News Briefs – October 2015
RESEARCH SHOWS THAT PEOPLE DEFICIENT IN VITAMIN D HAVE A 21% GREATER RISK OF DEVELOPING ALZHEIMERS
Vitamin D Deficiency Linked to Alzheimer’s Disease
Researchers have found that people who are deficient in vitamin D have a 21% greater risk of developing Alzheimer’s disease (AD). (Vitamin D is a fat-soluble steroid hormone that possesses a wide range of health-promoting effects and that can potentially help combat many disorders, including non-skeletal, age-associated disorders. There has been increased scientific interest in recent years in the association between vitamin D status and dementia and AD, the most common form of dementia in the elderly. Earlier, it was observed that a higher number of Alzheimer’s Disease patients are low in vitamin D relative to the general population.)
This new meta-analysis, based on the combined results of previously published studies on the subject, found this higher risk of AD among vitamin D-deficient persons, as well as a significantly greater risk of non-AD dementia. More studies are needed to further confirm these associations and to evaluate the beneficial effects of vitamin D supplementation in preventing AD and dementia.
A critical drawback of this study is that there was no way to determine whether AD itself caused the deficiency in vitamin D or whether there was any causal link at all.
This study was published in the August, 2015 issue of Nutrition Journal. The full-text report can now be viewed online at https://tinyurl.com/og7vxjx free of charge.
Diabetics Show Higher Use of Antibiotics Years Before Diagnosis
New research has found that people with Type II diabetes tended to take significantly more antibiotics for many years leading up to their diagnosis than those who did not develop the condition. This higher exposure to antibiotics was also shown to continue after diagnosis with diabetes. (People with Type II diabetes do not make enough of the hormone insulin or their insulin does not work well enough to clear sugar from the blood.)
The scientists tallied antibiotic prescriptions filled by more than 170,000 persons with Type II diabetes and about 1.3 million other adults between 1995 and 2012. Individuals later diagnosed with Type II diabetes filled an average of 0.8 antibiotic prescriptions annually compared to 0.5 a year among those who did not develop diabetes. Notably, the more prescriptions filled, the more likely those people were to develop Type II diabetes.
Those who took an antibiotic, regardless of the type, were 50% more likely to later get a diabetes diagnosis if they had filled five or more prescriptions compared to those who filled none or just one. Narrow-spectrum antibiotics such as penicillin V conferred a slightly higher risk than broad-spectrum antibiotics.
Although this research shows some association between antibiotic use and Type II diabetes, it is important to note that it does not establish a cause-and-effect relationship. For instance, higher diabetes risk may be caused by a greater number of repeated infections. Or higher infection rates may be caused by diabetes, which slowly develops over many years in later-diagnosed patients.
However, it is also possible that antibiotics alter gut bacteria, which in turn may hypothetically affect sugar and fat metabolism. More research is needed.
This study was posted online August 27, 2015, ahead of eventual publication in the Journal of Clinical Endocrinology and Metabolism. The entire report can be read at https://tinyurl.com/nq53hrc free of charge.
Dietary Links to Inflammation and Disease Genesis
In an upcoming journal report, a coalition of scientists will show how nutrition influences inflammatory processes and may be able to reduce the risk of chronic diseases. (Inflammation is a normal component of host defense and is essential to metabolic regulation. But elevated unresolved chronic inflammation is a core element in the early stages of disease development. Controlling inflammation is crucial to human health and a key future preventive and therapeutic target. Control of low-grade inflammation may be an attractive target effect for healthy food ingredients.)
The report presents approaches to assess inflammatory status and to help quantify how much diet can reduce inflammation. An ineffective or excessive inflammatory response can result from a deficiency or an excess of certain micronutrients such as folate, vitamin B12, vitamin B6, vitamin B1, vitamin E, or zinc.
Also, high consumption of fat and glucose (sugar) may induce inflammation that occurs after meal consumption and that may have consequences for the development of diabetes and cardiovascular diseases. The Western-style diet, rich in fat and simple sugars but often poor in specific micronutrients, is linked to increased prevalence of diseases with immunological and autoimmune components, including allergies, food allergies, atopic dermatitis, and obesity.
A summary has been posted online by the British Journal of Nutrition, ahead of the full report to be published in a future edition of the journal. The abstract is available at https://tinyurl.com/nln3mwl
Colon Cancer May Be Inhibited by Cranberry Extract
Scientists have found that orally administered cranberry extracts diminish the number and size of tumours in mice with colon cancer. (Cranberries are often touted as a way to protect against urinary tract infections, but their potential benefits against colon cancer have not been fully investigated. Previous studies did find that chemicals derived from cranberry extracts could selectively kill off colon tumour cells in laboratory dishes. One in 20 Americans will develop colon cancer at some point in his or her lifetime; it is the second leading cause of cancer-related deaths.)
This study on mice looked at a type of colon cancer that is associated with colitis, an inflammatory bowel condition. After 20 weeks, the mice that were given whole cranberry extract had about half the number of tumours as mice that received no cranberry in their chow. The remaining tumours in the cranberry-fed mice were also smaller.
Plus, the cranberry extracts seemed to reduce the levels of inflammation markers in the mice. Identifying what therapeutic molecules in the cranberry are involved could lead to a better understanding of its anti-cancer potential, suggested the researchers.
Three powdered cranberry extracts were tested: a whole fruit powder, an extract containing only the cranberry polyphenols, and one containing only the non-polyphenol components of the fruit. All preparations were effective to some degree, but the whole cranberry extract was the most effective. (The mouse dose used was not an absurd amount as is often the case in animal studies. It was equivalent to about a cup a day of cranberries for a human. However, humans may not get the same benefits from juice, which lacks some of the components in the skin of the cranberry.)
If cranberry extracts are ultimately demonstrated to protect against colon cancer in humans, researchers may investigate its effects against other cancers. The team will now look deeper into the cranberry to see if it can isolate individual components responsible for its anti-cancer properties. The researchers are also analyzing the metabolites in the mice that consumed the fruit extracts to better understand what happens to mouse metabolism after the cranberry components are digested.
The study was presented August 18, 2015 in Boston at the national meeting of the American Chemical Society but has not yet been published in an ACS journal.
Taking Omega-3 Now May Prevent Psychosis Years Later
According to a new study, consuming omega-3 fatty acid for just 12 weeks may help prevent the onset of various psychotic disorders, such as schizophrenia, in individuals who are at ultra-high risk for psychoses, for up to seven years after this period. (Schizophrenia, which is characterized by delusions and hallucinations, including hearing voices and seeing things that do not really exist, typically emerges during adolescence or early adulthood, either abruptly or gradually. The illness occurs in 1% of the general population, but in 10% of people with a first degree relative with the disorder. There is no cure in conventional medicine. Current treatment focuses on managing symptoms.)
It has long been known that patients with schizophrenia exhibit reduced levels of polyunsaturated fatty acids, specifically omega-3 and omega 6, in their cell membranes. Seven years ago, this prompted researchers to run clinical trials that found that supplementing with omega-3 for 12 weeks delayed a first episode of psychotic disorder in high-risk subjects by up to a year, compared to the placebo group.
Now, seven years later, scientists have conducted a followup study and found that, of the original omega-3 group, only 10% have since developed a psychosis compared to 40% in the placebo group. The original 12-week supplementation appears to have had the carry-over effect of significantly reducing future risk. Because replication of these findings is needed first, the researchers stopped short of recommending that at-risk individuals start taking the fatty acid, which is available as a supplement and in many foods, including salmon, sardines, and walnuts. (Several replication trials have already been started.)
The team advised that fish oil rich in omega-3 has no clinically relevant side effects. Scientists still do not understand the underlying mechanism by which omega-3 might prevent the onset of schizophrenia, which has both genetic and environmental origins. This research was published in Nature Communications on August 11, 2015. The entire study can be read online at https://tinyurl.com/pfpaoex free of charge.
Heavy Smoking Linked to Fat Belly
Scientists have found that while smoking might be associated with lower overall weight, it tends to push fat into central areas resulting in a bigger abdomen, resulting in an unhealthy shape. (Fear of weight gain is one reason that smokers give for not kicking the habit, but this research suggests that smoking plays a critical role in excess abdominal fat, known commonly as ‘pot belly’.)
Researchers conducted a meta-analysis of 29 studies involving almost 150,000 participants and containing data on their smoking habits, weight, and waist circumference. The analysis revealed an association between an increase in the number of cigarettes smoked and a lower mean body mass index (BMI), thus adding evidence that heavier smoking leads to lower BMI. But the data also showed that while overall BMI in heavy smokers was lower, their waist circumference was significantly higher than that of nonsmokers (once BMI was accounted for). The result suggests smokers experience a preferential redistribution of fat towards the stomach. In other words, when smokers put on weight, they will show bigger tummies than nonsmokers for exact same weight gain. Weight in this area may also be linked to a greater risk for diabetes.
This study was published in the August 2015 issue of the BMJ Open. The full report can now be read online at https://tinyurl.com/npculr7 without cost.
Did You Know…?
Working 55 hours or more weekly is linked to a 33% higher risk of stroke than a 40-hour work week, according to a study of 600,000 individuals in The Lancet.
Sunlight Triggers City Grime to Spew Air Pollution
Scientists have determined that natural sunlight triggers the release of smog-forming nitrogen oxide compounds from the grime that typically coats buildings, statues, and other outdoor surfaces in urban areas. (Urban grime is a mixture of thousands of chemical compounds spewed into the air by automobiles, factories, and other sources. Among these compounds are nitrogen oxides. When in the air, these compounds may combine with other air pollutants known as volatile organic compounds to produce ozone, which is the main component of smog. Scientists had long suspected that nitrogen oxides become inactive when trapped in grime on a city surface.)
This one-of-a-kind finding confirms previous laboratory work using simulated sunlight and upends the long-held notion that nitrates found in urban grime are locked in place. These pollutants do not emanate from grime in shade or nighttime, only in direct sunlight. These findings are based on field studies conducted in Leipzig and Toronto. (Interestingly, Leipzig was found to have 20 times more grime than Toronto, suggesting Leipzig has a potential for 20 times more recycling of nitrogen oxides into the local atmosphere.)
According to the lead researcher, the current understanding of urban air pollution does not include the recycling of nitrogen oxides and potentially other compounds from building surfaces. It may be a substantial, unaccounted contributor to air pollution in cities.
Scientists presented this study in Boston on August 17, 2015 at the national meeting of the American Chemical Society (ACS). It is expected to be published in a future edition of one of the ACS journals.
What Position You Sleep in May Affect Your Alzheimer’s Risk
Scientists have reported findings that sleeping on your side (the lateral position, as compared to sleeping on your back or stomach) may more effectively remove brain waste, which in turn may help reduce the chances of developing Alzheimer’s, Parkinson’s, and other neurological diseases. (It may be interesting that in humans and many animals, the lateral sleeping position is most common. The build-up of brain waste chemicals may contribute to the development of Alzheimer’s disease and other neurological conditions.)
The team imaged the glymphatic pathway, which is a complex system that clears wastes and other harmful chemical solutions from the brain in the same way that the lymphatic system clears waste from organs. Brain waste includes beta amyloid and tau proteins, the build-up of which is linked to the development of Alzheimer’s. This imaging was done using dynamic contrast magnetic resonance imaging (MRI) on rodents. Compared to lying face down or face up, the lateral position showed the most efficient glymphatic transport.
The report recommends that body posture during sleep and sleep quality should be considered when assessing the clearance of proteins from the brain and their contributions to the development of brain diseases.
This study adds support to the concept that sleep serves to clean up waste that accumulates while we are awake. Many types of dementia are linked to sleep disturbances, including difficulties in falling asleep. It is increasingly acknowledged that these sleep disturbances may accelerate memory loss in Alzheimer’s disease. This new finding shows that what position you sleep may be another factor.
This study was published August 5, 2015 in the Journal of Neuroscience. The full report can be accessed at https://tinyurl.com/nky5r6v for a fee.
Did You Know…?
A Canadian PhD graduate has developed The Drinkable Book, a book with nanoparticles of silver or copper impregnated into its pages, any one of which can be used as a filter to turn polluted bacteria-riddled water, even sewage, into pure drinking water. For information: https://drinkablebook.tilt.com/the-drinkable-book
Dry Eye Syndrome Linked to Vitamin D Deficiency
Scientists have found a link between vitamin D deficiency and dry eye syndrome. They assessed the relationship between dry eye and impaired tear function and vitamin D status in 98 premenopausal women. (Dry eye syndrome occurs when the tear glands do not produce enough tears or when your tears evaporate too quickly, causing your eyes to feel itchy, scratchy, and irritated. This problem is more common in older adults and in those with certain diseases, such as diabetes.) Patients with vitamin D deficiency had lower scores in tear function tests (known as the Schirmer’s test and the tear break-up time test or TBUT) and higher scores in the ocular surface disease index (OSDI). Dry eye and impaired tear function in patients with vitamin D deficiency may indicate a protective role of vitamin D in the development of dry eye, perhaps by enhancing tear film parameters and reducing ocular surface inflammation.
This study was posted online August 13, 2015 on the site of the International Journal of Rheumatic Diseases in advance of publication in a future issue. The study can now be accessed at https://tinyurl.com/ne8qo5d for a small fee.
Did You Know…?
The human brain burns up to 25 percent of the energy produced by the body and up to 60 percent of its blood sugar.
Access to Nature Tied to Better Sleep Quality
Researchers have found that individuals who have access to natural environments in the form of parks, mountain and ocean vistas, or sandy beaches experience significantly better sleep quality. The team explained that while they found a positive link between sleep and exposure to natural amenities for all adults, it was much stronger for men, and for both men and women 65 and over. (Quality sleep is known to be critical to maintaining good health. Studies show that inadequate sleep is associated with declines in mental and physical health, reduced cognitive function, and increased obesity.)
The researchers used data on 255,171 adults recorded in a survey by the Centers for Disease Control and Prevention. Poor-quality and insufficient amounts of sleep on most nights was shown to be linked to having fewer natural environments nearby. The study also underlines the importance of preserving our natural environment for improving sleep quality.
This study is published in the September 2015 issue of the journal Preventive Medicine. It can be accessed now at https://tinyurl.com/nughmra for a fee.
