Posts Tagged: heart

Antioxidants in soy protein may help protect against heart disease

Diet and lifestyle choices are major factors contributing to the risk of cardiovascular disease, which is responsible for more deaths in the United States than any other cause.

One dietary component that has received considerable attention for its potential heart-protective effects is soybeans, which contain lean vegetable protein, dietary fiber and antioxidants called isoflavones.

In a recent issue of the University of California’s California Agriculture journal, scientists reviewed research concerning the relationship between soy and heart disease. Several potential mechanisms have been identified for the observed cardioprotective effects of soy, including cholesterol-lowering properties, antioxidant activity and gene regulation.

“Soybeans and foods made from soy are the major source of isoflavones, which serve as antioxidants, scavenging and neutralizing free radicals that might otherwise cause inflammation and increase the risk of heart disease,” wrote Emily R. Cena, senior writer, and Francine M. Steinberg, professor and chair of the UC Davis Department of Nutrition.

Soy acts like compounds similar to the hormone estrogen, such as blood vessel dilation and gene regulation. “Some health concerns have been raised related to soy's estrogenlike properties, particularly with regard to breast cancer risk, but these concerns were beyond the scope of the current article,” the authors wrote.

The preponderance of research shows that soy isoflavones increase levels of cardioprotective HDL (“good”) cholesterol and decrease levels of LDL (“bad”) cholesterol, thereby lowering the risk of heart disease. Soy may also help ameliorate metabolic syndrome, a constellation of risk factors including abdominal obesity, high blood pressure, insulin resistance and alterations in blood lipids that result in increased risk of heart disease and type 2 diabetes.

A current research project funded by the UC Davis Center for Health and Nutrition Research is investigating the effects of consuming whole soy foods on biomarkers of cardiovascular risk in individuals with metabolic syndrome; it may be completed in 2012.

“Soy isoflavones have a broad variety of biological actions,” Cena and Steinberg wrote. “The beneficial effects of soy are modest compared to pharmacological treatment, such as statin drugs. However, the cumulative effects over a lifetime are likely to be significant.”

The authors highlight epidemiological studies suggesting that Asian populations consuming large amounts of soy have lower rates of cardiovascular disease than Western populations. For example, in the mid-1990s a meta-analysis of 29 clinical trials found that compared to animal protein, soy protein significantly reduced blood levels of several fats (total cholesterol, LDL cholesterol and triglycerides). This prompted the U.S. Food and Drug Administration to approve the current health claim that 25 grams of soy protein per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.

The review article on soy and heart health was featured in a special issue of California Agriculture journal, “Food as medicine: Can what we eat help cure what ails us?”

Depressed people eat more chocolate

Depressing news for those who love chocolate. A recent study published by UC Davis and UC San Diego medical scientists in the Archives of Internal Medicine found that consumption of the delicacy appears to be associated with depression.

The scientists examined the relationship between chocolate and mood among 931 women and men who were not using antidepressants. Their surprising conclusion: Participants who screened positive for possible depression ate an average of 8.4 servings of chocolate per month; those who weren't depressed ate on average 5.4 servings per month.

People who reflected major depression ate an average of 11.8 servings per month. What does that say about people like me who eat 30 or more servings of chocolate every month? It is depressing to contemplate.

The study's authors offered some possible explanations for the seeming correlation of chocolate consumption with depression:

• Depression could stimulate chocolate cravings as 'self-treatment'
• Depression may stimulate chocolate cravings for other reasons
• Chocolate could contribute to depressed mood
• Inflammation could drive both depression and chocolate cravings

"Future studies are required to elucidate the foundation of the association and to determine whether chocolate has a role in depression, as cause or cure," the authors conclude.

If you are looking for some good news associated with chocolate consumption, go to the UC ANR website Feeling Fine Online and view the 15-minute video of UC Davis nutrition professor Carl Keen explaining the health benefits chocolate.

According to Keen, a diet high in flavanols, such as those in chocolate, can reduce inflammatory conditions associated with cardio vascular disease, vasoconstriction and the risk of forming a blood clot.

A new study indicates that flavanols may increase a population of certain cells in the blood that scientists think help repair the inner walls of blood vessels, improving blood flow and potentially lowering blood pressure. This suggests that, in the future, isolated flavanols or flavanol-rich foods might be useful in preventing or possibly even treating coronary artery disease. For more information, read the UC Davis College of Agricultural and Environmental Sciences story Flavanol-rich foods may help heart disease patients, study suggests.

(Ann King Filmer contributed to this story.)

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