They reduce blood pressure and cholesterol. This kind of thing always makes me question such studies, though:
Chen and his colleagues turned to hamsters for the study, animals that serve as stand-ins for humans in research that cannot be done in people. They gave the hamsters high-cholesterol diets, divided them into groups, and supplemented each group’s food with either no capsaicinoids (the control group) or various amounts of capsaicinoids. The scientists then analyzed the effects.
In addition to reducing total cholesterol levels in the blood, capsaicinoids reduced levels of the so-called “bad” cholesterol (which deposits into blood vessels), but did not affect levels of so-called “good” cholesterol. The team found indications that capsaicinoids may reduce the size of deposits that already have formed in blood vessels, narrowing arteries in ways that can lead to heart attacks or strokes.
Capsaicinoids also blocked the activity of a gene that produces cyclooxygenase-2, a substance that makes the muscles around blood vessels constrict. By blocking it, muscles can relax and widen, allowing more blood to flow.
Emphasis mine. The assumption is that one gets high cholesterol from dietary cholesterol, when in fact there’s little evidence to substantiate that. But in this case, I don’t think it invalidates the research, fortunately.
Speaking of nutrition myths, here’s one that says bacon is good for you, but still gets it wrong:
Nutritionist Zoe Harcombe says: ‘Typically, about 45 per cent of the fat in pork is unsaturated. Most of that is oleic acid, the same healthy fat found in olive oil, which is known to help lower cholesterol levels.
‘Of course, the rest is unhealthy saturated fat, so moderation is key.’
Repeat after me: there is nothing wrong with saturated fat. In fact, it is much healthier than seed oils with their high omega 6s, which is where we got too much of our dietary fat. The key is to cut back on the high-glycemic carbs.