By April Cashin-Garbutt, BA Hons (Cantab)
There have been several news stories over the years reporting that curry may be good for us. Most of them refer to a chemical in curry, known as curcumin.
Curcumin has been reported to be of benefit to dementia, stroke and bowel cancer patients. (1) But what is this chemical? Does it really have such a positive effect in so many medical conditions?
And what about the rest of the ingredients in curry: overall, is curry good for you?
What is curcumin?
Curcumin’s chemical name is diferuloylmethane. It is the chemical that gives the yellow colour to turmeric. (2)
Tumeric is an ingredient added to many cooking dishes. In particular, it is known for giving Indian curries their flavour. (3)
Curcumin has been shown to demonstrate many potentially useful properties, including anti-inflammatory, antiviral and anticancer. (2)
Perhaps its most widely known property is that curcumin is an antioxidant. This means that it helps fight against free radicals, which are chemicals that may damage cell DNA and other cellular components such as cell membranes. (3)
Curcumin and dementia
The link between curry and dementia has been reported several times.
In June 2009, the BBC reported “eating a curry once or twice a week could help prevent the onset of Alzheimer’s disease and dementia, a US researcher suggests.” (4)
More recently, in February 2012 both the Telegraph and the Daily Mail reported that “eating curry once or twice a week could stave off dementia, research suggests.” (5, 6)
The NHS, however, has stated that this “is not a good representation of the research”, in reference to the Daily Mail’s report. (7)
They stress that the research was carried out on fruit flies and that the chemical may not have the same effect on diseases in humans.
Moreover, the NHS also report that not all fruit flies tested had an improved lifespan and some even had a reduced lifespan. (7)
Curcumin and stroke
It has also been reported that the spice in curry may be beneficial in stroke patients.
In February 2011, the BBC reported that promising research had been carried out on rabbits which showed that the curry spice may be able to help patients recover from the damage caused by stroke. (8)
They also reported that the research was going to be extended to include trials in humans. (8)
There were, however, problems with curcumin itself as it is not absorbed very well by the body. This is problematic in a stroke treatment – which needs to be quick in order to be effective. (9)
In addition, curcumin has problems crossing the blood-brain barrier in order to enter the brain. (9)
Consequently, the researchers, in fact, developed a new molecular compound, which was a hybrid of curcumin. They called it CNB-001. (9)
It is this new compound that the researchers expected to enter human clinical trials, rather than just curcumin itself. This is because the hybrid compound was able to cross the blood-brain barrier and thereby has the potential to resolve the medical problems caused by stoke, such as problems with muscle and movement control. (9)
Curcumin and bowel cancer
In May 2012, Cancer Research UK announced a new study into the possibility of using a drug containing curcumin for treating bowel cancer that has spread. This is because research has suggested that curcumin could have the ability to enhance chemotherapy to kill bowel cells.
This would be particularly beneficial as around 40-60 percent of patients do not respond to the standard treatment for bowel cancer - three chemotherapy drugs called FOLFOX. (10)
The chief investigator of the study, Professor William Steward of the University of Leicester, did however say, “This research is at a very early stage, but investigating the potential of plant chemicals to treat cancer is an intriguing area that we hope could provide clues to developing new drugs in the future.” (10)
Curcumin and other conditions
Curcumin has also been linked to many other potential health benefits. These include:
- Helping to prevent infections by increasing levels of a protein that is important in the innate immune system (16)
- Helping to prevent clumping of proteins in Parkinson’s Disease (17)
- Helping to prevent the growth of prostate tumors that are resistant to castration (18)
- Suppressing the cellular mechanism behind the growth of head and neck cancer (19)
- Helping to treat tendonitis and tendon inflammation (20)
Other ingredients in curry
In addition to curcumin, curry contains many other ingredients which are not so good for you. One of these ingredients is salt. (11)
If you eat too much salt you are at a higher risk of developing hypertension, otherwise known as high blood pressure, which can lead to heart disease and stroke. (12)
But how much salt is too much? According to the Consensus Action on Salt & Health (CASH) the maximum salt intake for an adult (anyone over the age of 11 years) is 6g. (13)
In April 2010, the BBC reported that researchers at CASH had found a worrying amount of salt in many curries. For example, “one chicken tikka masala takeaway had 6.8g per portion, while curries on sale at Iceland also had more than the daily limit.” (11)
Another downside of eating curry is that the consumption of very spicy foods has been positively linked to the risk of esophageal cancer. (14)
This may be due to the alkali kalakhar, which is sometimes used in the preparation of curry. Researchers have found that daily consumption of kalakhar is greatly linked to an increased risk of esophageal cancer. (15)
Overall is curry good for you?
Overall it is clear that curry usually contains curcumin, which has been reported to have many potential medical benefits.
In reality, however, there are limitations with many of the studies into the medical benefits of curcumin:
- the study of curcumin and dementia was badly represented in the popular press according to the NHS; (7)
- the study of curcumin and stroke actually involved a variant on the standard ingredient of curcumin - the research involved using a hybrid molecule rather than curcumin alone (9)
- the research on curcumin and bowel cancer is still at an early stage so it is difficult to make any conclusive judgements over its benefits (10)
It is also important to remember that in addition to the potential medical benefits of curcumin, curry also contains many other ingredients, which may not be as good for you.
Perhaps most importantly, curry tends to contain high salt levels. (11) This can cause medical problems in itself, as high salt intake is linked to high blood pressure and increased risk of heart disease and stroke. (12)