Preventive Neurology

Photo by engin akyurt on Unsplash "I was told to try the Snack-All-Day diet plan, but it has been a disaster. I was eating 7 or 8 small snacks per day but instead of losing weight, I have gained weight. Why?"   It is quite clear that obesity is a major public health problem and contributes to a substantial burden of disease at a population level. Why do we get obese? This is complex, but a lot of it can be explained by the food environment we live in and the change in our eating habits over the last 3 or 4 generations. The study below shows that the extent of the postprandial dip in glucose, which occurs 2-3 hours after a meal predicts hunger, a shorter time until the next meal and greater additional energy intake at 3-4 hours.  The reason why we get low blood glucose 2-3 hours after a meal is that there is too much insulin released relative to the amount of sugar or glucose in the baseline meal. In other words, our bodies produce too much insulin in anticipation of the...

The role sleep plays in normal human brain physiology is becoming more clear as the link between abnormal sleep and dementia gets stronger. Here is yet another epidemiological study linking reduced sleep in middle age to a higher risk of dementia. Quin Stevenson on Unsplash Is the association between reduced sleep and dementia causal or is it due to reverse causation? Sleep is required to consolidate memories and to allow the brain to cleanse itself, i.e. flush out all the intracellular debris that could aggregate to cause Alzheimer’s disease. Therefore, sleep deprivation by impairing memory consolidation and not allowing you to clear the brain's intracellular debris properly could lower your threshold for developing dementia in the future. Reverse causation states that people who are destined to develop dementia have pathology that starts decades before dementia manifests, for example, amyloid deposition and neurofibrillary tangles. The pathology affects parts of the brain that c...

Kinga Cichewicz on Unsplash The study below found that people who experience unconscious wakefulness most often and for longer periods of time had nearly double the risk of dying from cardiovascular disease during an average of between 6 and 11 years’ follow-up when compared to the risk in the general population. The association was particularly strong in women and less clear in men. Unconscious wakefulness also referred to as cortical arousal, is a normal part of sleep. It occurs spontaneously and is part of the body’s ability to respond to potentially dangerous situations, such as noise or breathing becoming obstructed. A full bladder, pain, limb movements, trauma, temperature, light, noise, sleep disorders, acid reflux, depression and anxiety can also be triggers. Clearly, unconscious wakefulness is a major modifiable risk factor for cardiovascular disease and is also a risk factor for all-cause dementia. Isn’t it about time we took this seriously and started a public health campai...

It is obvious, yet it is not. We need to ban sugar! Rod Long on Unsplash When I was on a road tour of the Southern USA in 2012 with my family, we went to the ‘Golden Corral’ all-you-can-eat buffet one morning for breakfast. The Golden Corral, like so many other fast-food and convenience-food outlets, was a church or cathedral to sugar. A place where you go to worship on the altar of sugar one of the most addictive substances known to man. I was horrified at how many obese Americans were eating at the Golden Corral, the types of food they were eating and the quantity they were eating.  Buffet Bar at the Golden Corral The rapid change in our diets driven by the cheap supply of processed carbohydrates has resulted in metabolic chaos, which is causing the obesity crisis and the cascade of health problems stemming from the resulting hyperinsulinaemia. The following international study confirms that the intake of foods with a high glycemic index is associated with increased cardiovascul...

From Kevin Boyd Is it not interesting that obesity, and its associated comorbidities, are associated with a higher lifetime prevalence of all-cause dementia? However, is it obesity that is a causal factor or the fact that obesity is strongly associated with (1) reduced exercise and a sedentary lifestyle, (2) hypertension and metabolic syndrome (insulin resistance), (3) systemic inflammatory syndrome, (4) mental health problems (depression/anxiety) and (5) sleep apnoea and other sleep disorders? All five of these factors may be the causal factor and not necessarily obesity itself. The modern epidemic of obesity is been driven largely by a change in our diets in particularly the ubiquitous consumption of processed and ultra-processed foods and the large increase in sugar (sucrose) consumption. Prior to the Victorian era, sugar was not a dietary staple and we tended to eat large quantities of unprocessed foods. Eating unprocessed foods meant we had to work hard at chewing food, which crea...

DESIGNECOLOGIST on Unsplash If you snore you should probably make sure you don’t have obstructive sleep apnea (OSA).  In this study below OSA severity was associated with Alzheimer’s disease pathology burden in the hippocampus the region of the brain responsible for memory. These results indicate that OSA may account for some of the “cognitively normal” individuals who have been found to have substantial amyloid burdens, and are currently considered to be at a prodromal stage of AD. The implications of this and other studies linking sleep deprivation to Alzheimer’s disease and dementia are profound and imply that sleep hygiene and preventing sleep disorders may be a strategy to reduce the lifetime risk and incidence of dementia. Sleep is critical for the brain to clear itself of protein debris and if you have insufficient sleep the debris accumulates, for example, amyloid plaques associated with Alzheimer's disease. OSA and other sleep disorders may therefore bring forward the AD ...