Diet has been shown to be an important factor for the prevention of first-time colon cancer. 2 large studies showed that a "western diet" with large amounts of red meat, sweets, and desserts, and refined grains increased risk of first time cancer. Large studies on the effect of diet on survival, and recurrence of cancer, in patients with treated advanced colon cancer have not been done until now. This population is of course more difficult for dietary intervention to have a major role, but in fact that is exactly what was found.

 

This study, published mid-August of 2007, looked at over 1000 patients who had been diagnosed and treated for stage III colon cancer. Generally this means that the cancer had already spread to the lymph nodes in the region. Treatment was done with surgery and chemotherapy, and then rates of death and recurrence of cancer were studied in long-term follow up in groups of patients with markedly different diets.

 

Diets were divided into two main types: the "prudent diet" with many fruits, vegetables, poultry and fish; and the "western diet" with more red meat, fat, refined carbohydrates and grains, and dessert.

 

Prudent diet

 

Rich in:

 

green leafy vegetables

yellow vegetables

cruciferous vegetables (broccoli etc)

legumes

fruit

light salad dressing

tomatoes

garlic

fish

poultry

fruit juice

whole grains

low fat mayo

wine

tea

 

Western diet

 

Rich in:

 

high fat dairy

low fat dairy

refined grains

condiments

red meat

dessert

margarine

processed meat

potatoes

regular mayo

butter

french fries

eggs

nuts

sugar beverages

beer

 

Items above that were colored red (potatoes and tomatoes) showed some over-lap and were generally in higher amounts in both types of diets. It should also be noted that patients in the prudent diet ate significantly less sugared beverages and french fries. Another thing to note from the data is that when the researchers compared the actual foods in the patients who were separated into different groups, there was very little overlap, so patients who ate the "western diet" really seemed to like those foods!

 

Not surprisingly, patients who ate the "prudent diet" tended to be more active, have less body weight for their height, and were less likely to smoke. However, the researchers did look at the results, and did adjust for many risk factors including weight, exercise, smoking, and so forth, but still found an independent dietary effect.

 

The results?

 

When looking at the rate of either cancer recurrence OR death, patients who ate the most (top 1/5th) of the "western diet" foods had 3.25 times more risk of cancer recurrence or deathcompared to patients who ate the least (bottom 1/5th) amount of "western diet" foods! The possibility of these results being due to chance was less than 1 in 1000. 

 

The increased rate of death wasn't from patients who found out they had a recurrence and thus started eating poorly either. If a patient had a recurrence or died within 90 days of completing the questionairre, their results were excluded.

 

Perhaps that was not so surprising, that a poor, high-fat, westernized diet would increase the risk of recurrence. 

 

There was a surprise in this study though, which is that the "prudent diet" - characterized by high fruits and vegetables, whole grains, chicken, and fish, showed no protective effect against recurrence of cancer or death. It is important to note that the researchers were looking at resultswithin the prudent diet group, meaning they were looking to see if that people in this group ate way more fruits and vegetables, and the other "prudent foods", would they have more protection compared to patients who ate less of those foods (but still ate mostly well). 

 

In my reading of the study, it did not seem to compare rates of cancer recurrence between the western and prudent diet groups.

 

In a nutshell, they found that if patients were eating a westernized diet, if they ate more of the western foods, they were at increased risk.

 

If patients were eating a "prudent diet", and they ate more of the prudent foods, they were not more protected than patients who still ate that diet, but less of those foods.

 

Confusing, but the take home is simple: less of the high fat, red meat, processed meat, refined grains, and other western foods is better.

 

So in combination of the steps that I wrote for prevention of first-time colon cancer:

 

1. General blood chemistry screen and comprehensive metabolic profile to assess for iron deficiency, other problems. History and physical exam to assess for any significant immune system issues.

 

2. 25-OH vitamin D3 blood test: this is vital to seeing what an ideal dosage of vitamin D3 is needed, if any, to achieve blood levels that are not just protective against bone loss, but preventive against colon cancer.

 

3. Hair analysis and provoked metal detoxification challenge: in those over 40 to assess for significant increased body burden of toxic metals. This is much better than a simple blood mercury and blood lead, which are usually only indicative of acute exposure. Remember, heavy metal toxins are likely human carcinogens, and there is evidence that removal will lower cancer risk.

 

4. Consider folic acid, calcium, green tea, curcumin, diet rich in fruits and vegetables, diet low in red meat and preserved meats. The ideal plan is also based on the blood chemistry and metabolic profile, as this can give hints as to the ideal type of diet for a particular person’s metabolism.

 

5. Aerobic exercise.

 

6. Screen for food allergy through either blood ELISA/RAST test, and/or intradermal (skin) injection, or sublingual (under the tongue) allergen challenge. Groups with inflammatory bowel diseases, such as Crohn’s and ulcerative colitis, are at known elevated risk for colon cancer. It is a stretch to say that the same risk is present in patients with undiagnosed food allergies, but remember it is the inflammation in the diseases that gives the increased risk, so if a patient’s history and exam indicate either inflammation or allergies, then work up for food allergies can help.

 

7. “watch-and-wait” colonoscopies and fecal occult blood tests.

 

Limiting the foods in the "Western diet" above should go a long ways to cutting the risk of recurrence of colon cancer to about 1/3rd.