Latest Research on Prevention of Alzheimer’s Disease

More than five million Americans are living with Alzheimer’s Disease (AD) which ranks as the sixth leading cause of death in the US.¹ Research into the prevention of AD ranges from diet and exercise, to dietary supplements, the microbiome, cognitive training, hypertension control, and the most recent and novel approach, utilizing body composition analysis to reverse or prevent brain changes. No cause has been identified to date.

Food

In persons who carry the ApoE4 gene variant, recent studies have shown that a high cholesterol, high fat and sugar diet may influence the development of AD. The relationship appears to be linked by inflammation that is found in obese persons and those with AD.²

The Mediterranean diet with its emphasis on vegetables, legumes, fruits, whole grains and healthy fasts such as olive oil and tree nuts with less red meat and dairy products as staples in the diet may delay the decline in cognitive function and AD.³

Exercise and Body Composition Goals

Physical activity has many health benefits with some related to cognitive health including stroke prevention. Encouraging research is demonstrating that exercise can slow the advent and progression of cognitive decline.⁴

Thirty-three unique studies on exercise and risk reduction of AD generated the following statement: “Regular participation in physical activity is associated with a reduced risk of developing Alzheimer’s disease. Among older adults with Alzheimer’s disease and other dementias, regular physical activity can improve performance of activities of daily living and mobility, and may improve general cognition and balance.”⁵

Exercise has been shown to help the body dispose of the AD causing amyloid proteins. By utilizing body composition analysis, one physician and researcher, believes that he may have found keys to preventing or delaying AD. He found that the less body fat mass and the more lean muscle mass a person has, the healthier their brain seems to be. The research focuses on prevention knowing that Alzheimer’s disease can begin 20-30 years before it presents itself, therefore there is time to make brain-healthy diet and activity changes that delay the onset of dementia and AD. By regularly using body composition scores, patients can see their changes in fat mass and lean mass and the impact diet and exercise are having on their brain health. ⁶

Antioxidants         

Natural herbal and nutrient compounds with anti-oxidative properties have the ability to prevent cognitive decline and dementia by protecting the function and integrity of the blood-brain barrier (BBB).⁷ Vitamins A, C, and E are among the most potent antioxidant vitamins and may improve cognitive decline and neurodegenerative changes by preserving the function and structure of the BBB.⁷

Gingko Biloba is a free radical scavenging supplement that may be of benefit by reducing the damage and oxidation of mitochondria and nuclear DNA often damaged in AD patients. Low folate status is also associated with poor cognitive function and dementia in the elderly and supplementation with folic acid may provide some protective effect for AD risk.³ Other natural antioxidants with emerging neuroprotective antioxidant properties include garlic, melatonin, resveratrol, and alpha lipoic acid.^4,7

Microbiome

In recent years researchers have begun to understand the importance of the gut microbiome in health and disease, and now its relationship to obesity, type 2 diabetes (T2DM), and more recently, AD. Evidence continues to mount regarding the role of the gut microbiota and obesity and obesity linked metabolic and neurologic diseases. T2DM is a risk factor for AD and thus directly, or indirectly, impacted by the gut microbiome.⁸

A review of epidemiological, genetic, environmental, and experimental studies revealed evidence that for some AD individuals the early life overgrowth of oral anaerobes provoked a pro-inflammatory innate response weakening the BBB and promoting the pathogenesis of AD.⁹

Hypertension and High Cholesterol

NIH clinical trials are looking at the impact of hypertension and high cholesterol as risk factors since most individuals with AD are older and often have a history of cardiovascular disease including hypertension and stroke.⁴

Socially Active

Epidemiological studies have demonstrated that those persons who are socially active and intellectually stimulated are at lower risk of cognitive decline and AD as they age. What is not known, however, is there a cause and effect relationship? Does mental concentration create a reserve that protects the person from cognitive decline, or are people who are at biologically lower risk, physically and mentally, naturally more active and thus possess a greater mental reserve?¹⁰

Summary

Regardless of age and genetics, there are certain lifestyle factors that appear to delay or possibly prevent the onset of AD. As with many other chronic lifestyle-related diseases, diet and physical activity can have a profound effect on AD development. Gut microbiota related to diet as well as oral health, impact T2DM and now it appears may impact brain health and AD. Dietary antioxidants, and in some cases supplements, may confer benefit. A newer approach to prevention is focusing on body composition by decreasing fat mass and increasing lean mass resulting in a healthier brain and it appears to be a coming resource for avoiding AD before the first noticeable symptoms of memory loss occur. With growing numbers of persons experiencing dementia and AD, more research may find healthy diet and sustained exercise as a person ages are the most important keys to prevention.

By Sarah E Harding Laidlaw, MS, RDN, MPA, CDE

References

1. Alzheimer’s Association. 2017 Alzheimer’ Disease Facts and Figures. Available at https://www.alz.org/facts/overview.asp. Accessed June 26, 2017.
2. University of Southern California. “Poor diet, plus Alzheimer’s gene may fuel disease: could a healthy diet protect against the onset of Alzheimer’s disease?” Science Daily. Science Daily, 13 June 2017. <sciencedaily.com/releases/2017/06/170613102059.htm>
3. Arab L, Sabbagh MN. Are certain lifestyle habits associated with lower Alzheimer disease risk? J Alzheimers Dis. 2010; 20(3): 785–794. doi: 10.3233/JAD-2010-091573.
4. National Institute on Aging. Preventing Alzheimer’s disease, what do we know? The search for Alzheimer’s disease prevention strategies. Available at https://www.nia.nih.gov/alzheimers/publication/preventing-alzheimers-disease/search-alzheimers-prevention-strategies. Accessed June 29, 2017.
5. Ginis KAM, Heisz J, Spence JC, et al. Formulation of evidence based messages to promote the use of physical activity to prevent and manage Alzheimer’s disease. BMC Public Health. 2017; 17:209 DOI 10.1186/s12889-017-4090-5.
6. https://www.inbodyusa.com/blogs/case-studies/how-the-alzheimer-s-prevention-clinic-used-body-composition-to-improve-patient-outcomes?mc_cid=104e87b8f0&mc_eid=df26ba4212. Accessed June 29, 2017.
7. Lam V, Hackett M, Takechi R. Antioxidants and dementia risk: Consideration through a cerebrovascular perspective. 2016; 8:828. DOI: 10.3390/nu8120828.
8. Naseer MI, Bebe F, Alqahtani MH, et al. Role of gut microbiota and obesity, type 2 diabetes, and Alzheimer’s disease. CNS & Neuro Disord – Drug Targets. 2014; 13:305-311.
9. Shoemark DK, Allen SJ. The microbiome and disease: Reviewing the links between the oral microbiome, aging and Alzheimer’s disease. J Alz Dis. 2015; 43:725–738. DOI 10.3233/JAD-141170.
10. Andrade C, Radhakrishnan R. The prevention and treatment of cognitive decline and dementia: An overview of recent research on experimental trials. Indian J of Psychiatry. 2009; 51(1):12-25. doi:10.4103/0019-5545.44900.