Each day of our lives we are creating memories, special moments with family and friends. We take pictures and post photos on social media. When we think about the future we think about looking back at the special times with warm smiles.We watch our children grow and mature and take shape right before our eyes. Soon enough we'll be older and today's special moments will be fond memories. Sadly for many of us as we age our memories of today and yesterday may slip into oblivion. Depending on both your genetic heritage and your current lifestyle your ability to pull together memories in the future may become more and more difficult.
Each year about one million Americans are diagnosed with Alzheimer’s disease (AD). And another 500 thousand Americans develop temporary or permanent memory loss not caused by Alzheimer's disease.
Both Alzheimer's and non-Alzheimer's dementia appear to be a result of damage to veins and arteries in the brain. The primary cause of Alzheimer's disease appears to be
caused by the buildup of an abnormal protein called amyloid. Amyloid is produced in your bone marrow and can be deposited in any tissue or organ. In the case of Alzheimer's disease, these amyloid protein clumps, also called plaque, accumulate in the brain and eventually cause so much damage that brain function is greatly diminished, with memory and executive cognitive function (the ability to do stuff from memory) affected the most.
Although researchers are not sure about what causes the plaques that result in Alzheimer's disease, they are pretty sure that most other types of dementia is caused by damage to veins and arteries as a result of high blood pressure, high cholesterol, obesity, insulin resistance, and type 2 diabetes.
Elevated homocysteine levels, on the other hand, have been linked to increased risk for developing both Alzheimer's and non-Alzheimer's dementia. High homecysteine levels are generally a result of not eating enough dark leafy greens, and other vegetables and fruits high in folate and other B vitamins. Drinking too much unfiltered coffee can also contribute to elevated levels of homocysteine.
While cardio-vascular disease (CVD) is primarily associated with the buildup of cholesterol-rich plaques in the artery wall and Alzheimer's is primarily associated with the buildup of amyloid plaques in the brain, it is increasingly clear that both Alzheimer's and CVD have many similar risk factors, including unhealthy eating habits, excess body fat, and lack of regular exercise and sleep.
Genetics is another factor. People who inherit the apoE4 allele (a protein involved in the transport of cholesterol and other lipid (fatty) substances) are much more likely to develop both Alzheimer's and cardio-vascular disease (CVD). People who inherit the apoE2 or apoE3 version of the genes are less likely to develop these diseases. Researchers in many fields caution throwing in the towel when it comes to knowing your genetic make up. The reason is due to gene suppression, something that lifestyle can influence.
In fact although the medical treatment of Alzheimer's is not very effective. It seems that lifestyle choices can actually prevent or at least slow down the onset of both Alzheimer's disease and other types of dementia. Preventing or slowing the accumulation of these amyloid plaques and the damage they cause in the brain is crucial.
Over the past several years, data from the FINGER* Study have helped clarify the important roles of diet and lifestyle factors (which have long been linked to cardio-vascular disease risk) to the development of dementia and the loss of cognitive function over time. Lifestyle-related cardio-vascular disease risk factors have increasingly been associated with dementia risk in observational studies.
The FINGER Study enrolled 1260 men and women aged 60-77 years who had taken part in previous Finnish national surveys. Inclusion criteria for FINGER were the presence of CVD risk factors, older age, and dementia. Initial cognition function tests showed that they had average or slightly lower than expected scores for their age. Over the next 2 years, the study group participants were encouraged to follow a heart-healthy diet and to exercise. They also received cognitive training (the memory/brain building activities) and had their cardio-vascular disease risk factors monitored. The results of the study showed that such intervention could have an impact on slowing or improving memory and cognitive function in people who are at risk.
The study also found that for people at greater risk of memory and cognitive function loss, adopting a healthy lifestyle including a heart-healthy diet and getting regular exercise had the most benefit. What they observed was that the strands that make up our DNA (our genes) tend to shorten as we age. The shorter our DNA strands, called telomeres, the less effective our brain is at remembering. But when we eat healthy and get lots of exercise the strands tend to lengthen or, in people at risk, they tend to not get shorter. All this means that our brains and memory stay healthy and we can hold on to our memory longer when we make healthy lifestyle choices.
A more recent paper from the FINGER study group examined secondary measures of cognitive function including memory, executive functioning, and processing speed and whether these changes correlated with any change in leukocyte DNA. The length of their DNA’s telomere was examined at the beginning of the study and again after 2 years in 775 participants (392 controls, 383 intervention). The shortening of the subjects telomeres is a biomarker of faster aging. The goal was to assess whether baseline telomere length was associated with better cognitive function than seen in the initial FINGER study. Since older age is the greatest Alzheimer's disease risk factor, the researchers wanted to see if telomere length was impacted by the participants eating a heart-healthy diet, exercising, and participating in cognitive training. Intervention and control groups did not significantly differ at baseline. The researchers observed that shorter telomeres were related to a less healthful baseline lifestyle. The intervention benefits of a healthy diet, exercise, and cognitive training on executive functioning were more pronounced among those whose initial telomere measurements were shorter (suggesting more advanced biological age). This suggests that lifestyle intervention was especially beneficial among subjects who were initially at a higher-risk of dementia. The results showed that after 2 years the heart-healthy diet and lifestyle intervention program was associated with significantly less loss of cognitive function.
The Atherosclerosis Risk in Communities (ARIC) study,published in April 2017 in JAMA, showed that our body composition also plays a role in our risk for Alzheimer's. This study examined a subgroup of 322 subjects who were an average of 52 years old at the beginning of the study 20 years ago.
These subjects underwent PET scans between 2011 and 2013 and were assessed for several cardiovascular risk factors. Elevated midlife body mass index, having at least one CVD risk factor significantly increased the risk of loss of cognitive function. These findings indicate that cardio-vascular disease risk factors long known to cause atherosclerotic plaques in arteries (hardening of the arteries) are also risk factors for amyloid plaque development in the brain, which leads to Alzheimer's disease.
The American Heart Association and American Stroke Association recently released an advisory on ways to preserve cognitive function and reduce the risk of developing dementia. They identified seven strategies that research indicates will help prevent cognitive decline and dementia.
- Do not smoke,
- Engage in regular physical activity,
- Adopt and maintain a heart-healthy diet,
- Maintain a body mass index of less than 25,
- Maintain an untreated systolic blood pressure below 120 mm Hg,
- Maintain an untreated total serum cholesterol level of less than 200mg/dl, and
- Maintain a normal fasting blood glucose level of less than 100 mg/dL.
Bottom Line: It is becoming increasingly clear that the adoption of a healthy lifestyle including a heart-healthy diet, regular exercise, and a healthy body-composition all of which have long been promoted to reduce the risk of heart disease may also be the best way to protect the brain from not only stroke but also dementia.
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Wishing you the best of healthy today and tomorrow.
*Finnish Geriatric Intervention Study (FINGER)
The majority of this post was based on the writings of James J. Kenney, PhD, FACN, with permission and attribution.
http://www.bmj.com/content/349/bmj.g4433/rr/761349 http://stroke.ahajournals.org/content/30/8/1548 Ngandu T; Lehtisalo J; Solomon A, et. al. A 2-year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomized controlled trial. Lancet 2015;385(9984) :2255-63. Sindi S; Ngandu T; Hovatta I; et. al. Baseline Telomere Length and Effects of a Multidomain Lifestyle Intervention on Cognition: The FINGER Randomized Controlled Trial. J. Alzheimers Dis 2017;59(4);1459-70. Gottesman RF; Schneider AL; Zhou Y; et. al. Association Between Midlife Vascular Risk Factors and Estimated Brain Amyloid Deposition. JAMA;317(14):1443-50. http://stroke.ahajournals.org/content/48/10/e284