Vitamin D protects against colon cancer

January 26, 2010

A huge European study now confirms that vitamin D may lower the risk of colon cancer by 40%.

The Danish Vitality Council has in several previous newsletters refered to scientific studies showing that vitamin D may lower the risk of cancer, and we have even been urged by journalists to withdraw those statements. Fortunately we have not complied.

A few days ago British Medical Journal published the largest study ever of the link between diet and health, known as the EPIC study, and this is just one of many results, we will see in the near future from this huge study.
More than half a million mostly healthy people from ten European countries have been closely studied and followed over 10 years by researchers from across Europe.

Participants completed detailed dietary questionnaires, and they have been checked with blood tests to identify their nutritional status.

At the time of analysis 1,250 cases of colon cancer had occurred and after comparison with a healthy control group researchers found that those who were low in vitamin D in their blood had significantly higher risk for this type of cancer.

Unlike many other studies this is characterized by being a prospective study. Thus looking-forward from the start time, and based on a group of healthy people. The study also distinguishes itself by involving so many different countries, cultures and – not least – food cultures.

Vitamin D, we primarily get from the sun, and a little bit from the diet. Danes are not the most tenacious fish eaters and much of the fish we eat is farmed and therefore does not include the fatty acids and other substances, we think they contain.

So we’re back at sunlight as the main natural source of vitamin D.

However, some of our ancestors for inscrutable reasons have found reason to settle north of the Alps, and it leads to midday sun high enough in the sky to make enough vitamin D in the skin for only 3-4 months a year (providing we have enough cholesterol).

So we must therefore tend to sunbathing when the Sun is at its highest point, ie the middle of the day, without sunblock, and therefore only half an hour, so we do not risk burning.

If it gets too complicated, you can also just grab a vitamin D capsule as a supplement. It is perhaps a little easier, and it can be done the whole year.
The dosage is somewhat controversial and should ideally be measured in a blood sample, but most serious scientists recommend between 2,000 and 4,000 IU, equivalent to 50-100 micrograms daily.

It will take a long time before we again will see such a thorough, multi-national study including so many people over such a long period.

So it is not just any study. It has high validity and ought to push the critically low RDA-value we have today.

By: Vitality Council

Litterature:
Jenab, M. et al (2010). Association between pre-diagnostic circulating vitamin D concentration and risk of colorectal cancer in European populations: A nested case-control study BMJ, 340 (jan21 3)
Can be downloaded directly at: www.bmj.com/cgi/content/abstract/340/jan21_3/b5500

Latest news on selenium

January 12, 2010

Intensive research is going on in utilization of selenium against cancer.
The public in Denmark do not hear much of it, but here is a selection of recent news.

The lack of television and newspaper information may give the impression that there is quiet on the antioxidant front concerning disease control. This is not the case. The news shortage is chiefly due to the censorship that has been introduced. Regarding selenium alone, being one of the major antioxidants, there were in 2009 published more than 900 scientific articles. Here we will mention a selection of recent articles about selenium in the fight against cancer.

A famous attempt to demonstrate whether antioxidants protect against cancer were performed in the years 1985-91 in the Chinese Linxian province. Nearly 30.000 participated in the study, which showed a strong decrease in cancer risk among those who received a supplement of selenium (50 micrograms) and Vitamin E and Beta Carotene (respectively 30 and 15 mg). Now it has been determined, what had happened to the participants 10 years later (2001). Even after so long a time, there were relatively more survivors in this group than among those who received other supplements (eg. Vitamin A + zinc, was of no benefit). In particular, the group had reduced incidence of cancer of the stomach, but it was the participants under 55 years of age who experienced the greatest gain – you must avoid lacking vital nutrients already from the youth.

Apparently this result is contradicted by another famous study, the SELECT trial conducted in the U.S. Here it appeared that you could not prevent prostate cancer using selenium, vitamin E or a combination of both. This study was in large scale and the result a huge disappointment.

One of the world’s leading selenium specialists, Margaret Rayman, did point out however, a few months ago what really is obvious: Supplementation with selenium is of no benefit if you already get enough! As a general rule you get enough in the U.S., where you typically get 3-4 times as much selenium in the diet as in Denmark. Sufficient selenium is essential for the body to form enough of the enzymes which we presume protects against cancer. Amongst others Rayman refer to another U.S. cancer trial where you just saw a massive impact in those who received the least amount of selenium, but no effect in those who got the most.

Heavy metals neutralized
One of the veterans in selenium research is Gerhard Schrauzer from San Diego University of California. He has been involved more than 20 years. Now he points out that selenium is able to detoxify numerous toxic metals that somehow during our civilized environment ends up in our bodies. This applies to lead, mercury, copper, cadmium, arsenic, etc. Selenium inactivates these metals by forming insoluble compounds with them. But, says Schrauzer, one must remember that at the same time selenium is used up, so we for that reason are less protected against cancer. In Europe we already get too little selenium, but heavy metals etc. increases the demand.

Taylor and associates have written an article on new advances in selenium research. They write that the renewed interest in selenium is linked to the fact that the anti-cancer effect is now very well documented in animal studies. This is worth noticing.

And precisely on animals a research team from San Diego University have demonstrated that the effect of chemotherapy (cisplatin) against cancer of the colon is reinforced considerably by large supplements of antioxidants (A and vitamin E and selenium) combined with fish oil. The group believes their achievement justifies that research is made with people. The result is very exciting because cancer doctors in this country often discourages in strong terms their patients from combining antioxidants with chemotherapy. The reason for this warning has hitherto been unclear.

Selenium and chemotherapy
Researchers from The Karolinska Hospital in Stockholm state without hesitation that it is well documented that selenium prevents cancer. They describe several experiments which have shown that selenium has strong anti cancer effects – especially against cancer, which no longer responds to chemotherapy. Normal cells will not be harmed by the selenium doses needed for this!

Italian researchers, however, stresses that people can get too much selenium (but living in Denmark you have take approx. two selenium tablets a day in order to get the same amount as a typical American). They argue that high doses may increase the risk of diabetes, an assertion, however, that is controversial.

In the Netherlands, like in China there has been an interest in selenium and cancer of the esophagus. More than 120,000 persons who was 55-69 years old in 1968, delivered at that time, a portion nail clips from their big toes. 16 years later it was found who and how many have got cancer of the esophagus or stomach in the meantime. Then the selenium levels in their nails was measured and compared with the levels in healthy subjects. It was found that the risk of both cancers was significantly higher among those who only had small amounts of selenium in their nails, and hence their body.

A curious study has been conducted in Japan. Here researchers cultivated broccoli-sprouts in a selenium-rich environment, so the sprouts got an extra high content of selenium. In a laboratory study the sprouts was investigated for their impact on prostate cancer tissue. The enriched sprouts inhibited cancer growth clearly better than normal sprouts. Now the Japanese suggests, that men eat that kind of sprouts to prevent cancer of the prostate.

Finally other Japanese mention, that it is well known that selenium can kill cancer cells from humans, but but precisely how this happens is still unclear. They have reached the conclusion that at least part of the effect is due to selenium starts off a cancer cell death process using the same mechanism (apoptosis) as when normal cells must be replaced and die. Such a mechanism is of course necessary, since almost all normal cells divide continuously. There would soon be twice as many, and we would grow indefinitely, if not worn-out cells were put out.

As you can see, the research is really alive. Much of our understanding of selenium is achieved in very recent years. More will undoubtly follow.

By: Niels Hertz, M.D.

References
1. Qiao YL et al. Total and cancer mortality after supplementation with vitamins and minerals: follow-up of the Linxian General Population Nutrition Intervention Trial. J Natl Cancer Inst. 2009 Apr 1;101(7):507-18. Epub 2009 Mar 24.
2. Lippman SM et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2009 Jan 7;301(1):39-51. Epub 2008 Dec 9.
3. Rayman MP. Selenoproteins and human health: insights from epidemiological data.
Biochim Biophys Acta. 2009 Nov;1790(11):1533-40. Epub 2009 Mar 25.
4. Schrauzer GN Selenium and selenium-antagonistic elements in nutritional cancer prevention.
Crit Rev Biotechnol. 2009;29(1):10-7.
5. Taylor D. Recent developments in selenium research. Br J Biomed Sci. 2009;66(2):107-16; quiz 129.
6. Ma H. Bi Efficacy of dietary antioxidants combined with a chemotherapeutic agent on human colon cancer progression in a fluorescent orthotopic mouse model. Anticancer Res. 2009 Jul;29(7):2421-6.
7. Selenius M. Selenium and selenoproteins in the treatment and diagnostics of cancer.
Antioxid Redox Signal. 2009 Sep 21. [Epub ahead of print]
8. Vinceti M. Risk of chronic low-dose selenium overexposure in humans: insights from epidemiology and biochemistry Rev Environ Health. 2009 Jul-Sep;24(3):231-48.
9. Steevens J. Selenium status and the risk of esophageal and gastric cancer subtypes: the Netherlands cohort study. Gastroenterology.. [Epub ahead of print]
10. Abdulah R. Selenium enrichment of broccoli sprout extract increases chemosensitivity and apoptosis of LNCaP prostate cancer cells. BMC Cancer. 2009 Nov 30;9:414.

Selenium still helps preventing cancer

January 26, 2009

A huge U.S. study showed that supplementation of selenium do not prevent cancer of the prostate. But this result is only valid if you get plenty of selenium in advance.

12 years ago it aroused hope and optimism when American Larry Clark could tell that the mineral selenium prevents cancer, particularly prostate cancer, the second most common cause of death from cancer in men. He had to stop his trial before expiry when he learned that far fewer selenium-treated than placebo-treated patients (placebo: Inert tablets) got cancer.

Now a second, much larger, selenium trial has been stopped prematurely. Also in this case the focus of interest was the effect against prostate cancer. This was also an American study. But SELECT, as the trial was named, unfortunately showed that selenium had no effect. One could even not exclude an, admittedly very little, harmful effect. So, it was stopped.

In the meantime, Clark’s trial has been studied more closely. Was it really as convincing as was first believed? With 1.312 participants it was not nearly as large as SELECT where 35.000 attended. Very important was that the final report which came in 2003 showed that the benefit was smaller than first believed. Some cases of prostate cancer among selenium treated had for various reasons been overlooked.

What was left was a statistically significant benefit among those who at the beginning of the experiment had the least selenium in the blood and with most certainty did not have incipient cancer of the prostate. The latter could be concluded from the very low values of PSA (Prostate-Specific Antigen) in the blood of these people. In this group, while the trial was in progress, the incidence of cancer of the prostate was three times less than in the placebo group.

More selenium in the U.S.
Now the question is whether the much larger SELECT trial cancels Clark’s trial. It seems to be the general opinion as for example reflected in the leading article of the same issue of the American medical journal, JAMA, where SELECT was published. So far physicians should not recommend selenium as a prevention against prostate cancer, it says.

And yet one can rightly come to the diametrically opposite conclusion: There is every reason to believe that selenium prevents cancer of the prostate, and presumably also other kinds of cancer.

The fact is that Americans, but not all Americans, get far more selenium in their diet than we Scandinavians. In Clark’s study, participants were selected on the basis of consistently having relatively little selenium in their diet for U.S. standards. Two-thirds had less than 122 micrograms of selenium per. liter of serum. In the SELECT study only one in five had that low values. In other words, it is conceivable that most of the SELECT participants already got plenty of selenium so that additional supplementation would not benefit them. In Denmark almost everybody get less selenium than the participants of both the first and the second study mentioned. Our values are typically 80 micrograms per liter.

This is in excellent compliance with the fact that incredible few participants died from prostate cancer during the SELECT study. Statistically one would have expected 75 to 100 deaths for this reason, during the 5.6 years duration of the study. But only one died (!).

A contributory cause may have been that the vast majority of participants in the SELECT study on their own underwent PSA measurement annually. Possible prostate cancer was therefore detected and treated early. On the other hand, other studies have shown that annual PSA measurement does not reduce mortality. Therefore it is not recommended in Denmark.

Despite the termination of the SELECT study, as a Dane you should still remember that the research that involves us – as opposed to Americans we get very little selenium in our diet – suggests that supplementation with selenium in the order of 1-2 tablets (100-200 micrograms) per day seems to reduce the risk of prostate cancer to a third.

By: Niels Hertz, M.D.

References:
1. Lippman SM et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers. JAMA online December 9, 2008: E1-E13
2. Gann PH. Randomized trials of antioxidant supplementation for cancer prevention. JAMA online December 9, 2008: E1-E2.
3. Selenium supplementation, baseline plasma selenium status and incidence of prostate cancer: An analysis of the complete treatment of the Nutritional Prevention of Cancer Trial. BJU Int. 2003;91:608-12.

jama.ama-assn.org
www.bjui.org

Vitamin C inhibits cancer. But How?

September 18, 2007

New research sparks new theories about how vitamin C inhibits cancerous growth.

A great deal of research indicates that vitamin C has a considerable inhibitory effect on the growth of cancer cells.

The biochemical effect of high-dose treatment with vitamin C is reasonably understood; vitamin C acts as a pro-oxidant on cancer cells at such doses. This causes increased free radical strain on the cancer cells and thereby acts as a poison to the cancer.

In moderate doses, the kind of doses which we can get through our diets, vitamin C is an antioxidant. But even at these doses, vitamin C has shown an inhibitory effect on the growth of cancer cells.

It was therefore believed that vitamin C blocks the free radicals which cause the cancer forming mutations in the cells, and that the reason for its protective effects is that it protects the cells’ DNA.

This is presumably not the whole truth.

Many years ago a famous professor by the name of Warburg was among the first to maintain that cancer cells grow in oxygen poor tissue. Today this is common knowledge, but there lacks knowledge on how this occurs. Ten years ago Gregg Semenza of John Hopkins University found that cancer cells are dependent on a protein called HIF-1 (hypoxia induced factor), which helps the cells by compensating for lacking oxygen in the surrounding tissue and thus allows cancer cells to convert sugar to energy without oxygen. HIF-1 also catalyses the creation of new blood vessels so that hungry cancer cells can get fresh supplies of nutrients and oxygen. If a cancer grows aggressively, it quickly uses up its oxygen supply and becomes entirely dependent on HIF-1. The HIF-1 protein is dependent on the presence of free radicals, which are also necessary for many other processes in the body. A powerful antioxidant like vitamin C eliminates the surplus of free radicals, which causes HIF-1 to become ineffective and thus inhibits cancer growth.

This new theory is based on a study done by a research group at the centre of oncology at John Hopkins University in conjunction with Dean Felsher of Stanford.

They set out to study antioxidants’ roles in cancer growth and found, to their great surprise, that antioxidants destabilise the protein on which cancer cells are dependent. As professor Chi Dang from John Hopkins University wisely stated, “By uncovering the mechanism behind anti-oxidants, we are now better suited to maximize their therapeutic use.”

By: Claus Hancke, MD

Reference

HIF-Dependent Antitumorigenic Effect of Antioxidants In Vivo. Cancer Cell, Volume 12, Issue 3, 11 September 2007, Pages 230-238Ping Gao, Huafeng Zhang, Ramani Dinavahi, Feng Li, Yan Xiang, Venu Raman, Zaver M. Bhujwalla, Dean W. Felsher, Linzhao Cheng, Jonathan Pevsner et al.

www.cancercell.org

Vitamin D inhibits cancer

June 26, 2007

An overlooked but very sensational study suggests that vitamin D could inhibit almost 80% of all cancer cases. We just need much more than we normally get (1).

One out of every three people in Britain die of cancer and a world without this feared disease seems utopian. But if an American study is correct, we can approach this unattainable goal with a historic leap forward. We just need more, much more, vitamin D, and maybe also more calcium. According to the study, a combination of calcium and vitamin D can reduce the risk of cancer by about 60%. Additionally, it seems that if cancer is avoided during the first year of taking supplements, then the risk of cancer the following year is reduced by nearly 80%! It is hard to expect more.

It is strange that such sensational news has received almost no official consideration. Especially because it comes from a highly trustworthy double blind, randomised trail published by highly respected researchers.

The participants in the study were 1,180 women with an average age of 67. They were from Nebraska, which is just as far south as southern Italy and receives a lot of sun. Not surprisingly the women had on average good blood levels of vitamin D before the study.

In the study 446 of the women received an advantageous daily supplement of as much as 1,100 units (27.5 micrograms) vitamin D. This is at least five times more than the contents of a normal vitamin pill and about three times the recommended dosage for people over age 60. They also received 1.5 gr. calcium (as carbonate or citrate), which is about the amount of calcium in a litre of milk.

Another 445 women received only calcium and 288 received placebo. Neither the women nor the researchers knew who got what. The study lasted for four years while it was noted who and how many got cancer.

We now have the results. The group which received the vitamin D and calcium was subject to many fewer cases of cancer than the group which received placebo. The difference was not coincidence! It was statistically extremely solid. The biggest difference (77% lower risk) was shown during the last three years of the study. The researchers surmised that this was because some of those who got cancer in the beginning of the study already had undetected cancer before the study started.

It could be true
The women who just received calcium also had a lower risk of cancer (40%). This finding was not completely certain statistically. The cancer risk for these women did not, as in them who received both vitamin D and calcium, become more reduced after the first year. It is therefore uncertain if this effect is actual or just the result of coincidence.

On the other hand, at least two further arguments indicate that vitamin D actually works. The first is that the women who had the poorest vitamin D status before the study, were those helped the most, their risk was the most reduced. The vitamin D status of the participants during the study also played a role, the lower the status, despite the supplements, the larger the cancer risk. The second argument that vitamin D has this effect is that the risk was directly link to the amount of vitamin D used.

Can it really be true that something as cheap as vitamin D can be so beneficial? We know that the vitamin regulates at least 200 genes, many of which control the cells’ growth and degree of specialisation. Animal studies have shown that vitamin D deficiency promotes cancer growth. For more than 60 years it has been known that cancer is less common in countries where the sun is high in the heavens leading to the production of more vitamin D in the skin. It has also be proven time and time again that low vitamin D status and high cancer risk in people go hand in hand (2,3).

The only thing that has been missing is a proper study with sufficient supplements so that cause and effect could be analysed. We now have just that study!

The women in Nebraska had a typical vitamin D status (25-hydroxy-vitamin-D3 in the serum) of 71 nanomolsl/L before the study. This is a very acceptable value. But the supplement increased this value to an average of 96. This is normally regarded as too high.

Vitamin D status is measured with a blood test! It is most important during the winter, when it is the lowest. According to the Nebraska study, this level should be no less than 100.

By: Vitality Council

References: 

1) Lappe J M et al. Vitamin D and calcium supplementation reduces cancer risk: Results of a randomized trial. Am J Clin Nutr 2007;85:1586-91.

2) Feskanich D et al. Plasma vitamin D metabolites and risk of colorectal cancer in women. Cancer Epidemiol Biomarkers Prev 2004;13:1501-8

3) Ahonen M H et al. Prostate cancer risk and prediagnostic serum 25-hydroxyvitamin D levels (Finland). Cancer Causes Control 2000;11:847-52

www.ajcn.org
cebp.aacrjournals.org
www.springerlink.com/content/0957-5243

Vitamin D Could Prevent Every Third Cancer-related Death

April 21, 2006

Several of the World’s leading vitamin researchers advocate a much higher vitamin D-intake. They believe that up to every third death from cancer may be prevented.

“I challenge anyone to find a field or a nutritional substance or any other factor with as effective cancer-fighting properties as vitamin D.”

So said Edward Giovanucci, professor at Harvard University, last year in a speech to the American Society for Cancer Research.

More and more agree with Giovanucci, amongst them, several professors from well-renowned universities. A few months ago Cedric Garland, an absolute pioneer in the field, stated that it has been proved that the risk of cancer can be lowered dramatically with vitamin D. These are big words. Garland is a professor at the University of California in San Diego.

Giovanucci has together with six others, of these, no less than three are professors from Harvard, confirmed the claim further. In a quite laborious study they have confirmed the close connection between a vitamin D deficiency and cancer.

Since World War II it has been known that especially cancer in the alimentary canal is seen relatively seldom in southern countries. Since sunlight is the most important source of vitamin D, it has earlier been guessed that it was vitamin D and not the sun, which offers protection. In numerous studies the incidence of cancer has been found to be highest where sunlight is weakest, and where the content of vitamin D in the blood is lowest. We are children of the sun. At the same time laboratory research in recent years has shown that this vitamin inhibits the growth of abnormal cells, counteracts the spread of cancer and prevents the formation of blood vessels in tumorous masses.

Giovanucci now finds further proof of the connection. Earlier in humans there has only been found an indirect connection between vitamin D and cancer. There has been a lack of data from whole groups of the population, that have had their blood content of vitamin D measured, and have then been followed for a number of years. But Giovanucci has found something to substitute this data.

Mega doses of Vitamin D
They took 1095 men from the big population study “Health Professionals Follow-Up Study”. These 1095 men had had their vitamin D-status measured (this means the content of vitamin D in the blood). In addition, a lot of things were known about their personal habits etc. Would it be possible to go backwards and calculate their vitamin D-status from their personal habits? Yes! An estimation of the approximate vitamin D blood content could be made, when the individual’s skin colour (eg. race), body mass, height, place of residence (southern/northern in the USA), the amount of physical activity, time of year and the content of vitamin D in the test subject’s diet and possibly supplements was known.

In this manner the group worked out a point-system for the direct calculation of vitamin D status. What especially contributed to a low status was a northern place of residence, dark skin colour, overweight and lack of exercise. The calculations proved correct for the 1095 test subjects. But would they be correct for other people? They were checked for another group of men with known vitamin D status. They were consistent!

Every single subject, of the 47,800 men in Health Professionals Follow-Up Study now had their vitamin D status calculated. In the course of approximately four years, about one in ten got cancer. About half that died from it.

To find the significance of vitamin D, they chose to compare dead men whose plasma values for vitamin D (25(OH)D3) deviated by 25 nmol/L (nanomol/liter). It was found that the risk of dying from cancer was no less than 29 percent lower in men with a high vitamin D status. Concerning cancer of the alimentary canal – it was 45 percent lower for men, who were otherwise identical with regards to age, weight and level of physical activity.

If these results are correct, every third death from cancer may be prevented in the course of a few years. Also in the UK. This is nothing but a sensation. But if one wishes to increase the plasma level of vitamin D by 25 nmol/L, one must receive a supplement of no less than 1,500 units of vitamin D during the winter. This is achieved if a supplement of four vitamin D tablets of 10 mcg (micrograms) is taken daily from August until April.

1,500 units will probably shock many. Is it not toxic? No, it is quite certain that there is no risk, even with a permanent supplement of 2,000 units daily. For comparison, the skin produces 20,000 units during half an hour in the sun in the summer.

Garland, who was mentioned above, recommends 1,000 units (25 micrograms) a day. Others say 2,000. Giovanucci and his colleagues from Harvard strongly recommend 1,500.

Under any circumstances: If you want the full advantage of vitamin D, it seems that the need is far greater than what we have gotten used to believe. Maybe it is close to what stone-age people received naturally from their diet.

By: Vitality Council

References
1. Giovanucci E et al. Prospective study of predictors of vitamin D status and cancer incidence and mortality in men. J Natl Cancer Inst 2006;98:451-9
2. Garland CF et al. The Role of Vitamin D in Cancer Prevention. Am J Public Health. 2006;96(2):9-18. 2005 Dec 27; [Epub ahead of print]

jncicancerspectrum.oxfordjournals.org
www.ajph.org
www.iom.dk

Calcium supplements with vitamin D against colon cancer?

February 18, 2006

A large study attempted to show whether or not calcium and vitamin D prevent colon cancer. It was a strange study, using low doses over a short period.

There are probably those who believe that the latest study on calcium and vitamin D shows that neither is good for anything. But we should hesitate before going to that extreme. One can also believe that the study was not suited to draw this conclusion. Or, as it is stated in a leading editorial in “The New England Journal of Medicine:” the conclusion should be interpreted in light of the study was complicated and in light of the probability that the doses of calcium and vitamin D were too low.

The debate regards the insidious and widespread cancers of the colon and rectum. Half of a group of 36,282 American women between the ages of 50 and 79 took part in a seven year study where they received daily supplements of 1,000 mg calcium and 400 units vitamin D to see if reduced their risk of these diseases. The supplements given are the same as two normal calcium and vitamin D vitamin tablets, which many take to strengthen their bones. After the seven years the researchers assessed the number of women who developed colon and rectum cancer. The result was disheartening: Whether the women received supplements or placebo had not effect on the risk.

There was a single positive find buried in the data. The women who had the least vitamin D in their blood during the study had with statistical certainty the greatest probability of developing colon cancer. This could indicate that vitamin D has a positive effect. There was also a tendency, but only a tendency, that these women had the greatest benefit from the supplements.

Quite a lot of things contribute to that this conclusion be taken with a grain of salt. This is partially due to that the study was very complex.

Possibly the most important objection is that it “only” lasted seven years. It is believed that colon cancer takes 10-20 years to develop before it is diagnosed. It the supplements prevent a new cancer from forming it is clear that for this reason no effects will be found as early as after seven years. This has been considered: Participants in the study will be monitored further for the next five years.

Strong objections
If the goal was to show a difference within the seven year period, those responsible should have at least ended the study by examining the intestines of all of the participants in order to find early cancer stages, or polyps. This did not occur. There was neither the money nor the resources necessary to do over 35,000 intestinal examinations. It was only possible to establish that the number of independently undertaken intestinal exams and the number of discovered cancers in the two groups were about the same. But maybe nothing more can be expected.

One confusing detail is that the study participants were allowed to continue taking the supplements that they had taken before the study along with the supplements that they received as a part of the study. On average they received 1,100 mg calcium and 350 units vitamin D, both close to the recommended dosages, before the study began. Many of them therefore must have received very large doses of calcium, over 2,000 mg, per day. Is it reasonable to guess that this is the reason for the slightly increased frequency of self-reported kidney stones? 2.4% of those who received supplements and 2.1% of those who received placebo, got kidney stones during the seven years.

Also, the average age was relatively low (62), which reduced the risk of cancer, and therefore weakened the study. It was further weakened by the fact that more than one out of four participants did not finish the study. Whether this dropout rate is because calcium pills can cause constipation is not considered in the article.

Just as important, the dose of vitamin D, as referred to in the editorial, may have been too low. Recently it has been estimated that about 1,000 units daily is necessary for most people in order to achieve any supposed cancer preventing effect. This amount of vitamin D (or more accurately 25-(OH)-vitamin D) is necessary to achieve a serum concentration of over 30 nano-grams per litre (75 nanomols per millilitre). Nevertheless, only a minority of the study participants received this amount.

What can be concluded from this? The editorial gives some suggestions for new studies. Much indicates that vitamin D, and maybe calcium, prevents cancer. But we still lack sufficient knowledge.

By: Vitality Council

References:
1. Wactawski-Wende J et al. Calcium plus vitamin D supplementation and the risk of colorectal cancer. N Engl J Med 2006;354:684-96.
2. Forman M C et al. Calcium plus vitamin D3 supplementation and colorectal cancer in women. N Engl J Med 2006;354:752-4.
3. Garland C F et al. The role of vitamin D in cancer prevention. Am J Publ Health 2006;96:9-18.

Selenium, A Potent Substance Against Cancer

January 18, 2006

Studies from all angles support the idea that selenium works against cancer. Even though there is need for more research, an optimal dose can be suggested.

Selenium prevents cancer. This is common knowledge which is only awaiting conclusive confirmation. It received recognition when, in 1996, an American researcher (Clark) showed in a randomised study that the frequency of cancer fell by 38%, and that the fatality rate of those with cancer fell by 50%, in participants who received daily supplement of 200 micrograms selenium.

The supposition that selenium is preventative for cancer is in fact much more extensively backed. This has been shown by a leading selenium expert, Margret Rayman from the University of Surrey in England, in a thorough, but also complicated, summary. She has also illuminated who selenium prevents cancer and, even more importantly, how much is needed.

Rayman reviews the many geographical studies that have, since the 1960’s, consistently shown that the populations who received the least amount of selenium also had the highest cancer rates. Animal studies are also discussed. If one gives selenium to a male dog, not only is there less damage to the DNA of prostate cells, but the damaged cells that remain also die normally instead of living on as cancer cells.

A certain pattern emerges when one looks at studies where the blood concentration of selenium is compared to the cancer rate in groups of people. In a French study of this type from 2005, the death rate from cancer after nine years was four times greater in the 25% of the study-group who received the least selenium than in those who received the most selenium. Typically the French receive as little selenium in their diets as the British. Many studies from many countries have shown similar results for lung cancer (a 26% lower risk of cancer was reported in those with diets rich in selenium), oesophagus cancer, stomach cancer, and not in the least, prostate cancer as well as possibly cancer of the large intestine.

How much is enough
The best evidence can always be found in randomised studies where neither the patients nor the doctors know who receives what. A Chinese study of this type has shown that selenium has an especially effective against liver cancer. As mentioned before, Clark’s study had similar results. It is intriguing that, even though Americans receive an average of 200 micrograms more selenium daily than us, an additional 200 micrograms was beneficial to most. The effects were nevertheless minimal in those who received the most selenium beforehand. These individuals already received close to the optimal dose. But third of the population who received the least beforehand, had their cancer risk halved, and their prostate cancer risk decreased by 86%, after taking supplementary selenium.

Typical Europeans receive too little selenium while Americans receive double as much and Japanese receive almost three times as much. It has become apparent that 70 micrograms of selenium is needed in the daily diet to maintain levels of the selenium based antioxidant GSHpx in the body. The Japanese and most Americans receive this amount in their diets while we do not. But why is their cancer risk reduced when they receive supplementary selenium? The reason cannot be GSHpx and may not even be the anti-oxidizing effects alone.

Rayman examines many possible explanations. One is that high doses of selenium lead to the formation of the simple selenium compound methylselenol; which can kill cancer cells, counteract the formation of blood vessels (which the cancer cells need to survive) and can inhibit cancer in other ways. But selenium is naturally an antioxidant, an immune system stimulant, an activator for cancer inhibiting genes, an inhibitor for growth factors, etc. There is not one, but many, mechanisms of action.

Unchecked amounts of selenium should not be taken. Studies indicate that sufficiently high doses of selenium can increase the risk of cancer as much as insufficient amounts. Clark’s study, as well as others, suggests that a daily supplement of 200 micrograms is optimal.

The reward can be large, but more research is needed. Currently a large clinical trail (called SELECT) is being undertaken in the U.S.A., but a study in the more selenium poor Europe would be better. Rayman believes that such a study should be undertaken. But who wants the placebo!?

By: Vitality Council

References:
1. Rayman M P. Selenium in cancer prevention: A review of the evidence and mechanism of action. Proceedings of the nutrition society. 2005;64:527-42.
2. Clark LC et al. Effects of selenium supplementation for cancer prevention in patients with carcinoma of the skin. A randomized controlled trial. Nutritional Prevention of Cancer study group. JAMA 1996;276:1957-63.
3. Akbaraly NT et al. Selenium and mortality in the elderly: Results from the EVA study. Clin Chem. 2005;51:2117-23.

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www.iom.dk

Vitamin D Prevents Cancer

December 30, 2005

A new and much discussed analysis, has shown that nearly every other cancer case can be prevented by D vitamin, if everyone is getting the suffient dosage, which almost no one is.

It has now been proven that the frequency of cancer can be reduced dramatically by increasing the population’s vitamin D intake.

This is the claim of the American researcher Cedric Garland, who is a professor of epidemiology at the University of Southern California, San Diego. He is behind the largest analysis of vitamin D research and cancer to date. 63 studies from 1962-2004 were analysed.

As a whole they strongly indicate that if the population’s intake of vitamin D is set up to 1,000 units per day, the frequency of colon cancer would be halved while the number of breast cancers and ovarian cancers would be reduced by a third. The 1,000 units of vitamin D (25 micrograms) would be, with certainty, without side effects. This is the same as five times the normally recommended dose, which only few receive.

Garland, who has studied vitamin D for 25 years, is very certain of his results. In a statement given to the BBC and The Independent he declared that there is now such an overwhelming amount of indications from the best observational studies, that governmental action is warranted.

It is worth noticing that these internationally respected media concerns both came with detailed reports, which also were followed by a leading editorial in The Independent. The study itself was published in the February 2006 issue of the American Journal of Public Health. The results were also published beforehand online in an extensive statement on the university’s (UCSD) official homepage.

Garlands interest for vitamin D was awakened when he noticed in the 1980’s that the risk of colon cancer and breast cancer in the northern United States was double that of the risk in the Southern states. He and others started a 12 year study, which lead to a hypothesis that the reason behind this phenomenon is sunlight’s ability to create vitamin D in the skin. This theory has subsequently been tested in many ways. It also fits with the increased cancer frequency in cities, when air pollution containing sulphur dioxide blocks the vitamin D producing short ultraviolet solar radiation.

This also fits with the diet and cancer studies on workers in Chicago and with the low frequency of breast cancer in Japan, where though there is little sunlight, the diet is largely fish based. Fatty fish are just about the only regular source of vitamin D outside of the summer months in Japan, Chicago, and Northern Europe. Additionally, the theory fits well with the fact that the many people, who for genetic reasons utilize vitamin D poorly, are strongly overrepresented among those who suffer cancers of the colon, breast, prostate, and more.

More and more indications
The faithful subscribers to this newsletter may remember our accounts of the studies of the last year which have shown that women with low vitamin D status have much more frequently lumps in their breasts than others. This is a relationship which fits with a higher risk of cancer.

They may also remember that an American (as well as a large Norwegian) study showed that the possibility of beating many cancer forms is best when the cancer is found during the summer, when vitamin D status is highest.

This indicates that the vitamin not only prevents cancer, but also inhibits cancer growth. Concordantly with Garland’s claim, African Americans have a lower chance of recovery form breast cancer than Anglo Saxon individuals. This may be due to a reduced vitamin D status brought on by the reduced ability to absorb vitamin D which comes with dark skin colour.

These results and others are strengthen by animal studies where it has been proven that vitamin D promotes cell death in abnormal cells in the process called apoptosis and has a general dampening effect on cell growth. This last principle is utilized by psoriasis salves, which contain a vitamin D – like substance which inhibits the overwhelming growth and lack of cell maturation which characterises this skin disease.

The optimal daily vitamin D dose, especially during the winter months between October and May, is according to Garland about 1,000 units (or 25 micrograms) per day. This recommendation is based on a study from October 2005. The 1,000 units lead to a concentration of the vitamin D precursor 25-OH-vitamin D of about 80 nmol/l (nanomol per litre), which Garland found to lead to the lowest risk of colon cancer.

Much also indicates that Garland is correct that vitamin D supplements could save thousands of lives. If this is the case, than any media claim that we get superfluous vitamins is contrary to public health.

By: Vitality Council

References:
1. Garland CF et al. The Role of Vitamin D in Cancer Prevention. Am J Public Health. 2006;96(2):9-18. 2005 Dec 27; [Epub ahead of print].
2. Gorham ED et al. Vitamin D and prevention of colorectal cancer. J Steroid Biochem Mol Biol. 2005 Oct;97(1-2):179-94. Epub 2005 Oct 19.
3. Garland CF et al. Serum 25-hydroxyvitamin D and colon cancer: eight-year prospective study. Lancet. 1989 Nov 18;2(8673):1176-8.
4. Jeremy Laurance, Health Editor. Revealed: the pill that prevents cancer. The Independent 28.12.05.

Dietary Supplement Strengthens Immuno-Therapy Against Breast Cancer

November 7, 2005

An American study has shown that the pioneering cancer medicine against breast cancer, Herceptin, can be made 30-40 times more effective when used in conjunction with a harmless dietary supplement: gamma-linolenic acid (GLA). The study’s results are preliminary but calls for further investigation.

Every year, almost 3,500 Danish women get breast cancer. Approx. every fifth of them have a particularly aggressive form of cancer, which you may fear in particular, if you find cancer in the lymph nodes of the armpit during surgery. The aggressive cancer is due to a gene in the affected women which is particularly active and forms large amounts of HER2, a protein. When HER2 adheres to the surface of a breast cell, it reacts with growth agents in the blood that can transform the cell into a cancerous cell and stimulate it to growth.

However, since 1998, there have been medicine available that, in the same way as an antibody, have been able to block HER2 and thus weaken the growth stimulation. The name of the drug is Herceptin® (Trastuzumab) and so far only women have been offered this, who in addition to being “HER2 positive”, have had recurrence of breast cancer that has spread.

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By: Vitality Council

References:
1. Piccart-Gebhart et al. Trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer. N Engl J Med 2005;353:1659-72.
2. Romond EH et al. Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer. N Engl J Med 2005;353: 1673-84.
3. Menendez JA et al. Effect of gamma-linolenic acid on the transcriptional activity of the Her2/neu (erbB-2) oncogene. J Natl Cancer Inst 2005;97:1611-15.