In 1979, one of the most important epidemiological studies was initiated at the Cochrane Institute at Cardiff University, UK. It is also famously known as Caerphilly Cohort Study (1).
The study tracked the lifestyle of over 2000 middle-aged men in the Town of Caerphilly in South Wales. The total duration of the study was 30 years (1979-2009).
Due to its longevity, this study is considered pivotal to establish the importance of lifestyle and brain and age-related disease onset.
The study concluded that 5 factors were crucial in reducing the onset/risk of dementia. These factors are also important for brain health.
These factors were: Diet, BMI, Smoking, Alcohol consumption, and exercise. The study points out that the risk of cognitive decline was reduced by 60% by eating healthy, keeping a good BMI (18-25 kg/m2), not smoking, limiting alcohol consumption, and regular exercise.
the most important factor was the regular exercise that included biking 10 miles a day, walking 2 miles a day, or vigorous exercise.
This comprehensive study confirms the other studies in the field of health science.
In this article, we will look at the current studies on these 5 factors for brain health.
- Diet
- BMI
- Smoking
- Alcohol consumption
- Exercise
1) Diet and brain health
There are plenty of studies linking a healthy diet to cognition.
It is important to note that both the kind of diet and the amounts have been shown to affect brain health.
Caloric restriction has been studied for brain health. Overeating can lead to cognitive decline. Unrestricted food consumption can lead to increased free-radical activity. Free radicals have cell-damaging properties (2).
BDNF (Brain-derived neurotrophic factor), is a brain neurotransmitter modulator. It is crucial to maintaining brain health, memory, and learning. Decrease levels of BDNF are associated with brain diseases such as Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, and Huntington’s disease (3).
Calorie restrictions in animals have been shown to maintain BDNF levels. The calorie restrictions increase BDNF levels (4,5,6). Therefore, calorie restriction may provide one of the ways to preserve cognitive abilities.
Both epidemiological and clinical suggest a strong connection between following a diet containing specific micro and/or macronutrients for long-term brain health. The known nutrients studied for brain health are Dietary fats, Flavonoids, Vitamin B, D, and E, calcium, Zinc, Selenium, iron, and curcumin.
These nutrients are crucial for oxidative stress. Oxidative stress has a damaging effect on brain cells. Omega-3 fatty acids , DHA (Docosahexaenoic Acid) are known to improve BDNF in animals (7) and it is positively correlated with fighting neuropsychiatric disorders such as Alzheimer’s’, Parkinson’s, and schizophrenia (8,9).
Good source omega-3 fatty acids is fish (salmon, mackerel, tuna, herring, and sardines), chia seeds, flaxseeds, and walnuts.
Saturated fatty acids are another factor. Saturated fats are shown to be bad for health. Saturated fats may increase the expression of proinflammatory obesity-linked genes (10). The risk of dementia increases with the increasing consumption of saturated fats (11). The risk was shown to decrease with the consumption of fish that has natural omega-3 fatty acids.
The source of saturated fatty acids is animal-derived fats and processed fats. This includes butter, bacon, cheese, cakes, and sweets. We should minimize the consumption of processed fats.
Flavonoids are polyphenolic metabolites beneficial for overall health. Flavonoids are also beneficial for brain health. Flavonoids are shown to improve brain health by fighting neurotoxins preventing cell death as well as promoting blood flow to the brain (12). Both these activities boost brain functioning and long-term memory and learning.
Good sources of Flavonoids are berries(blueberries), tea, red wine, dark chocolate, onions, and green vegetables.
Vitamins B, D, and E are also important micronutrients for brain health. Low vitamin B complex(B6, B9, or B12) is associated with an increased risk of dementia (13).
Vitamin D is a known regulator of Calcium. The deficiency of vitamin D has been associated with neurodegenerative diseases such as Alzheimer’s (14). Vitamin E is good for brain health Due to its antioxidative properties (15).
Good sources of vitamins are milk, eggs, fish, fruits, and vegetables. The Mediterranean diet and MIND diet are considered popular examples of a healthy diet.
In summary, eating a balanced diet that contains healthy proteins, carbs, fats, and vitamins is good to keep your brain healthy.
2) BMI and brain health
BMI (body mass index) is a gross measurement of body fat. BMI is a measure of obesity. Obesity is known to cause many of the aliments known today. There is some evidence that BMI increase is linked to declining cognition (16).
It is difficult to pinpoint a simple relationship between high BMI with brain function. However, it is a well-established fact that obesity is associated with a plethora of diseases.
One of the themes in obesity and disease is inflammation. Obesity is known to promote pro-inflammatory mechanisms in the body. The increase in pro-inflammation in the body leads to cardiovascular diseases, metabolic syndrome, and diabetes (17).
Inflammatory agents in the body causing mental decline (18). Therefore, we can obesity may be important for been mental health via the pro-inflammatory nature of obesity.
Here are important BMI numbers (19).
BMI < 18kg/m2 is underweight
BMI 19-24.9 kg/m2 is normal
BMI 25 – 29.9kg/m2 is overweight.
BMI 30 – 34.9 kg/m2 is class I obesity
BMI 35 – 39.9 kg/m2 is class II obesity
BMI 40 kg/m2 and above is Class III obesity
Based on current information available a BMI between 19-25 kg/m2 is considered normal and will be desirable.
3) Smoking and brain health
We all know that smoking is bad for health. Many studies have linked smoking with different types of metabolic diseases as well as cancer.
There is some evidence that suggests that smoking negatively affects cognition.
Nicotine present in tobacco is known to have addiction properties as well as cognition-enhancing effects. But many have shown that decline in cognition especially information processing is affected by smoking (20).
Long-term smokers perform poorly compared to ex-smokers and non-smokers (21). Also, age-related decline onset of dementia may be contributed by smoking(22).
Cigarettes are shown to promote proinflammatory pathways using immune cells (23). Since inflammation is bad for brain health, it may contribute to the direct cognitive decline due to inflammatory pathways.
Therefore, abstinence from smoking can protect from the adverse effects of nicotine.
4) Alcohol consumption and brain health
Alcohol consumption and brain health is a complicated topic. Light to moderate use of alcohol is associated with decreased risk of Alzheimer’s disease (24). High consumption of alcohol is associated with a high risk of disease onset (25).
In fact, this study measures the relationship in a dose-dependent manner. Higher doses were associated with higher risk. The adverse effects of alcohol on the brain may due to the cell toxic nature of alcohol. Thus, moderation in alcohol consumption is important to slow down cognitive decline.
Some point out the benefits of moderate drinking to brain health (26).
This benefit may come from antagonist properties of alcohol towards beta-amyloid deposition in the brain. Beta-amyloid plaques deposition in the brain is believed to be a major cause of Alzheimer’s disease.
Red/white wine is a good option because wine has antioxidants that good for health.
Based on the current knowledge, low to moderate consumption of alcohol does not adversely affect the human brain. High alcohol consumption on the other hand can negatively affect cognition.
5) Exercise and brain health
Of all the 5 factors, exercise is perhaps the most important factor. They are plenty of reliable studies showing that exercise is crucial to maintaining healthy cognition. Most of this benefit comes from gene modulation of factors.
Studies have found that Exercise affects neuroplasticity. Neuroplasticity is “the ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections” (27). It is an important aspect of learning and engaging in day-to-day activities and overall well-being.
Physical exercise helps increase brain volume. Aerobic exercises result in an increase in both grey and white matter in older adults. Therefore, physical exercise is great for brain health (28, 29)
Physical exercise also increases BDNF (30, 31). Thus, in addition, to the dietary aspect, physical exercise can help boost BDNF as well.
Physical exercise has been shown to improve oxygenation and blood flow to the brain (32).
Physical exercise can also improve learning and even academic achievement in children (33).
Moreover, physical exercise can also protect against dementia (34).
Adding physical exercise to our lifestyle can be of great benefit both for the brain and body.
In summary, physical exercise from mild to medium intensity can help improve brain function, improve memory, and delay the onset of dementia. Adding physical exercise to our lifestyle can be of great benefit both for the brain and body.
The Gist
For brain health and good cognition, following these factors can have lasting effects. Interestingly, with training and positive habit reinforcement, these factors can be followed with comfort. Eat healthily should not be an impossible task once you have decided to eat healthily. Prioritize to keep the body fat in check. Quit smoking if you smoke. Limit the use of alcohol to wine and Exercise daily.
