Marc Joseph Nutrition - Blog

Even more research evidence just out reinforcing the importance of adequate vitamin D levels for avoiding the development of breast and colon cancers.

In the first paper published in the Journal of Steroid Biochemistry and Molecular Biology, researchers pooled data from two previous studies and found that individuals with the highest vitamin D levels (greater than 50 ng/mL) had one-half the risk of developing breast cancer versus individuals with the lowest vitamin D levels (less than 10 ng/mL).

“The data were very clear, showing that individuals in the group with the lowest blood levels had the highest rates of breast cancer, and the breast cancer rates dropped as the blood levels of 25-hydroxyvitamin D increased,” said study co-author Cedric Garland, Dr.P.H. “The serum level associated with a 50 percent reduction in risk could be maintained by taking 2,000 international units of vitamin D3 daily plus, when the weather permits, spending 10 to 15 minutes a day in the sun.”

In the second paper published in the American Journal of Preventive Medicine, researchers found that individuals with the highest vitamin D levels had the lowest colon cancer risk.

“Through this meta-analysis we found that raising the serum level of 25-hydroxyvitamin D to 34 ng/ml would reduce the incidence rates of colorectal cancer by half,” said co-author Edward D. Gorham, Ph.D. “We project a two-thirds reduction in incidence with serum levels of 46ng/ml, which corresponds to a daily intake of 2,000 IU of vitamin D3. This would be best achieved with a combination of diet, supplements and 10 to 15 minutes per day in the sun.”

Sources

The primary source of vitamin D is sunshine (UVB rays) hitting the skin, converting cholesterol-based molecules there into a molecule called cholecalciferol, which is then converted by two more reactions in the liver and kidneys into the final, active form of vitamin D (calcitriol).

Interestingly, researchers have learned in recent years that the final conversion that takes place in the kidneys can also take place in other cells in the body, such as breast, colon, prostate, and skin cells, four cell types that are prone to cancer.

Food is a poor source of vitamin D. Only fortified dairy really contains significant amounts, and then, only about 100 IU in an 8 oz. glass of milk. Not much.

If you get vitamin D through sun exposure, you want to avoid getting too much exposure and damaging the skin. You don’t want the skin to change color. 10 to 15 minutes per day of noontime sun on a clear day three or four times a week for a fair-skinned person should be fine. Dark-skinned people need significantly more exposure, e.g., 25 to 30 minutes exposure each time out.

In Northern latitudes during the winter months, the sun isn’t strong enough to generate adequate vitamin D, even during mid-day sun. Supplementation is the preferred source.

Getting 2000 IU/day of vitamin D through supplementation is both easy and inexpensive (less than $15 a year). As long as people aren’t getting regular, significant sun, such an intake level year-round is likely to be safe and promote healthful vitamin D levels that may:

• reduce the risk for several types of cancer
• improve calcium utilization and bone density
• strengthen immunity and reduce susceptibility to the flu

As the evidence continues to mount, last month’s appeal by leading researchers for an increase in the vitamin D upper intake level, as well as higher daily recommended intake levels for optimal health, needs to be taken seriously.

Researchers from the from the Salk Institute for Biological Studies and the La Jolla Institute for Allergy and Immunology have found what could be a potentially important link between inflammation and cancer:

[T]he study, published in the January 26 issue of the journal Cell, shows that what scientists thought were two distinct processes in cells—the cells’ normal development and the cells’ response to dangers such as invading organisms—are actually linked. The researchers . . . say that the linkage of these two processes may explain why cancer, which is normal growth and development gone awry, can result from chronic inflammation, which is an out-of-control response to danger.

Here’s a visual depiction of that concept:

Normal dialogue between cell defense and development (left) and chronic inflammation leading to hyperactive developmental signaling that may promote cancer (right). (Credit: Alexander Hoffmann, UCSD)

Specifically, the research team found a protein that is common to both inflammation and cancer development pathways:

[The research] team showed that these pathways are not distinct from one another because they are linked by a protein called p100. They found that inflammation leads to an increase in p100, but that p100 is also used in certain steps in development. Therefore p100 allows communication between inflammation and development.

Importance of Balance

Your body needs some inflammation to fend off invaders (bacteria, viruses, fungi, etc.), but excessive, chronic inflammation is detrimental and implicated in many chronic conditions (e.g., cancer, diabetes, heart disease, rheumatoid arthritis, inflammatory bowel disease, etc.). You need a balance.

To be clear, the inflammation I’m referring to is not necessarily visible or felt. It’s not like a red, swollen joint or a scratch on your arm. This inflammation is chronic and low-level, like invisible fires simmering underneath the surface. But over time, this inflammation causes damage to the cells, tissues, and systems of your body, and in turn, leads to the development of disease.

The Role of Nutrition

Nutrition can play an important role in helping to keep inflammation in check. For example:

• Omega-3 fats, as found in fish oil, can help to reduce inflammation. These fats produce substances (prostaglandins) that inhibit inflammation in cells throughout the body.
• Conversely, excess consumption of most Omega-6 fats, as found in vegetables oils, such as the corn and soybean oils used in high amounts in processed and restaurant-prepared foods, can promote the production of pro-inflammatory prostaglandins.
• One Omega-6 fat, gamma linolenic acid (GLA), found in borage, evening primrose, and black currant oils, actually can help to promote the production of anti-inflammatory prostaglandins, as well as encourage normal cell death (apoptosis) — a primary process gone awry in cancer.
• Trans fats promote chronic inflammation.
• High sugar and refined grain intake, and the resulting chronically elevated blood glucose and insulin levels, is another primary cause of chronic inflammation.

There are numerous other substances found in both foods and supplements that can help to reduce and/or manage chronic inflammation, including:

• Vitamin D (primary source: sunshine)
• Tumeric
• Ginger
• Boswellia
• And many others …

Avoiding chronic inflammation is one of the most important steps you can take in helping to reduce the risk of developing many chronic diseases, such as cancer, heart disease, diabetes, cognitive decline, arthritis, and more.

In a recent study published in the American Journal of Epidemiology, researchers found that long-term exposure to trihalomethanes (THMs) may significantly increase bladder cancer risk. THMs are created when chlorine, which is used as a water disinfectant, comes in contact with organic matter in the water system, such as leaves, branches, etc.

The study’s authors examined over 1,219 people with bladder cancer and 1,271 control people without the disease. They found that long-term exposure to high THM levels through drinking, bathing, and swimming in chlorinated water significantly increased bladder cancer risk.

• Individuals who drank chlorinated water were at 35% greater risk for developing bladder cancer.
• Individuals taking the longest showers had an 83% greater risk of getting bladder cancer.
• Individuals who regularly swam in pools with chlorinated water were 57% more likely to develop bladder cancer.

Overall, households with long-term exposure to THM levels greater than 49 mcg/L had more than a two-fold increased bladder cancer risk versus households in areas with THM levels less than 8 mcg/L.

THM levels are monitored by water municipalities, with current regulations limiting THM levels in treated water to 80 mcg/L. Water municipalities in industrialized countries often have THM levels greater than 50 mcg/L. As noted above, such levels of chronic THM exposure may put consumers at risk.

Your best bet for avoiding both chlorine and their THM by-products is to use an in-home water filter. You can find information on different filters and what contaminants they remove through NSF International’s water treatment unit review database.

Note that not all filters remove THMs. It’s important to check the review listings to make sure the one you’re considering purchasing will remove THMs and other contaminants of potential concern, such as heavy metals.

A new study just out in Cancer Research journal found that tomato and broccoli consumption (10% of the diet) helped to significantly reduce prostate cancer tumor size in rats (34% and 42%, respectively). Interestingly, reduction in tumor size was even greater (52%) in rats consuming both tomatoes and broccoli.

On the other hand, rats given supplements of lycopene, a carotenoid found in tomatoes and associated with the prevention of prostate cancer, only saw reductions in tumor growth of 7 to 18 percent, depending on the dose. Not bad, but the foods themselves proved superior.

Broccoli and other vegetables, such as cabbage and cauliflower, are high in glucosinolates (e.g., sulforaphane, indole-3-carbinol) that are also associated with cancer prevention.

A few comments:

1. This study was an animal study and the results may not directly correspond to results in humans. However, as discussed in the links above, there is significant evidence that phytochemicals found in vegetables such as tomatoes and broccoli may have anti-cancer effects.

2. The study authors note that you’d likely have to eat a fairly large amount of tomatoes or broccoli daily to get the effects in this study (1.4 cups of raw broccoli and 2.5 cups of fresh tomato, or 1 cup of tomato sauce, or half a cup of tomato paste). That’s quite a bit (watch the salt on that tomato paste), but it’s doable.

3. I wouldn’t eat broccoli every day. As part of the cabbage family, it’s a goitrogen, and may inhibit thyroid function if eaten too frequently in large quantities. A few times a week should be no problem.

4. Lycopene seems to be better absorbed through food than supplements.

5. Lycopene and other carotenoids are best absorbed with meals
containing fat (e.g., olive oil).

6. An easy, inexpensive way to incorporate tomatoes into your diet on a regular basis is to use Low-Sodium V8 juice. It has only 140 mg sodium and 17 mg lycopene per 8 oz. serving. Of course, it would be best to drink it with a meal containing fat or mix a little added healthy fat (e.g., olive oil) in with it to promote best absorption of the lycopene and other beneficial phytochemicals.

In short, regular consumption of tomatoes and/or broccoli (don’t always have to be together) can be a good part of a cancer prevention/treatment diet.

You can read more about things you can do to help maintain a healthy prostate here.

Vitamin B12 is a critical nutrient in helping to maintain cognitive function, as one of its primary roles is to aid in the formation of myelin, the insulation that lines nerve cells, such as brain cells. It’s also a key nutrient in a process called methylation, which helps control the expression of genes and proteins that are involved in many important chemical pathways in the body. An imbalance in methylation may also play a role in cancer development.

Deficiency of vitamin B12 is most commonly observed in older adults, partly because of dietary changes (less meat intake), but also as the result of impaired absorption. When foods containing vitamin B12 (e.g., meat) are eaten, intrinsic factor, a substance secreted by cells in the stomach, binds to vitamin B12. That compound travels to the end of the small intestine, where it separates and vitamin B12 is absorbed. If for some reason the stomach or gastrointestinal tract is damaged (e.g., as in atrophic gastritis) or stomach acid production is slowed (e.g., with medications such as proton pump inhibitors), this multi-step absorption process may be interrupted.

Once vitamin B12 is absorbed, utilization in the body and methylation pathways may also be impaired by the presence of heavy metals, such as mercury, lead, and aluminum.

Several laboratory measures are used together (by thorough practitioners) to test for vitamin B12 deficiency, including:

• Serum vitamin B12
• Methylmalonic acid (MMA)
• Homocysteine

In a recent paper published in the American Journal of Clinical Nutrition, researchers found that high MMA values (suggestive of vitamin B12 deficiency) were associated with significantly lower scores on a standard cognitive assessment tool, especially in the areas of language comprehension and expression.

Low serum folic acid levels also were associated with poorer cognitive function scores. Folic acid, along with vitamin B12, is essential in the proper functioning of methylation pathways, which often are not working correctly in conditions such as cognitive decline, autism, and ADD/ADHD.

Lest you think that these deficiencies only affect a small percentage of people, 43 percent of the non-demented individuals age 69 and older in the study had MMA values that suggested significant vitamin B12 deficiency.

It’s critically important to make sure that both vitamin B12 and folate levels are maintained at adequate levels to reduce the risk of cognitive decline. You can learn more about treatment approaches for preventing and slowing cognitive decline here.

With many baby boomers about to retire, maintaining independence and the ability to live an active, engaged retirement are top of mind. A recent study published in the Archives of Internal Medicine found that deficiencies in several micronutrients may increase the risk for having difficulty performing daily tasks as people age.

Specifically, the study looked at women over the age of 65 and found that deficiencies in selenium, vitamin B6, and vitamin B12 were all associated with significantly greater risk of experiencing disability, which was defined as self-reported difficulty in performing two or more activities such as bathing, dressing, toileting, transferring and eating.

Selenium is an essential trace mineral that is used by the body in important antioxidant-related enzymes. Selenium also plays an important role in immune function and may help to prevent the onset of certain cancers, such as prostate cancer.

Vitamin B6 and B12 are involved in important enzyme reactions, nervous system function, and help to maintain low homocysteine levels. High homocysteine levels are associated with oxidative stress, endothelial dysfunction, vascular diseases (heart disease, stroke), and, in particular, with decline of cognitive function.

Nutritionally, your best bet for avoiding the potential problems highlighted by this study are to follow a good diet, including mostly whole foods, lots of fresh vegetables & fruits, healthy fats, and lean protein sources.

Also, supplementation with a broad-based multi-vitamin/mineral containing at least 200 mcg selenium and the B vitamin equivalent of a B-50 complex, may help to ensure that you get adequate amounts of these essential nutrients on a regular basis and to prevent/delay the onset of disability. It’s important to select supplements containing both adequate and well-absorbed forms of the different nutrients.

In a recent study, Italian researchers found that southern Europeans consuming the highest amounts of onions and garlic had a significant reduction in risk for many cancers.

Listed below in parentheses are the percent declines in cancer risk that researchers found for high onion and garlic consumption, respectively:

• Oral cavity & pharynx (84%, 39%)
• Esophageal (88%, 57%)
• Colorectal (56%, 26%)
• Laryngeal (83%, 44%)
• Breast (25%, 10%)
• Ovarian (73%, 22%)
• Prostate (71%, 19%)
• Kidney (38%, 31%)

The results are consistent with other studies that have found beneficial effects for these vegetables in helping to prevent cancers of the digestive tract, prostate, and breast.

Garlic and onions are both members of the allium vegetable family. Organosulfur compounds found in these vegetables are believed to help prevent cancer development by:

• Promoting metabolism of carcinogens by promoting Phase II and slowing Phase I detoxification pathways in the liver.
• Enhancing cellular production of glutathione, the body’s primary and most important antioxidant.
• Arresting unregulated cell growth, which is seen with cancer, and promoting apoptosis (normal programmed cell death).
• Inhibiting microbial growth (yeast, bacteria, viruses), which may be involved in cancer development.

So, mangia! Grab the (xylitol-sweetened) breath mints and get going…

More recent evidence of the importance of vitamin D in this study that shows higher intakes of the vitamin are associated with significantly lower risk of pancreatic cancer in both men and women. Although the large-scale study is one of the first to closely look at that relationship, the results shouldn’t be too surprising.

Sunshine is the primary source of vitamin D for most people. The sun’s UVB rays hit the exposed skin and convert a molecule there into a different molecule (cholecalciferol, or vitamin D3), which is then converted in a couple of steps in the body into the active form of vitamin D.

Here’s an interesting site discussing the effects of sunlight and vitamin D deficiency on chronic disease:

http://www.sunarc.org

The site includes some neat maps that show cancer mortality maps and average UVB exposure. Cancer rates clearly increase the farther north one lives. The evidence is strongest for breast, colon, ovarian, and prostate cancer. (Multiple sclerosis, hypertension, type 1 diabetes, cardiovascular disease, and rheumatoid arthritis, too).

The site also has a good position paper overview:

http://www.sunarc.org/evidencevitd.htm

With the change in seasons and the inability in the winter time to get sunshine in latitudes above 40 degrees (basically, anywhere north of San Francisco, Denver, Washington DC, etc.) strong enough to produce vitamin D, the importance of supplementation increases. Cholecalciferol is the form of vitamin D supplement you want to look for. It’s very inexpensive and widely available.

Since vitamin D is fat-soluble, it can be toxic at high levels. However, leading nutrition researchers agree that the current suggested intake levels from all sources (diet and sunshine) of 400 to 600 IU per day for adults are likely far below optimal. Recent research suggests that a total daily intake level of closer to 2000 IU is probably much more desired for otherwise healthy people.

(For comparison sake, someone at the beach in a swimsuit in mid-day summer sun generates about 10,000 IU of cholecalciferol in 15 minutes.)

As discussed in other posts, limited amounts of regular sun exposure can help the body to maintain adequate vitamin D levels.

It’s also clear, though, that excessive sun exposure may damage the skin and increase the risk for skin cancer. That’s why the recent trend toward frequent use of tanning salons, especially by young women, is especially concerning.

As noted in the article linked above, “Caucasian women between age 16 and 49 make up 70 percent of those who regularly visit tanning salons.”

And yet, this group of mostly fair-skinned people actually needs the least amount of sun exposure. It’s kind of scary when you read comments like this:

“I was a high school teacher, and I remember sending one girl to the school nurse because her skin was so leathery I thought she had a condition of some sort,” said Vivian Viloria-Fisher, the Suffolk County legislator who sponsored the measure. “The nurse just said, ‘Oh, she’s just been tanning at a salon.’ ”

Hopefully this trend of always trying to maintain a mid-summer beach tan will fade away, and people will start to once again value blemish-free skin that doesn’t leave people looking like wrinkled leather in their 30s and 40s.