11 Apr, 2023

Weight is one of the physical characteristics that physicians consider when determining a person’s overall state of well-being. Doctors specifically apply weight measures in finding out the body mass index (BMI), the ratio of a person’s height to their weight. The result reveals the amount of fat in the body and is used by physicians to pre-screen for potential health problems, such as obesity, diabetes, eating disorders, and now, even dementia.

Studies on dementia show that a high BMI correlates to a higher cognitive impairment risk. Find out how being overweight and obese impacts one’s risk of dementia.

Is Obesity Linked to Neural Dysfunction?

Obesity increases the incidence of cardiovascular diseases, a major risk factor for vascular dementia (VaD), the second most common type after Alzheimer’s disease.

In another study, researchers observed people at least 50 years old to prove if obesity was a risk factor for dementia. Researchers followed up 11 years later, and the findings revealed that participants with a BMI associated with obesity at the start of the study were 31% more likely to have dementia than those with normal weight.

Furthermore, people with abdominal obesity or excessive visceral fat around the waist area were 28% more likely to have dementia.

How Does Obesity Cause Alzheimer’s and Other Dementias?

Excessive body fat can increase inflammation, which may contribute to the abnormal buildup of toxic proteins in the brain.

Once a person gains weight, an inflammatory marker known as C-reactive protein (CRP) found in the blood also increases. When there’s inflammation, the body’s ability to regulate insulin levels is disrupted, resulting in insulin resistance. What happens next is that excess sugar in the body gets converted into fat and stored in the liver. Too much fat in the liver can elevate the risk of heart disease, raising the risk of dementia.

There's also evidence that obesity can induce neuroinflammation and cognitive dysfunction in the hippocampus, amygdala, and cerebellum areas of the brain. Moreover, a higher waist circumference due to obesity has led to changes in white and grey matters in the brain.

Does Being Underweight Affect Your Brain?

Weight loss is an early symptom of mild cognitive impairment. A 39-year study on changing BMI revealed that a pattern of declining BMI raised the incidence rate of dementia. Additionally, people who experienced an initial increase in BMI followed by declining BMI occurring in midlife also have a higher risk.

Another study using magnetic resonance imaging (MRI) compared the brains of 32 women diagnosed with anorexia nervosa (an eating disorder marked by abnormally low body weight) and 21 women with a healthy weight. It was found that there's a substantial deficit in the volume of gray matter in women with anorexia nervosa compared to healthy women.

Other Risk Factors of Dementia Besides Weight

Imbalances in weight alone don’t directly indicate a potential cognitive impairment. To measure the probability of dementia, physicians consider other observable risk factors, such as one’s ability to do tasks independently, overall memory ability and retention, behavior changes, and more.

Here are other dementia risk indicators physicians measure alongside weight changes:

  • Age
  • Family history or genes
  • Current health condition and comorbidities (e.g., cardiovascular diseases, diabetes, sleeping disorders, depression)
  • Lifestyle (i.e., if the person is a chain smoker, an excessive alcohol drinker, or leads a sedentary lifestyle)
  • History of traumatic brain injury

The more dementia indicators are present in a loved one, the higher the odds of developing dementia.

Prevent Dementia by Minimizing the Risks

There’s no single way to avoid dementia altogether. However, you can reduce your risk and lessen the potential damage to the brain, which can delay the emergence of the symptoms and progression of the disease.

Here are some ways to do so:

  1. Know your baseline risk.
    If your family has a history of dementia (i.e., a great-grandparent was diagnosed with Alzheimer’s), get assessed to measure your risk. If the chance of developing Alzheimer’s is high, you can make immediate changes to your lifestyle and overall health.
  2. Avoid drinking and smoking.
    Abuse of alcohol and excessive smoking can harm the brain. If you need to quit, work with a therapist.
    Don’t even consider vaping or e-cigarettes as alternatives, as studies have shown that they can negatively affect the brain.
  3. Stay active.
    Exercise can improve cognitive function and make you happy. Another common feature of older people diagnosed with dementia is their sedentary lifestyles. Avoiding sitting all day at home and engaging in physical activities can substantially diminish the risk of dementia.
  4. Join social events.
    Loneliness and depression are connected with dementia. Make sure you participate in the community, family, and other group activities to stay socially active. Some meaningful activities are going to church every Sunday with friends and joining social events at a nearby senior recreational facility.
  5. Keep your brain sharp.
    Any form of physical activity is good for keeping the brain alert. Other ways to sharpen cognition are meditation and hobbies that require concentration, such as knitting, painting, cooking, sculpting, and more.

Maintaining a Healthy Weight Is a Form of Self-Care

Maintaining a healthy weight begins with being conscious and smart of your food options, calorie intake, and the amount of physical activity you need daily.

Weight changes, both weight gain and weight loss can signal a health condition. If weight change happens along with other key dementia symptoms, such as mild memory loss, social withdrawal, and changes in behavior, it can mean a possible cognitive impairment.

If you notice these changes in your elderly loved one, visit your doctor for a cognitive examination.

Here is an article about 7 Foods To Fight Alzheimer’s Disease that will inspire you or your loved one to change your diet to promote brain health.


Syed Rizvi


Syed has years of experience dealing with people, understanding their needs, and helping them find solutions to their problems.
As a Certified Senior Advisor (CSA), Certified Dementia Practitioner (CDP), Certified Montessori Dementia Care Professional (CMDCP), Syed is committed to working closely with Senior and their family knowing what is it like for individuals facing a challenging time, at times groping in dark trying to figure what is the appropriate next step or care level for their unique situation.
Syed and Senex Memory Advisors are fully committed to working closely with families in creating a personalized, step-by-step process memory care plan at zero cost.

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