Brain Health: How to Reduce your Risk of Alzheimer’s and Age-Related Cognitive Decline

The ageing global population has people questioning now, more than ever before, how they can prevent cognitive decline. Clinical Nutritionist and Researcher Cliff Harvey, discusses how we can optimise our brain health to reduce the risk of developing age-related brain conditions below.

In my clinical practice, we periodically survey our clients on the health conditions or outcomes that most concern them. In the early years, we would consistently hear that the biggest concern was quite simply, weight. Now though, weight and body fat have fallen behind brain health and day-to-day energy as major client concerns. This is unsurprising given the rising incidence of the neurodegenerative conditions Alzheimer’s and Parkinson’s, and other diseases that affect the brain and central nervous system.

What are ‘neurodegenerative disorders’?

Neurodegeneration is the progressive damage and destruction of neurons (brain and nervous systems cells) and/or components of those cells. This breakdown of cells results in age-related cognitive decline and in more serious cases the common neurodegenerative disorders; dementias such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis (known as Lou Gehrig’s disease) and Huntington’s disease. According to Alzheimer’s Disease International, someone in the world develops dementia every three seconds. Additionally, over 50 million people now live with dementia worldwide and this number is expected to double every 20 years. Neurodegenerative disorders cause progressive disability, incurring a loss of cognition, memory and physical function. Survival times are also typically short—for example, the average survival time post-diagnosis for Alzheimer’s disease is only three to nine years.

What causes cognitive decline?

Neurodegenerative disorders and age-related cognitive decline are both inherited (genetic) and also result from diet and lifestyle factors. These causes include head injuries, pesticide exposure (Parkinson’s), hypertension, lack of sleep, and a poor diet, along with additional risk factors of metabolic syndrome and diabetes, depression, excessive alcohol use and tobacco use¹.

How can I improve my brain health and reduce my risk of cognitive decline?

1. Exercise your brain and body

Lifestyle factors can reduce your risk of cognitive decline and even improve cognitive function. These include engaging in leisure and physical activities, playing a sport, listening to music, and doing brain-taxing activities (such as crosswords)^1,2. People who regularly and actively participate in a variety of social, cultural, and intellectual activities that challenge them, experience lesser cognitive decline, perform better on cognitive tests and are less likely to develop neurodegenerative disorders³. Physical activity shows a consistent, yet not always significant effect on cognitive decline and dementia^4–6. It’s likely that the effects of physical activity alone on cognitive decline are limited and that the best effects come from a combination of physical activity, improved diet and regularly challenging the brain with new activities^5,6.

2. Get enough sleep

Not sleeping enough, or poor sleep quality (i.e. insomnia and lack of REM sleep) is a risk factor for cognitive decline and dementia^7,8. It is recommended that people get between seven and nine hours of high-quality sleep per night.

3. Eat a healthy diet based on natural, unrefined foods

There is a relationship between diet and cognitive decline and it’s likely that eating a diet (such as the Mediterranean diet) based mostly on natural, unrefined foods will reduce the risk of cognitive decline and dementia². In a review of studies, it was shown that following a Mediterranean diet was associated with up to a 48% reduced risk of dementia, and those with pre-existing Alzheimer’s disease had a 73% lower mortality risk than those who did not adhere to the diet⁹.

4. Increased fruits and vegetables

Increased intakes of fruit and vegetables are associated with both a lower risk of dementia and slowing rates of age-related cognitive decline^1–10. However, subtype analysis has demonstrated that this effect is restricted to vegetables (and not fruit), with the strongest effects from cruciferous (like cabbage and broccoli) and green leafy vegetables¹⁰. It has been further suggested that a minimum of three servings of vegetables should be consumed daily for this effect¹⁰.

5.    Vitamin C

Maintaining healthy levels of vitamin C from nutrient-rich foods to avoid a deficiency (rather than mega-dosing) is likely to have a protective function against age-related cognitive decline¹¹.

6. Omega-3 fats

The omega-3 fats EPA and especially DHA, play an important role in brain development and healthy functioning of the brain and central nervous system¹². Omega-3 fats are linked to reduced mental fatigue¹³, improved memory and cognition and reduced cognitive decline^1,14,15, reduced rates of depression and improved structural integrity of the brain^16,17. Plausible mechanisms also exist to suggest a protective role for fish oil in neurodegeneration in Parkinson’s disease¹⁸.

7. Coffee and tea

Caffeine is a well-known cognitive enhancer. Evidence shows that caffeine improves attention, vigilance, reaction times, and problem-solving (especially in sleep-deprived people)^19,20, and improved mood and reduced fatigue even at low doses of caffeine-containing beverages (≈1 cup of tea or coffee per day)^20,21. In addition to its acute effect on mood and cognition, caffeine-containing beverages may be protective against cognitive decline and dementia²², and coffee and tea are also associated with a reduced incidence of Parkinson’s disease^23,24. Tea constituents other than caffeine (L-theanine and epigallocatechin gallate) could also improve cognition. A review of the research in this area suggested that caffeine combined with theanine (as found in tea) improved alertness and attention more than caffeine alone²⁵.

8. Multi – vitamins and minerals

Many people do not consume sufficient essential and secondary nutrients from diet alone^26,27. Multivitamin/mineral supplements have resulted in improved cognitive and memory performance in trials and reduced stress and anxiety^28,29, and it is likely that supporting nutrient-sufficiency of the diet could improve long-term brain health and reduce cognitive decline.

9. Medium-chain triglycerides

Medium-chain triglycerides (MCT) are naturally occurring fats found in small amounts in dairy products and greater amounts in coconut oil. They are also commonly used as isolated supplement oils. MCT supplemented diets improve mental performance in those with Alzheimer’s Disease and age-related cognitive decline^30,31, and a single dose of 20g MCT has been shown to improve cognition³²

10. Lion’s mane mushroom

Lion’s mane or Hericium erinaceus is an edible and medicinal mushroom native to North America, Europe and Asia belonging to the tooth fungus group. Lion’s Mane has been shown to increase ‘nerve growth factor’³³, which helps nerves and brain cells to grow and repair^34–39. Because of this brain-repair effect, lion’s mane is being considered as one of the most promising preventatives for dementia and cognitive decline^40,41. It’s also been demonstrated to significantly reduce depression and anxiety³⁵, as well as improve cognitive function⁴².

There is also evidence for a range of other nootropic or cognitive ‘boosting’ supplements which may help to prevent cognitive decline. Read our article on nootropics to find out what they are and how they may help.