Study linking Vitamin D levels and cancer prevention

A study in the Annals of Epidemiology linking vitamin D and Cancer Prevention.

It is projected that raising the minimum year- round serum 25(OH)D level to 40 to 60 ng/mL (100–150 nmol/L) would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three fourths of deaths from these diseases in the United States and Canada, based on observational studies combined with a randomized trial. Such intakes also are expected to reduce case-fatality rates of patients who have breast, colorectal, or prostate cancer by half. There are no unreasonable risks from intake of 2000 IU per day of vitamin D3, or from a population serum 25(OH)D level of 40 to 60 ng/mL. The time has arrived for nationally coordinated action to substantially increaseintake of vitamin D and calcium.

Routine Removal of Ovaries During Hysterectomy May be Harmful

The advice I’ve always given women past menopause who were having hysterectomies for some good reason (it used to be simply medical fashion), has been to leave their ovaries in place—and especially so for women who haven’t yet reached menopause.   A recent study conducted by Saint John’s Health Center and reported on Reuters seems to confirms my advice.

During hysterectomy operations, surgeons often remove a woman’s ovaries as well as her uterus. But new research suggests that for women are not at high risk for ovarian cancer, removing the ovaries during hysterectomy may adversely impact long-term health.

For decades gynecologists have taken them out with the idea that after menopause ovaries no longer functioned, and were just laying around waiting for ovarian cancer to develop. Well, turns out, as it seemed reasonable to me, that ovaries DO function after menopause, they just function differently than before, making less estrogen and progesterone, but they continue to contribute to health—in fact, it would appear that they play a role in preventing heart disease, stroke, and death from many causes, including lung and other cancers.

Taking them out does indeed reduce the risk of ovarian and breast cancer, but this benefit is far outweighed by the detriment. For women who survive 35 years after hysterectomy, there is 1 premature death for every 9 cases where healthy ovaries are removed. I think its generally a good policy to assume that all the parts we arrive with on this planet have a purpose throughout life, even if we haven’t figured out yet what it is. Just because we can survive without an appendix, tonsils, or ovaries, doesn’t mean it’s a good idea to surgically remove it unless it is irreversibly damaged, infected, containing cancer, or otherwise a serious liability and beyond repair.

Omega-3 Kills Cancer Cells

Medical News today reported the results of a study showing DHA’s role in reducing tumor size:

Docosahexanoic acid (DHA), an omega-3 fatty acid found in fish oils, has been shown to reduce the size of tumours and enhance the positive effects of the chemotherapy drug cisplatin, while limiting its harmful side effects.

Ever since a case report was published in the journal Nutrition and Cancer in 2005 in which an elderly man with a large and inoperable lung sarcoma went into complete remission with high dose fish oils, predominantly DHA, I’ve been emphasizing DHA (and vitamin D) in my nutritional recommendations for people facing cancer challenges.

In the case report, the intake of EPA+DHA was in the range of 15-18 grams per day, about the amount that the Innuit on their traditional diet of seal, fish, and whale blubber used to consume. That’s a lot of omega 3, and should be supervised by a nutritionally knowledgeable physician, but even 4-6 grams per day, especially with a high DHA product can be a big help.

Grape seed extract kills leukemia cells

A new study from the University of Kentucky (where I graduated from medical school in 1975!) was published Jan 1st 2009 in Clinical Cancer Research.

An extract from grape seeds forces laboratory leukemia cells to commit cell suicide, according to researchers from the University of Kentucky. They found that within 24 hours, 76 percent of leukemia cells had died after being exposed to the extract.

This one is particularly dear to my heart, as I have seen (and experienced) first hand the amazing results of supplementation with high quality grape seed (and pine bark) proanthocyanodins (OPCs). One of the frequent comments/questions I receive is “I heard that OPCs were bad to take if you have leukemia or a high white blood cell count”. My answer has always been that I know of no reason for this. Now we have strong evidence,  even including the molecular mechanism (see full article) for the first time, to the contrary

vitamin D supposedly doesn’t protect against breast cancer

A study of 36,000 women, half of whom took a gram of calcium and 400 IU of vitamin D for a period of 7 years was recently published in the Journal of the National Cancer Instutute

The main findings do not support a causal relationship between calcium and vitamin D supplement use and reduced breast cancer incidence, despite the association observed in some epidemiological studies

Commentary:  When I see studies like this, its hard to know whether the authors are just uninformed, or actually malicious. OF COURSE there was no difference in breast cancer incidence from taking a gram of calcium and 400 IU of vitamin D (the calcium is mostly irrelevant, its the vitamin D that is important in cancer prevention). There is a very rich scientific literature about vitamin D that has appeared over the past decade, which these authors apparently have not been reading.  Given that somewhere between 50 and 80% of adults in the US are vitamin D deficient or insufficient (levels below 30 ng/ml), and that during the wintertime, taking even 1000 IU of vitamin D a day will not raise the blood level of 25-hydroxy vitamin D above 30 ng/ml (recently published by Dr. Michael Holick), drawing conclusions from a study in which 18,000 women took 400 IU of vitamin D is ludicrous! Now if they had given these women 4,000 IU of vitamin D instead of 400, its very likely that they would have seen very different results. In fact, a study by Lappe et al reported that postmenopausal women who took 1100 IU of vitamin D3 a day for 4 years (along with calcium) showed a 60% reduced risk of developing all cancers compared to a group with similar cancer risk factors that took placebo. So just because a study is in the Journal of the National Cancer Institute, don’t assume that its authors know what they’re talking about!

Example of partial responsibility of epidemic of vitamin D deficiency

Scaring ourselves out of the sun may be fueling epidemics of cancer and autoimmune disease. Here’s a classic example:

There is no such thing as a safe tan, U.S. and British researchers said on Thursday.

They said in their review of published studies that tans and skin cancer both begin with DNA damage caused by exposure to ultraviolet light but many people, especially the young, ignore or are unaware of this danger in a quest for a bronzed body.

Humans developed over many centuries working, playing, and living outside, under the sun. About 40 years ago, we went inside, put on sun screen and hats when we’re outside, because science told us we were killing ourselves with skin cancer. But guess what? We’re killing ourselves with all kinds of cancers, because hiding from the sun has created an unprecedented epidemic of vitamin D deficiency–so much so that Rickets has returned in the children of dark skinned mothers (who are also not out in the sun).

Our food supply doesn’t have nearly the sources of vitamin D to make up for what we are not getting from the sun. In an hour of sun exposure, most people (if they get just slightly pink) will make between 10 and 20 THOUSAND units of vitamin D-3. So when you read that you should increase your vitamin D intake from 400 IU per day (which dose nothing to correct D deficiency) to 1000 units a day (which dose just a little to start to correct deficiency), think about how much vitamin D our bodies are designed to make in the summer sun. We’re designed to live off the vitamin D stores in our body fat during the winter months, but most people run low–which many vitamin D experts believe is what’s behind “flu season”.

If you’re going to replace sun with vitamin D supplements, better be thinking more along the line of 4-6 thousand units a day (and 10 thousand if you’re overweight, since vitamin D gets lost in body fat stores). True, too much sun can spoil your fun, and eventually lead to skin cancer for some, but the kinds of cancer caused by cumulative sun exposure are basal cell and squamous cell cancers, which are more “nuisance” cancers–almost nobody dies from them. The deadly one is melanoma. Since the anti-sun campaign was started in Australia, melanoma rates have continued to soar–probably because robust levels of vitamin D in the body help to prevent melanoma, as well as most of the other common skin cancers.

There is some reasonable scientific evidence that antioxidants in diet and supplements, as well as omega-3 fatty acids can protect our skin’s DNA from sun damage, and reduce the risk of the “nuisance” skin cancers, as well as retard skin aging.

Walnuts Slow Growth of Tumors in Mice

Here an interesting study I’ve come across:

Researcher W. Elaine Hardman, Ph.D., of Marshall’s Joan C. Edwards
School of Medicine said the study was designed to determine whether mice
that got part of their calories by eating walnuts had slower breast cancer
growth than a group eating a diet more typical of the American diet.

“When we fed the mice the walnuts, the growth rate of the tumors they
had was dramatically suppressed,” Hardman said.

To read the full news report, go to

Prostate screening controversy

As NBC chief science correspondent commented:

What is needed are better methods of differentiating the cancer that is truly dangerous and needs to be treated, from the cancer that poses no risk. Such research is underway. Meanwhile, the National Institutes of Health has been running a study of 74,000 men since 1993, trying to determine whether screening saves lives. So far, it has not come to enough of a conclusion that the results have been released.

As with so many other aspects of this disease, men and their doctors must decide for themselves.

I would add to this that Dr. Dean Ornish’s group has shown that drinking 8 oz of pomegranate juice daily doubles the time required for the PSA to double in men with prostate cancer (reflecting slowed growth of the prostate cancer). More recently, laboratory studies have shown that rats fed the equivalent of 2 servings of walnuts per day show a decrease in tumor growth rate by a factor of 2.  So it can’t be a bad idea to eat walnuts and drink pomegranate juice frequently–while you decide whether or not you want a PSA screening test.