For many years, spices have been used in cuisines to add different flavours and bring out great tastes. In the Indian sub-continent, spices like turmeric and chilli are used in almost every savoury dish.
Some spices have been unofficially promoted from everyday culinary staples to all-healing superfoods. Turmeric has been used in Asia for millennia as it is believed that it can boost the immune system.
Recently, turmeric has made its way to coffee shops in different parts of the world as a key ingredient in "golden latte."
But the question remains, do these spices add any health benefits to our food, or can they actually become harmful for us?
Are there benefits in consuming chillies?
Many studies and experiments have demonstrated the potential effects of chillies on our health – some of them have found both beneficial and adverse results.
Capsaicin is the main active ingredient in chillies. When we eat chillies, capsaicin molecules interact with the temperature receptors in our bodies, which send signals to the brain to create the feeling of heat.
Some studies on chillies have found out that capsaicin may help us live longer. Last year, an Italian study found that people, who ate food seasoned with chilli peppers four times a week, had a lower risk of mortality compared to those who never ate chillies.
During the research many lifestyle habits and factors were considered, including age, sex, level of education, marital status, smoking habit, exercise and overall diet quality.
In 2015, Chinese researchers found that consumption of chilli lowers the risk of mortality. The researchers examined chilli consumption and health of nearly 500,000 Chinese adults during their study.
Those who consumed spicy foods almost every day had a 14 percent lower risk of mortality than those who ate spicy foods less than once a week.
Interestingly, researchers at Harvard School of Public Health, found that higher intake of spicy foods are related to a lower risk of mortality, particularly due to cancer, heart disease, and respiratory diseases.
However, higher intake of spicy foods increases chances of other diseases and it does not guarantee that if you start to eat large quantities of chilli peppers, it would protect your health – or protect you from respiratory illness – in the short-term.
The Chinese study followed people for a median time of seven years each. Thus, the study showed that the effects of chillies or chilli peppers effect is likely to build up over time – not within weeks or months.
On the other hand, a number of studies also have shown that capsaicin can increase the amount of energy we burn and can decrease our appetites. The burning sensation also comes with eating chillies which has long fascinated scientists.
Zumin Shi, associate professor at Qatar University's human nutrition department, has found that consumption of chilli is associated with lower risk of obesity and it is beneficial to reduce high blood pressure.
But from her research she also found that people who ate more chillies had poorer cognitive function. And her study found that more chilli consumption affects our memory. Chilli intake above 50g per day was associated with almost double the risk of self-reported poor memory.
On the other hand, even if a compound within a certain spice may have beneficial effects, we normally do not consume enough of it to make any difference.
Cure in curcumin
Turmeric is one of the vastly used spices at almost every household in South Asia. This spice is regarded to have beneficial effects on human health because of the presence of curcumin.
Turmeric is commonly used in alternative medicine to treat inflammation, stress and many other health conditions.
However, numerous studies have found curcumin to have anti-cancer effects in the laboratory.
Curcumin has poor water solubility, causing the body to not being able to use it properly from the way we consume turmeric.
When turmeric is heated, its chemical components change. Subsequently, the spice loses many beneficial qualities.
Correlation vs causation
Scientists have studied chilli and turmeric widely but most studies have only compared data on consumption and different health outcomes. The trials do not separate cause from effect. And research done in labs does not necessarily translate to the human body.
For nutritional studies, it is difficult to rule out correlation versus causation.
For example, a 2019 Italian study found out that there was a lower risk of mortality associated with chilli consumption. It was an observation, thus, it is impossible to know whether eating chilli made people live longer, or already healthy people tend to consume more chilli.