Alzheimers prevention

Improving fitness may counteract brain atrophy in older adults, including those with MCI

  • A small study involving physically inactive older adults found that a three-month exercise program reversed some brain atrophy.

A study involving 30 previously physically inactive older adults (aged 61-88) found that a three-month exercise program reversed some brain atrophy.

Participants included 14 with MCI. The exercise program included moderate intensity walking on a treadmill four times a week over a twelve-week period. On average, cardiorespiratory fitness improved by about 8% as a result of the training in both the healthy and MCI participants. Fitness was assessed using peak oxygen capacity rates.

Those who showed the greatest improvements in fitness had the most growth in cortical thickness. Those with MCI showed greater improvements compared to healthy group in the left insula and superior temporal gyrus, two brain regions that have been shown to exhibit accelerated neurodegeneration in Alzheimer’s disease.

Reference: 

Reiter, K., Nielson, K. A., Smith, T. J., Weiss, L. R., Alfini, A. J., & Smith, J. C. (2015). Improved Cardiorespiratory Fitness Is Associated with Increased Cortical Thickness in Mild Cognitive Impairment. Journal of the International Neuropsychological Society, 21(Special Issue 10), 757–767. https://doi.org/10.1017/S135561771500079X

Source: 

http://www.eurekalert.org/pub_releases/2015-11/uom-ifm111915.php

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Exercise may be #1 way to prevent dementia

  • A long-running study involving women only found that regular exercise in middle age was the most effective they could do to prevent later cognitive decline.

A long-running study following 387 Australian women found that regular exercise in middle age was the best lifestyle change they could make to prevent cognitive decline in their later years.

The women were aged 45-55 when the study began in 1992. Health and lifestyle factors were assessed at intervals over the next 20 years.

Memory was assessed using a Verbal Episodic Memory test in which they were asked to learn a list of 10 unrelated words and attempt to recall them 30 minutes later.

Frequent physical activity, normal blood pressure, and high good cholesterol were all strongly associated with better recall, with regular exercise of any type emerging as the number one protective factor against memory loss.

The benefits of exercise were cumulative, meaning that every year’s activity counted. Similarly, the negative effects of high blood pressure were also cumulative. What you do over the course of your life, especially in middle age, matters! Which is not to say that’s a reason not make changes later in life. Better late than never definitely applies.

Reference: 

Szoeke, C., Lehert, P., Henderson, V. W., Dennerstein, L., Desmond, P., & Campbell, S. (2016). Predictive Factors for Verbal Memory Performance Over Decades of Aging: Data from the Women’s Healthy Ageing Project. The American Journal of Geriatric Psychiatry, 24(10), 857–867. https://doi.org/10.1016/j.jagp.2016.05.008

Source: 

http://www.futurity.org/exercise-dementia-1180482-2

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Moving more in old age may protect brain from dementia

  • A long-running study found older adults who moved more were less likely to develop dementia, even when they had brain pathologies characteristic of dementia.

A long-running study involving 454 older adults who were given physical exams and cognitive tests every year for 20 years has found that those who moved more than average maintained more of their cognitive skills than people who were less active than average, even if they have brain lesions or biomarkers linked to dementia.

Participants wore an activity monitor for a week, an average of two years before death. The range of physical activity was extreme, with the average being 155,000 counts/day and the standard deviation being 116,000 counts. Daily physical activity was affected by age (unsurprisingly) and education.

For every increase in physical activity by one standard deviation, participants were 31% less likely to develop dementia. For every increase in motor ability by one standard deviation, participants were 55% less likely to develop dementia.

191 had dementia and 263 did not. The participants donated their brains for research upon their deaths. The average age at death was 91 years. Almost all (95.6%) showed at least one brain pathology, with 85% having at least two, and the average being three. Pathologies include Alzheimer's pathology, Lewy Bodies, nigral neuronal loss, TDP-43, hippocampal sclerosis, micro- and macro-infarcts, atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy.

https://www.eurekalert.org/pub_releases/2019-01/rumc-mmi011119.php

https://www.theguardian.com/science/2019/jan/16/activity-sharpens-even-dementia-affected-brains-report-suggests

Reference: 

Buchman, Aron S. et al. 2019. Physical activity, common brain pathologies, and cognition in community-dwelling older adults. Neurology, 92 (8), e811-e822; DOI: 10.1212/WNL.0000000000006954

Source: 

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Slower walking speeds linked to dementia risk

  • A large, long-running study has found older adults with a slower walking speed were more likely to develop dementia in the next decade.
  • Another long-running study has found that slowing over 14 years was linked to brain atrophy in the hippocampus, and cognitive impairment.

Data from the English Longitudinal Study of Aging, in which nearly 4,000 older adults (60+) had their walking speed assessed on two occasions in 2002-2003 and in 2004-2005, those with a slower walking speed were more likely to develop dementia in the next 10 years. Those who experienced a faster decline in walking speed over the two-year period were also more likely to develop dementia.

https://www.eurekalert.org/pub_releases/2018-03/ags-oaw032318.php

A long-running study involving 175 older adults (70-79) found that slowing in walking speed over a 14-year period was associated with cognitive impairment, and with shrinkage of the right hippocampus specifically.

Gait slowing over an extended period of time was a stronger predictor of cognitive decline than slowing at a single time point. All the participants slowed over time, but those who slowed by 0.1 seconds more per year than their peers were 47% more likely to develop cognitive impairment.

The finding held even when the researchers took into account slowing due to muscle weakness, knee pain and diseases, including diabetes, heart disease, and hypertension.

Typically, a slowing gait is seen as a physical issue, but doctors should consider that there may be a brain pathology driving it.

http://www.futurity.org/gait-hippocampus-brains-dementia-1472892/

Reference: 

[4491] Hackett, R. A., Davies‐Kershaw H., Cadar D., Orrell M., & Steptoe A.
(2018).  Walking Speed, Cognitive Function, and Dementia Risk in the English Longitudinal Study of Ageing.
Journal of the American Geriatrics Society. 66(9), 1670 - 1675.

[4492] Rosso, A. L., Verghese J., Metti A. L., Boudreau R. M., Aizenstein H. J., Kritchevsky S., et al.
(2017).  Slowing gait and risk for cognitive impairment.
Neurology. 89(4), 336.

Source: 

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Fruit & veges slow memory decline in long-running study

  • A large, long-running study has found an association between consumption of fruit & vegetables and subjectively assessed memory skills in older men.

A study following nearly 28,000 older men for 20 years has found that regular consumption of leafy greens, dark orange and red vegetables and berry fruits, and orange juice, was associated with a lower risk of memory loss.

The study looked at 27,842 male health professionals, who were an average age of 51 in 1986, when the study began. Participants filled out questionnaires about how many servings of fruits, vegetables and other foods they had each day, at the beginning of the study and then every four years.

Specifically:

  • those who consumed the most vegetables (around six servings a day) were 34% less likely to develop poor thinking skills than the men who consumed the least amount of vegetables (around two servings)
  • 6.6% of men who consumed the most vegetables developed poor cognitive function, compared to 7.9% of men who consumed the least
  • those who drank orange juice every day were 47% less likely to develop poor thinking skills than those who drank less than one serving per month
  • 6.9% of men who drank orange juice every day developed poor cognitive function, compared to 8.4 % of men who drank orange juice less than once a month

Interestingly, those who ate larger amounts of fruits and vegetables 20 years earlier were less likely to develop cognitive problems, whether or not they kept eating larger amounts of fruits and vegetables about six years before the memory test.

Cognition was not, however, assessed objectively, nor was it tested at baseline. In 2008 and 2012, participants were given a short cognitive test to assess their subjective judgments of their memory and cognition. The brief test included such questions as:

  • "Do you have more trouble than usual remembering a short list of items, such as a shopping list?"
  • "Do you have more trouble than usual following a group conversation or a plot in a TV program due to your memory?"

Just over half the participants (55%) had good thinking and memory skills, 38% had moderate skills, and 7% had poor thinking and memory skills.

https://www.eurekalert.org/pub_releases/2018-11/aaon-ojl111918.php

Reference: 

Changzheng Yuan et al. 2019. Long-term intake of vegetables and fruits and subjective cognitive function in US men. Neurology, 92 (1) e63-e75.

 

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Rigorous exercise does not slow dementia decline

  • A study involving nearly 500 people with dementia has found that a rigorous physical exercise program did nothing to slow their decline.

A number of studies have found that physical exercise can help delay the onset of dementia, however the ability of exercise to slow the decline once dementia has set in is a more equivocal question. A large new study answers this question in the negative.

The study involved 494 people with mild-to-moderate dementia (average age 77; 61% male), of whom 329 were randomly assigned to a four-month aerobic and strength exercise programme and 165 were assigned to usual care. The exercise program was personalized, and involved two 60-90 minute gym sessions every week, plus a further hour at home. Nearly two-thirds of the exercise group attended more than three-quarters of the gym sessions.

While the exercise group did get physically fitter, their cognitive fitness (as measured by ADAS-cog score) actually worsened slightly.

The researchers emphasize that this was a specialized and intense exercise program, and in no way should it be taken to mean that gentle exercise, which is good for dementia sufferers, should be avoided.

https://www.theguardian.com/society/2018/may/16/rigorous-exercise-makes-dementia-worse-study-concludes

Reference: 

[4353] Lamb, S. E., Sheehan B., Atherton N., Nichols V., Collins H., Mistry D., et al.
(2018).  Dementia And Physical Activity (DAPA) trial of moderate to high intensity exercise training for people with dementia: randomised controlled trial.
BMJ. 361, k1675.

Source: 

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Different kinds of physical activity improve brain volume & cut Alzheimer's risk

  • A large long-running study adds to growing evidence that higher levels of physical activity reduce brain atrophy and Alzheimer's risk, and shows that many types of aerobic activity are beneficial.

Data from 876 patients (average age 78) in the 30-year Cardiovascular Health Study show that virtually any type of aerobic physical activity can improve brain volume and reduce Alzheimer's risk.

A higher level of physical activity was associated with larger brain volumes in the frontal, temporal, and parietal lobes including the hippocampus, thalamus and basal ganglia. Among those with MCI or Alzheimer's (25% of the participants), higher levels of physical activity were also associated with less brain atrophy. An increase in physical activity was also associated with larger grey matter volumes in the left inferior orbitofrontal cortex and the left precuneus.

Further analysis of 326 of the participants found that those with the highest energy expenditure were half as likely to have developed Alzheimer's disease five years later.

Physical activity was assessed using the Minnesota Leisure-Time Activities questionnaire, which calculates kilocalories/week using frequency and duration of time spent in 15 different leisure-time activities: swimming, hiking, aerobics, jogging, tennis, racquetball, walking, gardening, mowing, raking, golfing, bicycling, dancing, calisthenics, and riding an exercise cycle.

The study does not look at whether some types of physical activity are better than others, unfortunately, but its message that overall physical activity, regardless of type, helps in the fight against cognitive impairment is encouraging.

http://www.eurekalert.org/pub_releases/2016-03/ip-dko030916.php

http://www.eurekalert.org/pub_releases/2016-03/uops-bmc031016.php

Reference: 

[4180] Raji, C. A., Merrill D. A., Eyre H., Mallam S., Torosyan N., Erickson K. I., et al.
(2016).  Longitudinal Relationships between Caloric Expenditure and Gray Matter in the Cardiovascular Health Study.
Journal of Alzheimer's disease: JAD.

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Fish reduces Alzheimer's risk for those with APOE gene

  • A new study finds that seafood consumption reduces Alzheimer's pathology, but only in those with the Alzheimer's gene APOEe4. While fish oil didn't appear to affect brain health, the omega-3 acid found in flaxseed did.

I've spoken before about how the presence or absence of the “Alzheimer's gene” may affect which lifestyle changes are beneficial for you. A new study has added to that idea with a finding that seafood consumption was associated with fewer signs of Alzheimer's-related pathology, but only among those with the APOEe4 gene.

Seafood consumption was also associated with increased mercury levels in the brain, with levels rising the more seafood was consumed. However, higher levels of mercury were not correlated with any neuropathologies.

Fish oil supplementation was not associated with any differences in neuropathology. However, higher levels of alpha-linolenic acid (an omega-3 fatty acid found in flaxseed, chia seeds, walnuts, etc) were associated with a reduced chance of cerebral infarctions.

The study involved 554 deceased participants (average age 89.9 years) from the long-running Memory and Aging Project (MAP) conducted by Rush University Medical Center. The participants had completed annual dietary questionnaires over a number of years. The brains of 286 participants were autopsied, to assess neuropathologies and mercury levels.

The average educational attainment of the participants was 14.6 years; 67% were women.

The finding tempers the evidence from many studies that eating fish reduces Alzheimer's risk. However, it is consistent with what I believe is becoming apparent: that there are different paths to Alzheimer's, and thus different factors involved in preventing it, depending on your own particular gene-environment attributes.

http://www.eurekalert.org/pub_releases/2016-02/nioe-scm020116.php

Reference: 

[4062] Morris, M., Brockman J., Schneider JA., & et al
(2016).  ASsociation of seafood consumption, brain mercury level, and apoe ε4 status with brain neuropathology in older adults.
JAMA. 315(5), 489 - 497.

Topics: 

tags lifestyle: 

tags problems: 

Alzheimer's disease consists of 3 distinct subtypes

  • A very small study points to three subtypes of Alzheimer's disease, each of which seems to be associated with:
    • different physiological abnormalities
    • different causes and risk factors
    • different symptoms / progression
    • different age-onsets.
  • This suggests that effective treatments need to be tailored to the subtype.

A two-year study which involved metabolic testing of 50 people, suggests that Alzheimer's disease consists of three distinct subtypes, each one of which may need to be treated differently. The finding may help explain why it has been so hard to find effective treatments for the disease.

The subtypes are:

  • Inflammatory, in which markers such as C-reactive protein and serum albumin to globulin ratios are increased.
  • Non-inflammatory, in which these markers are not increased but other metabolic abnormalities (such as insulin resistance, hypovitaminosis D, and hyper-homocysteinemia) are present. This tends to affect slightly older individuals than the first subtype: 80s rather than 70s.
  • Cortical, which affects relatively young individuals (typically 50s- early 70s) and appears more widely distributed across the brain than the other subtypes, showing widespread cortical atrophy rather than marked hippocampal atrophy. It typically presents with language and number difficulties first, rather than memory loss. Typically, there is an impaired ability to hold onto a train of thought. It is often misdiagnosed, typically affects people without a family history of Alzheimer's, who do not have an Alzheimer's-related gene, and is associated with a significant zinc deficiency (Zinc is implicated in multiple Alzheimer's-related metabolic processes, such as insulin resistance, chronic inflammation, ADAM10 proteolytic activity, and hormonal signaling. Zinc deficiency is relatively common, and associated with increasing age.).

The cortical subtype appears to be fundamentally a different condition than the other two.

I note a study I reported on last year, that found different molecular structures of amyloid-beta fibrils in the brains of Alzheimer's patients with different clinical histories and degrees of brain damage. That was a very small study, indicative only. However, I do wonder if there's any connection between these two findings. At the least, I think this approach a promising one.

The idea that there are different types of Alzheimer's disease is of course consistent with the research showing a variety of genetic risk factors, and an earlier study indicating at least two pathways to Alzheimer's.

It's also worth noting that the present study built on an earlier study, which showed that a program of lifestyle, exercise and diet changes designed to improve the body's metabolism reversed cognitive decline within 3-6 months in nine out of 10 patients with early Alzheimer's disease or its precursors. Note that this was a very small pilot program, and needs a proper clinical trial. Nevertheless, it is certainly very interesting.

http://www.eurekalert.org/pub_releases/2015-09/uoc--adc091615.php

Reference: 

Bredesen, D.E. 2015. Metabolic profiling distinguishes three subtypes of Alzheimer's disease. AGING, 7 (8), 595-600. Full text at http://www.impactaging.com/papers/v7/n8/full/100801.html

Bredesen, D.E. 2014. Reversal of cognitive decline: A novel therapeutic program. AGING, Vol 6, No 9 , pp 707-717. Full text at http://www.impactaging.com/papers/v6/n9/full/100690.html

tags development: 

tags lifestyle: 

tags problems: 

Limited benefit of physical activity for preventing cognitive decline

  • A large study of older adults (70+) found no cognitive benefit from a regular exercise program, compared to another social & mental intervention.
  • However, a subset of participants (those over 80, and those with poor physical function at the beginning of the study) did show improvement in executive function.
  • Participants in both programs showed no cognitive decline over the two-year period, suggesting both interventions were helpful.

A large, two-year study challenges the evidence that regular exercise helps prevent age-related cognitive decline.

The study involved 1,635 older adults (70-89) who were enrolled in the Lifestyle Interventions and Independence for Elders (LIFE) study. They were sedentary adults who were at risk for mobility disability but able to walk about a quarter mile. Participants had no significant cognitive impairment (as measured by the MMSE) at the beginning of the study. Around 90% (1476) made it to the end of the study, and were included in the analysis.

Half the participants were randomly assigned to a structured, moderate-intensity physical activity program that included walking, resistance training, and flexibility exercises, and the other half to a health education program of educational workshops and upper-extremity stretching.

In the physical activity condition, participants were expected to attend 2 center-based visits per week and perform home-based activity 3 to 4 times per week. The sessions progressed toward a goal of 30 minutes of walking at moderate intensity, 10 minutes of primarily lower-extremity strength training with ankle weights, and 10 minutes of balance training and large muscle group flexibility exercises.

The health education group attended weekly health education workshops during the first 26 weeks of the intervention and at least monthly sessions thereafter. Sessions lasted 60 to 90 minutes and consisted of interactive and didactic presentations, facilitator demonstrations, guest speakers, or field trips. Sessions included approximately 10 minutes of group discussion and interaction and 5 to 10 minutes of upper-extremity stretching and flexibility exercises.

Cognitive assessments were made at the beginning of the study and at 24 months, as well as a computerized assessment at either 18 or 30 months.

At the end of the study, there was no significant difference in cognitive score, or incidence of MCI or dementia, between the two groups. However, those in the exercise group who were 80 years or older ( 307) and those with poorer baseline physical performance ( 328) did show significantly better performance in executive function.

Executive function is not only a critical function in retaining the ability to live independently, research has also shown that it is the most sensitive cognitive domain to physical exercise.

Note also that there was no absolute control group — that is, people who received no intervention. Both groups showed remarkably stable cognitive scores over the two years, suggesting that both interventions were in fact effective in “holding the line”.

While this finding is disappointing and a little surprising, it is not entirely inconsistent with the research. Studies into the benefits of physical exercise for fighting age-related cognitive decline and dementia have produced mixed results. It does seem clear that the relationship is not a simple one, and what's needed is a better understanding of the complexities of the relationship. For example, elements of exercise that are critical, and the types of people (genes; health; previous social, physical, and cognitive attributes) that may benefit.

http://www.eurekalert.org/pub_releases/2015-08/tjnj-eop082115.php

Reference: 

[3975] Sink, K. M., Espeland MA., Castro CM., & et al
(2015).  Effect of a 24-month physical activity intervention vs health education on cognitive outcomes in sedentary older adults: The life randomized trial.
JAMA. 314(8), 781 - 790.

Topics: 

tags development: 

tags lifestyle: 

tags problems: 

Pages

Subscribe to RSS - Alzheimers prevention