Here at Penny Brohn, we really love our herbs and spices. In fact, they are so important to us, we gave them a dedicated section on our healthy eating plate! But, why do we love them so much? Well, firstly, they’re super tasty and can easily jazz up the simplest of vegetables. Secondly, we can significantly reduce how much salt we use as the herbs and spices add so much flavour. And, lastly, they are a rich source of phyto (plant) nutrients such as polyphenols, which have potent antioxidant, anti-inflammatory and immune supportive properties.
During the second century the spice trade is known to have flourished. Spices were transported from east to west; flooding markets across the world with cinnamon, pepper, ginger, cloves and nutmeg. Herbs and spices have been used medicinally for centuries in places like ancient Egypt and Assyria, where people understood and respected their health benefits. Only recently has modern science begun to make sense of the beneficial properties of these health-promoting plant foods.
Human research into the benefits of kitchen herbs and spices in the context of cancer is limited, but if we consider that reducing inflammation and supporting immunity are two strategies, we want to emphasise in an anti-cancer diet, these special foods come in to their own.
Here is a look at just a few of our favourite culinary herbs and spices.
Since the turn of the century there has been an explosion of research on turmeric – a richly coloured golden spice, and a member of the ginger family. Turmeric’s most active ingredient is a group of phytochemicals called curcuminoids, of which curcumin is the most abundant. Curcumin has been shown to possess anti-microbial (anti-fungal, anti-bacterial and anti-viral) properties, also antioxidant, antitumor and anti-inflammatory properties.
Much of the research into curcumin has focused on its anti-inflammatory properties, perhaps because inflammation is implicated in most modern diseases, including cancer. Multiple animal and in vitro (laboratory) studies suggest that curcumin may: have a preventative effect in some cancers; inhibit the survival and proliferation (the process that results in an increase number) of cancer cells; inhibit tumour growth and spread; encourage apoptosis (programmed death of abnormal cells); and, enhance the efficacy of chemotherapy.
While it’s exciting to see this huge interest in the role of curcumin in cancer, it’s worth keeping in mind that not all animal and laboratory research is applicable to humans, and that most studies have used standardised doses of extracted curcumin, rather than the whole spice, turmeric. It is difficult to know how much curcumin is present in the whole powdered spice we consume at home, but research suggests it is little more than 3%. In addition, curcumin has limited bioavailability and is difficult to absorb, so it’s use as a therapeutic spice extract, while promising, still needs more research benefits.
As advocates of a diverse, wholefood diet, we think there’s undoubtedly more to turmeric than curcumin alone and like to use turmeric regularly in our recipes. To improve the bioavailability, it’s helpful to cook with or use turmeric, together with a source of fat and piperine (an extract from black pepper), as this can increase intestinal absorption.
If you’re looking to use turmeric more therapeutically, we recommend you work with a qualified herbalist to establish if a curcumin extract is suitable for you. In general, curcumin is well-tolerated – though some studies do suggest it may impair iron absorption if used long term and at high doses. Meanwhile other studies suggest it may have a blood thinning effect, which means it would be contraindicated where blood thinning medication – such as warfarin – is prescribed.
Ginger demonstrates anti-inflammatory, antioxidant and anti-proliferative properties, indicating its promising role in cancer. Several clinical trials have researched the effects of ginger on colorectal cancer, with promising results. In prostate cancer, several animal studies indicate whole ginger extract may inhibit growth and encourage apoptosis (death) of the cancer cell.
Ginger is also well known for its anti-nausea effects, and many people find it helpful for chemotherapy induced nausea. One interesting clinical trial showed inhaled ginger aromatherapy might be a helpful for chemotherapy-induced nausea and vomiting in women with breast cancer.
Garlic’s natural sulfur compounds exhibit potent antioxidant activities and demonstrate significant immune enhancing effects. Multiple in vitro breast cancer studies suggest some of these natural compounds may inhibit breast cancer growth and encourage apoptosis (programmed cell death). In one animal study, the sulfur compound, allicin, was shown to enhance the response to tamoxifen and reduce liver injury commonly associated with it.
Garlic’s anti-carcinogenic effects have also been displayed in upper digestive tract cancers, colorectal cancer and leukemia. Compounds extracted from garlic have been studied for their role in many other cancers, including glioblastoma, lung, ovarian, pancreatic, bladder and melanoma – and all warrant further research.
Along with some other foods, garlic also has prebiotic effects, meaning it can encourage positive changes in the microbial diversity in our gut.
Black pepper is one of the most commonly used flavour enhancers in the world. A major constituent of black pepper is piperine which has been shown to exert antitumor activities in a variety of cancers. In both breast and colorectal cancer, in vitro studies suggest cell proliferation is inhibited. And in prostate cancer, animal studies indicate that piperine may inhibit cancer cell proliferation in both hormone dependent and non-hormone dependent tumours. Piperine has also showed promise as a therapeutic agent in melanoma and osteosarcoma.
Capsaicin is the most abundant ingredient of red chilli and is known to exert potent anti-cancer effects in various human cancers. In vitro studies suggest capsaicin has a range of anti-cancer effects, including suppressing formation of new blood vessels to the cancer cells, encouraging cancer cell death and inhibiting proliferation. Promising studies exist for many cancers, including breast, gastric, lung and bile duct cancer. In a mouse model, one study demonstrated oral capsaicin slowed the growth of prostate cancer cells and resulted in more favourable outcomes.
Black cumin – also known as nigella sativa – contains a compound called thymoquinone, which has been isolated and shown to possess potent anti-tumour properties. Multiple animal studies suggest promising results for lung and breast cancer. One study also indicated that the combined use of thymoquinone with tamoxifen enhanced the beneficial effects. Promising results have also been demonstrated in pancreatic, colorectal, and many other cancers.
Cinnamon has been shown to have several health benefits, though the most researched is its role in blood sugar balance. In one study, 0.5-2 teaspoons per day, cinnamon significantly reduced fasting blood sugars in diabetic individuals. Studies also show that cinnamon has antioxidant, anti-inflammatory, antimicrobial, and cardiovascular-disease-lowering compounds. More recently, animal studies have indicated that cinnamon may have a role in cancer prevention and management since it has been demonstrated to inhibit tumour growth. Cinnamon can easily be added to smoothies, porridge, granola, pancakes, cakes, cookies, breads and crumbles!
Rosemary contains several active components, including carnosol, rosmanol and carnosic acid, all of which may offer anti-cancer activity. Several promising in vitro studies exist for colon cancer, breast, liver, kidney, prostate and lymphatic cancers.
Research to date also suggests rosemary and sage may have a beneficial effect on brain and memory function, as well as anti-microbial activity.
How to use herbs and spices
Most herbs and spices will complement a soup and can be used dried, for ease. Leafy green herbs, such as parsley, can be used to enhance salads. Mint and parsley both work well in green smoothies, and can also jazz up hummus along with basil and coriander. Mint, coriander and chilli go beautifully in guacamole. Black pepper can be added to pretty much anything! Curcumin is included in our Spiced Latte, Spicy nuts and Masala Omlette recipes. Ginger is deliciously warming in soups, curries and in our Ginger & Almond cookie recipe.
One final note
Overall, the research into herbs and spices and their use in cancer is very promising but large clinical trials are required to demonstrate their effectiveness in humans. Issues to overcome include bioavailability – not just of curcumin, which we discussed above – but also of other spices, such as piperine and capsaicin which are known to be equally difficult to absorb. And consideration needs to be given to the possible long-term side effects of using compounds that have been separated from the whole spice.
While some herbs and spices have been studied in far greater detail than others, it is important to note that ALL herbs and spices are a rich source of antioxidants, and many of them have potent anti-inflammatory activity. Furthermore, research suggests there may be a synergistic effect of combining different herbs, or consuming them together, with other polyphenol rich foods, thus supporting our recommendation to use herbs and spices widely in your kitchen. And, if you’re wondering whether fresh gives greater nutritional value than dried, in the case of herbs and spices, the opposite is true as studies show dried herbs and spices have a higher antioxidant content than fresh.
So, while the research continues to evolve on the beneficial effects of herbs and spices, we encourage you to use, experiment with, and enjoy a diverse range of herbs. While dosages used in clinical trials do not necessarily reflect the amount we use in everyday life – when put together with other dietary support – herbs and spices offer additional protection and support us in maintaining a strong antioxidant base. As one study concludes ‘the relatively low intake levels of culinary herbs and spices does not necessarily mean that they are of little value as their high polyphenol content, and thus ultimately the potential biological impact of this content, cannot be ignored.’
Should you be considering using herbal extracts therapeutically, especially alongside cancer treatment, we recommend you do this in conjunction with both a qualified herbalist, and your oncology team.