Science is Linking Alzheimer’s and Heart Disease

Alzheimers CroppedFor many years, Alzheimer’s disease has bewildered the scientific world. However, recently researchers have discovered many triggers and biological characteristics of Alzheimer’s disease, giving them a better understanding of how it develops. The surprise is that it is connected to heart disease. At the turn of the century, researchers reported a high prevalence of heart disease in people with Alzheimer’s. Then, they discovered similar biological markers in the two diseases, including free radicals and cholesterol.

The Big Picture

It may all come down to blood flow. When blood vessels are stiffened and hindered by plaque build up, blood flow is reduced. That limits the amount of oxygen that can be delivered to parts of the body, such as the brain. In the brain, when plaque in blood vessels reduces available oxygen, free radicals form and damage delicate structures. Damage in the brain over time leads to dementia, including Alzheimer’s disease.

Quick Insight into Alzheimer’s Disease

Alzheimer’s disease is a form of dementia in which the brain develops amyloid plaques, tangles and loses connections between brain cells. These physiological changes to the brain result in trouble with thinking, remembering and reasoning. At first, just a small area of the brain experiences physiological changes, but as the area expands more brain tissue becomes affected resulting in progressively worsening dementia.

Risk Factors for Alzheimer’s

Genetics, lifestyle and environment each affect one’s risk of developing Alzheimer’s disease. Of those we can control, research suggests that nutritious diets, physical exercise, socializing and stimulating mental activities may reduce the risk of cognitive decline and Alzheimer’s disease.

Disease Development Theories

For more than 20 years, the amyloid cascade hypothesis continues to dominate thinking as to how Alzheimer’s disease develops. The hypothesis is that a build up of toxic β-amyloid initiates a series of events that causes degeneration of the brain and symptoms of Alzheimer’s. According to a clinical trial at the University of British Colombia, as plaque builds in blood vessels and less oxygen reaches the brain, gene expression changes causing more β -amyloid plaque formation. In other words, as plaque builds up in the brain it spins a vicious cycle leading to more plaque, less oxygen and a worsening environment in the brain.

A Cholesterol Connection

For a long time physicians have considered high levels of cholesterol plays a role in heart disease and now researchers say it plays a role in Alzheimer’s disease. In the brain, high cholesterol levels stimulate an increase in β-amyloid, which forms deposits or plaques in neurons that cause Alzheimer’s disease. Studies have looked into the potential of cholesterol-blocking drugs as a treatment of Alzheimer’s by helping to block the production of β-amyloid plaque. Clinical trials using cholesterol-blocking drugs are showing positive results in reducing plaque formation in the brain, but do not appear to offer a cure or prevention. A natural alternative to these drugs is red yeast rice, which is not available in Canada. Or, glucomannan, some Lactobacilli probiotics and psyllium fibre can lower cholesterol through a different mechanism of action.

A Little Sunshine to Help

According to research out of Germany, published late in 2013, vitamin D3 appears to beneficially reduce amyloid peptide formation and helps improve its degradation. The study suggests vitamin D3 supplements may be beneficial in Alzheimer’s disease prevention. Vitamin D3 is available to your body in supplement form, or if it’s the right season (or you live at the right latitude) you can have your skin make it for you by exposing your skin cells to sunlight.

Time for a Food Swap

Lowering blood cholesterol levels is important for both reducing plaque formation in vessels around the heart, as well as β-amyloid plaque formation in the brain. Perhaps it’s time to replace deep-fried chicken wings and reclining chairs for chickpeas and a stationary bike. It’s also time to start thinking about a diet that reduces LDL – that’s one that minimizes refined, processed and simple sugars, and increases good fats (such as omega 3 and 6). A healthy diet may also include a glass of red wine.

Drink to Your Health

Cheers to your brain and your heart! Researchers have known for decades about red wine’s ability to promote heart health, called by scientists ‘The French Paradox.’ And, perhaps as no surprise, what is good for the heart may also be good for the mind: a glass of red wine helps reduce plaque build up in your brain. Population studies have found moderate consumption of red wine is linked to a lower incidence of Alzheimer’s disease. Scientists believe it is the resveratrol in red wine that can be thanked – resveratrol appears to enhance intracellular breakdown of β-amyloid, thus preventing plaque formation in the brain.

Inflammation in Alzheimer’s

Another area of interest to Alzheimer’s researchers is inflammation seen in the disease; yet, researchers are still unsure exactly how it is triggered. It may be caused by hypoxia (a lack of oxygen in the brain). Researchers have shown that when neurons are deprived of oxygen they increase their production of not only β-amyloid but of free radicals. Free radicals destabilize proteins, cell membranes and DNA causing damage. Luckily, we have antioxidants to neutralize free radicals, preventing damage. At the University of Leeds, researchers discovered that neurons that don’t get enough oxygen open more calcium channels, which leads to an increased chance of cell suicide. What is most exciting about the research at the University of Leeds is the calcium pathways that free radicals open can be closed by antioxidants.

Antioxidants for Health

There is a growing body of research suggesting that antioxidants are very helpful in the fight against Alzheimer’s disease. The Cache County Study investigated the effects of antioxidant vitamin supplements in over 4700 patients in the United States. They found the combined use of vitamin E and C, or a multivitamin including vitamin C, reduced prevalence and incidence of Alzheimer’s disease. Perhaps this connection between antioxidant intake and Alzheimer’s should come as no surprise – scientists have known for years about antioxidants’ ability to prevent heart disease.

Supplements with Promise

Alzheimer’s research is showing promising results in the areas of lemon balm extract, panax ginseng, alpha-lipoic acid, phosphatidyl choline and omega-3 fatty acids. Also, there are researchers debating as to the potential benefits of vinpocetine in dementia patients including Alzheimer’s. 

Today we know more about Alzheimer’s disease and how it develops. With so many similarities in its etiology to heart disease, there are many heart healthy lifestyle choices one can do that may also help your brain. What is good for your heart is good for your mind. 

Ways to Help the Heart and Mind

  • Switch to a diet that promotes low LDL
  • Eat lots of antioxidants
  • Supplement with vitamins (E and C particularly)
  • Reduce stress (meditate, yoga)
  • Exercise
  • Use your brain (puzzles, socialize, reading)
  • Research natural supplements like lemon balm, omega-3s and vitamin D3

References:

Grimm MO et al. Impact of Vitamin D on Amyloid Precursor Protein Processing and Amyloid-β Peptide Degradation in Alzheimer’s Disease. Neurodegener Dis. 2013 Oct 30. http://www.ncbi.nlm.nih.gov/pubmed/24192346

Health Canada – Glucomannan Monograph. http://webprod.hc-sc.gc.ca/nhpid-bdipsn/monoReq.do?id=105

Hoglund K et al. Effect of HMG-CoA reductase inhibitors on beta-amyloid peptide levels: implications for Alzheimer’s disease. CNS Drugs. 2007;21(6):449-62. http://www.ncbi.nlm.nih.gov/pubmed/17521225

Hypoxia and Alzheimer’s Disease. The Journal of Quality Research 2007, Issue 4. www.alzheimers.org.uk/site/scripts/download.php?fileID=156

National Center for Complimentary and Natural Medicine. Red Yeast Rice. http://nccam.nih.gov/health/redyeastrice

Marambaud P, Zhao H, Davies P. Resveratrol promotes clearance of Alzheimer’s disease amyloid-beta peptides. J Biol Chem. 2005 Nov 11;280(45):37377-82.

http://www.ncbi.nlm.nih.gov/pubmed/16162502

National Institute of Healthy Aging http://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-fact-sheet

Obulesu M, Rao DM. Effect of plant extracts on Alzheimer’s disease: An insight into therapeutic avenues. J Neurosci Rural Pract. 2011 Jan;2(1):56-61. http://www.ncbi.nlm.nih.gov/pubmed/21716802

Shinto L, et al. A randomized placebo-controlled pilot trial of omega-3 fatty acids and alpha lipoic acid in Alzheimer’s disease. J Alzheimers Dis. 2014;38(1):111-20. doi: 10.3233/JAD-130722. http://www.ncbi.nlm.nih.gov/pubmed/24077434

Smith IF, et al. Hypoxic remodelling of Ca2+ mobilization in type I cortical astrocytes: involvement of ROS and pro-amyloidogenic APP processing. J Neurochem. 2004 Feb;88(4):869-77. http://www.ncbi.nlm.nih.gov/pubmed/14756807

Sparks, D. L., Martin, T. A., Gross, D. R. and Hunsaker, J. C. (2000), Link between heart disease, cholesterol, and Alzheimer’s disease: A review. Microsc. Res. Tech., 50: 287–290. http://onlinelibrary.wiley.com/doi/10.1002/1097-0029(20000815)50:4%3C287::AID-JEMT7%3E3.0.CO;2-L/abstract;jsessionid=9BE8E2EDC1FB34F253AB3624C0FE9EF9.f04t04?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Schott, J and Revesz T. Inflammation in Alzheimer’s disease: insights from immunotherapy

Brain (2013) 136 (9): 2654-2656 http://brain.oxfordjournals.org/content/136/9/2654.extract

Sun X, He G, Qing H, et al. Hypoxia facilitates Alzheimer’s disease pathogenesis by up-regulating BACE1 gene expression. Proc Natl Acad Sci USA. 2006 Dec 5;103(49):18727-32.

 Zandi PP, Anthony JC, Khachaturian AS, et al. Reduced risk of Alzheimer disease in users of antioxidant vitamin supplements: the Cache County Study. Arch Neurol. 2004 Jan;61(1):82-8. http://www.ncbi.nlm.nih.gov/pubmed/14732624