Brain Health and Alzheimer’s

Foods Worth Remembering: How diet can protect against Alzheimer’s disease

Alzheimer’s disease is perhaps one of the most dreaded diseases of our time. It is the most common type of dementia and is characterized by the deterioration and death of brain cells, leading to memory loss and cognitive decline. The disease progresses until basic bodily functions are lost, followed by eventual death. As anyone who has watched a loved one succumb to the disease will attest, it is a painful and frightening disease. As baby boomers progress toward old age the rates of Alzheimer’s are expected to rise significantly, and because researchers don’t know exactly what causes the disease, there is no cure. However, we do know that the structural changes in the brain associated with Alzheimer’s disease begin to develop as early as 25 years before the onset of symptoms and a diagnosis. Many experts believe that interventions to stop the disease in its tracks years before symptoms develop are our best hope. And you guessed it—these interventions begin with food.

The Disease

For years, our understanding of Alzheimer’s disease has centered on the beta-amyloid plaques and tau protein tangles that form in the brains of Alzheimer patients. These structures damage brain cells and interfere with cell-to-cell communication. But many questions surround the hypothesis that these abnormal proteins are the cause of Alzheimer’s disease. For example, drugs aimed at breaking down the plaques have not been shown to be beneficial in improving the symptoms of Alzheimer’s disease. Also the plaques are not found exclusively in Alzheimer’s patients, but are also seen in the brains of elderly people without signs of dementia. As research questions the role these plaques and tangles play, other theories have emerged that consider Alzheimer’s not just as a disease of the brain, but as a disease of the whole body. New research is beginning to connect the dots between diseases of the vascular system and Alzheimer’s disease.

Could Alzheimer’s Be a Vascular Disease?

Alzheimer’s disease risk is greatly increased when diseases such as hypertension, diabetes, atherosclerosis, metabolic syndrome, and stroke are present—all of which are vascular diseases.[1] Of course, an association does not establish a cause and only indicates that a relationship may exist, but it has lead some researchers to hypothesize that Alzheimer’s disease is actually vascular in nature, rather than neurological. There are several ways in which these vascular risk factors may affect the brain. First, anything that interferes with blood flow, like clogged arteries, will impair the normal delivery of glucose, nutrients, and oxygen to brain cells. Likewise, impaired blood flow also impedes the removal of toxic waste products from brain cells. Decreased blood flow in the brain, or hypoperfusion, is a hallmark of Alzheimer’s disease, and may increase inflammation.[2] Bringing us to the next major connection between vascular health and Alzheimer’s disease. It is well know that inflammation affects the brains of Alzheimer’s patients and that both acute and chronic inflammation is associated with a decline in cognitive function for these people.[3],[4] Inflammation also underlies all of the vascular risk factors associated with Alzheimer’s disease. The presence of inflammatory molecules (such as C-reactive protein, or CRP) may be a critical step in the development of the beta-amyloid plaques, which then promote even more inflammation.[5] Talk about a vicious cycle!

The final connection lies in the fact that Alzheimer’s disease is also closely related to blood sugar and insulin levels, just like most vascular diseases. People with type-2 diabetes are twice as likely to develop Alzheimer’s disease, and some researchers have even begun to refer to Alzheimer’s as “type-3 diabetes.”[6] The brain is dependant on blood glucose for energy, but is also very sensitive to the spikes and dips of uncontrolled blood sugar. While the cells of the brain are not dependent on insulin to use glucose the way other cells in the body are, they are still dependent on insulin for other important functions, such as memory formation and nerve cell growth.[7],[8] Research has indicated that brain cells can and do become resistant to the effects of insulin, which then interferes with normal brain function.[9]

Brain Food

While more research is needed to fully understand the puzzle that is Alzheimer’s, there are protective dietary and lifestyle practices that can be adopted now. In fact, we know that many of the same changes that are beneficial for the vascular system are also associated with a lower risk of Alzheimer’s disease. Making the following changes in your diet now can help maintain your brain function now and in the future.

Keep your blood sugar balanced by eliminating flours and sugars from your diet. Instead focus on a variety of vegetables, organic and naturally-raised meats, wild fish, pastured eggs, unrefined olive oil and coconut oil, raw nuts and seeds, and fresh fruits.

Choose organic foods

Choose organic foods whenever possible to limit pesticide exposure. A recent study found that blood levels of the chemical DDT were four times higher in Alzheimer’s patients than in the control group.[10] Even though DDT was banned in the United States more than 40 years ago many people still have a “legacy” amount of it in their bodies. While this study focused only on DDT, most pesticides work as neurotoxins on insects and some worry that long-term exposure of these chemicals may also affect human brains.

Eat foods rich in polyphenols

Polyphenols are a category of micronutrients that act as antioxidants in our bodies. They have been shown to help protect the vascular system in general, but also to decrease inflammation in the brain, protecting nerve cells from degeneration.[11] There are many types of polyphenols and they are widely available in brightly colored plant foods. Some particularly good food sources for protecting the brain include:

Grapes (and red wine, in moderation) contain polyphenols that have been shown to reduce inflammation and decrease levels of a specific type of amyloid protein in the brain.[12]

Green tea contains the polyphenol EGCG (epigallocatechin-3-gallate) that is protective of brain cells through its anti-inflammatory and antioxidant properties.[13]

Turmeric, which contains the compound curcumin, is not only a potent antioxidant but it also appears to reduce inflammation and to prevent the clumping of proteins that eventually turn into beta-amyloid plaques.[14]

Dark chocolate is well recognized for its vascular health benefits, but the polyphenols in chocolate also improve blood flow to the brain.[15]

Darkly colored berries such as blueberries, cherries, strawberries, and blackberries are all rich in polyphenols that help protect the brain.[16]

Increase your intake of vitamin E

Increase your intake of vitamin E from foods such as sunflower seeds, almonds, leafy greens, and olives. In one study, participants with the highest dietary intakes of vitamin E were 25 percent less likely to develop Alzheimer’s disease compared to those with the lowest intakes. Vitamin E is a powerful vascular protector and maintains the health of the beneficial fats used to make brain cells.[17]

Decrease inflammation

Decrease inflammation by reducing your intake of inflammatory omega-6 fats found in processed vegetable oils (corn, soy, cottonseed, safflower), processed foods, and conventionally-raised meat, while increasing your intake of omega-3 fats. The omega-3 fatty acids have been found to improve memory in both young and old brains, and it’s been found that those who consume the most omega-3 fatty acids have 20 to 30 percent lower levels of beta-amyloid protein in their blood compared to those that consume the least.[18],[19][20] The best dietary sources of omega-3 fatty acids are cold-water, wild fish such as sardines, anchovies, mackerel, and salmon. Walnuts are another good source.

While diet is a critical starting point to maintain the health of the brain, there are other ways to protect our brains, including regular exercise, staying socially active, getting adequate sleep, managing stress, and regularly challenging the brain with puzzles or by learning new skills. Though there is a genetic component in the development of Alzheimer’s, our genes are not our destiny. By making positive changes now, you can protect your brain from the devastating changes that lead to memory loss, cognitive decline, and potentially, Alzheimer’s disease.

Recipes

Fast Curried Fish Salad

Serves 2

  • 1/3 cup mayonnaise OR 1/3 cup plain Greek yogurt
  • 1-2 teaspoons curry powder
  • ½ teaspoon turmeric powder
  • 1 teaspoon apple cider vinegar
  • 1 8-oz. can wild salmon
  • 1/3 cup chopped celery
  • 1/3 red pepper, chopped
  • 1 tablespoon currants or golden raisins
  • ¼  cup chopped apple
  • 2 tablespoons sunflower seeds

Thoroughly combine the first four ingredients in a medium bowl. Add the remaining ingredients and mix well. Allow mixture to sit for at least 10 minutes for flavors to develop. Serve over leafy greens.

Green Tea and Blueberry “Panna Cotta” Squares

Makes 9 squares

  • 1 tablespoon gelatin
  • 2-3 tablespoons cold water
  • 1 13.5-oz can full-fat coconut milk
  • 4 green tea bags or 2 teaspoons matcha powder
  • ¼ cup honey
  • ½ teaspoon vanilla extract
  • 1 cup of blueberries

In a medium bowl, combine gelatin with the cold water until no dry powder remains and set aside. Bring coconut milk just to boil then remove from the heat and add the green tea bags or matcha powder. Allow mixture to steep for 5-7 minutes, then remove the tea bags. While the tea steeps, spread the berries in the bottom of an 8”x 8” glass baking dish. Add honey and vanilla to the tea-infused coconut milk; if mixture has cooled, return it to the burner and gently warm. Once the mixture is hot again, add the gelatin and water mixture and stir well until the mixture is smooth. Pour over the berries, cover, and transfer dish to the refrigerator. Allow to cool for 2-3 hours or until mixture is set. Cut into squares and enjoy!


 

References

[1] de la Torre JC. Alzheimer’s disease as a vascular disease. Stroke. 2002;33:1152-1162.

[2] Grammes P. Neurovascular dysfunction, inflammation and endothelial activation: Implications for the pathogenesis of Alzheimer’s disease. Journal of Neuroinflammation.  2011; 8(26): 12 pages.

[3] Wyss-Coray T. Inflammation in Alzheimer’s disease: driving force, bystander or beneficial response? Nature Medicine. 2006;12:1005-1015.

[4] Holmes C, Cunningham C, Zotova E, et al. Systemic inflammation and disease progression in Alzheimer’s disease. Neurology. 2009;73(10):768-774.

[5] Grammes P. Neurovascular dysfunction, inflammation and endothelial activation: Implications for the pathogenesis of Alzheimer’s disease. Journal of Neuroinflammation.  2011; 8(26): 12 pages.

[6] Granic I, Dolga AM, Nijholt IM, van Dijk G, Eisel ULM. Inflammation and NF-κB in Alzheimer’s disease and diabetes. Journal of Alzheimer’s Disease. 2009;16(4): 809-821.

[7] Paradise C. Biology 112 – Blood Glucose, Insulin and Diabetes. Dept of Biology, Davidson College. Available at: http://www.the-scientist.com/?articles.view/articleNo/33338/title/Metabolism-and-the-Brain/

[8] Challem J. Blood Sugar, Insulin, and Brain – Could Alzheimer’s Disease be “Type 3 Diabetes?” Natural Grocers website. Oct 29, 2011. Available at: http://www.naturalgrocers.com/nutrition/blood-sugar-insulin-and-brain-could-alzheimer-s-disease-be-type-3-diabetes

[9] Talbot K, Wang HY, Kazi H, Han LY, Bakshi KP, Stucky A, et al. Demonstrated brain insulin resistance in Alzheimer’s disease patients is associated with IGF-1 resistance, IRS-1 dysregulation, and cognitive decline. J Clin Invest. 2012;122(4):1316-38.

[10] Sneed A. DDT, other environmental toxins linked to late-onset Alzheimer’s disease. Scientific American. Feb 10, 2014. Available at: http://www.scientificamerican.com/article/studies-link-ddt-other-environmental-toxins-to-late-onset-alzheimers-disease/

[11]Kresser C. How to prevent spending the last 10 years of your life in a diaper and a wheelchair. Chris Kresser website. May 2011. Available at: http://chriskresser.com/how-to-prevent-spending-the-last-10-years-of-your-life-in-a-diaper-and-a-wheelchair

[12] The Mount Sinai Hospital/Mount Sinai School of Medicine. Natural chemical found in grapes may protect against Alzheimer’s disease. ScienceDaily. July 18, 2011. Available at: http://www.sciencedaily.com/releases/2011/07/110715135211.htm

[13] Weinreb O, Mandel S, Amit T, Youdim MB. Neurological mechanisms of green tea polyphenols in Alzheimer’s and Parkinson’s diseases. J Nutr Biochem. 2004;15(9):506-16.

[14] Aggarwal BB, Yost D. Healing Spices. New York, NY: Sterling Publishing Company; 2011.

[15] Aggarwal BB, Yost D. Healing Spices. New York, NY: Sterling Publishing Company; 2011.

[16] Murray M, Pizzorno J, Pizzorno L. The Encyclopedia of Healing Foods. New York, NY: Atria Books; 2005.

[17] Challem J. Ample vitamin E may help protect against Alzheimer’s. The Nutrition Reporter. July 2011. Available at: http://www.naturalgrocers.com/nutrition/ample-vitamin-e-may-help-protect-against-alzheimer-s

[18] Challem J. Omega-3s improve memory, found to help both young and old brains. The Nutrition Reporter. June 2013;24(6): 1.

[19] Challem J. Both omega-3 fish oils and vitamin D might prevent Alzheimer’s disease. The Nutrition Reporter. July 2012:23(7):1.

[20] Gu Y, Schupf N, Costentino SA, Lucksinger JA, Scarmeas N. “Nutrient intake and plasma B-amyloid.” Neurology. 2012. Epub ahead of print.