They’re used to make beer taste better.
But now scientists say hops could do more than keep you craving another pint.
For tests have found the compounds in the plant can kill liver cancer cells, as well as colon cancer cells.
However, the Oregon State University study was based only on cells in the laboratory and didn’t look at whether drinking beer could help.
Hops, used to flavour and colour beer, have been shown to kill cancer cells in laboratory tests
Hops, the flowers of the humulus lupulus plant, contain a compound called xanthohumol, also known as XN.
Scientists first found it had potential cancer-fighting properties 20 years ago.
But now researchers have found two more derivatives within XN that show similar benefits.
And they believe the compounds – called DXN and TXN – could be even more effective than XN itself.
Professor Adrian Gombart, the lead researcher, said: ‘XN had been shown to inhibit proliferation of a variety of cancer cell lines.
‘And in this study, we demonstrated XN’s ability to halt cell growth and kill two liver cancer cell lines and two colon cancer cell lines.
‘We tested liver and colon cancer cell lines because oral consumption of XN and its derivatives can lead to high concentrations in the gut and liver.’
HOW PREVALENT IS LIVER CANCER?
Liver cancer is a leading cause of cancer deaths worldwide, accounting for more than 600,000 deaths each year.
Liver cancer is the 18th most common cancer in the UK, accounting for two per cent of all new cancer cases.
Around a quarter of people in England diagnosed with liver cancer aged 15-39 survive their disease for five years or more, compared with around 5 in 100 people diagnosed aged 80 and over.
Although primary liver cancer is uncommon, its incidence has been increasing.
In the US, liver cancer incidence has more than tripled since 1980. However, rates in young adults have recently begun to decline.
Liver cancer death rates have increased by almost three per cent per year since 2000.
The exact cause of liver cancer is unknown, but most cases are associated with damage and scarring of the liver known as cirrhosis.
Cirrhosis can have a number of different causes, including drinking too much alcohol and having long-term hapatitis B or hepatitis C viral infection.
It’s also believed obesity and an unhealthy diet can increase the risk of liver cancer
XN is a source of phytoestrogen, a chemical found in plants that are similar to the female sex hormone oestrogen.
Studies have shown phytoestrogens are beneficial for fighting hormonal cancers, such as breast cancer and ovarian cancer.
But the chemical, found in soy foods, some fruits and legumes, has also been found to affect fertility and hormone balance.
Professor Gombart said enzymes in the liver can break XN down into the ‘most potent’ phytoestrogen known to science.
But DXN and TXN don’t metabolise into phytoestrogens, the research, published in the International Journal of Molecular Sciences, showed.
For the first time, Professor Gombart and colleagues showed that the derivatives could inhibit cancer cells, and with more effectiveness.
Professor Gombart said: ‘In all the cell lines tested, DXN and TXN inhibited cell growth and caused cell death, as did XN.
‘And for most cell types, DXN and TXN were slightly more potent.’
Colorectal cancer is the third most common cause of cancer-related death in the world and liver cancer ranks sixth, according to World Cancer Research Fund.
The incidence of liver cancer has tripled in the last four decades in the US, and increased by around two-and-a-half times since the early 1990s in the UK.
Colorectal cancer cases are rising in adults in their 30s and 40s in the US, but over the last decade, bowel cancer rates have remained stable in the UK.
‘For both of those cancers, discovering new compounds for prevention and treatment is imperative,’ Professor Gombart said.
Studies have already shown DXN and TXN have the potential to reduce weight gain, Professor Gombart added.