Tips to Keep Your Brain Healthy

Is Cognitive Decline With Age Inevitable?

This blog post is a special feature about how to improve and maintain your mental acuity. You may have been told that as you age, you can expect your cognitive function to decline. This is not a foregone conclusion. We now know that cognitive decline is as much a function of lifestyle as age. In fact, many large-scale studies show that people can make some fairly simple lifestyle changes to maintain and even improve cognitive health as they age.

What Is the FINGER Study?

For example, the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) was a two-year intervention of diet, exercise, cognitive training and blood pressure monitoring in older Finnish adults at risk for dementia (Ngandu et al., 2015). The program intervention was very modest. It consisted of dietary advice, a combination of aerobic and strengthening exercises up to five times weekly, 72 sessions (total) of 10- to 15-minute cognitive training, and meetings every three months with a study nurse to monitor weight and blood pressure and recommend seeing a doctor if intervention was needed.

In my opinion, the FINGER protocol could have made stronger diet recommendations. They recommended eating many fruits and vegetables (excellent), low-fat dairy (full fat would be better), meat, vegetable margarine and oil rather than butter, olive and avocado oils, and fish at least twice per week. As you will see in Chapter 6: Diet in my eBook More Light, a low-fat diet does not decrease cardiovascular risk, and vegetable oils are no safer than butter.

Despite these weaknesses, the intervention group showed improvements in overall cognitive function, executive function (planning and problem-solving), and processing speed. No improvement was noted in memory. The FINGER study offers proof of concept that by addressing several modifiable risk factors at the same time, people with mild cognitive decline can improve function and not merely avoid getting worse.

Since the FINGER study was published, it has been estimated that 45% of the risk factors for dementia are modifiable (Livingston et al., 2020). Some risk factors require changes in public policy, such as ensuring access to education and decreasing air pollution. Others can be acted on by individuals, such as wearing a hearing aid, getting treatment for high blood pressure, and stopping smoking (or, better yet, not starting in the first place).

The FINGER study group is now conducting multiple large-scale studies worldwide to learn more about how diet and lifestyle can improve cognitive health.

Can Cognitive Ability Be Improved? (Spoiler alert, the answer is yes, through neuroplasticity.)

If I got your attention with those optimistic study findings, you may be asking what you need to do to maintain and improve your sharp brain. Good brain health requires the ability to continue creating new neural connections (synapses) throughout the lifespan. Without neuroplasticity to make new connections, we would slowly lose those we have, and our function would steadily decline.

It turns out that growing new neural connections depends on switches in the brain that are either set to “GROW” new neural connections or “BREAK DOWN” those that exist (Bredesen, 2017). Bredesen calls the two modes “synaptoblastic,” which means to grow, and “synaptoclastic,” which means to break down. Growing new neural connections (neuroplasticity) requires multiple biological processes, including the presence of nerve growth factors, the best-known of which is brain-derived neurotrophic factor or BDNF.

Brain-derived neurotrophic factor (BDNF) was first discovered in 1982 by Joseph L. Barde, a German biologist, and his colleagues. It is one of a group of molecules that play critical roles in the growth, survival, and repair of neural connections and pathways. BDNF is important for neuroplasticity, our ability to rewire the brain to learn and remember new things. 

So far, so good. You may be wondering how to ensure you have enough neural growth factors to keep the brain switched to “GROW” rather than “BREAK DOWN,” which leads to losing neuronal connections and even neuronal death.

In this blogpost, I share 7 strategies proven to increase your overall health and cognitive function through increased BDNF and neuroplasticity. Suppose you are already in a neuroplasticity-based “brain training” program. In that case, you may progress faster if you maintain your brain health by implementing some of the no-to-low-cost self-management strategies discussed below.

1. Increase Exercise as You Are Able

Exercise improves cognitive health in healthy older adults and adults with cognitive decline. Over 1,000 clinical trials in humans measure the impact of exercise on brain health. A recent review of 98 well-designed controlled studies shows that exercise benefits the overall ability to think clearly, quickly and accurately, as well as attention span, planning and problem-solving (Gomes-Osman et al., 2018).

Effective exercise types include

• aerobic activities such as walking, swimming or dancing,
• high-intensity interval training,
• resistance (strength) training,
• some less vigorous activities such as yoga and qi gong, and
• combinations of the above.

In studies, the average successful participant engaged in exercise

• 1 hour/day,
• three times/week,
• for 6 months or more.

Those who improved were more likely to have

• done moderate to vigorous exercise, and
• exercised for more than 60 hours cumulatively over time.

Exercise works by increasing arousal and waking the brain up so it realizes you are asking something of it. Despite tempting programs that claim you can learn things in your sleep, this isn’t biologically possible. An awake and alert brain is more likely to rewire and learn. BDNF and neuroplasticity mediate these positive changes. Virtually all successful anti-dementia programs, including the FINGER studies mentioned above, include exercise as a key component.

The keys in real life include

• overcoming post-exertional malaise so that you can exercise,
• finding an activity you enjoy and will be motivated to do on a regular basis,
• engaging activity buddies to keep you motivated, 
• pairing activity with other things you enjoy, like talking to friends by phone while walking,
• being active regularly so that the activity hours increase over time.

2. Try the MIND Diet

It cannot be overstated that to function optimally and refrain from decline, the brain must have the nutrients it needs.

There is substantive evidence that the Mediterranean diet is beneficial for brain health. The DASH diet was designed to benefit people with high blood pressure. It is more restricted than the Mediterranean diet in terms of recommended limits for salt, saturated fat from animal sources and added sugar.

The two diets have been combined into one called the MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diet. The MIND research study specifically tailored a diet to promote cognitive health. Participants who followed the MIND diet had a 53% lower risk of developing Alzheimer's disease. Even those who didn’t adhere perfectly had a 35% reduction (Morris et al., 2015).

You can read more about the MIND diet at the MIND website. The reported benefits are remarkable, given that the MIND diet is suboptimal, in my opinion. They recommend only two servings of vegetables/day. Olive oil was used for cooking. This may not be optimal given the low smoke point of olive oil. Avocado oil, ghee and coconut oil are better in this regard. They suggested three servings of whole grains/day. This is a heavy starch load for people with metabolic challenges. And they recommend fish only once per week.

It is often the case that after an exciting research finding is published, other groups repeat the study and don’t get the same results. A 2024 study found that adherence to the MIND diet decreased the risk of dementia by only 4% rather than 53% (Sawyer, Blair, Shatz, Manly, & Judd, 2024). Nevertheless, when it comes to brain health, every small step helps.

What is it about the Mediterranean diet that might help brain health? I discuss several possibilities in Chapter 6: Diet in my eBook More Light. Here, I will focus on one of the most important dietary components for brain health: fish, especially small, fatty fish like sardines and mackerel, which are rich in omega-3 fatty acids.

The brain is 60% fat by weight and needs a hefty supply of certain types of fat, including omega-3 fats, to stay healthy. It is thought that easy access to seafood in coastal paleolithic humans is the reason for the growth of the human brain and man’s world dominance.

DHA, or docosahexaenoic acid, is found in high concentrations in the brain, eyes, and heart. It plays a crucial role in brain development, cognitive function, and overall neuronal health. DHA’s sister molecule EPA, or eicosapentaenoic acid, is very important for mood and is as effective in treating depression as the SSRI drugs. I discuss the anti-depressant protocol for EPA in Session 8: Psychological Symptoms of my manual Let Your Light Shine Through.

How much fish/fish oil does one need to improve brain health? An average 1000 mg capsule of fish oil contains 200 mg DHA. A healthy person may want to supplement with 500 mg DHA daily if they don’t eat fish often. Someone with neurological problems or dementia may want to take 1000 mg DHA daily (5 capsules).

3. Increase Mental Stimulation

No discussion of brain health would be complete without talking about what is commonly called “brain training.” Remember those switches I mentioned in the introduction? They are either set to grow or break down neural connections. These switches are stimulus-dependent, which means that they require brain activity to be turned on. The strongest stimulus is when we use our brains. The brain is not a muscle, but keeping it fit requires regular workouts—doing things that require focus and effort.

Many forms of brain training have been shown to enhance cognitive function by increasing BDNF. Popular programs showing benefits in controlled research studies include BrainHQ and CogniFit. I find the evidence supporting Brain HQ among the most compelling. It focuses on improving auditory and visual processing speed. When you process information faster, many other functions improve. For example, Brain HQ has been shown to decrease the rate of automobile accidents in older adults.

As with exercise, results can be seen relatively quickly, sometimes after only 2 months of regular practice. The recommended practice time varies from (Nguyen, Murphy, & Andrews, 2022)

• 20 - 30 minutes/day,
• 3 - 5 days/week,
• for a total of 90 - 150 minutes/week, depending on the protocol.

The same training strategies benefit healthy older adults and people showing early signs of decline (minimal cognitive impairment MCI).

4. Improve Sleep 

The duration, quality and timing of sleep are all critical for brain health. We produce BDNF during deep sleep and REM (dreaming) sleep. During the night, if asleep, BDNF helps us hardwire the memories created during the previous day. Therefore, getting enough deep and REM sleep is critical to learning and remembering new information and skills.

If you take time for neuroplasticity-based practice during the day, following this up with good-quality sleep may help you progress faster.

A recent study showed that people who sleep less than 6 hours a night during middle age (50s and 60s) are at a 30% higher risk of developing dementia as they get older (Sabia et al., 2021). To learn more about how to get a good night’s sleep, consider my Self-Study Sleep Pathway.

5. Manage Stress

You are undoubtedly aware of the negative effects chronic stress can have on health. This effect is mediated by cortisol, sometimes called the stress hormone. I have talked before about how this negative impact is mediated in part by our beliefs about stress. If we believe stress to be harmful, cortisol levels go up more, and the negative effects increase.

Even temporary increases in cortisol levels decrease BDNF temporarily. This has a negative impact on cognition and may decrease the birth of new neurons in the hippocampus or memory center of the brain. Acute stress causes short-lived effects, while chronic stress leads to longer-lasting impacts. The diagram shows how this works in the brain.

If you are interested in the science behind this diagram, here are some key findings (Numakawa & Kajihara, 2023):

• Chronically high cortisol levels lead to brain inflammation, decreased brain plasticity and neuronal death.
• Chronically high cortisol levels lead to the accumulation of amyloid beta and tau in the brain. These molecules are associated with Alzheimer’s Dementia.
• The adverse effects also occur if steroids are being taken for medical treatment.
• Injecting the BDNF gene into the brains of mice genetically modified to develop dementia leads to improved cognitive function.

As an aside (stay tuned for an upcoming blog), it turns out that cortisol level also impacts mood. For this reason, the tips in this blogpost are also helpful to stave off and recover from depression.

Finding ways to understand, accept, and manage daily stressors could help you maintain your most valuable asset—your brain. Notice that I don’t recommend avoiding stressors. This is impossible. Life is uncertain and always changing. The key is to maintain a sense of calm and safety in the face of uncertainty and disappointment. Some people benefit from mind-based strategies such as practicing positive self-talk or meditation. Some benefit more from body-based strategies such as paced breathing, progressive muscle relaxation or exercise.

I find perspective is key. If I understand that stress is an unavoidable part of life and I lean into the stress instead of being frustrated by it, I can ride the waves of stress much more easily. I love water metaphors. Imagine riding through a stressful period as you might raft down a stream or river. If you let the river carry you downstream, you can let go and relax, knowing you will end up downstream no matter what. How could you stay calm, save your energy, keep your cortisol level low, and hang on for the ride?

6. Minimize Toxic Exposure

For the brain to function optimally, you not only need to supply enough of the things it requires, like healthy food, but you also need to avoid exposing it to toxic substances. Unfortunately, in our modern world, toxins are everywhere and impossible to avoid. Luckily, we can take steps to decrease our exposure.

Two well-studied brain toxins are alcohol and smoking tobacco, both of which reduce BDNF levels and negatively affect brain health. I’ll focus here on alcohol since the guidance for consumption has recently changed. There is no change in guidance for smoking – it is better to avoid smoking any substances altogether.

We used to think that some alcohol was OK, even good for health. Remember the theory that the French are healthier because they drink red wine, which contains the polyphenol resveratrol? It turns out the amount of resveratrol in red wine isn’t enough to do much good.

And new Canadian guidelines for safe alcohol consumption based on recent research suggest limiting intake to one drink/week for women and two for men. Yes, you read correctly – per week. This is down from the previous recommendations (still on US websites) that 1-2 drinks daily is OK. The shift came from research showing that even in small amounts, alcohol is toxic to the brain. Click here for a one-page summary of the 2023 guidelines from Health Canada and the Canadian Centre on Substance Use and Addiction.

How does alcohol impact the brain? Alcohol disrupts the critical blood-brain barrier. A leaky brain allows toxins and infections to lead to neuroinflammation. As our body metabolizes alcohol, free radicals are generated, and these are neurotoxic. According to the guidelines, even moderate drinking impairs neuroplasticity and memory.

In addition, anything that decreases mitochondrial function negatively affects brain health. The brain is a high-energy user and relies on healthy mitochondria to produce that energy in the form of ATP. Common substances that impair mitochondrial function include:

• heavy metals like lead, mercury and cadmium,
• some antibiotics like tetracyclines,
• statin drugs used to lower cholesterol,
• many cancer chemotherapy drugs (after weighing the risk/benefit ratio, you may choose to continue these drugs despite the risks),
• metformin, a common diabetes drug,
• toxic mold like Stachybotrys and
• anything that increases oxidative stress.

To learn more about how to support your mitochondria, check out this recent blogpost from August 2024.

7. Spend Time in Nature

I won’t go into depth about the benefits of nature in this blogpost as I’ve created several recent posts about it on my YouTube channel and in other blog posts. Suffice it to say that our mitochondria, hormones and neurotransmitters (all necessary for good brain health) depend on exposure to natural sunlight every day to function optimally. And to maintain our body’s electric voltage we need to be connected to the earth—a practice called earthing. So, walk in nature, barefoot if possible, dip into a stream or lake and hug a tree. Your brain will thank you. To read more about earthing, see this blogpost from October 2024.

A Summary of How to Restore Normal Brain Function

Even if you have early signs of cognitive decline, there is hope. The brain and the body are inextricably connected. Therefore, to maintain and even improve your cognitive function as you age—yes, this is possible—you need to do what you can to maintain your overall health. If you sit around eating Twinkies and playing mindless video games, your brain will think it is not needed, and the switch will turn from GROW to BREAKDOWN.

To help your brain thrive, consider these 7 strategies.

1. Exercise as much as you are able.
2. Consider a Mediterranean-type diet rich in colorful plant-based foods and fatty fish.
3. Do something to stimulate your brain, ideally, something you enjoy, so you will do it regularly for 90 - 150 minutes/week.
4. Find ways to get good quality sleep every night.
5. Find ways to manage your stress, including changing your mindset about it.
6. Minimize your exposure to brain and mitochondrial toxins.
7. Spend time outside in nature, and to get the healthy ions from the earth, consider hugging a few trees.

References

Bredesen, D. E.,. (2017). The End of Alzheimer's: Avery.

Gomes-Osman, J., Cabral, D. F., Morris, T. P., McInerney, K., Cahalin, L. P., Rundek, T., . . . Pascual-Leone, A. (2018). Exercise for cognitive brain health in aging: A systematic review for an evaluation of dose. Neurol Clin Pract, 8(3), 257-265. doi:10.1212/CPJ.0000000000000460

Livingston, G., Huntley, J., Sommerlad, A., Ames, D., Ballard, C., Banerjee, S., . . . Mukadam, N. (2020). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. Lancet, 396(10248), 413-446. doi:10.1016/s0140-6736(20)30367-6

Morris, M. C., Tangney, C. C., Wang, Y., Sacks, F. M., Bennett, D. A., & Aggarwal, N. T. (2015). MIND diet associated with reduced incidence of Alzheimer's disease. Alzheimers Dement, 11(9), 1007-1014. doi:10.1016/j.jalz.2014.11.009

Ngandu, T., Lehtisalo, J., Solomon, A., Levälahti, E., Ahtiluoto, S., Antikainen, R., . . . Laatikainen, T. (2015). A 2 year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. The Lancet, 385(9984), 2255-2263. doi: 10.1016/S0140-6736(15)60461-5

Nguyen, L., Murphy, K., & Andrews, G. (2022). A Game a Day Keeps Cognitive Decline Away? A Systematic Review and Meta-Analysis of Commercially-Available Brain Training Programs in Healthy and Cognitively Impaired Older Adults. Neuropsychol Rev, 32(3), 601-630. doi:10.1007/s11065-021-09515-2

Numakawa, T., & Kajihara, R. (2023). Involvement of brain-derived neurotrophic factor signaling in the pathogenesis of stress-related brain diseases. Frontiers in Molecular Neuroscience, 16. doi:10.3389/fnmol.2023.1247422

Sabia, S., Fayosse, A., Dumurgier, J., van Hees, V. T., Paquet, C., Sommerlad, A., . . . Singh-Manoux, A. (2021). Association of sleep duration in middle and old age with incidence of dementia. Nature communications, 12(1), 2289. doi:10.1038/s41467-021-22354-2

Sawyer, R. P., Blair, J., Shatz, R., Manly, J. J., & Judd, S. E. (2024). Association of Adherence to a MIND-Style Diet With the Risk of Cognitive Impairment and Decline in the REGARDS Cohort. Neurology, 103(8), e209817. doi:https://dx.doi.org/10.1212/WNL.0000000000209817