Department of Food Science and Human Nutrition
Extension
Colorado State University
Fort Collins, CO 80523-1571
Healthy Heart Beats
October-December 2008
Vol 30, Issue 4
Nutrition and Research Updates
- Heart Attack Risk Increases with 'Western' Diet
- Mediterranean Diet Protective
- Fiber Reduces Risk of Coronary Heart Disease
- Vitamin D Critical to Longevity
Heart Attack Risk Increases with 'Western' Diet
Though diet is accepted to be a major modifiable risk factor for cardiovascular disease, dietary patterns vary according to different regions of the world. The INTERHEART study examined the dietary patterns of 16,000 participants in 52 countries by analyzing 5,761 heart attack cases (experimental group) and compared them to 10,646 people without known heart disease (control group). The researchers were able to identify three dietary patterns in the world:
- Oriental - higher intake of tofu, soy and other sauces
- Prudent - higher intake of fruits and vegetables
- Western - higher intake of fried foods, salty snacks, eggs and meat
"The objective of this study was to understand the modifiable risk factors of heart attacks at a global level," said Salim Yusuf, professor of medicine at McMaster University and director of the Population Health Research Institute at Hamilton Health Sciences in Ontario, Canada and the study's senior author. The researchers created a dietary risk score questionnaire including both "healthy" and "unhealthy" foods for heart attack patients and adjusted it for dietary preferences for each country. Trained medical personnel interviewed both groups. After adjusting for known risk factors, researchers found:
- People consuming a Prudent diet of more fruits and vegetables had a 30 percent lower risk of heart attack compared to people who ate little or no fruits and vegetables.
- People consuming a Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.
- The Oriental dietary pattern showed no relationship with heart attack risk. Researchers said that while some components of the Oriental pattern may be protective, others such as the higher sodium content of soy sauces may increase cardiovascular risk, resulting in neither positive nor negative relationships.
The dietary pattern recommended by the American Heart Association is similar to the Prudent diet described in this study. This study helped confirm current dietary recommendations that emphasize the consumption of more fruits and vegetables to help reduce the risk of having a heart attack in populations worldwide, he said. "At the same time, an unhealthy dietary intake, assessed by a simple dietary risk score, accounts for nearly one-third of the world population's attributable risk," Yusuf said.
Source: American Heart Association, October 20, 2008-Circulation: Journal of the American Heart Association http://circ.ahajournals.org/cgi/content/abstract/CIRCULATIONAHA.107.738716v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=Yusuf+western+diet&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT.
Mediterranean Diet Protective
Greater adherence to a traditional Mediterranean diet rich in fish, fruits and vegetables, olive oil and low in red meat, dairy products and moderate consumption of red wine especially during meals offers substantial protection against cancer, heart disease and degenerative diseases, Italian researchers concluded.
This is the first known study which reviewed all the available data for a possible association between sticking to the Mediterranean diet, premature death, and the occurrence of chronic diseases in the general population. Previous research on the Mediterranean diet suggests that it has a protective role in cardiovascular disease and cancer, but no study has reviewed all the available data for a possible association between sticking to the Mediterranean diet, premature death, and the occurrence of chronic diseases in the general population. People who did this had a 9 percent drop in death from heart disease, a 13 percent reduction in incidence of Parkinson's and Alzheimer's disease and a 6 percent reduction in cancer compared to those who were not as diligent, their study found.
Francesco Sofi, a clinical nutrition researcher, and colleagues at the University of Florence reviewed 12 international studies which included more than 1.5 million people whose eating habits and health were followed for periods of three to 18 years. All the studies examined the concept of using a numerical score to estimate how much people stuck to the diet, called an "adherence score." Using a random effects model, the researchers found a two point increase in the adherence score for a Mediterranean diet, which was significantly associated with a reduced risk of mortality from any cause.
"These results seem to be clinically relevant for public health, particularly for encouraging a Mediterranean-like dietary pattern for primary prevention of major chronic diseases," wrote Sofi. The researchers suggested this tool could be used by doctors to help educate patients to eat better resulting in better health and increased longevity. The findings confirm the current guidelines and recommendations from all major scientific institutions.
Source: British Medical Journal, 2008, 337:a1344. (September).
Fiber Reduces Risk of Coronary Heart Disease
In a study investigating the effect of dietary fiber on coronary heart disease and long term mortality, data was collected from 1,373 men born between 1900 and 1920. During a 40-year period (1960 to 2000) the subjects were examined. Out of the 1,130 who died during that 40-year period, 348 died of coronary heart disease. Mortality due to coronary heart disease was reduced by 17 percent and all-cause mortality was reduced by 9 percent for every additional 10 grams of dietary fiber consumed daily.
The strength of the association between long-term dietary fiber intake and all-cause mortality decreased from age 50 years to age 80 years. The study authors were unable to draw conclusions regarding specific associations for different types of dietary fiber. The authors concluded that "a higher recent dietary fiber intake was associated with a lower risk of both coronary heart disease and all-cause mortality. For long-term intake, the strength of the association between dietary fiber and all-cause mortality decreased with increasing age."
Source: American Journal of Clinical Nutrition, 2008, 88(4): 1119-1125. (October).
Vitamin D Critical to Longevity
The risk of death from all-cause mortality may increase by 26 percent due to inadequate vitamin D according to a study investigating levels of vitamin D in a nationwide survey examining mortality in the overall population. The results showed 41 percent of men and 53 percent of women in the United States were not getting enough vitamin D. "The importance of vitamin D may be underappreciated," said lead author Dr. Michal Melamed, a clinical fellow at Johns Hopkins University. "There are studies that link low vitamin D levels to the development of cardiovascular disease (CVD), peripheral arterial disease, diabetes, hypertension and different cancers," she said.
The researchers collected data on more than 13,000 men and women who took part in the Third National Health and Nutrition Examination Survey. Levels of vitamin D were collected in 1988 and 1994, and the participants were followed through 2000. During more than eight and a half years of follow-up, 1,806 people died. Among these, 777 died from cardiovascular disease. Of these, 400 were found to be deficient in their vitamin D levels.
"Those who had the lowest levels of vitamin D had a 26 percent higher risk of death from all causes compared to those with the highest vitamin D levels," Melamed noted. Among other things, vitamin D is essential for maintaining levels of calcium and phosphorus in the body. "Vitamin D may be very important for overall health," Melamed said.
Melamed explained that when the subgroups were analyzed, the risk for mortality was more evident in those who did not have CVD at the beginning of the study compared with those who did have CVD. "This suggests to us that maybe, if vitamin D is playing a role in CVD, it is acting before the disease is established," she said, adding that the time has now come for a randomized controlled trial with vitamin D looking specifically at cardiovascular events or mortality as an end point.
Source: Archives of Internal Medicine, 2008, 168(15):1629-1637. (August).
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