Updated: Jun 16, 2020
Spices and herbs have been used for medicinal as well as culinary purposes for centuries. We know that they enhance flavour, aroma and colour but is it a myth that they are nutritionally beneficial to health? Let’s look at the evidence…
There is now plenty of evidence showing that herbs and spices possess nutritional and health benefits. Research has stated antioxidant, anti-inflammatory, antitumorigenic, anticarcinogenic, and glucose- and cholesterol-lowering activities as well as improved cognition and mood as the most common benefits of eating spices and herbs. The evidence is so strong that some herbs and spices have been actively used in preclinical, clinical, and therapeutic trials investigating new treatments of diseases for many years. But what does the evidence say?
Biological activities of spice & herbs
According to research, herbs and spices contains bioactive molecules such as:
sulphur-containing compounds (organic compound necessary to make anti-oxidant producing proteins)
tannins (reduces blood pressure and serum lipids & increases blood clotting)
vitamins (essential nutrients for all systems of the body, repairing damage & for converting food into energy)
flavonoids (antioxidants which regulate cell damaging free radicals and metallic ions in the body)
polyphenols (antioxidants which protect against oxidative stress & can be grouped into flavonoids)
These biological properties then aid or promote health benefits to the human body.
Effects of spices on human health
This means that it helps to protect the body from free radicals, some of which are normally created from burning foods (e.g. glucose & fat) for energy. Chillies have been shown to reduce oxidative stress (creation of reaction oxygen species or free radicals) in various tissues. Other spices and herbs such as turmeric, clove, rosemary, sage, oregano, and cinnamon are also excellent sources of antioxidants and have a high content of phenolic compounds (potent antioxidants).
Gut health & digestion
Evidence suggests that spices such as turmeric, black pepper, cloves and chillies are gastroprotective agents especially in those who have stomach issues such as ulcers. Root spices like cinnamon and ginger can also promote good digestion by stimulating motility and enzyme production. Likewise, herbs such as coriander have been found to help lower cholesterol and aid digestion. Some spices & herbs stimulate saliva and bile production and aid and support healthy digestion. Examples include curry leaves/bay leaves, cloves & cayenne.
Anti-inflammatory agents fights inflammation in the body, including joints and muscles. Spices and herbs such as garlic help to significantly improve stiffness, pain, and physical function, especially in overweight women. Another example is rosemary which helps to shut down specific enzymes involved in inflammation as well as reduce membrane damage and inhibit lipid peroxidation (oxidative breakdown of fats which produces free radicals). Other spices such as turmeric, black pepper, nutmeg & ginger among many others, have been suggested by research to be anti-inflammatory.
Antimicrobial agents help to fight against microorganisms like bacteria, virus, and fungus. Chillies have been found to reduce bacteria such as helicobacter (a gut bacteria that can cause sores & ulcers) and fungi. Garlic, cloves, ginger & rosemary have also been commonly named as potent antimicrobial promoting spices and herbs.
Antidepressants help to alleviate depression and some spices such as ginger, turmeric & rosemary have been found to be effective in improving mood. Rosemary has also been found to be have a protective effect on dopaminergic neural cells (cells which release dopamine) which aside from mood, has also been linked to cognition, attention and learning improvements.
Some spices and herbs contain certain biologically active ingredients which demonstrate neuro-protective properties. Cinnamon for example, is so effective that it has been linked to the treatment of patients with mild-to moderate Alzheimer’s disease. According to research, it works by preventing protein accretion, helping to prevent the creation and build-up of peptides (very large protein chains) into neurotoxic molecules.
Chilli plays an important role in regulating energy metabolism, reducing LDL levels (bad cholesterol) and increasing HDL levels (good cholesterol). Cinnamon and cinnamon extract are high in type A polyphenols and have been observed to lower sugar-induced blood pressure.
Chemo preventative/anticarcinogenic potential
Some spices and herbs may reduce the effects of carcinogenic (the potential to cause cancer) or toxic agents in human cells. This gives it a chemo preventative trait (something e.g. medicinal product that when administered prevents disease or infection). An example is rosemary, which has been found to aid in reducing the production of many proinflammatory genes (those capable of promoting inflammation).
Garlic extract has been shown to prevent platelet build up and helps to activate fibrinolytic activity which basically means it helps to dissolve small blood clots.
Thermogenesis, satiety, and weight management
Consumption of red chillies may have the potential to indirectly assist in body weight management. This is because eating chillies increases satiety and fullness, which can then lead to reduced energy and fat intake as a result of eating less. Eating chillies also increases thermogenesis (body heat production) which can raise metabolic rate (rate at which food is broken down) and help with weight management. Cinnamon has been found to help regulate blood sugar which can decrease levels of ghrelin (hunger hormone) while boosting levels of leptin (satiety hormone, responsible for fullness).
Brain function, memory, concentration, stress
Turmeric, ginger, rosemary, ginseng, saffron & black pepper have all been linked to improved memory, focus, and some protection to brain cells. Cinnamon has been shown to be highly effective in regulating attention and focus. Garlic has also been found to help increase blood flow to the brain. This may help to increase attention and concentration. Finally, spices such as saffron extract has been found to be effective in helping those with stress and anxiety disorders.
What should I take from this?
The evidence seems to tell us that frequent consumption of spices and herbs have been linked with lower rates of chronic, non-communicable disease (non-transmissible disease e.g. cardiovascular disease). The biological agents within our culinary herbs and spices seem to have a protective effect against reactive oxygen species which can cause oxidative stress, inflammation which is, one of the most common cause of all human diseases, bacteria & fungi growth and gut issues such as ulcers and sores.
The evidence supporting the link between culinary herbs & spices and improved health is so strong that some herbs and spices have been actively used in preclinical, clinical, and therapeutic trials investigating new treatments of diseases for many years. The evidence is strong mostly for turmeric which is currently being studied in human clinical trials for colon and pancreatic cancers, Alzheimer’s disease, blood disease and psoriasis.
But it is important to note that the actual role of how these spices and herbs work in the maintaining our health, specifically with regards to protecting us against noncommunicable diseases, is currently unclear. This doesn’t discredit the evidence, rather it makes it difficult for us as nutritionists and dietitians to explain to you exactly how it works in generating these health benefits.
While there are plenty of benefits of spices and herbs for health, no natural remedy should be used as a substitute to standard care in the treatment of any conditions that you may have. Whenever in doubt, always ask a nutritionist or dietician or GP for advice.