Health care industry in the San Fernando Valley: shifting carbs, protein and fats can lower heart disease risk.

Substituting protein or monounsaturated fats for 10 percent of dietary carbohydrates in a healthy diet can take a bite out of heart disease risk, researchers reported last week at a late-breaking clinical trials session at the American Heart Association's Scientific Sessions 2005.

"Both the general public and the scientific research community are extremely interested in the health effects of shifting calories from carbohydrates. Our study provides evidence that substituting carbohydrates with protein (about half from plants) or with unsaturated fat (mostly monounsaturated fat) can lower blood pressure, improve cholesterol levels, and reduce heart disease risk," said Lawrence J. Appel, M.D., lead author of the National Institutes of Health-funded OmniHeart study and professor of medicine at Johns Hopkins University in Baltimore, Md.

The study is being simultaneously published today in Journal of the American Medical Association.

Researchers studied 164 adults with systolic blood pressure of 120-159 millimeters of mercury (mm Hg) or diastolic at 80-99 mm Hg. This range of blood pressure is higher than normal and includes people with prehypertension and hypertension.

About half the subjects were African American, a population that has a greater-than-average risk of developing hypertension.

Researchers said their study didn't compare the test diets to the standard American diet. Instead. they tested three healthy diets. One diet was rich in carbohydrates (55 percent of calories, and is yen, close to the Dietary Approaches to Stop Hypertension (DASH/diet. The DASH diet has proven to lower blood pressure. and emphasizes fruits, vegetables, and low-fat or fat-free dairy products. A second diet shifted 10 percent of its calories to protein, compared to the carbohydrate diet. A third diet shifted 10 percent of its calories to unsaturated fat, predominantly monounsaturated fat. All of the diets were low in saturated fat (6 percent of calories).

Researchers provided all of the food during the study. The 164 participants followed each diet for six weeks at a time.

"In comparison to baseline levels obtained when participants were eating their own food, all three diets lowered systolic blood pressure by 8.2 mm Hg to 9.5 mm Hg and low-density lipoprotein (LDL) or "bad cholesterol" by 11.6 milligrams per deciliter (mg/dL) to 14.2 mg/dL," Appel said.

When compared to the carbohydrate diet:

* The protein diet further reduced systolic blood pressure (the force of blood against arteries when the heart beats) by 1.4 mm Hg overall and lowered LDL by 3.3 mg/dL overall. However, high density lipoptotein (HDL)--the "good cholesterol"--significantly decreased by about 1.4 mg/dL.

* The unsaturated fat diet further reduced systolic blood pressure by 1.3 mmHg overall. The unsaturated fat diet had no significant effect on LDL but raised levels of HDL--by 1.1 mg/dL.

Compared to both baseline and the carbohydrate diet, the protein diet reduced triglycerides (another fat in the blood) by about 16 mg/dL, and the unsaturated fat diet lowered triglycerides by about 9 mg/dL.

Researchers kept the patients' weight and exercise the same.

Researchers estimated each diet's effect on the 10-year risk of coronary heart disease based on well-established formulas. While all three diets lowered risk, the researchers concluded that the risk was lowest and similar for people following the protein and the unsaturated fat diets. Compared to baseline, each diet reduced heart disease risk--16 percent reduction in the carbohydrate diet and about 20 percent reduction in the unsaturated fat and protein diets.

"All three diets are good; it's just that two of these diets are somewhat better," said Frank Sacks, M.D., lead investigator from the study center at Brigham & Women's Hospital, Harvard Medical School.

The sources of protein in this study were mixed; (plant, meat and dairy). However, Appel stressed that in the protein diet, about half the protein calories came from plant sources such as beans, nuts and seeds and vegetable-based meat substitutes. It included roughly 6 oz per day of chicken, fish, meat, and egg-product-substitutes.

The unsaturated fat was mostly monounsaturated fat, which is found in peanuts, olives, and oils such as canola oil, and margarines made from these oils.

"There are many aspects of diet that we know affect heart disease risk. This study provides convincing evidence that the amount of carbohydrates, protein and fat people eat also influence risk," Appel said. "This work will help policy makers in making dietary recommendations and guidelines to help prevent heart disease."

The study was conducted at Johns Hopkins Medical Institutions and the Brigham and Women's Hospital and was funded by the National Heart, Lung, and Blood Institute.

Information for this article was provided by the American Heart Association 

RELATED ARTICLE: Life expectancy hits record high.

Life expectancy for Americans has reached an all-time high, according to the latest U.S. mortality statistics released recently by the Centers for Disease Control and Prevention (CDC).

The report, "Deaths: Preliminary Data for 2003," prepared by CDC's National Center for Health Statistics (NCHS). shows life expectancy at 77.6 years in 2003, up from 77.3 in 2002.

The gap between male and female life expectancy closed from 5.4 years in 2002 to 5.3 years in 2003, continuing a trend toward narrowing since the peak gap of 7.8 years in 1979. Record-high life expectancies were found for white males (75.4 years) and black males (69.2 males), as well as for white females (80.5 years) and black females (76.1 years).

Other findings in the report include:

* The preliminary age-a0justed death rate in the U.S. reached an all-time low in 2003 of 831.2 deaths per 100,000 population.

* Age-adjusted death rates declined for eight of the 15 leading causes of death. Declines were seen for heart disease (down 3.6 percent) and cancer (down 2.2 percent), the two leading causes of death which account for more than half of all deaths in the United States each year. Declines were also documented for stroke 14.6 percent), suicide (3.7 percent), flu/pneumonia (3.1 percent), chronic liver disease and cirrhosis (2.1 percent), and accidents/unintentional injuries (2.2. percent).

* After the first infant mortality rate increase in 44 years in 2002, the rate for 2003 did not change significantly (6.9 deaths per 1,000 live births in 2003 compared to a rate of 7.0 per 1,000 in 2002.)

* Firearm mortality dropped nearly 3 percent between 2002 and 2003.

* The preliminary age-adjusted death rate for HIV declined 4.1 percent between 2002 and 2003, continuing a downward trend observed since 1994.

* Age-adjusted death rates from alcohol dropped 4.3 percent and the rate for drug-related deaths fell 3.3 percent in 2003.

* Mortality increased for the following leading causes of death: Alzheimer's disease, kidney disease, hypertension, and Parkinson's disease.

Information for this article was provided by the Center for Disease Control (CDC). The report is based on data recorded from approximately 93 percent of state death certificates issued in 2003. "Deaths: Preliminary Data for 2003" is available at the www.cdc.gov/nchs.