Stress and Other Things That Can Lead to Memory Loss and Brain Shrinkage

“It’s not 100% clear how obesity affects brain health,” Finney said. It can be because it can lead to many conditions and diseases such as diabetes and high blood pressure, both of which can hurt the brain, he noted. “But the direct effect is not fully known.” Indirectly or not, obesity may accelerate the onset of neurocognitive impairments in adulthood, according to research. Children are also at risk. Extra weight in kids has been linked to problems with executive function, bad memory, attention, mental flexibility, and decision-making.

The link between brain injury and brain atrophy is an emerging field, Finney said. People are generally more aware of the subconcussive head impacts that over decades put one at risk of chronic traumatic encephalopathy (CTE).Gaining attention thanks to the many athletes affected — mainly boxers and football players — CTE is a brain condition linked to repeated blows to the head. Even one serious brain injury can increase the risk of Lewy body dementia, one of the most common types of progressive dementia in the United States, he added. Abnormal deposits of a certain protein build up in parts of the brain that are responsible for behavior, cognition, and movement.

“We know that Vitamin B12 is important for many functions in the brain,” Finney said. Even mild deficiency — levels below 400 mg in the blood — can cause memory loss, he noted. “Megadosing will not help either.” Vitamin B1, also known as thiamin, plays a key role in nerve function, among others, and affects the memory. “Very low levels can cause serious brain disease, even though this happens rarely, but lower than normal levels — between 74 and 222 nanmoles per liter — can worsen memory loss, Finney added.

“Alcohol has a complicated relationship with the brain,” Finney said. While consumed in low amounts — such as one glass of wine a day — it can reduce the risk of dementia, having two or more drinks can lead to loss of all the health benefits that may come with alcohol, he noted. “The good news is that drinking too much is a reversible cause of brain shrinkage, if you stop early enough.” But excessive drinking for a long period of time can lead to permanent damage to the structure and function of the brain, significantly increasing the risk of alcohol-related dementia and brain damage.

Lack of sleep can cause mild memory problems that can be reversed once proper sleep has been restored, Finney said. The theory is that “[d]uring good sleep the brain clears a protein that can accumulate in the brain and increase the risk of Alzheimer’s.” This is currently an area of active research, he noted. Some studies have suggested that sleep helps the brain get rid of the protein, called beta-amyloid, found between neurons. A buildup of this metabolic waste product has been linked to impaired brain function.