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Answer: There is growing evidence for a link between cardiovascular (heart) disease and Alzheimer’s disease (AD). Both diseases share common risk factors including hypertension (high blood pressure), cholesterol, diabetes, obesity, smoking, and ApoE4 (a gene which has been associated with atherosclerosis, AD, and possibly vascular dementia). The intriguing part of these findings is that it may be possible to prevent cognitive decline and AD by targeting these cardiovascular risk factors.

It is well known that hypertension is a direct risk factor for stroke and vascular dementia. However recent studies have suggested that hypertension during midlife is also a risk factor for the development of AD; those with hypertension are twice as likely to develop AD. Other studies suggest that high systolic pressure with low diastolic pressure in older adults is associated with an increased risk of developing of AD. In the proposed mechanism, atherosclerosis due to long-standing hypertension leads to poor blood flow to the brain, which may contribute to the development of dementia. Low diastolic blood pressure in late-life may further worsen blood flow to the brain. Peripheral arterial disease (narrowed arteries leading to poor circulation in the arms or legs) has also been associated with a two-fold increase in the risk for AD, further supporting the theory that inadequate blood circulation may contribute to AD. Other modifiable risk factors include cholesterol level, obesity, and smoking. High cholesterol levels (≥ 6.5 mmol/L or 250 mg/dL) during midlife have been associated with a two- to three-fold increase in the risk for AD. Diabetes, obesity, and smoking also roughly double the risk for dementia.

These cardiovascular risk factors appear to have an additive effect. Therefore if you have two of these risk factors, your risk of AD increases by about four times, and if you have three risk factors, your risk for AD increases by about six times, and so on. Some of these risk factors also affect the rate of progression of AD. Specifically, atrial fibrillation, hypertension, and angina have been associated with a greater rate of decline among people with AD.

It is important to recognize the link between cardiovascular disease and AD, because cardiovascular disease is often preventable or treatable. By managing cardiovascular disease, it may be possible to decrease the risk of developing AD. Those at high risk of developing AD include those with hypertension, high cholesterol, diabetes, obesity, smoking, and/or atrial fibrillation (see Table 1). Studies have shown that treating high blood pressure with antihypertensive medication reduces not only the risk of stroke but also of vascular dementia and AD. A class of antidiabetic drugs called thiazolidinediones have been shown to decrease the risk of dementia in people with diabetes, and preliminary studies suggest that these drugs may slow AD progression in people without diabetes as well. Some studies suggest that treating high cholesterol with a class of drugs called statins may decrease the risk of AD, but this remains controversial. Research into the effect of treating cardiovascular risk on the risk of AD is ongoing. But based on the available evidence, managing cardiovascular risk factors should be an integral part of managing AD.

Cardiovascular Risk Factors Associated with Dementia

• Hypertension (high blood pressure)
• Hyperlipidemia (high fats including cholesterol in the bloodstream)
• Diabetes
• Obesity
• Smoking
• Atrial fibrillation
• Hyperhomocysteinemia
• ApoE4

Tips for Decreasing Cardiovascular Risk Factors

• Eat a heart-healthy diet that is
  1. nutritious and well-balanced
  2. low in saturated fat, trans fat, cholesterol, and salt
  3. high in fruits, vegetables, and whole grains
• Maintain a healthy weight
  1. Don’t eat more calories than you use every day
  2. If you are overweight, start a weight loss program that includes exercise and a healthy, lean diet
• Get at least a total of 30 minutes of moderate physical activity on most days of the week or, if possible, every day
• Quit smoking or do not start to smoke
• Minimize stress
• Get regular physical examinations, at least yearly

For more information on healthy nutrition and lifestyles, see the American Heart Association, the FDA Food and Drug Administration’s Heart Health Online, the US Department of Health and Human Services.

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About Dr. Mindy

Dr. Mindy Kim-Miller is a trained medical physician who provides useful, but general answers to questions provided by online visitors. While Dr. Mindy can not provide specific medical advice or services, we hope you find her responses useful in your personal education. All information is provided for informational and educational purposes only and is not meant to be a substitute for professional medical advice, diagnosis or treatment. If you suspect you have an illness or disease, or a health related condition of any kind, seek professional medical care with an appropriate health care professional immediately. Do not postpone or delay seeking treatment or disregard professional advice based upon the general answers provided by Dr. Mindy. Dr. Mindy's advice is not intended to substitute for a visit to your personal physician or other qualified health provider. Any specific medical concerns or questions you may have should be directed to your personal physician or other qualified health provider.

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