University of Cambridge researchers analyzed genetic, lifestyle and health data on more than 500,000 adults, 40-69 years old, and found that those people who were later diagnosed with dementia had tested poorly up to nine years before on measures of problem solving, memorizing, reaction times and grip strength (Alzheimer’s & Dementia, Oct 12, 2022). The study authors believe that this information could lead to earlier diagnosis to start preventive treatments that target known risk factors for dementia.
Known heart attack risk factors such as high blood pressure, high cholesterol, and diabetes have been associated with an increased risk for dementia (Lancet, June, 2022), probably because anything that damages the blood vessels leading to the heart can also damage those leading to the brain. For example, an MRI study of 125 healthy people, ages 18 to 40, showed that those who had fewer heart attack risk factors also had far less brain damage and risk for dementia: more blood vessels in their brains, a greater blood flow to their brains, and far fewer white-matter hyper-intensity lesions associated with brain damage (JAMA, Aug 21, 2018;320(7):665-673). Long before a person suffers from heart disease, an elevated resting heart rate and a thickening of the left heart ventricle on an echocardiogram can predict heart disease and also dementia (Neurology, January 26, 2022). Having low good HDL cholesterol at a young age predicts dementia as well as a heart attack in later life (Int J of Ger Psych, August 23, 2020).
Reducing Heart Attack Risk Also Reduces Dementia Risk
You can reduce your risk of suffering from dementia by up to 70 percent when you follow the same healthful habits that help to prevent heart attacks (JAMA, Aug 21, 2018;320(7):657-664). A study of 6,600 people over 65, followed for 8.5 years, found that each lifestyle risk factor for heart attacks is also a risk factor for dementia, and that correcting each heart attack risk factor reduces risk for dementia. The seven healthful habits used in the study were:
• Healthful eating
• Weight loss if overweight
• No smoking
• Control blood pressure
• Control cholesterol
• Control blood sugar
The American Heart Association promotes this list as the “Simple 7” (Circulation, 2022;145:808–818). See my report on this study at Healthful Habits Reduce Risk for Dementia
Lack of Exercise and Dementia
Many studies show that exercise increases blood flow to the brain to stimulate growth of new blood vessels and cells, and reduces risk for diabetes and obesity which can damage the brain. Older adults who do not exercise have a markedly increased rate of dementia and loss of white matter in their brains that helps them to retain memory and make wise decisions (J of Alzheimer’s Disease, Dec 19, 2017;61(2):729-739). See How Exercise Reduces Dementia Risk
Treat High Blood Pressure to Reduce Dementia Risk
Among people with high blood pressure — defined as systolic pressure of ≥140 mm Hg, or diastolic pressure ≥90 mm Hg — those who used any of five major classes of antihypertensive drugs, singly or in combination, had a 12 percent lower risk for dementia and a 16 percent lower risk for Alzheimer’s disease than those not using blood pressure medication (Lancet Neurology, 2020 Jan;19(1):25-272019). See High Blood Pressure Increases Risk for Dementia
More than 30 percent of North Americans over 85 suffer from some degree of dementia. Risk for dementia can be detected long before it occurs, and may be able to be delayed or prevented by following all the rules for preventing heart attacks. I think that everyone should be checked for heart attack risk factors such as blood pressure, cholesterol, diabetes, HBA1c, overweight, and so forth, and if any of these tests are abnormal, that should be a major stimulus to change your lifestyle immediately because at this time dementia is not reversible.