Scientists have found a new and surprising approach in the fight against obesity: hot peppers.
There’s a substance in hot peppers that ensures you burn off more fat. Because of that, you could continue eating the same food, and still lose weight. A medicine made from hot peppers is therefore being made in the US. Dutch scientists now want to make a food supplement, or even a completely new pepper variety.
Medicine against obesity
Half of the Dutch people is obese, and this number is growing. It’s often too difficult to lose weight; diets don’t work or cause a yo-yo effect. A stomach reduction does work, but can be dangerous. Scientists are therefore looking for a safe and effective medicine against obesity. They think they’ve now found such a medicine in hot peppers. A medicine with the substance capsaicin from hot peppers is already being tested in the US. In the Netherlands, Marjolein Wildwater from Vivaltes BV and the EVERGREEN project is researching whether hot peppers have any other active substances.
Burning fat with capsaicin
Hot peppers have at least one active substance: capsaicin. This substance causes the warm and burning feeling in your mouth when eating a hot pepper. This is because capsaicin activates the heat receptors in your mouth. The receptors send a signal to your brain that you’re feeling warm and are in pain. As a response, your body burns off fat and you start to sweat. Your body cools down because you’re sweating. But that’s not the only effect capsaicin has on fat. Capsaicin also turns your white fat cells brown. Brown fat cells differ from white ones because they don’t store the fat but burn it. Obese people often have few brown fat cells, so it’s more difficult for them to lose weight. Capsaicin permanently turns white fat cells brown. That means you’ll continue to lose weight, even when you stop taking capsaicin. In the US, the first medicine with capsaicin has already been tested on mice. The mice lost weight and remained slimmer.
There’s more to hot peppers
Researcher Marjolein Wildwater of the EVERGREEN project thinks the medicine with capsaicin is too simplistic. Earlier, she already showed hot peppers indeed stimulate the burning of fat. However, according to Wildwater, it’s not just the substance capsaicin that ensures this. She says: “A plant has as many as 20,000 substances that all work together. A tomato, for example, has vitamin E and lycopene. These substances can separately both halt the growth of a tumour, but combined, the effect is much more significant.” Wildwater is therefore researching whether hot peppers have any active substances besides capsaicin.
Her hot peppers have been grown under varying circumstances in the botanic garden of Hortus Alkmaar. Wildwater: “A plant creates substances based on stress, and the substances that are created is based on different kinds of stress.” The pepper plants therefore grow inside a greenhouse or outside in the sun or in the shade. Some plants are given salt water and others get a large amount of water or hardly any at all. When the plants are fully grown and produce peppers, Wildwater studies which substances have an effect on the burning of fat. She does that by researching which substances cancel each other out. “Imagine if one pepper variety causes weight loss and the other doesn’t. The effective pepper is the result of one set of growing conditions, and the non-effective pepper from another. That means the substances of the peppers cancel each other out, leaving you with the effective substances.” You can continue working with these substances.
In the US, the medicine with capsaicin is being tested on mice. Wildwater prefers using nematodes, also called C. elegans, for her research. The worms are similar to humans in many ways: they have neurons and exhibit animal behaviour that can be compared. The short film shows the worms also have a digestive system. The DNA of C. elegans can be adjusted in such a way that parts of the digestive system glow. This makes it relatively easy to study the effect of hot peppers on the burning of fat. Source: Marjolein Wildwater.
Wildwater expects the first results of her research in the spring of 2019. It’s still unknown what will happen to the results. Perhaps a food supplement with a high dose of active substances will be created, or a specially grown pepper variety, one that could contain an extra large amount of active substances. The American capsaicin medicine won’t be arriving on the market any time soon either. The medicine first has to be tested on people, and it then has to be approved by the European Medicines Agency. This process could take years.
Don’t try this at home
You might be thinking: never mind that medicine, I’ll just eat spicy food tonight. But it’s not that easy to ingest enough capsaicin to lose weight. Research shows you have to eat at least 150 milligrammes of capsaicin per day; that’s half a kilogram of red chilli peppers. People who ate this amount of capsaicin for scientific research got stomach aches and intestinal complaints. They couldn’t function for twelve hours because of the pain. It’s therefore better to wait for the medicine if you want to lose weight using capsaicin.
But what about Wildwater’s theory? When she’s correct, other substances increase the effect of capsaicin. That would mean fewer hot peppers would be necessary to lose weight. Wildwater just doesn’t know which pepper variety is the right one, under which circumstances the pepper should be grown and whether the increasing effect of the substances is big enough. She’s still waiting for these results as well. Until then, you could of course eat spicy food more often. Perhaps you’ll be lucky and choose the pepper variety with the right substances.
Lot Isarin is doing her Master’s in Science Education and Communication, with an additional focus on research and development, at the University of Utrecht. She wrote this article for the Communicating Science with the Public course. In the future, she would like to enthuse children and adults about her favourite subject, science.