Adipose tissue is the type of tissue designed to store fat (ideally to be used for energy). It also helps to protect parts of the body by cushioning it. Fat is also a known insulator keeping the body warm.
There are two main types of adipose tissue: white and brown. White adipose tissue is responsible for storing fat. Brown adipose tissue (BAT) on the other hand is responsible for converting energy into heat. In fact, the only way that a body can make heat except for shivering is with BAT (Cannon & Nedergaard, 2004).
Until recently the common scientific thinking was that babies and small animals had significant amounts of BAT but that BAT wasn’t really found in adults. Newer research however has found BAT in adult humans. It has also found that high quantities of BAT are associated with lower body weight (Saely, Geiger, & Drexel, 2012). Although the research is still looking into whether or not this is a causal relationship there is, as you might imagine, a lot of interest in what can “turn on the BAT switch”.
Generally speaking BAT will generate heat by burning glucose (sugar) and lipids (fats); this is energy and energy equals calories. So when BAT is working metabolism is higher. So the question becomes can we artificially make BAT work?
That’s where the red peppers come in. Capsaicin, the ingredient that givers peppers their spiciness, work the same as cold temperatures do when it comes to BAT: they both turn on the BAT switch. As a result of exposure to capsaicin and related chemicals BAT starts converting energy into heat (Saito, Yoneshiro, & Matsushita, 2016).
This is still a long way from being able to confront the obesity epidemic with spicy food but it might give you an extra excuse to put some extra spice into your meals.