Marc Joseph Nutrition - Blog

In a study published in the Journal of Clinical Investigation, researchers found that mice missing a key prostate cancer tumor suppressor gene were much more likely to survive with a high omega-3 fat, low omega-6 fat diet.

Specifically, survival rates in the study were:

• 60% for the mice fed a high omega-3 fat diet (1-to-1 omega-6 to omega-3 fat ratio)
• 10% for the mice fed a low omega-3 fat diet (20-to-1 omega-6 to omega-3 fat ratio)
• 0% for the mice fed a high omega-6 fat diet (40-to-1 omega-6 to omega-3 fat ratio)

In addition to improving survival times, omega-3 fatty acids slowed both the progression of cancer cell formation and tumor growth.

As one of the study’s co-authors notes, the implications are significant:

“This suggests that if you have good genes, it may not matter too much what you eat,” said Chen, a professor of cancer biology. “But if you have a gene that makes you susceptible to prostate cancer, your diet can tip the balance. Our data demonstrate the importance of gene-diet interactions, and that genetic cancer risk can be modified favorable by omega-3 PUFA.”

The bad news: The tumor suppressor gene absent in the mice in this study is estimated to be missing in 60% to 70% of human metastatic cancers. So, counting on good genes may not be a good bet.

The good news: Since prostate cancer cells are typically slow-growing, improving the omega-3 / omega-6 fat intake balance is one factor that may play an important role in determining whether one ultimately develops the disease.

Possible Mechanism

As discussed in an earlier post, a higher omega-3 / omega-6 fat intake tends to promote the production of anti-inflammatory immune system modulators (e.g., prostaglandin PGE-3), while a high omega-6 / omega-3 fat intake tends to promote the production of pro-inflammatory substances (e.g., prostaglandin PGE-2 and cytokines IL-6 and TNF-alpha).

(more…)

Last month, I wrote a post questioning the conclusions of a poorly designed National Cancer Institute study that suggested taking “excessive” multivitamins could increase your risk for prostate cancer.

More recently, the Life Extension Foundation (LEF) put together an even more damning and detailed critique of the study’s results that raises other excellent points worth considering:

1. Study participants may have been mis-classified.

As mentioned in my earlier post, the study used self-reported food frequency questionnaires (FFQs) to ask study participants about prior supplement usage. FFQs are subject to significant error, as participants may over- or under-report supplement use.

As LEF notes:

Questionnaire-based information collection is limited in accuracy to the memory recall of the study subjects. The majority of people cannot recall what they ate for breakfast one week ago, or which shirt they wore to work two weeks ago, or how many gallons of gas they purchased during their last trip to the gas station, never mind specific doses and frequency of use of a myriad of dietary supplements months or years ago.

But it gets better when we learn what the researchers actually did in this case:

In this government-funded study bashing multivitamins, the researchers had the audacity to place each subject who stated they did not know how much vitamin E they took into the 400 IU a day category. This means when the results where tabulated to see if multivitamin use was associated with prostate cancer risk, men who may or may not have taken any vitamin E were deemed to have taken 400 IU a day.

Men who reported taking even one multivitamin supplement a month were recorded as taking a multivitamin every single day. This meant that when the data was tabulated, those who may have taken as few as twelve multivitamin supplements a year where considered to have taken a multivitamin each day.

If one were designing a study to make it impossible to conclude anything meaningful from the results, this would be a good way to do it.

(more…)

And on it goes. The latest salvo against nutritional supplements is a new study published in the Journal of the National Cancer Institute that suggests men taking “excessive” multivitamins are at increased risk for advanced and fatal prostate cancers.

Specifically, researchers found that men who took multivitamins more than 7 times a week had a 32% and 98% greater risk of developing advanced and fatal prostate cancers, respectively.

Advanced prostate cancer is certainly serious condition, but let us count the ways why the results of this study should not be of significant concern:

- No association was observed between multivitamin use and overall prostate cancer risk.

- No association was observed between multivitamin use and localized prostate cancer risk. With regular screening (prostate specific antigen - PSA & digital rectal exam - DRE) now much more common, the vast majority of prostate cancers are caught at a localized, early stage. Many treatment options are available and prognoses are good in such cases. In fact, most older men, and many younger men, have cancerous cells in their prostates. Yet, since the cancer is often slow growing, those affected individuals identified through screening often go on to die years later from another condition.

(Just to be clear, I’m not trivializing prostate cancer and its potential effects. It is the most common form of cancer affecting men, and more aggressive forms of prostate cancer, although infrequent, can be deadly. Regular screening and accurate diagnosis are important.)

(more…)

There is recent research published in the journal Molecular Cancer Therapeutics that suggests low-level exposure to the plastic molecule bisphenol-A may accelerate the growth of prostate cancer cells and interfere with a common treatment called androgen ablation therapy (also known as androgen deprivation therapy).

This article from Environmental Health News provides an excellent summary:

A common plastic molecule to which virtually all Americans are exposed may interfere with the standard medical treatment for prostate cancer, according to new experiments with human prostate tumors implanted into mice. The doses of the plastic molecule, bisphenol A, were chosen specifically to be within the range of common human exposures. Tumor size and PSA levels were significantly greater in exposed animals just one month after treatment.

One of the principal known sources of exposure to bisphenol A in the U.S. is through its use to make a resin that lines the majority of food cans sold in markets. These new results by Wetherill et al. suggest men concerned about prostate cancer may want to reduce their consumption of canned goods and their use of polycarbonate water bottles, another common source of exposure.

The entire article is worth checking out, including the other cited references at the end.

Importance of Prevention

Prostate cancer is the most common type of cancer and the second leading cause of cancer-related death in U.S. men. Although 1 in 6 men will be diagnosed with prostate cancer during their lifetimes, only 1 in 34 will die from it. Nevertheless, it is important to regularly screen for prostate cancer and take preventive steps to avoid its development and progression, as later-stage forms are much more difficult to treat successfully.

Nutrition can play a big role in helping to prevent and/or slow the development of prostate-related issues, including cancer. You can read an overview of my approach to helping people with prostate issues here.

Related articles:

Popular Baby Bottles, Plastic Containers, and Canned Foods Leach Toxic Chemical Bisphenol-A

____________________________

Discover How Nutrition Can Make a Difference in Your Life …

Marc Joseph Nutrition

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.