Friday, January 31, 2014
Does Vitamin E FUEL cancer in smokers? Supplements may speed growth of tumours
Supplements are getting a pounding lately. Long overdue -- JR
Vitamin E and other common supplements fuel lung cancer in smokers, researchers fear.
They say that rather than preventing tumours, popular antioxidant pills may speed their growth and spread and hasten death.
The experiments were done on mice, but the Swedish researchers believe they are relevant to people.
Cancer Research UK recently said that we should be able to get all the vitamins we need from a healthy diet, without resorting to supplements.
Antioxidants, such as vitamins A, C and E, are credited with protecting against a host of ills, including cancer. However, recent studies have hinted that in some cases they may actually fuel the disease.
When the University of Gothenburg researchers give vitamin E to mice in the very early stages of lung cancer, the disease grew and spread more quickly and the animals died twice as fast.
Experiments on human cells confirmed the finding.
A second antioxidant, a drug used to treat smoking-related lung conditions, had a similar effect.
Vitamin E and other antioxidants are credited with boosting health by mopping up harmful molecules called free radicals, which are unstable and highly reactive so that in animal tissues they can damage cells.
But it is thought that if cancer has already started to develop, antioxidants may actually feed the disease by switching off the body’s natural defences.
Although anyone can have small lung tumours that are yet to be spotted by doctors, they are most common in smokers.
The researchers said the amounts of vitamin E used were similar to those found in supplements.
They advised that the vitamin and other antioxidants are ‘used with caution’ by smokers, lung cancer patients and people with bronchitis, emphysema and other smoking-related lung conditions known collectively as chronic obstructive pulmonary disease.
They said it is too early to give any advice to healthy people – or to say if vitamins speed the spread of other cancers.
The warning, published in the journal Science Translational Medicine, is unlikely to apply to vitamin-rich ‘superfoods’ such as blueberries as they would have to be eaten in huge amounts to provide the levels of antioxidants contained in supplements.
Dr Emma Smith, of Cancer Research UK’s senior science communications officer, cautioned that the study was done on mice and it is not clear what it means for people.
However, she added: ‘There’s no strong evidence that antioxidants or vitamin supplements could reduce cancer risk, and some types of supplement can actually raise the risk.
‘There have also been concerns raised that antioxidants may interfere with cancer treatments. ‘We recommend that people stick to a healthy, balanced diet, which should provide all the nutrients you need without taking supplements.’
Taking multivitamins 'can raise risk of a miscarriage'
Women who take multivitamin tablets while trying to become pregnant are more at risk of having a miscarriage, research shows.
A study of 35,000 mothers-to-be found they were 32 per cent more likely to lose their baby early on if they had taken the supplements regularly in the six weeks before conceiving.
Millions of women rely on the pills to boost their body’s stocks of vital vitamins and minerals and so increase their chances of having a successful pregnancy.
The researchers say in the International Journal of Epidemiology: ‘Women are advised to take multivitamins when they plan to conceive, believing it can do no harm.
‘We found a modest but consistent increased risk of early foetal death in multivitamin users, especially in women with a regular preconceptional intake.’
They said the finding ‘causes concern’ but were unable to explain why multivitamins raised the risk.
The NHS supplies women with multivitamin tablets after the ten-week point of their pregnancies as part of the Healthy Start scheme.
They contain vitamins C, D and B9 (also known as folate), which helps protect babies from spina bifida.
Many women begin taking pills while trying to conceive. But official advice warns only against consuming too much vitamin A.
The latest study, which is the largest of its kind and focused on mothers-to-be in Denmark, was conducted by the universities of Southern Denmark, Aarhus and Pittsburgh in the US.
Taking folate supplements on their own or multivitamins while expecting had a slight beneficial effect. But the study isolated a particular risk of miscarriage among those who took the all-in-one tablets several weeks before conception, around a third of the women.
Compared with taking no pills at all, regular multivitamin use for three or four weeks beforehand saw the chances of losing the baby rise by 23 per cent. For the period of five to six weeks, it was 32 per cent.
Although the authors couldn’t find a reason for the trend, they were able to rule out links with obesity, smoking, poverty, previous miscarriage or difficulty in conceiving.
Professor Lucilla Poston, head of the Division of Women’s Health at King’s College, London, urged women not to panic.
She said: ‘It is critical that the data are not interpreted as evidence against current recommendations for folate supplementation.
‘The authors rightly recommend that further studies are needed. In the meantime, supplements should be taken in accordance with current clinical guidelines.’
Posted by jonjayray at 12:05 AM