Boosting Brain Health with Age - Naturopathic Approaches

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Forgetfullness is often considered a normal part of aging. As we get older, we might all expect to notice changes in our memory, ability to focus, mulit-task and problem solve. Dementia is when these changes in cognition begin to impact daily functioning. With an aging population, dementia is expected to become the leading cause of disability worldwide by 2020 (4). Current treatments for dementia are limited and do not have great success rates. Finding ways to prevent, or at the very least slow the process of, age-related cognitive decline is tremendously important.

What’s Happening in the Aging Brain?

In some cases of dementia, genetics and neurological conditions are the primary cause. However, as part of the normal aging process, there are changes in the functioning, metabolism and structure of our brains which are understood to lead to changes in memory and cognition, in us all. A few of the key processes we observe in an aging brain and believe to contribute to a decline in cognitive function include:

• Less efficient use of glucose (the brain’s favoured fuel source) – If the brain can’t properly use its main source of fuel, we can’t expect that it will be able to function as well as it should. This is especially relevant for those with diabetes, where there is already impairment in the body’s ability to regulate and utilize glucose.
• Increase in oxidative stress – Free radicals are created as a by-product of metabolism and other cellular processes. We need anti-oxidants in our cells to help quench these free radicals, as too much can cause damage to our cells. With age, we see an increase in free radicals with a general decrease in antioxidant status, which results in a higher amount of oxidative stress damaging our cells.
• Decrease and alterations in blood flow – Cardiovascular disease and plaque formation in the arteries, which is very common with aging, can interfere with proper circulation and blood flow to and within the brain. Adequate blood flow is crucial for bringing in fresh oxygen and nutrients, as well as clearing waste products, for optimal functioning.
• Low-grade inflammation – This is observed in many parts of the body with age, and may be the result of many different things. Changes in our immune cells may occur with time, which makes them more prone to create inflammation, and a history of infections or mild brain injuries are another couple of examples.
• There are a lot of different factors that may affect all of the above processes over our lifetime. Some of these, such as genetics and ethnic background we don’t have control over, but many others we can affect. Our activity level, lifestyle and diet can have a huge impact on how these processes unfold, and are the best tools we have for preserving our cognitive function as we age.

How Diet can Impact Aging Brain

The foods we eat are incredibly important for influencing glucose metabolism, inflammation, as well as providing anti-oxidants and the nutrients needed for optimal brain functioning. While sometimes we think of specific foods as being healthy for our brains, it is more beneficial to look at how diet as a whole can be used to slow brain aging. The interaction between multiple, beneficial nutrients and compounds in an overall healthy diet pattern is likely more impactful than single nutrients added on their own (6). Diet also plays a huge role in reducing our risk of cardiovascular disease and diabetes, major risk factors for dementia later in life. Its known that diets lower in vegetable and fruits, while being higher in sugar, saturated and trans fats are associated with a higher risk of experiencing cognitive decline and even Alzheimer’s disease. There a few different diets have been studied to try and uncover what we should be eating to reduce our risk of dementia.

The Mediterranean Diet

The Mediterranean Diet is one of the most well-studied diets for helping to prevent and manage cardiovascular disease. It follows a pattern of eating observed in Mediterranean regions, where rates of chronic disease are very low and we see individuals living long and healthy lives. The basis of the diet is lots of vegetables and fruits, whole grains, legumes and fats from nuts, seeds and olive oil. Fish and seafood are favoured as sources of protein, with less consumption of poultry and even more minimal consumption of red meats. Consumption of dairy products is also minimal, as well as sweets.

As the Mediterranean diet has been shown to help improve cardiovascular health, it may also be expected to help slow cognitive decline in aging, since we know alterations in blood flow are a part of this process. Studies have shown high adherence to a Mediterranean diet, especially one that is rich in olive oil and nuts, may help prevent dementia (3). The interaction of many specific foods and nutrients found in the Mediterranean diet can have a powerful effect on the aging brain (3). It is thought to have a positive effect on oxidative stress, neuroinflammation, insulin resistance and cerebral blood flow (7) and may help to maintain synaptic function (communication between nerve cells) (3), which are all key contributors to cognitive decline with age. The Mediterranean diet has also been shown to have a beneficial effect on the neuropsychological state of older individuals (7), suggesting that it can still have an impact on the brain even after the aging process is well underway.

The MIND Diet

The MIND Diet was specifically developed to help slow cognitive decline. It is very similar to and was based upon the Mediterranean diet, but also takes into consideration some of the other things we know about diet and brain health. The MIND Diet emphasizes the consumption of green leafy vegetables, other vegetables, nuts, berries, beans, whole grains, seafood, poultry, olive oil and red wine, and discourages the consumptions of red meats, butter, margarine, cheese, pastries, sweets and fried foods (6). In addition to lots of veggies of and fruits, one of the main reasons both the Mediterranean and MIND diets are thought to be so beneficial for brain health is the regular consumption of fish. Fish are the best dietary source of omega-3 fatty acids, which have excellent anti-inflammatory effects in the body. These omega-3s have been shown to reduce plaque formation in the brain (which we see both in normal aging and in Alzheimer’s disease) reduce levels of oxidative stress and improve synaptic structure for better communication between neurons (6). When studied in direct comparison to the Mediterranean and DASH diets, the MIND diet seems to substantially slow cognitive decline above these other two (although all show some benefit) (4). The specific emphasis on including green leafy vegetables and berries may be part of the reason for this. Green, leafy vegetables contain high amounts of folate, vitamin E, carotenoids and flavonoids; all nutrients in which higher consumption has been linked to a lower risk of developing dementia (6). Eating more berries has been shown to boost learning and memory in animals, and also shown to slow cognitive decline in human observational studies (7).

The Ketogenic Diet

Compared to the MIND and Mediterranean diets, the ketogenic diet has not been studied very well as a way to reduce the risk of dementia. However, there is a strong theoretical basis for the ketogenic diet to be used in this way. It has been shown to have neuroprotective (brain protective) effect and has been used as part of treatment for in a few brain-based diseases, such as epilepsy and certain brain tumours (9). We know the brain becomes less effective at using its main fuel source of glucose with age, and this is one of the factors thought to contribute to the development of dementia (5). Following a ketogenic diet essentially forces to body to utilize ketones (which we make from fat) instead of glucose for energy (5). If our brain cells have this alternative fuel source to use, perhaps we would see better functioning with age.

The ketogenic diet is a high-fat diet, with 80-90% of calories coming from fat, and the remainder coming from protein and even less from carbs (usually around 5%) (9) A couple small studies have shown that individuals with Alzhimer’s disease have been able to improve their scoring on cognitive tests while following a ketogenic diet (9). Another small study assessed the effect of following a low-carbohydrate diet (5-10% of calories from carbohydrates) compared to a higher carbohydrate (50% of calories from carbohydrates) for those with mild cognitive impairment. Six weeks later, improvements in verbal memory was seen in the group who followed the lower carbohydrate diet (9). It was concluded that even short-term lower carbohydrate diet may be able to to improve memory in those at risk of Alzheimer’s disease (9). More research is definitely needed to know if a ketogenic or lower-carbohydrate diet long-term can help prevent cognitive decline and preserve brain function. It is also important to note that a ketogenic diet can be very difficult to adhere to long-term, and in older individuals may put them at a higher risk of malnutrition (9). Short-term use of these styles of diets however, may be promising new preventative avenue.

Conclusion

There are of course many other lifestyle changes that are important as part of a holistic approach to preventing dementia. Regular exercise, cognitive training and keeping our minds active, as well as social engagement are all valuable strategies as well. Consistently we see those that make lifestyle changes along with dietary changes have a greater reduction in their risk of dementia, than those that only change their diets (8). It is also important to note that it is never too early or too late to make some of these changes. As part of an early prevention plan, or even in someone already experiencing a decline in memory, dietary and lifestyle changes can have a powerful impact on the health and functioning of our brains!