Middle-aged people with risk factors for heart disease such as high blood pressure and high cholesterol may also be at risk for memory decline, according to a new study.

With every 10 percent increase in heart disease risk, men scored 2.8 percent worse and women scored 7.1 percent worse on memory tests, the study said.

And people with many cardiovascular risk factors saw their mental abilities decline over a 10-year period faster than people who had only a few risk factors, the study said.

The finding should give people extra incentive to improve their heart health, because it may also enhance their brain health , said study researcher Sara Kaffashian, a doctoral student at the French National Institute of Health & Medical Research.

Heart disease and cognitive impairment share many risk factors, Kaffashian said. For example, smoking and the accumulation of cholesterol in the blood vessels result in thickening and hardening of the vessels, she said.

"The same changes that may lead to heart disease may also result in a reduction of blood flow to brain regions supplied by the affected vessels, causing cerebral damage and leading to cognitive deficits," Kaffashian told MyHealthNewsDaily.

The new study will be presented at the upcoming annual meeting of the American Academy of Neurology.

Assessing memory

The researchers assigned a Framingham risk score to 3,486 men and 1,341 women with an average age of 55. The score predicts a person's risk of having a cardiovascular event, such as a heart attack , in the next 10 years, and is based on age, sex, cholesterol and blood pressure levels, smoking history and diabetes status.

The study participants took memory tests three times over 10 years. The tests measured their reasoning, memory, phonemic fluency (ability to generate words that start with certain letters), semantic fluency (ability to generate words that belong to certain categories) and vocabulary.

With every 10 percent increase in cardiovascular risk, men scored more poorly on all aspects of the memory test except for reasoning. And women scored more poorly on all aspects of the test except for fluency, the study said.

The brain is connected to the ... heart?

It's no surprise that brain and heart health are connected, said Dr. Larry Goldstein, a professor of medicine and director of the Duke Stroke Center at Duke University in North Carolina, who was not involved with the study.

"These factors aren't independent," Goldstein told MyHealthNewsDaily.

In fact, vascular dementia, which is one of the most common types of dementia, occurs because of problems with blood supply to brain cells, he said.

Past studies have linked other heart risk factors with memory problems. A 2010 study in the Journal of the American Geriatric Society showed that every one-point increase in body mass index was correlated with a one-point drop on a memory test.

And a 2010 study in the journal Frontiers in Aging Neuroscience showed that adults who had low levels of HDL ("good") cholesterol had a lower volume of gray matter in parts of the brain associated with neurodegenerative diseases , compared with adults with high levels of HDL cholesterol.

Pass it on: High cholesterol and blood pressure in middle age is linked with an increased risk of memory problems.

Follow MyHealthNewsDaily staff writer Amanda Chan on Twitter @AmandaLChan.