Department of Food Science and Human Nutrition
Extension
Colorado State University
Fort Collins, CO 80523-1571
Nutrition and Research Updates
July-September 2007
Vol 29, Issue 3
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Source of Fat Tied to Heart Disease Risk
Authors of a study on markers for cardiovascular disease (CVD) concluded that the source of fat may have more impact than the quantity. "The perception that all high-fat snacks are unhealthy may be wrong," wrote lead author Marie-Pierre St-Onge. In this study both low- and high-fat snacks were replaced with snacks high in polyunsaturated fatty acids (PUFAs) and low in trans fat and saturated fat.
Thirty three volunteers were randomly assigned to receive one of the following: snacks classified as low-fat (30.8 per cent of calories from fat, 5.2 per cent from PUFAs), high-PUFA (36.3 per cent from fat, 9.7 per cent from PUFAs), or high-fat (37.9 per cent from fat, 5.8 per cent from PUFAs). While each of the three diets led to reductions in total and LDL-cholesterol levels, the low-fat and the high-PUFA diets showed a larger decrease when compared to the high-fat diet.
"These data show that snack type affects cardiovascular health," wrote the authors. "Consuming snack chips rich in PUFAs and low in saturated or trans fatty acids instead of high-saturated fatty acid and trans fatty acid or low-fat snacks leads to improvements in lipid profiles concordant with reductions in cardiovascular disease risk," they concluded.
Source: American Journal of Clinical Nutrition, 2007, 85(6):1503-1510 (June)
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A Diet Rich in Omega-3 Fatty Acids Can Lower Blood Pressure
Foods containing omega-3 fatty acids can lower blood pressure. "A large percentage of people between ages 20 and 60 have a rise in blood pressure, and by middle age many have high blood pressure," said Dr. Jeremiah Stamler, professor emeritus of preventive medicine at Northwestern University in Chicago, one of the authors of the study. "We're looking at dietary factors that may help prevent that rise, and omega-3 fatty acids are a small, but important piece of the action," Stamler said.
 The study, based on analysis of data from INTERMAP, looked at diet and its relation to blood pressure in 4,680 men and women, ages 40 to 59, who lived in Japan, China, Britain and the United States. All the study's participants provided information about their food and alcohol consumption, gave urine samples and had their blood pressure measured twice at each of four study visits. Adjustments were made for age, gender, weight, salt intake, exercise and other variables which might influence blood pressure.
People who eat diets containing fish, nuts, seeds and vegetable oils that contain omega-3 fatty acids tend to have lower blood pressure, according to a report in Hypertension: Journal of the American Heart Association. Fatty fish such as trout, salmon and mackerel and walnuts, flaxseed and canola oil are all good sources of omega-3 fatty acids. People who got their omega-3s from nuts had just as much benefit as those who get them by eating fish, the study found.
"With blood pressure, every millimeter counts. The effect of each nutrient is apparently small but independent, so together they can add up to a substantial impact on blood pressure," said Dr. Hirotsugu Ueshima of Shiga University of Medical Science in Otsu, Japan, lead author of the study. "If you can reduce blood pressure a few millimeters from eating less salt, losing a few pounds, avoiding heavy drinking, eating more vegetables, whole grains and fruits (for their fiber, minerals, vegetable protein and other nutrients) and getting more omega-3 fatty acids, then you've made a big difference," Ueshima said in a statement.
Source: http://www.americanheart.org/presenter.jhtml?identifier=3048211
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Whole Grains Linked to Healthy Heart
 "Many consumers and health professionals are unaware of the health benefits of whole grains," lead study author Dr. Philip B. Mellen, of Wake Forest University in Winston-Salem, North Carolina, said in a statement. Americans can benefit personal heart health by including more servings of whole grains like oatmeal, barley and brown rice.
The researchers in this study found that higher whole grain intake was consistently linked to a lower risk of heart disease and stroke. On average, adults who ate 2.5 servings of whole grains per day were 21% less likely to develop cardiovascular disease. Few Americans get the recommended three servings of whole grains per day, according to the authors of the study. More than 40 percent of U.S. adults say they eat no whole grains.
Based on these latest findings of the inverse association between whole grains and cardiovascular disease, Mellen and his colleagues concluded health professionals should focus their efforts to get people to include more whole grains. For the study, the researchers collated data from seven major studies involving more than 285,000 men and women who were followed for 6 to 15 years. Overall, those who ate the most whole grains were less likely to suffer a heart attack or stroke, or die of cardiovascular causes.
Source: http://www.nmcd-journal.com/article/PIIS0939475307000026/abstract
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Exercise Increases HDL-Cholesterol
 The evidence from a meta-analysis study of 1,404 participants aged 23 to 75 indicates that individuals who are more physically active have higher HDL-cholesterol (HDL-C). In all the studies combined, HDL-C increased by an average of 2.53 milligrams per deciliter in the exercise groups. "Thus, the value of regular aerobic exercise in increasing serum [blood] HDL-C level and in reducing the risk of cardiovascular disease has received widespread acceptance," the authors write. The effect of exercise was greater in those who had a higher total cholesterol level (220 milligrams per deciliter or greater) and in those with a body mass index of less than 28.
 "In a previous observational study, every 1-milligram per deciliter increment in HDL-C level was reported to be associated with a 2 percent and 3 percent decreased risk of cardiovascular disease in men and women, respectively," the authors write. "If this observation were applied to our results, the increase in HDL-C level by exercise determined by this analysis would, by a rough estimate, result in a cardiovascular disease risk reduced by approximately 5.1 percent in men and 7.6 percent in women. This is potentially of substantial importance in public health, although the effect of reducing cardiovascular risk by increasing HDL-C level might be smaller than that by use of medications such as fibrates or niacin."
The minimum amount of weekly exercise that appeared necessary to change HDL-C levels was 120 minutes or the amount needed to burn 900 calories. When duration, intensity and frequency were evaluated, HDL-C showed the most improvement when time per session was increased, not frequency or intensity.
Source: Archives of Internal Medicine, 2007, 167(10):999-1008 (May)
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Lower Salt Intake Reduces CVD Risk
 A recent study has concluded that reducing sodium intake can lower the risk of cardiovascular disease (CVD) by 25 percent and the risk of dying from CVD by 20 percent. This study looked at people who participated in two randomized trials (TOHP I and TOHP II) in which they were either in the sodium restriction intervention group or the control group. Their blood pressure was monitored to note the effects of sodium restriction. The observational follow-up for cardiovascular disease began in 2000, about 10 years after the end of TOHP I and five years after the end of TOHP II, and ended in 2004-5. Of the 2,415 participants (total from both trials) those who were in the sodium restriction group had fewer cardiovascular events than those who did not change their sodium consumption. The study's authors conclude that though sodium reduction has previously been shown to lower blood pressure, it may also reduce long term risk of cardiovascular events.
Source: British Medical Journal, 2007, 334(7599):885 (April) or http://www.bmj.com/cgi/content/full/334/7599/885
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