Abstract
Breastfeeding may reduce Alzheimer’s risk
The report, newly published in the Journal of Alzheimer’s Disease, suggests that the link may be to do with certain biological effects of breastfeeding. For example, breastfeeding restores insulin tolerance which is significantly reduced during pregnancy, and Alzheimer’s is characterised by insulin resistance in the brain.
Although they used data gathered from a very small group of just 81 British women, the researchers observed a highly significant and consistent correlation between breastfeeding and Alzheimer’s risk. They argue that this was so strong that any potential sampling error was unlikely.
At the same time, however, the connection was much less pronounced in women who already had a history of dementia in their family. The research team hope that the study – which was intended merely as a pilot – will stimulate further research looking at the relationship between female reproductive history and disease risk.
The findings may point towards new directions for fighting the global Alzheimer’s epidemic – especially in developing countries where cheap, preventative measures are desperately needed.
More broadly, the study opens up new lines of enquiry in understanding what makes someone susceptible to Alzheimer’s in the first place. It may also act as an incentive for women to breastfeed, rather than bottle-feed – something which is already known to have wider health benefits for both mother and child.
Dr. Molly Fox, from the Department of Biological Anthropology at the University of Cambridge, who led the study, said: “Alzheimer’s is the world’s most common cognitive disorder and it already affects 35.6 million people. In the future, we expect it to spread most in low and middle-income countries. So it is vital that we develop low-cost, large-scale strategies to protect people against this devastating disease.”
Previous studies have already established that breastfeeding can reduce a mother’s risk of certain other diseases, and research has also shown that there may be a link between breastfeeding and a woman’s general cognitive decline later in life. Until now, however, little has been done to examine the impact of breastfeeding duration on Alzheimer’s risk.
Fox and her colleagues – Professor Carlo Berzuini and Professor Leslie Knapp – interviewed 81 British women aged between 70 and 100. These included both women with, and without, Alzheimer’s. In addition, the team also spoke to relatives, spouses and carers.
Through these interviews, the researchers collected information about the women’s reproductive history, their breastfeeding history, and their dementia status. They also gathered information about other factors that might account for their dementia, for example, a past stroke, or brain tumour.
Dementia status itself was measured using a standard rating scale called the Clinical Dementia Rating (CDR). The researchers also developed a method for estimating the age of Alzheimer’s sufferers at the onset of their disease, using the CDR as a basis and taking into account their age and existing, known patterns of Alzheimer’s progression. All of this information was then compared with the participants’ breastfeeding history.
Despite the small number of participants, the study revealed a number of clear links between breastfeeding and Alzheimer’s. These were not affected when the researchers took into account other potential variables such as age, education history, the age when the woman first gave birth, her age at menopause, or her smoking and drinking history.
The researchers observed three main trends:
Women who breastfed exhibited a reduced Alzheimer’s Disease risk compared with women who did not.
Longer breastfeeding history was significantly associated with a lower Alzheimer’s Risk.
Women who had a higher ratio of total months pregnant during their life to total months breastfeeding had a higher Alzheimer’s risk.
The trends were, however, far less pronounced for women who had a parent or sibling with dementia. In these cases, the impact of breastfeeding on Alzheimer’s risk appeared to be significantly lower, compared with women whose families had no history of dementia.
The study argues that there may be a number of biological reasons for the connection between Alzheimer’s and breastfeeding, all of which require further investigation.
One theory is that breastfeeding deprives the body of the hormone progesterone, compensating for high levels of progesterone which are produced during pregnancy. Progesterone is known to desensitize the brain’s oestrogen receptors, and oestrogen may play a role in protecting the brain against Alzheimer’s.
Another possibility is that breastfeeding increases a woman’s glucose tolerance by restoring her insulin sensitivity after pregnancy. Pregnancy itself induces a natural state of insulin resistance. This is significant because Alzheimer’s is characterized by a resistance to insulin in the brain (and therefore glucose intolerance) to the extent that it is even sometimes referred to as “Type 3 diabetes.”
“Women who spent more time pregnant without a compensatory phase of breastfeeding therefore may have more impaired glucose tolerance, which is consistent with our observation that those women have an increased risk of Alzheimer’s disease,” Fox added. (Source: EurekAlert! A service of AAAS and the University of Cambridge).
Early detection and treatment of Alzheimer’s disease prevents psychological and behavioral symptoms
Persons with Alzheimer’s disease are able to manage their everyday activities longer and they suffer from less psychological and behavioral symptoms if the diagnosis is made and treatment begun at a very early phase of the disease, indicates a recent study conducted at the University of Eastern Finland.
The study followed persons with Alzheimer’s disease over a course of three years. The study participants were diagnosed either at the very mild or mild phase of the disease and treated within the standard healthcare system.
According to the study, persons with a very mild Alzheimer’s disease at the time of the diagnosis and start of the Alzheimer’s disease targeted therapy are better able to manage their everyday activities than persons diagnosed at a more advanced phase of the disease. In addition, in relation to the stage of the disease, they also had less psychological and behavioral symptoms during the follow-up.
According to the researchers, Psychologist Ilona Hallikainen and Adjunct Professor, Psychologist Tuomo Hänninen, the results show that an early detection of the disease is important. Persons with Alzheimer’s disease may be able to live at home longer if they are able to manage their daily activities and have less psychological and behavioral symptoms.
In addition, the study enhanced knowledge about the use of common diagnostic tests during a follow-up. The results have been accepted for publication in the journal International Psychogeriatrics. Ms. Hallikainen presented the results at the Alzheimer’s Association International Conference (AAIC) in Boston on 17 July. (Source: EurekAlert! A service of AAAS and the University of Eastern Finland).
Dementia sufferers more likely to be diagnosed with urinary or fecal incontinence
Patients with a diagnosis of dementia have approximately three times the rate of diagnosis of urinary incontinence, and more than four times the rate of fecal incontinence, compared with those without a diagnosis of dementia, according to a study in this week’s issue of PLOS Medicine by Robert Grant (Kingston University and St. George’s, University of London) and colleagues. Furthermore, patients with dementia and incontinence were more likely to receive incontinence medications and indwelling catheters than those with incontinence but without dementia, the authors state.
The authors analyzed records of patients in The Health Improvement Network (THIN) database, a database of nearly 500 UK primary care practices. They extracted data on 54,816 people aged 60 years with a diagnosis of dementia and an age-gender stratified sample of 205,795 people without a diagnosis of dementia from 2001 to 2010. The THIN database does not distinguish nursing home (care home) residents from those who live in their own homes.
Men with a diagnosis of dementia had an annual rate of first diagnosis of urinary incontinence of 42.3 (95% confidence interval, 40.9.8) per 1000, compared with 19.8 (19.4.3) per 1000 men without a dementia diagnosis. Among women, the rates of a first diagnosis of urinary incontinence were 33.5 (32.6.5) per 1000 women with a dementia diagnosis versus 18.6 (18.2.9) per 1000 women without a dementia diagnosis. Rates of a first diagnosis of fecal incontinence were 11.1 (10.4.9) per 1000 men with a dementia diagnosis versus 3.1 (2.9.3) per 1000 men without a dementia diagnosis. For women with a dementia diagnosis, 10.1 (9.6.6) per 1000 had a first diagnosis of fecal incontinence, versus 3.6 (3.5.8) per 1000 women without a dementia diagnosis. The adjusted rate ratio for first diagnosis of urinary incontinence was 3.2 (2.7.7) in men and 2.7 (2.3.2) in women, and for fecal incontinence was 6.0 (5.1.0) in men and 4.5 (3.8.2) in women.
The rate ratio of use of pharmacological treatment for urinary incontinence was 2.2 (1.4.7) for both genders, and for indwelling urinary catheters was 1.6 (1.3.9) in men and 2.3 (1.9.8) in women. Urinary catheters are known to increase the risk of urinary tract infection.
A limitation of the study was that the authors had to depend on coding of diagnoses and prescriptions in the database to determine the diagnosis of dementia and incontinence.
The authors state, “Incontinence is a common problem for community dwelling people with dementia. Providers and planners of services for dementia should anticipate high levels of need, including advice and support for carers managing incontinence. Some aspects of clinical management of urinary incontinence are different for patients with dementia compared with those without. Further study is required to understand the clinical reasoning of health care practitioners providing care for this population, particularly in the use of indwelling catheters, given the known risks.” (Source: EurekAlert! A service of AAAS and the Public Library of Science).
New scoring system allows clinicians to predict dementia risk in older people with type 2 diabetes
Age, education, and six different diabetes-related health complications (acute metabolic event, microvascular disease, diabetic foot, cerebrovascular disease, heart disease, and depression) were all identified as the most important predictive factors, and the researchers incorporated them into an easy to use point scoring system.
The scores allow patients to be allocated to one of 14 categories, with the lowest score (-1) indicating the lowest risk of dementia, and the highest scores (12 – 19) indicating the highest risk. Patients with the highest score were 37 times more likely to develop dementia within ten years than those with the lowest score, and patients with higher scores also developed dementia more quickly than those with lower scores. By testing the scoring system against an unrelated group of older patients with type 2 diabetes, the researchers found that it accurately predicts patients’ risk of developing dementia.
Although scoring systems to predict the risk of dementia have previously been developed for different populations, this is the first time that researchers have developed a scoring system to predict dementia specifically tailored to people with diabetes. The risk score is likely to prove especially useful to practicing clinicians, as it does not rely on expensive, complicated brain imaging or cognitive testing, although the researchers plan to incorporate a second stage into the scoring system in future including some of these aspects, which may lead to improved accuracy.
According to Dr. Whitmer, “Unfortunately, there is an epidemic of both type 2 diabetes and dementia, and the link between these two illnesses portends a possible public health crisis. Our model shows that in two large populations of patients with type 2 diabetes a combination of diabetes-associated complications, education, and age is highly predictive of the likelihood of dementia within the next decade. Early detection of patients with type 2 diabetes who are at increased risk of dementia could help to develop and target preventive treatment, and our scoring system has the potential to change clinical care by giving clinicians a simple and accurate way of predicting the risk of dementia in older people with type 2 diabetes.”
Writing in a linked Comment, Dr. Anna-Maija Tolppanen, of the University of Eastern Finland, Kuopio, Finland, states that, “Generally, risk scores might be useful in the identification of individuals who should be monitored for disease symptoms, selection of high-risk individuals for clinical trials, targeting of preventive interventions towards those at greatest risk, and assessment of the effectiveness of an intervention at reducing the risk of future illness. [The risk score developed in this paper] might be useful for clinicians for the first purpose, but clinical trial data on effective preventive interventions for dementia are currently lacking.” (Source: EurekAlert! A service of AAAS and Lancet).
Oprah’s and Einstein’s faces help spot dementia
CHICAGO — Simple tests that measure the ability to recognize and name famous people such as Albert Einstein, Bill Gates or Oprah Winfrey may help doctors identify early dementia in those 40 to 65 years of age, according to new Northwestern Medicine research.
The research appears in the August 13, 2013, print issue of Neurology, the medical journal of the American Academy of Neurology.
“These tests also differentiate between recognizing a face and actually naming it, which can help identify the specific type of cognitive impairment a person has,” said study lead author Tamar Gefen, a doctoral candidate in neuropsychology at the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern University Feinberg School of Medicine.
Gefen did the research in the lab of senior author Emily Rogalski, assistant research professor at Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center.
Face recognition tests exist to help identify dementia, but they are outdated and more suitable for an older generation.
“The famous faces for this study were specifically chosen for their relevance to individuals under age 65, so that the test may be useful for diagnosing dementia in younger individuals,” Rogalski said. An important component of the test is that it distinguishes deficits in remembering the name of a famous person from that of recognizing the same individual, she noted.
The study also used quantitative software to analyze MRI scans of the brains of the individuals who completed the test to understand the brain areas important for naming and recognition of famous faces.
For the study, 30 people with primary progressive aphasia, a type of early onset dementia that mainly affects language, and 27 people without dementia, all an average age of 62, were given a test. The test includes 20 famous faces printed in black and white, including John F. Kennedy, Lucille Ball, Princess Diana, Martin Luther King Jr. and Elvis Presley.
Participants were given points for each face they could name. If the subject could not name the face, he or she was asked to identify the famous person through description. Participants gained more points by providing at least two relevant details about the person. The two groups also underwent MRI brain scans.
Researchers found that the people who had primary progressive aphasia, a form of early onset dementia, performed significantly worse on the test, scoring an average of 79 percent in recognition of famous faces and 46 percent in naming the faces, compared to 97 percent in recognition and 93 percent on naming for those free of dementia.
The study also found that people who had trouble putting names to the faces were more likely to have a loss of brain tissue in the left temporal lobe of the brain, while those with trouble recognizing the faces had tissue loss on both the left and right temporal lobe.
“In addition to its practical value in helping us identify people with early dementia, this test also may help us understand how the brain works to remember and retrieve its knowledge of words and objects,” Gefen said. (Source: EurekAlert! A service of AAAS and Northwestern University).
Study suggests late adolescent risk factors for young-onset dementia
A study of Swedish men suggests nine risk factors, most of which can be traced to adolescence, account for most cases of young-onset dementia (YOD) diagnosed before the age of 65 years, according to a report published by JAMA Internal Medicine, a JAMA Network publication.
Dementia is a major public health concern that affects an estimated 35.6 million people worldwide. The cost and disability associated with dementia are expected to increase in the next 40 years, affecting more than 115 million people by 2050, Peter Nordström, Ph.D, of Umeå University, Sweden, and colleagues write in the study background.
The study included 488,484 Swedish men conscripted for mandatory military service from September 1969 through December 1979 with an average age of 18 years.
“Young-onset dementia (YOD), that is, dementia diagnosed before 65 years of age, has been related to genetic mutations in affected families. The identification of other risk factors could improve the understanding of this heterogeneous group of syndromes,” the study notes.
During a median follow-up of 37 years, 487 men were diagnosed as having YOD at a median age of 54 years. Significant risk factors for YOD included alcohol intoxication (hazard ratio [HR], 4.82); stroke (HR, 2.96); use of antipsychotics (HR, 2.75); depression (HR, 1.89); father’s dementia (HR, 1.65); drug intoxication other than alcohol (HR, 1.54); low cognitive function at conscription (HR, 1.26); low height at conscription (HR, 1.16); and high systolic blood pressure at conscription (HR, 0.90), according to the results.
“Collectively, these factors accounted for 68 percent of the YOD cases identified,” the authors comment.
The results also indicate that men with at least two of the nine risk factors and in the lowest third of overall cognitive function had a 20-fold increased risk of YOD during follow-up.
“In this nationwide cohort, nine independent risk factors were identified that accounted for most cases of YOD in men. These risk factors were multiplicative, most were potentially modifiable, and most could be traced to adolescence, suggesting excellent opportunities for early prevention,” the study concludes. (Source: EurekAlert! A service of AAAS and The JAMA Network Journals).
Dementia risk tied to blood sugar level, even with no diabetes
SEATTLE — A joint Group Health–University of Washington (UW) study in the New England Journal of Medicine has found that higher blood sugar levels are associated with higher dementia risk, even among people who do not have diabetes.
Blood sugar levels averaged over a five-year period were associated with rising risks for developing dementia, in this report about more than 2,000 Group Health patients age 65 and older in the Adult Changes in Thought (ACT) study.
For example, in people without diabetes, risk for dementia was 18 percent higher for people with an average glucose level of 115 milligrams per deciliter compared to those with an average glucose level of 100 mg/dl. And in people with diabetes, whose blood sugar levels are generally higher, dementia risk was 40 percent higher for people with an average glucose level of 190 mg/dl compared to those with an average glucose level of 160 mg/dl.
“The most interesting finding was that every incrementally higher glucose level was associated with a higher risk of dementia in people who did not have diabetes,” said first author Paul K. Crane, MD, MPH, an Associate Professor of Medicine at the UW School of Medicine, Adjunct Associate Professor of Health Services at the UW School of Public Health, and Affiliate Investigator at Group Health Research Institute. “There was no threshold value for lower glucose values where risk leveled off.”
“One major strength of this research is that it is based on the ACT study, a longitudinal cohort study, where we follow people for many years as they lead their lives,” said senior author Eric B. Larson, MD, MPH, a senior investigator at Group Health Research Institute who also has appointments at the UW Schools of Medicine and Public Health. “We combine information from people’s research visits every other year with data from their visits to Group Health providers whenever they receive care. And this gave us an average of 17 blood sugar measurements per person: very rich data.”
These measurements included blood glucose (some fasting, some not) and glycated hemoglobin (also known as HbA1c). Blood sugar levels rise and fall in peaks and valleys throughout each day, but glycated hemoglobin doesn’t vary as much over short intervals. Combining glucose and glycated hemoglobin measures into a composite measure required special statistical techniques, which Drs. Crane and Larson’s co-authors Rod Walker, MS, a biostatistician, and Rebecca Hubbard, PhD, an associate investigator, both from Group Health Research Institute, had developed. (Dr. Hubbard is also an Affiliate Assistant Professor of Biostatistics at the UW School of Public Health.) These sophisticated statistical models required specialized data on the relationships between glycated hemoglobin and glucose levels, and they used data generated by co-author David M. Nathan, MD, a Professor of Medicine at Harvard Medical School and Director of the Diabetes Center at Massachusetts General Hospital.
So should people try to eat less sugar—or foods with a lower “glycemic index"? Not necessarily, Dr. Crane said: “Your body turns your food into glucose, so your blood sugar levels depend not only on what you eat but also on your individual metabolism: how your body handles your food.” But he does suggest that taking walks couldn’t hurt: The ACT study has previously linked physical activity to later onset and reduced risk of dementia, including Alzheimer’s disease.
Furthermore, Dr. Crane emphasized that these results come from an observational study: “What we found was that people with higher levels of glucose had a higher risk of dementia, on average, than did people with lower levels of glucose,” he said. “While that is interesting and important, we have no data to suggest that people who make changes to lower their glucose improve their dementia risk. Those data would have to come from future studies with different study designs.”
More research is planned to delve into various possible mechanisms for the relationship between blood sugar and dementia. “This work is increasingly relevant,” Dr. Crane said, “because of the worldwide epidemics of dementia, obesity, and diabetes.” (Source: EurekAlert! A service of AAAS and the Group Health Research Institute).