Can High Blood Pressure Boost Your Memory?

Moderately elevated blood pressure enhanced memory, concentration in elderly, study says

THURSDAY, May 16, 2002 (HealthDayNews) -- Controlling high blood pressure, particularly in the elderly, may come with a price.

New research suggests that elevated pressures may actually improve cognitive functioning in those 70 years of age or older.

The conclusion was arrived at by three Israeli researchers who will present their findings tomorrow at the annual meeting of the American Society for Hypertension in New York City.

But cardiologists warn that the new research is very preliminary, and they recommend against any changes in the ways high blood pressure -- or hypertension -- is currently treated.

The three researchers from Ben-Gurion University of the Negev first measured the blood pressure of 495 people, ages 70 to 85, while they were at home. Next, they gave basic tests gauging such skills as memory and concentration. The people were classified into four groups: normal pressure, normal with medication, high even with medication, and high but not treated.

Two groups did better on tests of memory, concentration, and visual retention -- those with hypertension that was not controlled and those whose hypertension was treated but not adequately controlled.

Blood pressure of 120/80 is considered desirable for healthy adults. The higher, first number is systolic pressure, defined as the pressure of the blood against the artery walls as the heart contracts. The lower, second number, reflects diastolic pressure, the pressure against the walls when the heart is at rest between beats.

When blood pressure stays at 140/90 or higher, pressure is considered high and some sort of treatment -- diet, exercise or medication, for example -- is typically recommended.

In the study, average systolic pressures ranged from 124 in the normal group to 160 in the treated-but-not-controlled group.

The Israeli researchers conclude that moderately elevated pressure seems to boost cognitive functioning. They also suggest that future research should focus on the possibility that reducing moderately elevated blood pressure in older people might come at the expense of cognitive impairment.

But research on the subject is conflicting.

In late 2000, British researchers reported in the journal Hypertension that high blood pressure in older adults with average systolic pressures of 164 was associated with impaired cognitive functioning, including adverse effects on word recognition, memory and reaction time, among other tasks.

Dr. Zi-Jian Xu, a staff cardiologist at Santa Monica-UCLA Medical Center in California, says the new study is viewed as very preliminary. While the research may spark further studies, he says there's no need for patients or doctors at this time to change the current management or thinking about high blood pressure.

"As a cardiologist, I wouldn't change anything about treating my patients [who have high blood pressure]," he says. "A lot of studies have been done showing a definite risk arising from uncontrolled hypertension, including the risk of stroke, heart disease and kidney dysfunction. Treating high blood pressure has been shown to reduce cardiovascular [disease] risk and mortality."

Dr. Robert Phillips, chairman of medicine at Lenox Hill Hospital in New York City, agrees with Xu's assessment of the new study.

"This study should be very cautiously interpreted," says Phillips, who points to many studies showing that people with normal blood pressure have better cognitive function than those with higher pressures.

What to Do: For more information on high blood pressure, visit the American Society of Hypertension, or the National Heart, Lung, and Blood Institute.

SOURCES: Zi-Jian Xu, M.D., Ph.D., staff cardiologist, Santa Monica-UCLA Medical Center, Santa Monica, Calif., and assistant clinical professor of cardiovascular disease, UCLA School of Medicine, Los Angeles; Robert Phillips, M.D., Ph.D., chairman of medicine, Lenox Hill Hospital, New York City, and professor of medicine, New York University School of Medicine, New York City; May 17, 2002, presentation, 17th annual scientific meeting of the American Society of Hypertension; December 2000 Hypertension
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