Obesity and high blood pressure may lead to a higher risk of dementia
Key takeaways
- Higher BMI and blood pressure are identified as direct causes of dementia rather than just associated risk factors.
- Researchers used genetic randomization to prove that early weight-loss and blood pressure interventions could effectively prevent the onset of the disease.
- While weight-loss drugs may not reverse existing cognitive decline, dietary changes like eating low-glycemic foods and increasing omega-3 intake show promise.
Dementia may pose a greater risk for people with obesity and high blood pressure, according to new research. The study analyzed data from participants in Copenhagen, Denmark, and the UK to pinpoint a causal link between higher body weight and the progressive brain disease.
“In this study, we found high body mass index (BMI) and high blood pressure are direct causes of dementia,” says study author Ruth Frikke-Schmidt, M.D., Ph.D., professor and chief physician at Copenhagen University Hospital, Denmark.
“The treatment and prevention of elevated BMI and high blood pressure represent an unexploited opportunity for dementia prevention.”
Causal link between high BMI and dementia
The study published in The Journal of Clinical Endocrinology & Metabolism established a direct causal link between high BMI and dementia, using a Mendelian randomization design that mimics a randomized controlled trial. This study design uses genetic variants as natural experiments to test whether a risk factor, such as BMI, causes a disease.
The researchers identified genetic variants that cause high BMI. Because external factors cannot skew a person’s genes, this reflects how participants are randomly assigned either a drug or a placebo in clinical trials.
This allowed the researchers to determine that a high BMI directly increases the risk of dementia.
They note that high blood pressure also appeared to increase the dementia risk, suggesting that preventing this condition alongside obesity could prove more effective. “Our present data would suggest that early weight-loss interventions would prevent dementia, and especially vascular-related dementia,” says Frikke-Schmidt.
“This study shows that high body weight and high blood pressure are not just warning signs, but direct causes of dementia,” she stresses. “That makes them highly actionable targets for prevention.”
“Weight-loss medication has recently been tested for halting cognitive decline in early phases of Alzheimer’s disease, but with no beneficial effect. An open question that remains to be tested is if weight-loss medication initiated before the appearance of cognitive symptoms may be protective against dementia.”
The study was funded by the Independent Research Fund Denmark, the Capital Region of Denmark, the Lundbeck Foundation, Hjerteforeningen, and Sygeforsikringen Danmark.
Nutrition interventions
Dementia is a growing global public health challenge, with no cure currently available. Its most common forms are Alzheimer’s disease, vascular dementia, and mixed dementia. However, the science behind preventative nutritional interventions is continually expanding.
In one analysis of more than 217,000 adults, published in Clinical Nutrition, researchers found that omega-3 blood levels are associated with reduced early-onset dementia risk, despite genetic predispositions for the condition.
Another paper in Nutrition and Metabolic Health revealed that the quality and quantity of dietary carbohydrates significantly impact dementia development. It suggested that lower glycemic index (GI) foods were associated with a reduced dementia risk. Conversely, higher GI foods were linked to an increased risk.
Meanwhile, a study in BMJ Evidence Based Medicine found that any amount of alcohol consumption raises dementia risk, challenging the previously held beliefs on the benefits of light drinking. Heavy drinkers who consumed 40 or more drinks a week reportedly had a 41% greater risk of developing the condition.
