Some older women who take calcium supplements commonly recommended to ward off age-related bone damage may face an increased risk of developing dementia, a small study suggests.
The heightened dementia risk appears limited to women who have had a stroke or suffer from other disorders that affect blood flow to the brain, researchers report in the journal Neurology.
"Our study is the first to show a relationship between calcium supplementation and increased risk for dementia in older women," said lead author Dr. Silke Kern of the University of Gothenburg in Sweden. Still, the findings from this observational study don't prove calcium supplements directly cause dementia, Kern added by email. Even for women who have had a stroke, it's too soon to say for sure whether it makes sense for them to avoid calcium supplements, Kern noted.
"These findings need to be replicated before any recommendations can be made," Kern said.
Millions of women take calcium supplements to strengthen bones made brittle by osteoporosis, a bone-thinning disorder that typically develops starting during menopause when the body slows production of new bone tissue.
For the current study, Kern and colleagues examined data on 700 women between the ages of 70 and 92 who didn't have dementia.
At the start of the study, and again five years later, women did a variety of psychiatric and cognitive tests including assessments of memory and reasoning skills. A subset of about 450 women also got brain scans. When the study began, 98 women were taking calcium supplements and 54 participants had already experienced a stroke. During the study, 54 more women had strokes, and 59 women developed dementia. Among the women who had brain scans, 71 percent had so-called white matter lesions, which are signs of mini-strokes and other disorders that affect blood flow to the brain. Overall, women who took calcium supplements were twice as likely to develop dementia as their peers who didn't, the study found.
But the increased risk appeared limited to people who had a stroke or other signs of existing cerebrovascular disease.
For women with a history of stroke, the dementia risk was almost seven times higher if they took calcium supplements than if they didn't.
When women had white matter lesions that can be a precursor to strokes, the dementia risk was three times greater when they took calcium supplements. Among women without a stroke history or white matter lesions, however, there wasn't any increased dementia risk associated with calcium supplements. Beyond its small size, other limitations of the study include the lack of follow-up brain scans at the end of the study, which made it impossible for researchers to assess how calcium supplements may have influenced the development of white matter lesions or silent strokes.
In addition, the study didn't look at how much calcium women got in their diets, which can affect the body differently than supplements and is thought to be safe or even protective against blood flow problems, the authors note. "Women and the public need to realize that when we talk about micronutrients -calcium included - and cognitive functioning, we need to consider that the combination of nutrients will be more predictive than one nutrient," said Dr. Neelum Aggarwal, a researcher at Rush University Medical Center in Chicago who wasn't involved in the study.
"For example, calcium, phosphorus and magnesium all are typically looked at for their effects on multiple organs, and cognitive functioning will be affected most likely by a combination of these nutrients," Aggarwal added by email. "To say that only one nutrient increases the risk of dementia is premature and more studies need to look at a combination of nutrients."
Sitting for too long may increase the risk of dementia in middle-aged adults, according to scientists, including one of Indian origin.
In a study published in the journal PLOS One, the researchers recruited 35 people (aged between 45 and 75 years).
The researchers, including Prabha Siddarth from the University of California, Los Angeles in the US, asked the participants about their physical activity levels and the average number of hours per day they spent sitting over the previous week.
Each person had a high-resolution MRI scan, which provides a detailed look at the medial temporal lobe, or MTL, a brain region involved in the formation of new memories.
The researchers found that sedentary behaviour is a significant predictor of thinning of the MTL and that physical activity, even at high levels, is insufficient to offset the harmful effects of sitting for extended periods.
MTL thinning can be a precursor to cognitive decline and dementia in middle-aged and older adults.
Reducing sedentary behaviour may be a possible target for interventions designed to improve brain health in people at risk for Alzheimer's disease, said Siddarth.
This study does not prove that too much sitting causes thinner brain structures, but instead that more hours spent sitting are associated with thinner regions, he said.
Do you have tiny yellow spots in the eye? Watch out, it could be an early indicator of dementia, a new study suggests. According to the researchers, the spots known as “hard drusen” are made of fat and calcium deposit that form in a layer underneath the retina and can be seen in scans.
Common signs of ageing, the spots have long been thought to be harmless. But, the findings showed that 25 per cent of people with Alzheimer’s have more number of such spots compared to four per cent of healthy people.
“We found that there were more areas associated with drusen deposition in Alzheimer’s disease,” lead author Imre Lengyel from Queen’s University in Belfast, Northern Ireland, was quoted as saying to the DailyMail. The results also showed that people with Alzheimer’s had thicker blood vessels which may slow down the blood flow. Thus, scanning for the spots and examining the eye’s blood vessels could be a valuable tool in Alzheimer’s disease monitoring, the researchers said.
“A brain disease is difficult to diagnose through the eye. But we can use ophthalmologic imaging to chart progression of the disease and monitor the effectiveness of medications used to combat it,” Lengyel added. “An eye imaging session would comprise 20 seconds of time and is very non-invasive. It’s exciting. We really hope that eye imagining will be a powerful tool in monitoring Alzheimer’s progression.”
In the study, published in the journal Ophthalmic Research, the team conducted eye test on 117 patients aged between 60 to 92 years.
The researchers hope that the study may be helpful in early detection of dementia so that early precaution is taken in order to combat the disease.
Even head blows that do not result in loss of consciousness may cause brain changes that increase the risk of dementia, new research has found. The study, which tracked more than 350,000 participants, showed that the likelihood of dementia more than doubled following concussion.
Concussion without loss of consciousness led to 2.36 times the risk for dementia, showed the findings published in the journal JAMA Neurology.
These risks were slightly elevated for those in the loss-of-consciousness bracket (2.51) and were nearly four times higher (3.77) for those with the more serious moderate-to-severe traumatic brain injury.
The researchers identified participants from two databases. The first group included all-era veterans whose traumatic brain injuries could have occurred during civilian or military life.
The second group included veterans serving in Iraq and Afghanistan, for whom most of these injuries had occurred in combat zones, such as from shockwaves in blasts.
“The findings in both groups were similar, indicating that concussions occurring in combat areas were as likely to be linked to dementia as those concussions affecting the general population,” said first author Deborah Barnes, Professor at the University of California, San Francisco, US.
In total, 357,558 participants, whose average age was 49, were tracked.
Half had been diagnosed with traumatic brain injury, of which 54 per cent reported experiencing concussion.
The study followed the participants for an average of 4.2 years.
“There are several mechanisms that may explain the association between traumatic brain injury and dementia,” said senior author and principal investigator Kristine Yaffe, Professor at the University of California, San Francisco.
“There’s something about trauma that may hasten the development of neurodegenerative conditions. One theory is that brain injury induces or accelerates the accumulation of abnormal proteins that lead to neuronal death associated with conditions like Alzheimer’s disease,” Yaffe said.
Alzheimer’s disease is the most common form of dementia. “It’s also possible that trauma leaves the brain more vulnerable to other injuries or ageing processes,” Yaffe said.
Researchers have found an increase in medication use by the patients who have been newly-diagnosed with dementia and they may consume unnecessary or inappropriate medicines that increase the risk of side effects.
“Our study found that following a diagnosis of dementia in older people, medication use increased by 11 per cent in a year and the use of potentially inappropriate medications increased by 17 per cent,” said lead author Danijela Gnjidic, Senior Lecturer from the Faculty of Pharmacy and Charles Perkins Centre at University of Sydney.
According to the researchers, potentially inappropriate or unnecessary medications included sleeping tablets, pain drugs, depression drugs and acid reflux drugs (proton pump inhibitors).
“These medications are typically recommended for short term use but are commonly used long term by people with dementia,” Gnjidic said.
The number of people living with dementia around the world is 50 million and in Australia is currently 425,000. Also, dementia is currently the second leading cause of death in Australia, the researchers said.
The longitudinal study, published in the Journals of Gerontology: Medical Sciences, of nearly 2,500 people was conducted in collaboration with Yale University and University of Kentucky.
The researchers conducted longitudinal study using the National Alzheimer’s Coordinating Center data.
“A number of reasons may account for this, including inadequate guidelines, lack of time during physician patient encounters, diminished decision-making capacity, difficulties with comprehension and communication, and difficulties in establishing goals of care,” the researcher said.
“These findings are of major concern and highlight the importance of weighing up the harms and benefits of taking potentially unnecessary medications as they may lead to increased risk of side effects such as sedation or drowsiness, and adverse drug events such as falls, fractures and hospitalisation,” the researchers added.