Also: soy nuts, high blood pressure, high cholesterol

We hear constantly about the importance of lowering our “bad” cholesterol, but what can we do to raise the “good” cholesterol?

Japanese researchers may have your answer: start exercising regularly for longer periods.

Such exercising may modestly increase levels of HDL “good” cholesterol, lowering your risk of heart attacks, strokes and other cardiovascular maladies, scientists from Ochanomizu University write about their research in today’s Archives of Internal Medicine.
 
A high level of “bad” cholesterol is a major risk factor for heart attacks, strokes and other cardiovascular conditions, but so is a low level of “good” cholesterol.

Duration, intensity and frequency

Evidence strongly shows that the more active you are, the higher your levels of “good” cholesterol, which may drive its “bad” sibling from your body. But results of aerobic exercise on cholesterol levels vary considerably, depending on duration, intensity and frequency of exercise regimens, and the characteristics of the people in the studies, said Dr. Satoru Kodama, who led the present research project.

To get some firm answers, Kodama and his team analyzed 25 articles on trials from 1966 to 2005 that measured the effects of exercise on “good” cholesterol. The studies included 1,404 people ranging in age from 23 to 75 whose exercise habits were tracked for about 27 weeks.

In each study, they worked out about four times a week for about 40 minutes each, burning about 1,019 calories a week.

“Good” cholesterol spiked by about 2.53 milligrams, a “modest” increase when people exercised for 120 minutes a week or burned 900 calories. In other words, only the length of exercise periods, not frequency or intensity, helped changed the cholesterol levels. 

'Substantial importance'

For people who exercised for 23 to 74 minutes per session, each 10-minute boost in duration corresponded to a 1.4-milligram hike in “good” cholesterol.

"This suggests that in improving HDL cholesterol, increasing time per session is better than performing multiple brief exercise sessions when total time for exercise is limited, as is the case for many people," the authors write.

Given previous studies that show for every one milligram hike in “good” cholesterol, your risk of cardiovascular disease drops two to three percent, Kodama’s results mean women and men could lower their risks of heart troubles by 7.6 percent and 5.1 percent, respectively, by exercising for the length time as participants in his study, he siad

“This is potentially of substantial importance in public health, although the effect of reducing cardiovascular risk by increasing HDL cholesterol might be smaller than that by use of medications,” the authors write.

Nutty findings

Meanwhile, in another article in the same Archives of Internal Medicine, soy nuts just may help post-menopausal women corral high blood pressure and “bad” cholesterol, researchers at Boston’s Beth Israel Deaconess Medical Center said.
 
More than 50 million Americans have high blood pressure, also known as hypertension. Women who have the condition are four times more likely to get heart disease than women with normal blood pressure, according to the American Heart Association.

Dr. Francine Welty, the lead researcher, and her team assigned 60 healthy women to two diets with the sme amount of calories, fat, protein, carbs, calcium, cholesterol, and fatty fish, such as salmon and tuna. However, with one of the diets, women  replaced 25 grams of protein with one-half cup of unsalted soy nuts.

According to the findings, the diet with the soy nuts reduced systolic and diastolic blood pressure by 9.9 percent and 6.8 percent, respectively, in women with hypertension. In women who didn’t have hypertension, the diet is credited with lowering their systolic and diastolic blood pressures by 5.2 percent and 2.9 percent respectively.

In a blood pressure reading, the top number is the systolic pressure, the bottom number the diastolic pressure.

The soy-nut diet also decreased “bad” cholesterol by about 11 percent in the women with high blood pressure. Cholesterol levels remained the same in women with normal blood pressure.