A recent story put out by the British Broadcasting Corporation proclaimed that eating broccoli could reverse the damage to heart blood vessels caused by diabetes.
The BBC based its announcement on research showing that sulforaphane, a compound found in broccoli, helps the production of enzymes that protect blood vessels and reduce the number of molecules that can cause cell damage.
It turns out that the BBC was doing a bit of hasty generalizing: Although sulforaphane is found in broccoli, researchers have come nowhere near to saying that eating the vegetable will reproduce the effects they saw in the lab.
Scientists at the University of Warwick and the University of Essex in England took blood vessel cells from non-diabetic persons and incubated some in high levels of sugar and others in low levels. The cells incubated in high levels of sugar suffered extensive damage, much like what happens in people with uncontrolled diabetes.
The researchers then applied sulforaphane directly to the damaged vessels. They found that sulforaphane activated a protein called nrf2 that caused a 300 to 500 percent increase in activity by enzymes (transketolase and glutathione reductase) that protect against cellular damage.
Incubation in high levels of sugar had caused a 300 percent increase in the presence of a free radical called reactive oxygen species (ROS), associated with cell damage. The presence of sulforaphane reduced ROS by 73 percent.
The researchers concluded that sulforaphane might eventually be useful in preventing blood vessel damage from high blood sugar, but noted that they have not yet tested it on patients with diabetes. They also said that it was way too early to conclude that sulforaphane could reverse—as opposed to stop—damage to injured vessels.
Where the BBC Erred
The BBC’s confusion came about in two ways: The first was when the researchers compared the concentrations of sulforaphane they used to the amounts that would be found in a person’s system after eating a helping of broccoli. What was intended as an easy-to-understand measure was misinterpreted by the BBC as an actual recommendation about eating broccoli.
The second was the leap of logic that the BBC made when it ignored the fact that the blood vessels under study did not come from people with diabetes and that the effects of sulforaphane appeared to be preventive, not restorative.
So, if you come across any articles touting the curative affects of broccoli, take them with a grain of salt.
Or maybe some pepper and a twist of lemon.
* Just kidding! We all know brocolli is good for us even if it does turn out to just prevent blood vessel damage rather than actually fix it.