Top Environmental Risk Factors for Dementia Identified

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“Dementia” is an umbrella term covering an array of neurological diseases and conditions that develop when neurons in your brain die or cease to function normally. The death or malfunction of neurons causes changes in memory, behavior and ability to think.

Alzheimer’s disease, which is the most serious form of dementia, eventually leads to the inability to carry out even the most basic of bodily functions, such as swallowing or walking. Alzheimer’s is ultimately fatal, as conventional treatment options are few and limited in effectiveness.

Disturbingly, Alzheimer’s has reached epidemic proportions, currently affecting an estimated 5.4 million Americans. In the next 20 years it is projected that Alzheimer’s will affect 1 in 4 Americans, rivaling the current prevalence of obesity and diabetes and by 2050, Alzheimer’s diagnoses are projected to triple.

Already, more than half a million Americans die from the disease each year, making it the third leading cause of death in the U.S., right behind heart disease and cancer. Considering there’s no known cure and so few treatments, prevention is key.

Top Environmental Risk Factors Identified

As with autism, it’s quite reasonable to suspect that a variety of factors are at play, collectively contributing to the rapid rise in Alzheimer’s prevalence.

Experts at the Edinburgh University’s Alzheimer Scotland Dementia Research Centre have now compiled a list of top environmental risk factors thought to be contributing to the epidemic. As reported by BBC News:

“Dementia is known to be associated with lifestyle factors such as high blood pressure in mid-life, smoking, diabetes, obesity, depression and low educational attainment, as well as genetic factors.

But the Edinburgh researchers said a third of dementia risk was unexplained, and they want to determine whether other issues are at play, including the environment.”

Not surprisingly (if you’ve been paying attention to the research), vitamin D deficiency, air pollution and occupational pesticide exposure top this list. Living close to power lines also has “limited yet robust” evidence suggesting it may influence your susceptibility to dementia.

1. All Forms of Air Pollution Raise Your Dementia Risk

Particulate matter, nitric oxides, ozone and carbon monoxide have all been linked to an increased risk. (Photo by Peter Macdiarmid/Getty Images)

The risk factor with the most robust body of research behind it is air pollution. In fact, they couldn’t find a single study that didn’t show a link between exposure to air pollution and dementia. Particulate matter, nitric oxides, ozone and carbon monoxide have all been linked to an increased risk.

Aside from raising your risk for dementia, a recent World Health Organization (WHO) report on environmentally related deaths claim that 1 in 4 deaths worldwide are now related to living and working in a toxic environment — with air pollution being the greatest contributor to this risk. As noted by WHO Director-General, Dr. Margaret Chan:

“A healthy environment underpins a healthy population. If countries do not take actions to make environments where people live and work healthy, millions will continue to become ill and die too young.”

During the World Health Assembly, held in May 2016, WHO vowed it “will propose a roadmap to increase the global response by the health sector to reduce the effects of air pollution.”

2. Pollution, Diabetes and Dementia

American researchers have also warned that exposure to air pollution for as little as one or two months may be enough to increase your risk of diabetes — especially if you’re obese.

Diabetes, in turn, is a significant risk factor for Alzheimer’s, doubling your chances of contracting this devastating form of dementia. Alzheimer’s was even tentatively referred to as type 3 diabetes at one time.

Recent research has also confirmed that the greater an individual’s insulin resistance, the less sugar they have in key parts of their brain, and these areas typically correspond to the areas affected by Alzheimer’s.

Needless to say, the most significant contributor to insulin resistance and type 2 diabetes is not pollution but rather your diet. More specifically, eating a diet that is excessively high in net carbohydrates (total carbs minus fiber) and too low in healthy fats can contribute to insulin resistance.

3. Sensible Sun Exposure Is Important for Brain Health

(Huy Phan/Shutterstock)

The Scottish Dementia Research Centre also noted there’s a very clear link between vitamin D deficiency and dementia. Indeed, studies have shown vitamin D plays a critical role in brain health, immune function, gene expression and inflammation — all of which influence Alzheimer’s.

In a 2014 study, considered to be the most robust study of its kind at the time, those who were severely deficient in vitamin D had a 125 percent higher risk of developing some form of dementia compared to those with normal levels. According to the authors:

“Our results confirm that vitamin D deficiency is associated with a substantially increased risk of all-cause dementia and Alzheimer disease. This adds to the ongoing debate about the role of vitamin D in nonskeletal conditions.”

The findings also suggest there’s a threshold level of circulating vitamin D, below which your risk for dementia increases. This threshold was found to be right around 20 nanograms per milliliter (ng/ml) or 50 nanomoles per liter (nmol/L). Please recognize that higher levels are associated with better brain health.

Based on a broader view of the available science, 20 ng/ml is still far too low, as the bulk of the research suggests a healthy range is between 40 to 60 ng/ml, certainly no lower than 40 ng/ml. Sadly, a vast majority of people are severely deficient, in large part because they’ve been fooled into fearing sun exposure.

Researchers have previously estimated that half of the general population is at risk of vitamin D deficiency or insufficiency. Among seniors, that estimate reaches as high as 95 percent. This suggests vitamin D may be a very important factor for successful prevention among the general population.

A wide variety of brain tissue contains vitamin D receptors, and when they’re activated by vitamin D, it facilitates nerve growth in your brain.

Researchers also believe that optimal vitamin D levels boost levels of important brain chemicals, and protect brain cells by increasing the effectiveness of glial cells in nursing damaged neurons back to health.

Vitamin D may also exert some of its beneficial effects on your brain through its anti-inflammatory and immune-boosting properties, which are well established.

4. Heart and Brain Health Are Closely Linked

It may be helpful to remember that Alzheimer’s shares many risk factors with heart disease. This includes smoking, alcohol use, diabetes, high fasting blood sugar levels, insulin resistance and obesity.

Arterial stiffness (atherosclerosis) is associated with a hallmark process of Alzheimer’s, namely the buildup of beta-amyloid plaque in your brain.

The American Heart Association (AHA) also warns there’s a strong association between hypertension and brain diseases such as vascular cognitive impairment (loss of brain function caused by impaired blood flow to your brain) and dementia.

In one clinical trial, test subjects who consumed high-fructose corn syrup (HFCS) developed higher risk factors for cardiovascular disease in just two weeks, demonstrating just how influential your diet can be on your heart and brain health in the long term.