Chocolate, soy protein and green tea show health benefits.
Since 1930, research has shown health benefits associated with flavonoids.  Limited research has left a solid understanding of these benefits elusive,   A first of kind study, published in the American Journal of Clinical Nutrition, has opened the door on this important health issue.

Flavonoids are a class of water-soluble plant pigments and are found in a wide variety of foods. For example, they are found in fruits, grains, soy products, wine, chocolate, and tea.
Antioxidants found in flavanoids help protect the body against free radicals created during normal metabolic function.  Free radicals react with certain chemicals in the body, and in the process, interfere with the cells’ ability to function normally.  Free radicals are believed to play a role in more than sixty different health conditions, including the aging process, cancer, and atherosclerosis.

For the study, researchers analyzed 133 studies on the effects of flavonoids and flavonoid-rich food sources on heart disease related risk factors.
Researchers found.

Chocolate helped increase blood flow and reduced systolic and diastolic blood. ( Systolic is the upper number, showing the maximum pressure exerted when the heart contracts, while diastolic is the bottom number, showing the maximum pressure when the heart is at rest).  Chocolate did not have an effect on LDL cholesterol.

Green tea educed bad cholesterol levels, while black tea actually boosted systolic and diastolic pressure.

Isolated soy protein lowered bad cholesterol and diastolic blood.

Researches noted that this is a limited study and much more work remains to be done to understand how flavanoid benefit works.

As for eating recommendations, common sense prevails, eat lost of fresh fruits and vegetables and whole grains.  Limit processed foods.

Source
American Journal of Clinical Nutrition