This is in women, but I"m sure it applies to guys as well:
http://www.worldhealth.net/news/lower-blood-pressure-blueberries/
"receive either 22 g rams of freeze-dried blueberry powder or 22 grams of a control powder, to consume for eight weeks. Blueberries are one of the richest sources of phenolic compounds, including flavonoids, phenolic acids, and stilbenes, which are known to have biological activity and high antioxidant capacity. At the end of the study period, mean systolic blood pressure was lower by 5.1% and mean diastolic blood pressure was lower by 6.3%"
And check out these all-important words:
"In addition, nitric oxide involved in endothelial vasodilation was significantly increased in the blueberry group, rising from 9.11 to 15.35 microMoles, with no change in the control group."
That's the power of plants...
I've been a big fan of blueberries for their health benefits for years.
One worthy note. Much of the good stuff from the blueberries is in their skin. So, the more skin you get, the better.
Standard blueberries are much larger than wild blueberries, and so the ratio of their surface area to volume (and hence percentage of skin) is higher in wild blueberries. You can figure this out using calculus or common sense, your choice.
Wyman's is a widely distributed brand of frozen wild berries from Maine. Trader Joe's sells both wild blueberries and, better yet, boreal wild blueberries (no pesticides) from Quebec. Price is quite reasonable relative to regular frozen berries.
I eat them every morning with yogurt and granola for breakfast. Unsweetened you have to get used to the lack of sweetness, but once you get used to that they are awesome.
Or, make a blueberry pie with wild blueberries. It is life-changing.