What's Good for the Heart Is Good for the Brain

Dr. DeCarli's research suggests that older people without vascular risk factors or evidence of vascular brain injury perform just like young people on cognitive tests. "If we could control vascular risk factors, maybe our brains could stay young and we wouldn't have to experience the memory loss that is typical of aging," Dr. DeCarli suggested. "We know that Alzheimer's disease, which 10 or 20 years ago was thought of as senility and a part of normal aging, is a pathological process. We need to take the next step and say the same is true of vascular disease." With that approach, we may prevent a lot of late life cognitive impairment if we prevent vascular disease from accumulating. "We have medications that may turn back some of the vascular injury, but isn't it better to prevent that injury in the first place?" DeCarli says, proposing that exercise and lifestyle changes that reduce heart disease may prevent Alzheimer's disease as well.

"When we think about high blood pressure, when we think about diabetes, when we think about high cholesterol, we usually think about heart attacks," he notes. Lowering cholesterol is important for the heart, but it may be just as important for the brain, maybe even more important, according to DeCarli. Prevention is key. "Some heart damage can be repaired surgically, but not brain damage. A memory lost is never recovered."

As the doctor indicated, we have prevention and treatment approaches for vascular disease, but people don't always follow them, or they begin too late. Half of people diagnosed with high blood pressure don't take their medications regularly. Many people who have had a stroke have not seen a doctor in years. There is danger here, because the longer vascular disease goes untreated, the more it damages the whole body, including the brain.

The damage often begins when people are in their thirties and forties. The early changes that increase the risk of vascular disease have few or no symptoms: high blood pressure, high blood cholesterol, and problems with insulin control, so it often goes undetected in the early stage unless a person has regular checkups and blood tests.

"People can make changes in exercise, diet, blood pressure, smoking, and cholesterol levels," Dr. DeCarli explained. "They can see their doctors regularly to check blood pressure, blood sugar, and cholesterol and to get conditions like high blood pressure, heart disease, and diabetes diagnosed early. They can control obesity and carefully manage their diabetes. All these steps will protect the blood vessels so they continue to deliver blood to the brain. If we take care of our bodies now, he suggests, our bodies might take care of our brains later.

Compared to 50 years ago, many more people can live vigorous, productive lives well into their eighties if they take care of themselves. Dr. DeCarli believes that people may be able to reach the age of 80 with no memory problems, if they've done everything they can to control their vascular risk factors. "I dream that the memory loss of old age will one day be history."

Previous: The Problem of Cholesterol

Next: Atherosclerosis and Alzheimer's Disease

Excerpted from THE ALZHEIMER'S PROJECT: MOMENTUM IN SCIENCE, published by Public Affairs, www.publicaffairsbooks.com.

Alzheimer's Disease (AD)

A progressive degenerative disease of the brain that causes impairment of memory and other cognitive abilities.

Amyloid Precursor Protein (APP)

The larger protein from which beta-amyloid is formed.

ApoE Gene

A gene that codes for a protein that carries cholesterol to and within cells; different forms of the ApoE gene are associated with differing risks for late-onset Alzheimer's disease. This gene may be referred to as a risk factor gene or a "susceptibility gene" because one form of the gene, called APOE4, is associated with the risk of developing late onset AD.

Beta-Amyloid

Derived from the amyloid precursor protein and found in plaques, the insoluble deposits outside neurons. May also be called A-beta.

Beta-Amyloid Plaque

A largely insoluble deposit found in the space between nerve cells in the brain. The plaques in Alzheimer's disease are made of beta-amyloid and other molecules, surrounded by non-nerve cells (glia) and damaged axons and dendrites from nearby neurons.

Cognitive Reserve

The brain's ability to operate effectively even when some damage to cells or brain cell communications has occurred.

Dementia

A broad term referring to a decline in cognitive function that interferes with daily life and activities. Alzheimer's disease is one form of dementia.

Functional MRI (fMRI)

An adaptation of an MRI (see magnetic resonance imaging) technique that measures brain activity during a mental task, such as one involving memory, language, or attention.

Hippocampal Formation

A structure in the brain that plays a major role in learning and memory and is involved in converting short-term to long-term memory. Also called the hippocampus.

Inflammation

The process by which the body responds to cellular injury by attempting to eliminate foreign matter and damaged tissue.

Insulin Resistance

A condition in which the pancreas makes enough insulin, but the cells do not respond properly to it; characterizes and precedes type 2 diabetes.

Magnetic Resonance Imaging (MRI)

A diagnostic and research technique that uses magnetic fields to generate a computer image of internal structures in the body.

Mild Cognitive Impairment (MCI)

A condition in which a person has cognitive problems greater than those expected for his or her age. Amnestic MCI includes memory problems, but not the personality or other cognitive problems that characterize AD.

Neurodegenerative Disease

A disease characterized by a progressive decline in the structure and function of brain tissue. These diseases include AD, Parkinson's disease, frontotemporal lobar degeneration, and dementia with Lewy bodies. They are usually more common in older people.

Oligomers

Clusters of a small number of beta-amyloid peptides.

Oxidative Damage

Damage that can occur to cells when they are exposed to too many free radicals.

Pittsburgh Compound B (PiB)

The radioactive tracer compound used during a PET (see Positron Emission Tomography) scan of the brain to show beta-amyloid deposits.

Pittsburgh Compound B (PiB)

The radioactive tracer compound used during a PET (see Positron Emission Tomography) scan of the brain to show beta-amyloid deposits.

Synapse

The tiny gap between nerve cells across which neurotransmitters and nerve signals pass.

Tau

A protein that helps to maintain the structure of microtubules in normal nerve cells. Abnormal tau is a principal component of the paired helical filaments in neurofibrillary tangles.

Tangles

A protein that helps to maintain the structure of microtubules in normal nerve cells. Abnormal tau is a principal component of the paired helical filaments in neurofibrillary tangles.

Memory

Normal Aging

Genetic Risk Factor

Dominant and Recessive Genes

Genes and Proteins

Protein-Misfolding Disease

Cholesterol

Biomarkers

Disease-Modifying Drug

Transgenic Mice

An animal that has had a gene (such as the human APP gene) inserted into its chromosomes for the purpose of research. Mice carrying a mutated human APP gene often develop plaques in their brains as they age.

Pathology

Microglia

Insulin & Insulin Resistance

Susceptibility Gene

A variant in a cell's DNA that does not cause a disease by itself but may increase the chance that a person will develop a disease.

Susceptibility Genes

A variant in a cell's DNA that does not cause a disease by itself but may increase the chance that a person will develop a disease.

Genome-Wide Association Study

Vascular Disease

Genetics

Genetics

Normal Aging