere shortening; and that smoking and obesity raise the risk of heart disease and death through their effect on telomeres, at the cellular level. Also, the researchers were able to measure telomere length through blood samples, showing that general practitioners could conduct simple blood tests to measure cellular wear and tear. This study was published in the March 2012 issue of Arteriosclerosis, Thrombosis and Vascular Biology.
TIME SPENT SITTING INCREASES DIABETES TYPE 2 RISK FOR WOMEN
A study has found a direct link, for women, between time spent sitting and risk of developing Type II diabetes. Scientists assessed over 500 people aged 40 or more, recording amount of time spent sitting over one week, and levels of specific chemicals in their bloodstream associated with diabetes and metabolic dysfunction.
Women who spent the longest time sitting had higher levels of insulin, as well as higher amounts of C-reactive protein and chemicals released by fatty tissue in the abdomen, leptin, and interleukin6, all of which indicate problematic inflammation. The risk for men was very weak, possibly because women tend to snack when sitting, or because men are more physical when not sitting. The implication is that even those women who get the recommended 30 minutes of exercise daily are still at higher risk of Type II diabetes if they spend the rest of the day sitting. This study was published in the March 2012 issue of the American Journal of Preventive Medicine, and is available online at https://bit.ly/AlSWIy with subscription or study access fee.
SHARK FIN SOUP POSES SIGNIFICANT RISK OF ALZHEIMER’S DISEASE
Scientists have found that shark fins contain highly concentrated amounts of a cyanobacterial neurotoxin, consumption of which carries a significant risk for neurodegenerative diseases, including Alzheimer’s disease and ALS (Lou Gehrig disease). An estimated 70 million sharks are killed annually, usually for their fins alone, especially prized as a delicacy in Asia. Dramatic, global shark depopulation, and the resultant unbalancing of marine ecology, has resulted from over-fishing of sharks, driven by this burgeoning Asian trade, and the popularity of shark fin soup. Researchers have found that these fins contain high levels of the cyanobacteria-produced neurotoxin known as beta-N-methylamino-L-alanine, or BMAA. (Cyanobacteria are algae-like bacteria that use photosynthesis.)
The toxin BMAA damages nerve and brain cells and can lead to Alzheimer’s disease, and other neurodegenerative disorders. BMAA has been detected in small amounts in fish in south Florida coastal waters and in the Baltic sea; but levels bioaccumulate up the food chain, causing high and dangerous concentrations in shark fins. Shark fin levels of BMAA were found to be seven times the BMAA levels found in the brains of dying Alzheimer patients, while the brains of people without Alzheimer’s or ALS seldom contain any measurable BMAA at all.
Just released by the journal Marine Drugs, this study will be published in a future issue. The entire study can be found at https://bit.ly/zZqCAN without cost or subscription.
EVEN MODEST RED MEAT CONSUMPTION INCREASES MORTALITY RATE
Researchers have discovered that one daily serving of unprocessed red meat correlates to a 13% higher death rate from any cause; and one serving of processed meat correlates to a 20% higher death rate. Every additional serving increased mortality risk by another 12%. During the 28-year study of over 121,000 men and women, 9.3% of male deaths and 7.6% of female deaths could have been prevented if subjects had limited intake of all kinds of red meat to less than one-half serving per day. Replacing one daily serving of red meat with another protein choice resulted in a lower risk of mortality: 7% lower risk of death for one substitution with fish; 14% lower for poultry; 19% lower for nuts; 10% lower for legumes; 10% for low-fat dairy products; and 14% lower death rate for one substitution with whole grains. Also, red meat correlated to a greater risk of diabetes, cardiovascular disease, and cancer. This study was released March 12, 2012 and will be published in a future issue of the Archives of Medicine. The full study is available now at https://bit.ly/J5oGAU without cost.
GREEN COFFEE BEANS TRIGGER SUBSTANTIAL WEIGHT LOSS
A study has confirmed that ground green coffee beans can produce a substantial weight loss in a relatively short period of time, with a fraction of an ounce daily triggering a loss of 10.6% of body weight on average within 22 weeks. (Green coffee beans are not roasted, and are available as extract capsules that have almost no caffeine.) The study involved 16 overweight or obese people aged 22-26 years who took capsules of the extract, or capsules containing a placebo (an inactive powder). The subjects took a low dose of 700 mg daily for six weeks, then a higher dose of 1,050 mg of the extract for six weeks, and finally a placebo for six weeks with a brief washout period between phases. All participants were monitored over the study period; their calories, carbohydrates, fats and protein intake did not change at all over the course of the study, nor did their exercise regimen change. Over 22 weeks, participants lost an average of 17 pounds, representing a 10.5% decrease in body weight and a 16% decrease in body fat. This study was presented March 29, 2012 in San Diego at the national meeting and exposition of the American Chemical Society. The full-text study is now available online at https://1.usa.gov/Hpf4OY without cost.
VITAMIN D INHIBITS PROSTATE CANCER CELL PROLIFERATION
Scientists have found that extremely large, short-term doses of vitamin D resulted in reduced markers for cell proliferation, and increased markers for inhibitory activity, in men with prostate cancer. (The role of vitamin D in prostate cancer is controversial; some experts suggesting a role, but others warn that excess vitamin D intake should be avoided.) In the new study, researchers gave 66 men, scheduled for prostate removal, daily vitamin D in doses of 400 IU, or 10,000 IU, or 40,000 IU, for 3-8 weeks before their operation. They found that each higher dosage, right up to the large 40,000 IU dose, correlated to further increases in calcitriol (a hormone made from vitamin D), lower prostate levels of Ki67 (a protein indicating prostate cancer cell growth), and higher levels of molecules called microRNA (indicating higher activity inhibiting cancer cell growth). The team warned against regular doses higher than 4,000 IU daily; some patients were given 40,000 IU only because of the short pre-surgery time frame.) This study was presented March 31, 2012 in Chicago at the annual meeting of the American Association for Cancer Research. It has not yet been published or posted online.
WEIGHT TRAINING IMPROVES PARKINSON’S DISEASE SYMPTOMS
Scientists have found that weight training for two years continues to significantly improve the motor symptoms of Parkinson’s disease more than other forms of rehabilitative exercise such as stretching or balancing exercises. Exercise was known to help Parkinson’s symptoms in the short term, but this is the first research to show its benefit over the long term, as well as the superiority of weight training. The different test groups exercised for one hour, twice a week for two years. All exercise types provided improvement at the six month mark, but all programs except the weight training program resulted in a complete reversal of improvement by the two-year point. Notably, the motor benefits of strength training included improvements in tremor control. All scores were taken when participants were not on any medications. The team suggested health practitioners should promote weight training as an integral component of Parkinson’s treatment program. This study was released February 16, 2012 at the annual meeting of the American Academy of Neurology in New Orleans.
