Updated: Feb 17
Did you know that early signs of cognitive impairment (the first step of dementia) may show as early as in our mid-40s? Men are now developing chronic systemic diseases (heart disease, diabetes, obesity, high cholesterol, cognitive decline, cancer;) much earlier than their fathers and grandfathers.
Research shows that factors such as high blood pressure, head injuries, alcohol, smoking, obesity, diabetes, severe nutritional deficiencies, and high toxin exposure seem to increase the risk of developing dementia, such as Alzheimer’s.
Could the changes in our lifestyle and diet over the past decades have a role to play, at least to some degree? Let's take a look.
Let us start this journey by turning to our diet first.
What we eat not only impacts our body weight, body fat and energy but also severely impacts our brain health, cognitive performance, and cognitive decline. Research over the past decade has analysed two dietary patterns and their association with cognitive decline: Ketogenic & Mediterranean diets.
Ketogenic Diet (KD) & Cognitive Health
KD, as a dietary pattern, limits carbohydrates from grains, potatoes, fruit and sugary snacks in favour of high-fat foods such as cheese, avocado, fish and olive oil.Researchers have studied its effects on the brain and nervous system for decades, initially focusing on epilepsy. Attention has gradually turned to other areas of health.
In 2020, a review of ketogenic diet studies for cognitive health found that when people diagnosed with Alzheimer's were put on experimental KD, their memory tests improved, however not their executive thinking (logics, reasoning, evaluation etc) or attention ability. Their mood did not improve either.
Some participants also lost weight which is beneficial for overweight people but may not be desirable in older people with a higher risk of bone loss and muscle loss.
It is worth noting that there was a relatively high dropout rate across all studies, potentially indicating difficulty adhering to the diet even with the assistance of dietitians.
Due to the limited research and mixed effects, KD is not widely recommended for cognitive decline.
f you're thinking of trying the diet yourself or supporting someone close to you, make sure to seek guidance from a qualified Nutritionist or Dietitian and discuss with your physician before making big changes.
however, for people who are concerned with their mental health and would like to try KD, support from the family and a medical professional or a dietitian would be recommended. As an alternative, our second dietary model may be a more practical option for most people.
Mediterranean Diet (MD) & Cognitive Health
Before 1950 when large-scale trade became available, the countries of the northern Mediterranean region (mainly Italy & Greek islands) would primarily consume products or local agriculture and pasture. Their diets were made of fresh & dried fruits, vegetables, herbs, legumes, whole grain products, tree nuts, and olive oil with a small amount of seafood, eggs, cheese, and lean meats.
Unsurprisingly these populations were less susceptible to heart disease, stroke, diabetes and obesity compared to countries in western Europe and the USA. In addition, high adherence to traditional MD compared to lowest adherence was associated with:
53% risk reduction of Alzheimer’s Disease
25% risk reduction of Parkinson’s Disease
Not only that, but these people also seem to have a more diverse and healthier composition of the gut microbiota, which is so essential for our immunity, digestion, metabolism, and mental health.
When individual food components of the MD diet were analysed;
Fruits, vegetables, greens, olive oil, walnuts, whole grains, legumes and fish were all favourable for cognitive health in extensive population studies.
In contrast, red meat, saturated fats, dairy, and cereals were less favourable and associated with worse cognitive health.
The highest consumption of saturated fats (commonly found in beef, high-fat dairy and eggs) was associated with up to 46% increased rate of Alzheimer’s disease and dementia.
How to Build a healthy MD-like diet?
"A picture is worth a thousand words", so here is what the UK Governmental Guidelines recommend based on the consensus of the nutritional research. While you may disagree with some of these foods depending on your personal, ethical and environmental preferences, this assortment has been created according to
Green Tea & Coffee
A Japanese study from the Ohsaki region, which followed 49,600 people for six years, found that those consuming the highest amount of green tea had a 27% reduced risk of dementia. This is probably due to a very high content of beneficial substances called catechins in green tea and their antioxidant function.
When it comes to coffee, there appears to be no additional protection against Alzheimer’s; however, regular coffee consumption is highly protective against Parkinson’s disease, although those sensitive to caffeine, prone to anxieties, panic attacks, or heartburn should be careful with their consumption of coffee. The most protective threshold was somewhere around 2-3 cups per day.
“Is that all I can do to keep my brain healthy?”
Well, not quite. Let’s now explore a variety of lifestyle choices and adjustments we can also make in addition to diet:
Sleep & Sleep Duration
Office environments are hives of chronically under-slept people. High workload and poor work-life balance force employees to go above and beyond to match KPIs and to not neglect their other duties & commitments; people tend to look towards their sleep to provide that additional time. But at what cost?
Chronic short-sleepers (5-6 hours/night) have an increased risk of heart disease, diabetes and becoming overweight,
Chronic long-sleepers (8-9+ hours/night) have an increased risk of all-cause dementia and Alzheimer’s.
Those suffering from an obstructive sleep disorder are at even higher risk of everything mentioned above.
It would appear that somewhere between 7 and 8 hours lies the perfect silver lining. Pushing our sleep limits to the extremes of too little or too much (despite some people seemingly being able to get away with it) might not be a good idea.
Exercise & Brain Health
The benefits of regular physical activity are well known. People who regularly exercise are more likely to live longer and have fewer cardiovascular disease, stroke, cancer, and diabetes incidents. They are also less likely to suffer from a bone loss disease such as osteoporosis later in life. But can exercise also protect our brain?
A very recent 2022 analysis of 58 observational studies found that those engaging in regular physical activity had a significantly reduced risk of all-cause dementia, vascular dementia and Alzheimer's disease compared to more physically passive individuals.
Resistance training (weightlifting, callisthenics, bodyweight training) appears to be the most effective for people with cognitive impairment. Other types of physical exercise, such as aerobic and mind-body exercises (e.g. yoga and tai chi), appear to be helpful for those who do not enjoy the typical gym environment or bodyweight training.
In terms of frequency, the World Health Organisation recommends that adults engage in either 150-300 minutes of moderate-intensity aerobic activity or 75-150 minutes of vigorous physical exercise per week as a minimum.
As the saying goes: "Some is better than none, but more is better than some"
Chronic vitamin D deficiency is rampant across global populations, and unsurprisingly our brain health gets negatively impacted by it.
Long-term observational studies show that chronically deficient people are at a 34% increased risk of Alzheimer’s, and in those who are highly deficient, the risk increases to 51%.
However, a recent 2022 review of clinical trials in adults diagnosed with cognitive impairment or Alzheimer's disease did not find consistent or clear benefits for vitamin D supplementation for up to 3 months.
Hence it appears that whilst it may be essential to maintain normal blood levels of vitamin D in the body, increasing levels after diagnosis may not be of many benefits.
This is a timely point, as September/October is an excellent time to check vitamin D levels, which often decline over the winter months, to help ensure year-round optimisation. (picture source: andro-health.com)
The image shows where the optimal blood levels of vitamin D are on the scale. Deficiency would be considered below 30nmol/L and extreme deficiency below 10nmol/L.
As you may see, there is much one can do during their lifetime, even with a family history of dementia or Alzheimer’s.
For people who are concerned, applying these habits offers a tremendous benefit, and while there is nothing out there that can 100% guarantee the prevention of neurodegenerative disease, taking control of our diet, our lifestyle, our vitamin D levels and reaching out for a daily cup of green tea with some small amounts of caffeine can go a long way in our life-long attempt at keeping a healthy brain.
Would you like to learn more?
If you would be interested in optimising your cognitive performance, mental health or minimising your risk of chronic neurodegenerative disease and are looking for someone to help you (or someone you know) on that journey, feel free to message me directly via this website or a book a free 30-minute call on the home page. We will discuss the best approach for you or the person you are concerned about.
Stay in touch
If you liked this content and want to learn more, you may follow me on Instagram, Facebook, or YouTube. You may also check out one of my free E-Books designed to provide easily digestible health advice for other men.
A new e-book that condenses all this content into smaller and reader-friendly chunks is coming out soon!
Thank you for your time!
Barbaresko J, Lellmann AW, Schmidt A, Lehmann A, Amini AM, Egert S, Schlesinger S, Nöthlings U. Dietary Factors and Neurodegenerative Disorders: An Umbrella Review of Meta-Analyses of Prospective Studies. Adv Nutr. 2020 Sep 1;11(5):1161-1173.
Cao GY, Li M, Han L, Tayie F, Yao SS, Huang Z, Ai P, Liu YZ, Hu YH, Xu B. Dietary Fat Intake and Cognitive Function among Older Populations: A Systematic Review and Meta-Analysis. J Prev Alzheimers Dis. 2019;6(3):204-211.
Chai B, Gao F, Wu R, Dong T, Gu C, Lin Q, Zhang Y. Vitamin D deficiency as a risk factor for dementia and Alzheimer's disease: an updated meta-analysis. BMC Neurol. 2019 Nov 13;19(1):284.
Coelho-Junior H, Marzetti E, Calvani R, Picca A, Arai H, Uchida M. Resistance training improves cognitive function in older adults with different cognitive status: a systematic review and Meta-analysis. Aging Ment Health. 2022 Feb;26(2):213-224.
Coelho-Júnior HJ, Trichopoulou A, Panza F. Cross-sectional and longitudinal associations between adherence to Mediterranean diet with physical performance and cognitive function in older adults: A systematic review and meta-analysis. Ageing Res Rev. 2021 Sep;70:101395.
Fan L, Xu W, Cai Y, Hu Y, Wu C. Sleep Duration, and the Risk of Dementia: A Systematic Review and Meta-analysis of Prospective Cohort Studies. J Am Med Dir Assoc. 2019 Dec;20(12):1480-1487.
Gil Martínez V, Avedillo Salas A, Santander Ballestín S. Vitamin Supplementation and Dementia: A Systematic Review. Nutrients. 2022 Feb 28;14(5).
Grammatikopoulou MG, Goulis DG, Gkiouras K, Theodoridis X, Gkouskou KK, Evangeliou A, Dardiotis E, Bogdanos DP. To Keto or Not to Keto? A Systematic Review of Randomized Controlled Trials Assessing the Effects of Ketogenic Therapy on Alzheimer Disease. Adv Nutr. 2020 Nov 16;11(6):1583-1602.
Irwin MR, Olmstead R, Carroll JE. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation. Biol Psychiatry. 2016 Jul 1;80(1):40-52.
Iso-Markku P, Kujala UM, Knittle K, Polet J, Vuoksimaa E, Waller K. Physical activity as a protective factor for dementia and Alzheimer's disease: systematic review, meta-analysis and quality assessment of cohort and case-control studies. Br J Sports Med. 2022 Jun;56(12):701-709.
Ma C, Lin M, Gao J, Xu S, Huang L, Zhu J, Huang J, Tao J, Chen L. The impact of physical activity on blood inflammatory cytokines and neuroprotective factors in individuals with mild cognitive impairment: a systematic review and meta-analysis of randomized-controlled trials. Aging Clin Exp Res. 2022 Jul;34(7):1471-1484.
McGrattan AM, McEvoy CT, McGuinness B, McKinley MC, Woodside JV. Effect of dietary interventions in mild cognitive impairment: a systematic review. Br J Nutr. 2018 Dec;120(12):1388-1405.
Rojer AGM, Ramsey KA, Amaral Gomes ES, D'Andrea L, Chen C, Szoeke C, Meskers CGM, Reijnierse EM, Maier AB. Objectively assessed physical activity and sedentary behavior and global cognitive function in older adults: a systematic review. Mech Ageing Dev. 2021 Sep;198:111524.
Solch RJ, Aigbogun JO, Voyiadjis AG, Talkington GM, Darensbourg RM, O'Connell S, Pickett KM, Perez SR, Maraganore DM. Mediterranean diet adherence, gut microbiota, and Alzheimer's or Parkinson's disease risk: A systematic review. J Neurol Sci. 2022 Mar 15;434:120166.
Tomata Y, Sugiyama K, Kaiho Y, Honkura K, Watanabe T, Zhang S, Sugawara Y, Tsuji I. Green Tea Consumption and the Risk of Incident Dementia in Elderly Japanese: The Ohsaki Cohort 2006 Study. Am J Geriatr Psychiatry. 2016 Oct;24(10):881-9.
Van den Brink AC, Brouwer-Brolsma EM, Berendsen AAM, van de Rest O. The Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) Diets Are Associated with Less Cognitive Decline and a Lower Risk of Alzheimer's Disease-A Review. Adv Nutr. 2019 Nov 1;10(6):1040-1065.
Yang K, Chen J, Li X, Zhou Y. Vitamin D concentration and risk of Alzheimer disease: A meta-analysis of prospective cohort studies. Medicine (Baltimore). 2019 Aug;98(35).