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Alzheimer’s Disease: Up to half of cases potentially preventable

November was proclaimed National Alzheimer’s Disease Awareness Month, in recognition of the five million Americans stricken with the devastating terminal illness, now the sixth leading cause of death in the United States. A new analysis suggests that up to half of these millions of cases may have been preventable through lifestyle changes.

We’ve known for almost 20 years that compared to long-time vegetarians, those eating meat (including poultry and fish) appear to have three times the risk of developing dementia. Since studies show “even moderately elevated cholesterol increased dementia risk,” the cognitive impairment more often seen in those eating meat may be due to atherosclerotic plaque building in the brain’s blood vessels, which can cause micro-infarctions or “ministrokes” that can kill off little parts of the brain the way clogged coronary arteries can kill off parts of the heart during a heart attack. A new autopsy study found that those with cholesterol levels over 224 had up to 25 times the odds of having Alzheimer’s pathology (neuritic plaques) in their brains compared to those with cholesterol under 224.

New evidence presented in a series of videos this week suggests that this may be only part of the puzzle. Maybe it’s not just what vegetarians don’t eat, but what they do; the phytonutrients found in plant-based diets have been shown to have a wide range of beneficial effects.

Last Thursday’s video-of-the-day Amyloid and Apple Juice featured new research suggesting there are components in apples and ginger root that may protect human nerve cells (in a test-tube at least) from the neurotoxic Alzheimer’s plaque protein amyloid Beta. It’s one thing to show benefits in a petri dish, though; it’s quite another to show benefit in a human population. That came in Friday’s video-of-the-day The Nutrition Facts Missing from the Label, in which I profile the class of phytonutrients thought to be responsible for cutting Alzheimer’s risk more than 75%. Yesterday’s video-of-the-day, Best Fruit Juice, ranked ten common fruit juices for these phenolic phytonutrients (with surprising results!) and today’s video Constructing a Cognitive Portfolio suggests that different fruits and vegetables support different cognitive domains of the brain, so both quantity and variety of plant foods may be important for the prevention of dementia.

What if you or a loved one already has Alzheimer’s? Tomorrow, in Alzheimer’s and Apple Juice I’ll feature a pilot study suggesting apple juice can affect the cognitive performance, day-to-day functioning, mood, and behavior of Alzheimer’s patients. Thursday in Is Pomegranate Juice That Wonderful? I’ll show how food companies (such as POM Wonderful) invoke the First Amendment to defend false and unsubstantiated health claims, and I’ll close out the week with Pink Juice with Green Foam, a recipe for DIY whole food cranberry cocktail with 25 times fewer calories and at least 8 times the phytonutrient content of the retail corn syrup concoction.

I think this week does a good job highlighting the three criteria I use to choose among the thousands of articles I sift through annually to create the hundreds of videos I post every year: interesting, groundbreaking, practical. If you find useful, please help me spread the word by sharing this resource with others.

For my previous videos on cognition see:

-Michael Greger, M.D.


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

27 responses to “Alzheimer’s Disease: Up to half of cases potentially preventable

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  1. Please post any ask-the-doctor type questions here in the comments section and feel free to pass this important information onto loved ones!

    1. I posted this earlier as a comment to your most recent video regarding weight loss, but this seems like a more appropriate spot, so I’m re-posting here:
      Dear Dr. Greger, I’m a fellow physician and a vegan. I saw a segment on the Oz show a couple of days ago with Dr. David Perlmutter, author of
      “Grain Brain”. Dr. Perlmutter says all carbs are bad for our brain health and the worst are the ones that come from grains (including whole grains) and veggies that grow under the ground like potatoes, sweet potatoes and beets. Perlmutter also says grapes, bananas, and pineapple are also very bad for us. He advocates
      for a diet high in fat, including saturated fat. His theory seems to be the opposite of Dr. Neal Barnard’s Power Foods For The Brain. Is there science to support a causal relationship between (healthy complex) carb intake and the incidence of Alzheimer’s disease, as Perlmutter suggests? Should I eat the beets I roasted last night?

      1. Richard Schwab, please know that David Perlmutter’s and William Davis’ (author of Wheat Belly) knowledge of nutrition wouldn’t fit onto a pin head. While it’s true that some people will have allergies to some grains and/or wheat, these two have simply re-organized the Atkins Diet which even the American Medical Association and the American Dietetic Association (again two organizations with limited nutritional knowledge) have called a “nightmare” diet. I would trust Neal Barnard, Dean Ornish, T. Colin Campbell, John McDougall, Joel Fuhrman and Caldwell Esselstyn. Perlmutter, Davis and their ilk are nothing more than charlattans.

    1.  This study goes against many others that say otherwise, and this was based on a questionnaire. Not any mechanisms were discussed. I would like to see the primary study itself rather then the interpretation from the author of the article.

      1. I see so many problems in the article it is hard to know where to start. When journalists start quoting folks from Atkins Nutritionals they lose all credibility. So much confusion in lay and professional literature around carbohydrates and simple sugar(?table,glucose,fructose). I agree with Toxins comments… go to the original research. In my opinion complex carbohydrates are great. Glucose is our primary fuel and no good scientific evidence linking it to Alzheimers. Fructose can be a problem. The balance of literature comes down in favor of minimizing fats especially saturated fat and cholesterol and minimizing protein intake. The best reference is Neal Barnard’s recent book, Power Foods for the Brain. Another book is the Starch Solution by John McDougall.

    1. There is no good treatment for Alzheimer’s Disease. The best approach would be to follow recommendations from Neal Barnard’s new book, Power Foods for the Brain(see above post for my summary of key points). Very important to start early and not wait until symptoms become apparent.

  2. Would be interesting to know what’s your take on coffee’s potential in prevention of Alzheimer’s. There are many articles on this subject, saying something about prevention of amyloid formation and/or bringing down an inflammation. Would be very nice to justify coffee consumption this way! :) (although I suspect you are a strong tea devotee :))

    1. Many factors associated with Alzhemier’s Disease. The best reference is Neal Barnard’s recent book, Power Foods for the Brain. In my opinion the bottom line to minimize risk of dementia( both multi stroke and Alzheimers) is avoid cholesterol and saturated fats along with Aluminum, Zinc, Copper and Iron plus adding in exercise, sleep and cognitive activities.

      1. I’ve been eating a cup of organic blueberries with my oatmeal every morning since reading Dr. Barnard’s book, Power Foods for the Brain, and I’m seriously considering getting a Reverse Osmosis filter to reduce both the background levels of Fluoride and Aluminum sulfate in our tap water, as also mentioned by Dr. Barnard.

        I wonder if the latter is too late. We are already age 72.

        1. It is never too late to make changes to improve your health. It is always better to start earlier. The first step is to test your water to see what is in it. We get reports from our water district but the water passes through alot of pipes before it comes out of our spigot. I am constantly amazed at the bodies ability to heal itself given the proper approach.

          1. I don’t know what all is in our water. The city says no arsenic, but I had arsenic tested and .5 ppt were found; there is background fluoride, but since it’s a poison and can affect both my thyroid levels and my bones I believe that it’s worth removing. And the city admits there is aluminum sulfate used as a clearing agent. They poo-poo its harmful affects. But, I’ve read in the HSDB at TOXNET that all salts of aluminum have been linked to dementia.

            The State of Louisiana cannot be trusted for what it claims, not with the petrochemical industry controlling the legislature and university system.

  3. Is there a study which shows that adding a Reverse Osmosis water filter alters the thyroid levels in the body?

    I read one study that I read said that fluoride was once used to adjust the parameters of thyroid levels in the body. And as near as I can see, the report at the National Academies Press, Fluoride in Drinking Water: A Scientific Review of EPA’s Standards (2006) may speak on this issue in chapter 8, Effects on the Endocrine System.

  4. I am really into eating vegan and these articles and videos are helping me to eat even better. I’m very thankful to you, Dr. Greger for the info.

    Recently, comments in a NYTimes article about Alzheimer’s led me to read about the work of Dr. Bredesen.
    His theory and practice make sense. And he’s apparently getting results.

    But the “no grains, no beans” thing is not going to work for me. I already gave up bagels, dammit!
    Any thoughts?

  5. Hi I’m a health support volunteer. Thanks for your great question. I think this is part of the “grain brain” idea that is on the low carb band wagon. Okinawa Japan had the highest longevity and some of the lowest disease rates, including dementia, before they started adopting our western diet and their diet was high in beans. I concur that we need to get processed grains out our diets, but not whole grains and beans. Keep the bagels out. But keep the beans and whole grains in. I would look at some of the videos Dr. Greger has done on Alzheimers and beans.


  6. Thanks to Dr. Greger for his highly informative materials, including those here.

    I wonder how this information intersects with growing evidence that the main cause of Alzheimer’s may be brain infection by oral bacteria. Two papers provide this evidence. The first is by the Swiss neuropathologist J. Miklossy, who finds that more than 90% of autopsied Alzheimer patient brains are found to be infected with oral spirochetes, similar to the syphilis bacterium, a known cause of dementia. Separately, the Lyme bacterium is found to infect about 25% (but less than 2% of controls). One important fact: amyloid beta has been found to be an anti-microbial protein, so its proliferation in AD brains may be a response to infection. The bar charts from Miklossy’s paper, by themselves, are informative:

    The second paper is by the NYU periodontist A. Kamer, who finds that just four biomarkers found in the blood, three of which are antibodies to oral bacteria associated with periodontal disease, provide an 82% accurate diagnostic for Alzheimer’s (see Table 5):

    If AD is caused largely by oral bacteria, it might be found that better oral hygiene and health might help to prevent it.

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