How Fitness Protects Aging Brains

by Joseph Mercola

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Story at-a-glance

• A new study finds physical exercise, more than mental exercise, protects your brain against age-related changes; people who engaged in the most physical exercise showed the least brain shrinkage
• Exercise, diet, and stress management are three primary factors that play key roles in maintaining sharp mental function as you age
• Exercise promotes brain cell regeneration and production of key brain chemicals and growth factors such as BDNF, which is important in maintaining memory, skilled task performance, and overall cognitive function
• Your dietary choices are another important factor in brain health; your brain is comprised mostly of fat so requires abundant dietary fats in order to repair and regenerate; one of the most potent and bioavailable sources of animal-based omega-3 fat for your brain is krill oil
• Some of the best brain foods are fresh vegetables, berries, organic eggs from pastured hens, raw milk and meat products from pastured animals, nuts, avocados, coconut oil and olive oil
  

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Aging Americans are experiencing cognitive decline in numbers never before seen. Alzheimer’s disease has reached epidemic proportions in the United States. Consider these troubling statistics from the Alzheimer’s Association¹:

• 5.4 million Americans are living with Alzheimer’s disease. It’s estimated that up to 16 million will have the disease by 2050.
• One in eight Americans age 65 and over has Alzheimer’s. Every 68 seconds, another American develops Alzheimer’s disease.
• Alzheimer’s disease is the 6th leading cause of death in the U.S. and the 5th leading cause of death for those aged 65 and older.
• Alzheimer’s deaths increased by 66 percent between 2000 and 2008.
• One in seven of the estimated 800,000 people with Alzheimer’s lives alone, left to fend for himself/herself.

If you develop Alzheimer’s disease, it’s a far greater problem than just memory loss – it can kill you. And it makes every other medical problem much more difficult to treat. Although many will claim Alzheimer’s is not preventable, there ARE measures you can take that will lower your odds of developing age-related cognitive decline or, worst case scenario, full on dementia.

The aspect of your brain function that typically begins to decline first is connected with your working memory, or your capacity to process information. Researchers have identified five functions that tend to be the first ones to decline with age:

1. Processes requiring your attention
2. Working memory capability, or the amount of information you can work with, without losing track
3. Understanding complex text
4. Making inferences and drawing conclusions
5. Putting information into your memory and retrieving it later

Three Major Requirements for Brain Power

Cognitive changes related to aging are actually related more to today’s diet and lifestyle, rather than to the aging process itself. As you age, the cumulative effects of environmental toxins, exposure to free radicals, poor nutrition, stress and other factors take their toll on your body. What has been called “age-related cognitive decline” is really an accumulation of this damage to your cells. But this cognitive decay is NOT set in stone!

There are three primary factors that play a powerful role in maintaining sharp mental function, even as you age:

1. Regular exercise
2. The foods you choose to eat or avoid
3. Managing your emotional stress

The latest studies, discussed in the following section, really underscore just how important exercise is in order for your brain to function optimally. You already know how important it is to “exercise” your brain by learning new skills, adopting new and varied daily routines, and engaging in creative activities. Such mental and social exercises stimulate brain activity and promote new neural connections. However, physical exercise is even more important than mental exercise, when it comes to protecting your brain from cognitive decline.

Latest Studies Show Exercise Builds Bigger Brains

Size does matter when it comes to brain function. Declines in thinking and memory have been linked to actual brain shrinkage (atrophy). However, a new study published in the journal Neurology² found that physical exercise not only protects against age-related brain changes, but also has more of an effect than mentally stimulating activities.

A team at the University of Edinburgh followed more than 600 people, starting at age 70, and kept detailed logs of their daily physical, mental and social habits. Three years later, their brains were imaged for age-related changes, such as brain shrinkage and damage to the white matter, which is considered the “wiring” of your brain’s communication system.

People who engaged in the most physical exercise showed the least amount of brain shrinkage.

In contrast, subjects showed no measurable benefit from mental or social activities. The researchers were not discouraging people from engaging in mental and social activities – just emphasizing that those activities are not as effective in preventing brain atrophy as is physical exercise. Crossword puzzles just can’t compete with a regular 30-minute workout at the gym.

Because the findings showed only an association, not a causal relationship, the authors could not rule out the possibility that people with less deterioration in their brains were simply more likely to be physically active³. However, other studies tend to support the Edinburgh study’s findings.

For example, Kirk I. Erickson, PhD of the University of Pittsburgh, found that adults aged 60 to 80 walking moderately (just 30 to 45 minutes, three days per week for one year) showed a two percent increase in the volume of their hippocampus. The hippocampus is a region of your brain important for memory⁴. Erickson told WebMD:

"Generally in this age range, people are losing 1 to 3 percent per year of hippocampal volume. The changes in the size of the hippocampus were correlated with changes in the blood levels of the brain-derived neurotrophic factor (BDNF).”

BDNF is part of a cascade of proteins, produced in your brain, that promote neuron growth and prevent neuron death. Erickson also found higher fitness levels associated with alarger prefrontal cortex. He called exercise “one of the most promising nonpharmaceutical treatments to improve brain health.” The important take-away from these studies is that mental decline is NOT inevitable! Exercise is as good for your brain as it is for the rest of your body.

Exercise Protects Your Brain from Stress Hormones

Exercise increases your brain health in a variety of ways. Exercise:

• Jump-starts neurogenesis – the creation of new brain cells. Neurogenesis is thought to be especially prevalent in your hippocampus. As you age, the stem cells in your brain tend to become less active and you produce fewer new cells, which may slow your brain function.⁵
• Encourages new brain cells to join the existing neural network, instead of “rattling around aimlessly in the brain before dying.” Exercise helps the new brain cells learn how to “multitask.”
• Upregulates production of brain chemicals and growth factors, like BDNF, which is key in maintaining memory, skilled task performance, and overall cognitive function.
• Lifts your mood and helps neutralize the harmful effects of stress by boosting neurotransmitters, such as serotonin, dopamine, and norepinephrine, and may even protect your brain cells against the effects of stress hormones.
• Increases insulin sensitivity and may even help you make better food choices.

Exercise doesn’t have to be exhausting to be effective – three to five hours per week has been shown to be adequate. According to one study, the odds of developing Alzheimer's were nearly quadrupled in people who were less active during their leisure time, between the ages of 20 and 60, compared with their peers.

The Healthy Brain Diet

The third major factor in supporting your brain as you age is diet. Your brain cells cannot regenerate and repair unless they have the necessary raw materials with which to rebuild. Ideally you want to upregulate repair and regeneration in your brain and this is best accomplished by optimizing insulin and leptin signaling in your body.

The best way to achieve this optimum signaling is by lowering your carb intake and limiting your protein consumption to one gram of protein per kilogram of LEAN body mass. For most adult men this is 75 grams or less of protein every day. The key to success with this program is to replace the reduced carb and protein intake with healthy fats such as coconut oil, avocado, butter, olive oil and fats from healthy pastured animals. Coconut oil is particularly beneficial for brain health and has actually been shown to be helpful in senile dementia

The two most important nutrients for your brain are fats and antioxidants, so those will be my focus in this article. Just keep in mind these foods should be part of a more comprehensive approach to your diet. Regardless of your particular health concerns, I encourage you to take this opportunity to review my total nutrition plan.

The Most Important Macronutrient for Your Brain is FAT

Sixty percent of your brain is fat. DHA alone makes up about 15 to 20 percent of your brain’s cerebral cortex, as well as 30 to 60 percent of your retina, making it an essential nutrient for both brain and eye health. Your neuron membranes are composed of a thin double layer of fatty acid molecules. Myelin, the protective sheath surrounding your neurons, is composed of 30 percent protein and 70 percent fat.

You can protect your brain by giving it healthful fats from whole foods, such as organic eggs from pastured hens, whole raw milk from pastured cows, raw nuts, avocados, and olive oil. Eggs and dairy are a rich source of lecithin, choline and vitamin B12 – nutrients especially important for good brain function. There is also evidence that coconut oil may offer very significant protection against brain diseases such as Alzheimer’s, and may even stop brain atrophy in its tracks.

They key to brain health, is to make sure you are consuming plenty of healthy fat as I mentioned above. That will be about 98 percent of your fat or so. But it is crucial to make sure you are getting the essential fats from marine life that in the form of omega-3 fats.

I believe it’s important to get the bulk of your omega-3 fats from animal-based sources because the DHA and EPA are far more important for your health than the plant-based ALA. While ALA can convert into DHA/EPA, this conversion is severely impaired when you have elevated insulin levels, which affects more than 80 percent of Americans.In two different studies, taking 800-900 mg of DHA per day for 16-24 weeks resulted in significant improvements in memory, verbal fluency scores, and rate of learning.

Chances are you’re not getting enough animal-based omega-3 fats from your diet alone, so you may want to consider a supplement. My favorite is krill oil. Krill oil is an extraordinarily potent – and environmentally sustainable – form of omega-3 fat that contains both DHA and EPA. Krill oil is special in that it crosses the blood-brain barrier, so it’s highly bioavailable to your brain. Most people only need two to three 500 mg capsules of krill oil per day in order to get all of the DHA and EPA they need.

Fresh Fruits and Vegetables Will Help Keep Your Brain Sharp

The best sources of antioxidants are from whole foods, especially fresh fruits and vegetables. If you chose to use a supplemental antioxidant I believe astaxanthin is likely your best choice here

Your diet should be rich in vegetables, preferably organic and locally grown. In a study published in the Journal of Neuroscience, a vegetable-rich diet was found to help prevent age-related mental decline. Veggies, particularly spinach, were found beneficial in retarding central nervous system and cognitive behavioral deficits. And a six-year study involving almost 2,000 Chicago-area seniors showed that older people who ate more than two servings of vegetables each day were mentally sharper than those who ate less.

Ideally, your diet should be low in sugar, especially fructose. Experts are starting to look at memory problems like Alzheimer's as a form of brain starvation, and glucose metabolism appears to play an important role in the disease. It's already known that diabetics have four times the risk of Alzheimer's, and those with prediabetes have triple the risk.

Veggies are generally better than fruits because they are lower in sugar, but the exception is berries. Berries contain pterostilbene, which has been found to reverse some of the negative brain effects of aging. Wild blueberries are high in anthocyanin and other antioxidants, and are known to guard against Alzheimer’s and other neurological diseases. Blueberries improved learning capacity and motor skills among aged rats in animal studies.

Studies show that the sleep hormone melatonin can also help slow down your brain’s aging. Artificially aged mice treated with melatonin had reduced oxidative stress and markers of cerebral aging and neurodegeneration, indicating the melatonin offered both neuroprotective and anti-aging effects⁶. Melatonin actually has antioxidant properties that may help explain its important anti-aging role, as it helps to suppress harmful free radicals in your body and even slows the production of estrogen, which can activate cancer.

Emotional Stress Accelerates Brain Aging

Besides exercise, in order for your brain to work its best, you simply must get a handle on your daily stress. When you feel stressed, your adrenal and pituitary glands go into their “flight, fight, or freeze” mode and dump adrenaline, cortisol and dopamine into your bloodstream. Cortisol in particular can be problematic when released too frequently in your brain, so if you are spending a lot of your time stressed, you will likely experience some undesirable effects.

Persistently elevated cortisol levels are associated with accelerated aging, mood problems such as depression and anxiety, and many chronic diseases. To avoid these, you must learn how to relax and help your body reestablish equilibrium. Restoring balance after an episode of stress gets easier with practice, even for those who find it difficult to relax.You may want to experiment with yoga, meditation, breath work, or your favorite stress reduction technique.

One of the best tools for decreasing stress is EFT (Emotional Freedom Technique). EFT has been scientifically shown to significantly improve both cortisol-related stress levels and self-reported psychological symptoms after a single treatment session⁷. And EFT is easy to learn.

Two Neurotoxic Metals to Watch Out For: Mercury and Aluminum

When it comes to maintaining brainpower, what you keep out of your body is as important as what you put into it. Minimizing your exposure to mercury is extremely important for your brain. Dental amalgam fillings are one of the worst sources of mercury. If you have amalgams, you may want to consider having them removed, but you should ONLY have this done by a qualified biological dentist. And you should be as healthy as possible prior to undergoing this procedure. You may find my mercury detox protocol helpful.

Also avoid aluminum, such as in antiperspirants, cookware, etc. Avoid flu vaccinations as they contain both mercury and aluminum. And stay away from all artificial sweeteners, such as aspartame, which are highly toxic to your brain.

Finally, challenge your mind daily. Even though the most recent exercise study found mental exercise less important than physical exercise, other studies show that mental stimulation, such as traveling, learning to play an instrument or doing crossword puzzles, is associated with a decreased risk of developing Alzheimer’s – not to mention increasing your quality of life! Just for fun, check out a couple of websites that specialize in “brain games”:

• www.lumosity.com
• www.gamesforthebrain.com

Additional Strategies to Significantly Lower Your Alzheimer's Risk

What is interesting and important to understand about chronic disease is that it very rarely exists in a bubble. What I mean is, if you are developing changes in your brain that are indicative of Alzheimer's, you're probably also experiencing signs of insulin resistance, such as diabetes or obesity.

And, meanwhile, you may also be showing signs of heart disease, such as high blood pressure, as, very often, chronic diseases are intricately intertwined; they're the product of imbalances in your body that are manifesting, likely after years spent festering just below the surface. This can actually be a good thing, however, as implementing a few simple techniques address the underlying causes of multiple chronic diseases, and Alzheimer's is no exception.

This includes:

• Optimize vitamin D. In 2007 researchers at the University of Wisconsin uncovered strong links between low levels of vitamin D in Alzheimer's patients and poor outcomes on cognitive tests. Scientists launched the study after family members of Alzheimer's patients who were treated with large doses of prescription vitamin D reported that they were acting and performing better than before.

  Researchers believe that optimal vitamin D levels may enhance the amount of important biomolecules in your brain and protect brain cells. Vitamin D receptors have been identified throughout the human body, and that includes in your brain. Metabolic pathways for vitamin D exist in the hippocampus and cerebellum of the brain, areas that are involved in planning, processing of information, and the formation of new memories.

  Sufficient vitamin D is also imperative for the proper functioning of your immune system to combat excessive inflammation, and, as mentioned earlier, other research has discovered that people with Alzheimer's tend to have higher levels of inflammation in their brains.

• Fructose. Ideally it is important to keep your level below 25 grams per day. This toxic influence is serving as an important regulator of brain toxicity. Since the average person is exceeding this recommendation by 300 percent this is a pervasive and serious issue. I view this as the MOST important step you can take. Additionally, when your liver is busy processing fructose (which your liver turns into fat), it severely hampers its ability to make cholesterol. This is yet another important facet that explains how and why excessive fructose consumption is so detrimental to your health.
• Keep your fasting insulin levels below 3. This is indirectly related to fructose, as it will clearly lead to insulin resistance. However other sugars, grains and lack of exercise are also factors here.
• Vitamin B12: According to a small Finnish study recently published in the journal Neurology, people who consume foods rich in B12 may reduce their risk of Alzheimer's in their later years. For each unit increase in the marker of vitamin B12 (holotranscobalamin) the risk of developing Alzheimer's was reduced by 2 percent. Very high doses of B vitamins have also been found to treat Alzheimer's disease and reduce memory loss.
• Eat a nutritious diet, rich in folate, such as the one described in my nutrition plan. Strict vegetarian diets have been shown to increase Alzheimer's risk, whereas diets high in omega-3's lower your risk. However, vegetables, without question, are your best form of folate, and we should all eat plenty of fresh raw veggies every day.
• High-quality animal based omega-3 fats, such as krill oil. (I recommend avoiding most fish because although fish is naturally high in omega-3, most fish are now severely contaminated with mercury.) High intake of the omega-3 fatty acid DHA helps by preventing cell damage caused by Alzheimer's disease, thereby slowing down its progression, and lowering your risk of developing the disorder. Researchers have also said DHA "dramatically reduces the impact of the Alzheimer's gene."
• Avoid and remove mercury from your body. Dental amalgam fillings are one of the major sources of mercury, however you should be healthy prior to having them removed. Once you have adjusted to following the diet described in my optimized nutrition plan, you can follow the mercury detox protocol and then find a biological dentist to have your amalgams removed.
• Avoid aluminum, such as antiperspirants, non-stick cookware, vaccine adjuvants, etc.
• Exercise regularly. It's been suggested that exercise can trigger a change in the way the amyloid precursor protein is metabolized, thus, slowing down the onset and progression of Alzheimer's. Exercise also increases levels of the protein PGC-1alpha. New research has shown that people with Alzheimer's have less PGC-1alpha in their brains, and cells that contain more of the protein produce less of the toxic amyloid protein associated with Alzheimer's. I would strongly recommend reviewing the Peak Fitness Technique for my specific recommendations.
• Avoid flu vaccinations as most contain both mercury and aluminum, as well as egg proteins (e.g. myelin basic protein), which the body may produce antibodies against and that cross-react with the myelin coating your nerves, in effect causing your immune system to attack your nervous system!
• Eat blueberries. Wild blueberries, which have high anthocyanin and antioxidant content, are known to guard against Alzheimer's and other neurological diseases.
• Challenge your mind daily. Mental stimulation, especially learning something new, such as learning to play an instrument or a new language, is associated with a decreased risk of Alzheimer's. Researchers suspect that mental challenge helps to build up your brain, making it less susceptible to the lesions associated with Alzheimer's disease.
• Avoid anticholinergic and statin drugs. Drugs that block acetylcholine, a nervous system neurotransmitter, have been shown to increase your risk of dementia. These drugs include certain night-time pain relievers, antihistamines, sleep aids, certain antidepressants, medications to control incontinence, and certain narcotic pain relievers.

  One study⁸ found that those who took drugs classified as 'definite anticholinergics' had a four times higher incidence of cognitive impairment. Regularly taking two of these drugs further increased the risk of cognitive impairment. Statin drugs are particularly problematic because they suppress the synthesis of cholesterol, which is one of the primary building blocks of your brain. As Dr. Stephanie Seneff reports:

  "Statin drugs interfere with cholesterol synthesis in the liver, but the lipophilic statin drugs (like lovastatin and simvastatin) also interfere with the synthesis of cholesterol in the brain. This would then directly impact the neurons' ability to maintain adequate cholesterol in their membranes. Indeed, a population-based study showed that people who had ever taken statins had an increased risk of Alzheimer's disease, a hazard ratio of 1.21. More alarmingly, people who used to take statins had a hazard ratio of 2.54 (over two and a half times the risk to Alzheimer's) compared to people who never took statins."

• ¹ Alzheimer’s Association Factsheet March 2012
• ² Neurology October 23, 2012
• ³ New York Times October 26, 2012
• ⁴ WedMD July 16, 2012
• ⁵ New York Times April 18, 2012
• ⁶ Rev Neurol May 2011
• ⁷ ACEP 2011
• ⁸ Neurology, July 13, 2010: 75(2); 152-9

November 17, 2012

Copyright © 2012 Dr. Joseph Mercola

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