reposted from: http://www.thetimes.co.uk/tto/health/article2839553.ece
Could the secret to a longer, healthier life really lie in popping a little pill every day? The news this week that taking low-dose aspirin could cut your risk of cancer by a quarter will send plenty of us rushing to the chemist.
Indeed, we are rapidly entering an era where everyone is taking some kind of preventive drug or supplement every day. For drug companies, the potential profits from preventive pills are huge; healthy people make far more sustainable customers than seriously ill ones.
But none of these pills is without its side-effects, and some of these can be serious. It is up to each of us to weigh the risks and benefits.
Aspirin
This week an Oxford University study revealed that a 75mg aspirin tablet a day substantially cuts death rates from common cancers. The Lancet study found that people taking it had a 25 per cent lower risk of death from cancer and a 10 per cent reduction in death from any cause, compared with patients who were not given the drug. Aspirin is already known to cut the risk of heart attack and stroke among those at increased risk. Professor Peter Rothwell, the lead researcher, is not urging healthy middle-aged adults to start taking aspirin immediately, but he says that the evidence on cancer “tips things towards it being well worth it”. His reticence is due to aspirin’s main side-effect, stomach bleeding.
A British study last year found that daily aspirin can increase the risk of dangerous internal bleeding by a third. It can also cause haemorrhagic strokes.
The complication rate means that if aspirin were submitted today as a new drug to clinical trials, it would fail. Some experts suggest that taking aspirin with milk reduces stomach irritation. Others, such as the scientists behind a review in the Drug and Therapeutics Bulletin, say the drawbacks may outweigh the benefits.
Cod liver oil
Cod liver oil has been revived in the past decade as a one-a-day golden wonder for healthy hearts, supple joints and sparky brains. Critics have suggested recently that there is a dearth of large-scale study evidence to support this. But in September, doctors at Imperial College London and the Royal Brompton Hospital in London, studied nearly 7,000 people with chronic heart failure and found that 1g of fish oil capsules a day cut the death rate by 9 per cent. Hospital admissions also fell.
A recent study by the University of California may help to explain why: omega-3 fatty acids in the oil switch on receptors in blood that prevent harmful inflammation in the heart and arteries. There are worries about harmful mercury contamination, particularly for pregnant women.
But Dr Jeremy Pearson, of the British Heart Foundation, says: “If people feel they can tolerate fish oil, I don’t think there is any suggestion that they might be doing themselves harm.”
Vitamins
We spent £398 million on vitamins last year, but there is alarmingly little medical research on them. Most studies say they are of little or no use, especially if you have a normal healthy diet. Some multivitamin supplements can even be dangerous. For example, Swedish researchers warn that an overdose of multivitamins increases the risk of breast cancer.
However, vitamin D shines through. It is essential for healthy bones and to protect against a range of diseases including cancer, heart disease, diabetes and multiple sclerosis. With most of us leading increasingly indoor lives, increasing numbers of us are becoming deficient.
For pregnant mothers, the balance of evidence indicates that taking a multivitamin may benefit their babies. A study in the Clinical Pharmacology & Therapeutics journal found a reduced risk for paediatric brain tumours, neuroblastoma, and leukaemia, though it’s not known why.
Statins
Statins lower cholesterol levels and have been hailed as wonder drugs. A Lancet study last year said that daily statins cut the risk of strokes by about a fifth. They have also been shown to prevent arteries ageing prematurely. Statins may also protect against arthritis and help the body to combat serious infections by activating bacteria-killing white blood cells.
Such is their promise that more than five million people take them. They were developed for people with high cholesterol, but drug industry-backed research recently concluded that they lower the death risk for everyone, even those with low cholesterol. One British cardiac consultant even said that they should be put in the water supply. This has sparked a huge academic row over accusations of research hype.
Certainly statins can have side-effects, including muscle problems, sexual dysfunction, serious depression, sleep disturbance and memory loss. Critics also fear that people wrongfully believe that statins can enable them to carry on overeating and under-exercising.
Sex hormones
Some studies estimate that hormone replacement therapy (HRT) extends life by three years because it cuts the risk of heart attack in women by 50 per cent. It also helps to beat osteoporosis. But in 2001 a large study in America showed that HRT considerably increases the risk of breast cancer. After that, use of HRT halved in Britain, to below 20 per cent of menopausal women. But it still has its proponents. Last month Durham University researchers reported that HRT can rejuvenate the brains of women in their fifties and sixties. The general expert consensus is that HRT remains an effective short-term treatment for menopausal symptoms.
The polypill
The idea of a single pill that wraps up the life-saving benefits of several other preventive drugs was mooted in 2003. Now scientists at Imperial College London are beginning a worldwide trial on it. The two-year trial tests a cheap pill that contains low-dose aspirin, a statin and two drugs to lower blood pressure. The test will see if it can cut heart attacks and strokes in 2,000 people who are thought to be at risk. A trial of one formulation has already proved disappointing at lowering blood pressure. And there is always a chance that a polypill might combine all the bad side-effects with few of the benefits. But researchers hope that within a few years they will have a proven, low-cost formula that millions will be taking every day.
Holy grail
The ultimate goal of researchers is to find a natural substance (after all aspirin comes from willow bark) that has no side-effects but protects against a primary cause of disease — ageing cells. Scientists thought they had got it in resveratrol, found in grape skins and red wine. Early tests indicated that it may act as a serum of cellular youth, preventing Alzheimer’s in mice. GlaxoSmithKline bought the patent off its developers, then trialled it on cancer patients. But it caused kidney damage and the trial had to be stopped earlier this year. GlaxoSmithKline says it won’t do any further trials.
Never mind, say the seekers of medicine’s ultimate one-a-day holy grail — there are many more natural candidates to try.
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Showing posts with label vitamins. Show all posts
Showing posts with label vitamins. Show all posts
Sunday, 12 December 2010
Friday, 22 October 2010
Safe Upper Levels for Vitamins, Minerals & Micronutrients
Source: http://www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/
Most people should be able to get all the nutrients they need by eating a varied and balanced diet. But if you choose to take supplements, it's important to know that taking too much or taking them for too long can cause harmful effects.
So if you choose to take supplements, make sure you're informed.
The advice given in this section is aimed at adults. You might also want to check out the information in the 'Ages and stages' section, which has nutrition advice for all ages and includes advice on what foods to avoid for women who are pregnant or trying for a baby.
Use the menu on the right hand side to go to a vitamin, mineral or trace element.
Fat-soluble vitamins
Fat-soluble vitamins are found mainly in fatty foods such as animal fats (including butter and lard), vegetable oils, dairy foods, liver and oily fish.
Your body needs these vitamins every day to work properly. However, you don't need to eat foods containing them every day.
This is because, if your body doesn't need these vitamins immediately, it stores them in your liver and fatty tissues for future use. This means the stores can build up so they are there when you need them. But, if you have much more than you need, fat-soluble vitamins can be harmful.
These are all fat-soluble vitamins:
Water-soluble vitamins are not stored in the body, so you need to have them more frequently.
If you have more than you need, your body gets rid of the extra vitamins when you urinate. Because the body doesn't store water-soluble vitamins, generally these vitamins aren't harmful.
Water-soluble vitamins are found in fruit, vegetables and grains. But unlike fat-soluble vitamins, they can be destroyed by heat or by being exposed to the air. They can also be lost in the water used for cooking.
This means that by cooking food, especially boiling, we lose lots of these vitamins from the food we eat. The best way to keep as much of the water-soluble vitamins as possible is to steam or grill, rather than boil.
These are all water-soluble vitamins:
Minerals can be found in varying amounts in a variety of foods such as meat, cereals (including cereal products such as bread), fish, milk and dairy foods, vegetables, fruit (especially dried fruit) and nuts.
Minerals are necessary for three main reasons:
Trace elements are found in small amounts in a variety of foods such as meat, fish, cereals, milk and dairy foods, vegetables and nuts.
These are all trace elements:
Safe Upper Levels for Vitamins and Minerals, May 2003 by the Expert Group on Vitamins and Minerals, 350 page report (pdf, 1MB) source: http://cot.food.gov.uk/pdfs/vitmin2003.pdf via http://www.food.gov.uk/multimedia/webpage/vitandmin/howsafetyadviceproduced via http://www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/
The data were adequate to establish Safe Upper Limits for vitamin B6 (page 81) ß-carotene (page 127),
vitamin E (page 145), boron (page 164), copper (page 187), selenium (page 232), zinc (page 253)
and silicon (page 306).
Guidance was given for biotin (page 36), folic acid (page 42), niacin
(page 52), pantothenic acid (page 62), riboflavin (page 68), thiamin (page 74), vitamin B12 (page 93),
vitamin C (page 100), vitamin A (page 110), vitamin D (page 136), vitamin K (page 154), chromium
(page 172), cobalt (page 180), iodine (page 203), manganese (page 213), molybdenum (page 219),
nickel (page 225), tin (page 240), calcium (page 264), iron (page 275), magnesium (page 287),
phosphorus (page 293) and potassium (page 299).
Most people should be able to get all the nutrients they need by eating a varied and balanced diet. But if you choose to take supplements, it's important to know that taking too much or taking them for too long can cause harmful effects.
So if you choose to take supplements, make sure you're informed.
The advice given in this section is aimed at adults. You might also want to check out the information in the 'Ages and stages' section, which has nutrition advice for all ages and includes advice on what foods to avoid for women who are pregnant or trying for a baby.
Use the menu on the right hand side to go to a vitamin, mineral or trace element.
What are vitamins?
Vitamins are essential nutrients that your body needs in small amounts to work properly. There are two types of vitamins: fat-soluble and water-soluble.Fat-soluble vitamins
Fat-soluble vitamins are found mainly in fatty foods such as animal fats (including butter and lard), vegetable oils, dairy foods, liver and oily fish.
Your body needs these vitamins every day to work properly. However, you don't need to eat foods containing them every day.
This is because, if your body doesn't need these vitamins immediately, it stores them in your liver and fatty tissues for future use. This means the stores can build up so they are there when you need them. But, if you have much more than you need, fat-soluble vitamins can be harmful.
These are all fat-soluble vitamins:
- vitamin A
- vitamin D
- vitamin E
- vitamin K
Water-soluble vitamins are not stored in the body, so you need to have them more frequently.
If you have more than you need, your body gets rid of the extra vitamins when you urinate. Because the body doesn't store water-soluble vitamins, generally these vitamins aren't harmful.
Water-soluble vitamins are found in fruit, vegetables and grains. But unlike fat-soluble vitamins, they can be destroyed by heat or by being exposed to the air. They can also be lost in the water used for cooking.
This means that by cooking food, especially boiling, we lose lots of these vitamins from the food we eat. The best way to keep as much of the water-soluble vitamins as possible is to steam or grill, rather than boil.
These are all water-soluble vitamins:
- vitamin B6
- vitamin B12
- vitamin C
- biotin
- folic acid
- niacin
- pantothenic acid
- riboflavin
- thiamin
What are minerals?
Minerals are essential nutrients that your body needs in small amounts to work properly. We need them in the form they are found in food.Minerals can be found in varying amounts in a variety of foods such as meat, cereals (including cereal products such as bread), fish, milk and dairy foods, vegetables, fruit (especially dried fruit) and nuts.
Minerals are necessary for three main reasons:
- building strong bones and teeth
- controlling body fluids inside and outside cells
- turning the food we eat into energy
- calcium
- iron
- magnesium
- phosphorus
- potassium
- sodium
- sulphur
What are trace elements?
Trace elements are also essential nutrients that your body needs to work properly, but in much smaller amounts than vitamins and minerals.Trace elements are found in small amounts in a variety of foods such as meat, fish, cereals, milk and dairy foods, vegetables and nuts.
These are all trace elements:
- boron
- cobalt
- copper
- chromium
- fluoride
- iodine
- manganese
- molybdenum
- selenium
- silicon
- zinc
Safe Upper Levels for Vitamins and Minerals, May 2003 by the Expert Group on Vitamins and Minerals, 350 page report (pdf, 1MB) source: http://cot.food.gov.uk/pdfs/vitmin2003.pdf via http://www.food.gov.uk/multimedia/webpage/vitandmin/howsafetyadviceproduced via http://www.eatwell.gov.uk/healthydiet/nutritionessentials/vitaminsandminerals/
The data were adequate to establish Safe Upper Limits for vitamin B6 (page 81) ß-carotene (page 127),
vitamin E (page 145), boron (page 164), copper (page 187), selenium (page 232), zinc (page 253)
and silicon (page 306).
Guidance was given for biotin (page 36), folic acid (page 42), niacin
(page 52), pantothenic acid (page 62), riboflavin (page 68), thiamin (page 74), vitamin B12 (page 93),
vitamin C (page 100), vitamin A (page 110), vitamin D (page 136), vitamin K (page 154), chromium
(page 172), cobalt (page 180), iodine (page 203), manganese (page 213), molybdenum (page 219),
nickel (page 225), tin (page 240), calcium (page 264), iron (page 275), magnesium (page 287),
phosphorus (page 293) and potassium (page 299).
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