Tag Archives: colon cancer

 Amazing study results - if true - about some health benefits of eating nuts. Just tree nuts, not peanuts (which are actually a legume). Researchers at the Dana-Farber Cancer Institute in Boston found that colon cancer survivors who ate at least two ounces (57 grams) of tree nuts a week were 42% less likely to have their cancer return or a 53% lower chance of dying from their cancer than those who did not eat nuts. One ounce or a handful of nuts is considered a serving, but two ounces of nuts is about 48 almonds, or 36 cashews, or 96 shelled pistachios, or 38 pecan halves, or 28 walnut halves, or 42 hazelnuts.

The benefits of eating tree nuts was so surprising and so big, that the researchers caution that the study needs to be repeated (and improved) to make sure. The problem is that the study was observational, and so can't say a definite cause and effect. Perhaps people eating the tree nuts may also be doing some other protective behavior - thus there is just an association. So can't say for sure, but....the studies are adding up that eating nuts is linked with all sorts of health benefits. From STAT:

Can cashews keep colon cancer patients alive? Study says yes — but cautions abound

Surprising new research scheduled to be unveiled at a major cancer meeting next month suggests that cashews and other tree nuts might be as effective as some of oncology’s most effective treatments at keeping colon cancer from recurring after treatment — and even keeping patients from dying. If the benefit is real, a daily handful or two of cashews (cost: less than $1) could work as well as standard chemotherapy (cost: thousands of dollars). But the reported benefit comes with a big “if.”

Although the study is from a respected clinical trial, this finding was not from the original research but, instead, an add-on. The original trial randomly assigned colon cancer patients to either of two drug treatments. Later, researchers looked at cancer survivors who simply went about their lives, doing as they pleased, and tried to evaluate whether eating nuts was associated with better outcomes.In that kind of observational study, it’s not possible to say whether a given behavior — in this case, eating nuts — caused an outcome, or was instead simply associated with the true cause.

Even the study’s lead author was cautious. “This is the first study to show an association between nut consumption and cancer outcomes,” said Dr. Temidayo Fadelu of Dana-Farber Cancer Institute. “When you see an association that is more dramatic than you expect, you have to repeat [the study] in another [group of patients]. … There could be underlying confounders that we didn’t control for.” In other words, people who eat tree nuts, such as pecans, almonds, and walnuts, might be different from people who do not, something called “healthy patient bias.” They “might be more health-conscious,” said Shah. They might be wealthier, or better connected to the health care system, or have healthier habits in general. Any of those attributes might help patients survive colon cancer.

The researchers did not find an association with eating peanuts. Only tree nuts seemed to matter, to an eye-popping degree. Of 826 patients, those who reported having two or more servings per week (as 19 percent did) had a 46 percent lower risk of their cancer returning and a 53 percent lower risk of dying than those who said they did not eat tree nuts.

The study is an outgrowth of a famous clinical trial that began in 1999, testing chemotherapies in 1,264 patients with stage 3 colon cancer (meaning it had spread to lymph nodes but not to distant sites like the liver and lungs). Some patients filled out questionnaires about diet and lifestyle, once while receiving chemotherapy and again six months after treatment ended. 

Fadelu and his colleagues studied nut consumption because that has been associated with lower mortality, mostly because of a reduced risk of cardiovascular disease. “We definitely think something is going on,” with tree nuts providing a biological benefit, Fadelu said. For one thing, they decrease insulin resistance, “a potential mechanism” by which they might keep colon cancer from recurring, he said.

 Reading this recent study, I was struck by how it is evidence for eating sulforaphane containing foods, such as kale, cauliflower, brussels sprouts, broccoli, and cabbage for health and preventing cancer (due to anti-tumor activity). It is debatable whether it is support for taking supplements (here a sulforaphane supplement called BSE), even though the researchers were testing the supplement. Seven days of taking a supplement without "serious adverse events" (but they did have minor ones such as "mild abdominal discomfort") is too short a length of time for any support for a product. The real test would be seeing what health effects, both positive and negative, are after a year or two of taking the supplement.

Numerous other studies have found that eating foods are linked to good health, while taking supplements are linked to various health problems. Some scientists speculate that it's because the doses in supplements are too high - that they're much higher than what is found in foods. Also, supplements may be missing important nutrients that are found in foods. Bottom line: eat real foods for health and and cancer prevention, including several servings a week of cruciferous vegetables (cauliflower, cabbage, garden cress,bok choy, broccoli, brussels sprouts and similar green leaf vegetables). From Futurity:

Can A Broccoli Sprout Pill Fight Cancer?

A compound in broccoli sprouts may not only help prevent cancer but also treat itSulforaphane is found in vegetables such as kale, cauliflower, and cabbage—and in particularly high concentrations in young broccoli sprouts. Sulforaphane also is available as a dietary supplement called BSE.

Researchers at the Texas A&M Health Science Center Institute of Biosciences and Technology, along with collaborators in Oregon, had previously found that sulforaphane could inhibit colon and prostate cancer cells in the laboratory. They’ve now shown that it seems to help humans as well. A paper published in the journal Clinical Epigenetics hints at the biological pathways involved and suggests BSE is generally safe.

“We have not seen any serious adverse events in healthy volunteers who consumed BSE pills for seven days,” says Praveen Rajendran, an assistant professor at Texas A&M University, although some people did experience mild abdominal discomfort.

In a separate clinical study, 28 human volunteers over the age of 50, who were undergoing routine colonoscopies, were surveyed for their cruciferous vegetable-eating habits. When their colon biopsies were examined, those who ate more servings were found to have higher levels of expression of the tumor suppressor gene p16 than those who ate few or no cruciferous vegetables.

This effect on p16 held even for people who didn’t eat these vegetables every single day, which may seem strange, as a single serving of sulforaphane is generally cleared from the body in less than 24 hours. “This hints at the possibility that epigenetic mechanisms are initially triggered by sulforaphane and its metabolites, and downstream mechanisms could be sustained, at least in the short-term, even after compounds are eliminated from the body.” In other words, eating vegetables containing sulforaphane may change your genes and help your body fight tumor growth.

However, it’s not all good news. In animal models, sulforaphane was shown to generally inhibit the development of colon cancer, but it’s a bit of a two-edged sword. Sulforaphane induces a protein called Nrf2, which has beneficial antioxidant and detoxifying effects—and is obviously good for fighting cancer. Later in the development of cancer, though, Nrf2 can also have a role in tumor growth and can even enhance the buildup of plaque in the arteries.

 Some recent studies looked at aspirin use and cancer and found that consistent use for a number of years (5 to 10 years) lowers the rate of a number of cancers, including colon cancer. However, the longer one takes daily aspirin - then harms start adding up, with a major one being gastrointestinal bleeding. NSAIDs (non-steroidal anti-inflammatory drugs) are also linked to lower rates of various cancers, but harms with long-term use are cardiovascular risks (stroke and heart attack). The first article discusses that many doctors think this lower cancer rate occurs because aspirin and NSAIDs lower inflammation, and as we know, inflammation is linked to cancer.

From Science News: Aspirin reverses obesity cancer risk

Research has shown that a regular dose of aspirin reduces the long-term risk of cancer in those who are overweight in an international study of people with a family history of the disease....They found that being overweight more than doubles the risk of bowel cancer in people with Lynch Syndrome, an inherited genetic disorder which affects genes responsible for detecting and repairing damage in the DNA. Around half of these people develop cancer, mainly in the bowel and womb. However, over the course of a ten year study they found this risk could be counteracted by taking a regular dose of aspirin.

 Lots of people struggle with their weight and this suggests the extra cancer risk can be cancelled by taking an aspirin.This research adds to the growing body of evidence which links an increased inflammatory process to an increased risk of cancer. Obesity increases the inflammatory response. One explanation for our findings is that the aspirin may be suppressing that inflammation which opens up new avenues of research into the cause of cancer."

When they were followed up ten years later, 55 had developed bowel cancers and those who were obese were more than twice as likely to develop this cancer -- in fact 2.75 times as likely. Following up on patients who were taking two aspirins a day revealed that their risk was the same whether they were obese or not....What is surprising is that even in people with a genetic predisposition for cancer, obesity is also a driver of the disease. 

The researchers believe the study shows that aspirin is affecting an underlying mechanism which pre-disposes someone to cancer and further study is needed in this area. Since the benefits are occurring before the very early stages of developing a tumour -- known as the adenoma carcinoma sequence -- the effect must be changing the cells which are predisposed to become cancerous in later years.

From Medical Xpress:  Low-dose aspirin, other painkillers may lower colon cancer risk

Regularly taking low-dose aspirin or other common pain relievers may lower long-term risk of colon cancer, new research suggests. Men and women who took low-dose (75 to 150 milligrams) aspirin for five years or more saw their risk of colon cancer drop by 27 percent. And taking non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen for that long was linked to a 30 percent to 45 percent drop in colon cancer risk, the study found.

The study did not assess the potential impact of high-dose aspirin, and no protective benefit was seen for irregular or short-term users of either low-dose aspirin or other NSAIDs.And the study did not prove that the use of painkillers reduced the risk of colon cancer, just that there was an association between the two. In the United States, NSAIDs include over-the-counter Aleve (naproxen), Advil and Motrin (both ibuprofen), and prescription drugs such as Celebrex and high-strength Motrin.

Baron emphasized that the drugs were taken continuously for years before any cancer-preventive benefits were realized. "For aspirin, you would have to take it fairly consistently, meaning at least every other day, for at least five to 10 years for the protective effect to even begin to appear," he said."That's a significant amount of time for side effects to accumulate, all without getting any benefit," he said. Potential side effects include gastrointestinal bleeding with aspirin, and heightened risk for heart attack and stroke with long-term use, or high-dose use, of NSAIDs, according to the U.S. Food and Drug Administration.

A comparison of cancer patients with more than 100,000 cancer-free Danes revealed that regular, long-term use of low-dose aspirin and NSAIDs seemed to confer long-term protection against colon cancer. The biggest benefit was linked to NSAIDs with the highest degree of so-called COX-2 selectivity. Celebrex is one such drug. That said, the U.S. Food and Drug Administration requires a "black box" warning—its strongest drug-related warning—on Celebrex packaging to alert users to the heightened risk for heart attack or stroke.

More from Medscape:  Nonaspirin NSAIDs Match Aspirin on Cancer Protection

A 2014 study mentioned in the Medscape article. They also discuss in-depth about who should not take long-term aspirin. From Annals of Oncology: Estimates of benefits and harms of prophylactic use of aspirin in the general population

Accumulating evidence supports an effect of aspirin in reducing overall cancer incidence and mortality in the general population. We reviewed current data and assessed the benefits and harms of prophylactic use of aspirin in the general population.

The effects of aspirin on cancer are not apparent until at least 3 years after the start of use, and some benefits are sustained for several years after cessation in long-term users. No differences between low and standard doses of aspirin are observed, but there were no direct comparisons. Higher doses do not appear to confer additional benefit but increase toxicities. Excess bleeding is the most important harm associated with aspirin use, and its risk and fatality rate increases with age. For average-risk individuals aged 50–65 years taking aspirin for 10 years, there would be a relative reduction of between 7% (women) and 9% (men) in the number of cancer, myocardial infarction or stroke events over a 15-year period and an overall 4% relative reduction in all deaths over a 20-year period.

Prophylactic aspirin use for a minimum of 5 years at doses between 75 and 325 mg/day appears to have favourable benefit–harm profile; longer use is likely to have greater benefits...It should also be recognised that our best estimates may be conservative, as bigger effects have been seen in several studies, and the overview of trials with long-term follow-up found a 20% relative mortality reduction in all cancers.

Although often not as serious as MI, stroke or cancer for the age groups considered here, major bleeding is the most important serious side-effect of aspirin.... Clear contraindications are those with peptic ulcer, recent bleeding episodes or bleeding tendencies. Other risk factors for bleeding in aspirin or non-steroidal anti-inflammatory drug (NSAID) users are: increasing age, male sex, diabetes, hypertension, being overweight or obese, smoking, alcohol consumption and H. pylori infection .

This study confirms all my recent posts on the importance of fiber, fruits, vegetables, whole grains, seeds, nuts, and legumes for beneficial gut bacteria health (have to feed them!). This study found dramatic changes in the colon (specifically in the colonic mucosa) from dietary changes in as little as 2 weeks. In the study the Americans ate the typical low-fat, high fiber diet of South Africa which included foods such as hi-maize corn fritters, beans, salmon croquettes, spinach, red pepper and onions, homemade tater tots, mango slices,okra, tomatoes, corn muffins, black-eyed peas, and pineapple. Meanwhile, people in South Africa ate an “American” high-fat, low-fiber diet: Foods included beef sausage links and pancakes for breakfast; hamburger and French fries for lunch; and meatloaf and rice for dinner. From Science Daily:

Diet swap has dramatic effects on colon cancer risk for Americans and Africans

Scientists have found dramatic effects on risk factors for colon cancer when American and African volunteers swapped diets for just two weeks. Western diets, high in protein and fat but low in fibre, are thought to raise colon cancer risk compared with African diets high in fibre and low in fat and protein.The new study, published in Nature Communications today, confirms that a high fibre diet can substantially reduce risk, and shows that bacteria living in the gut play an important role in this effect.

Colon cancer is the fourth commonest cause of death from cancer worldwide, accounting for over 600,000 deaths per year. Colon cancer rates are much higher in the western world than in Africa or the Far East, yet in the United States, African Americans shoulder the greatest burden of the disease.

To investigate the possible roles of diet and gut bacteria, an international team including scientists from the University of Pittsburgh and Imperial College London carried out a study with a group of 20 African American volunteers and another group of 20 participants from rural South Africa. The two groups swapped diets under tightly controlled conditions for two weeks.... At the start, when the groups had been eating their normal diets, almost half of the American subjects had polyps -- abnormal growths in the bowel lining that may be harmless but can progress to cancer. None of the Africans had these abnormalities.

After two weeks on the African diet, the American group had significantly less inflammation in the colon and reduced biomarkers of cancer risk. In the African group, measurements indicating cancer risk dramatically increased after two weeks on the western diet.

"The findings suggest that people can substantially lower their risk of colon cancer by eating more fibre. This is not new in itself but what is really surprising is how quickly and dramatically the risk markers can switch in both groups following diet change. These findings also raise serious concerns that the progressive westernization of African communities may lead to the emergence of colon cancer as a major health issue."

Professor Stephen O'Keefe at the University of Pittsburgh, who directed the study, said: "Studies on Japanese migrants to Hawaii have shown that it takes one generation of westernization to change their low incidence of colon cancer to the high rates observed in native Hawaiians. Our study suggests that westernization of the diet induces changes in biomarkers of colon cancer risk in the colonic mucosa within two weeks. Perhaps even more importantly, a change in diet from a westernized composition to a 'traditional African' high fiber low fat diet reduced these biomarkers of cancer risk within two weeks, indicating that it is likely never too late to change your diet to change your risk of colon cancer."

The study found that a major reason for the changes in cancer risk was the way in which the bacteria in the gut -- known as the microbiome -- altered their metabolism to adapt to the new diet. In the American group, the researchers found that the African diet led to an increase in the production of butyrate, a byproduct of fibre metabolism that has important anti-cancer effects.

The American subjects switched to a low-fat, high-fibre diet based on that of rural Africans in KwaZulu-Natal.Photograph: brianafrica / Alamy/Alamy

The following medical article is strongly in favor of Americans gettiing their Vitamin D levels tested, and taking vitamin D3 (if needed) to raise serum levels of vitamin D's metabolite 25(OH)D to at least 30 ng/mL and preferably more. It is suggested that taking 1000 IU of vitamin D3 daily would achieve these levels in most people. From Medscape:

Vitamin D and Mortality Risk: Should Clinical Practice Change?

Traditionally associated with skeletal disease including osteoporosis and fractures, low levels of serum 25-hydroxyvitamin D (25[OH]D), the metabolite usually measured as a mark of vitamin D status, more recently have been linked to a wide range of nonskeletal diseases, including some cancers and autoimmune, cardiometabolic, and neurologic diseases. A number of studies also have reported an inverse association between 25(OH)D concentration and all-cause mortality.

To explore this association more, Medscape reached out to Dr. Cedric Garland, a well-known expert on vitamin D. Dr. Garland is a professor in the Division of Epidemiology, Department of Family and Preventive Medicine, and a Fellow of the American College of Epidemiology. He has a Doctor of Public Health degree from University of California San Diego and studied epidemiology at Johns Hopkins. His research has focused on vitamin D status in health and the association between vitamin D deficiency and increased risk for disease, including some common cancers (breast cancer, colon cancer, leukemia, and melanoma) and diabetes. He is active in seeking to reduce the risk for cancer and diabetes by improving vitamin D status among the US population.

To examine the relation between serum 25(OH)D and mortality, Dr. Garland and colleagues at the University of California San Diego and others in the United States pooled data from 32 studies published between 1966 and 2013.[6] They found an overall relative risk of 1.8 (95% confidence interval [CI]: 1.7-1.8; P <.001) comparing the lowest (0-9 ng/mL) with the highest (>30 ng/mL) category of 25(OH)D for all-cause mortality. Serum 25(OH)D concentrations ≤30 ng/mL were associated with higher all-cause mortality than concentrations >30 ng/mL (P <.01).

The investigators noted that these findings confirmed observations from the Institute of Medicine (IOM) that 25(OH)D levels of <20 ng/mL are too low for safety,[8] but they suggested a cut-off point of >30 ng/mL rather than >20 ng/mL for all-cause mortality reduction. This level "could be achieved in most individuals by intake of 1000 IU per day of vitamin D3," the investigators said, noting that this is described as a safe dose in almost all adults by both the IOM[8] and Endocrine Society[9] clinical guidelines on dietary intake of vitamin D.

In particular, a randomized clinical trial by Lappe et al[12] had demonstrated a reduced risk for all cancers with vitamin D supplementation in postmenopausal women.... Only one third of the US population is below 20 ng/mL,[15] but two thirds of the population is below 30 ng/mL.[16]

We decided to look at what would happen if we put together all the existing studies that have looked at the survival of "ordinary" people; that is, mostly people in general practices who did not, for the most part, have illnesses. Studies that only included people who were already ill were not eligible for inclusion in our analysis. We found 88 relevant studies, of which 32 presented their data by quartiles of intake, allowing us to see a dose response

The incidence of colon cancer is very high in countries like Iceland and Sweden, and other countries nearer the North Pole, and in countries like New Zealand, which is closer to the South Pole, and intermediate in countries at intermediate latitudes such as the United States, which is, on average, 38º north of the Equator. By the time you get down within the tropics, which is 23º from the Equator, it begins to decrease, and within 5º of the Equator there are vanishingly low incidence rates of colon cancer. In the past, some scientists theorized that the low incidence rates near the equator were due to intake of a high-fiber diet, but now my group believes -- and many others are leaning more in this direction -- that it is the high UVB irradiance and high circulating 25(OH)D year-around nearer the equator rather than a high-fiber diet that best explains the inverse association with solar UVB irradiance

Raising the serum 25(OH)D from 30 to 40 ng/mL reduces the incidence of breast, bowel, and lung cancer by 80%, as reported by Lappe and colleagues in their clinical trial.[12]On the other hand, if you lump all cancers together, in both sexes, and include countries where there is a whole lot of cigarette smoking, then you may obscure the effect of the vitamin D. Vitamin D is not able to overcome the effect of heavy smoking, and the CHANCES analysis[7] included data from people in countries like the Czech Republic, Poland, and Lithuania, where there is a huge amount of smoking. Although the effects are still there, they are weakened.

Studies such as our meta-analysis have provided us an opportunity to not just be locked into the present but to predict mortality on the basis of vitamin D levels in the present. I had expected our results to be convincing, but we were shocked at the persistence of the belief that very low levels of vitamin D, such as approximately 20 ng/mL, are safe. They are not safe with regard to breast and colon cancer, several other cancers, diabetes in youth and adulthood, fractures, and other complications of 25(OH)D <30 ng/mL. Even higher levels, such as 40-60 ng/mL, would be even safer, according to a letter of consensus of expert vitamin D scientists and physicians.

In addition, 2 ongoing trials, the CAPS study[23] (aiming to replicate the findings of Lappe et al[12]) and the VITAL study,[22] are both using a vitamin D3 dose of 2000 international units (IU)/day. I think that if I were to design a trial, knowing what we know today, I would use 4000-5000 IU/day. It seems as though each time we do a clinical trial, by the time the trial is completed, we know that the doses were too small to elicit an effect.

I am also concerned that there may be not enough calcium to see an effect. In CAPS, the women are being given 1500 mg of calcium, which was done in the original randomized controlled trial in which 80% of the cancers in postmenopausal women were prevented. I would have stayed with this design and dose for the VITAL trial. We know that it helps because in their original trial, Lappe and colleagues[12]examined the effects of vitamin D alone vs vitamin D plus calcium, and the effects were stronger when the calcium was included.

Testing should be universal. And ideally it should be done in March when the vitamin D is at its lowest levels. This will prevent hundreds of thousands of cases of serious diseases worldwide annually, beginning with postmenopausal breast cancer and including colon cancer and types 1 and 2 diabetes. Skipping this test would be equivalent to not measuring blood pressure, serum lipids, or weight at an annual exam.

No one should run a serum 25(OH)D less than 30 ng/mL. This means that two thirds of the US population needs supplementation. You may have noticed that President Obama was recently tested for his vitamin D, and it was 22.9 ng/mL.[35] His physicians wisely decided to treat him, and he is now taking vitamin D.

Daily sitting for hours on end is no damn good. From Medical Daily:

Too Much Sitting And Watching TV Increases Your Risk Of Certain Cancers: Why Sitting Is The New Smoking

Or the nice scientific write-up of the same study. Bottom line: to lower the risk of cancer, sit less and move more. From Science Daily:

Sedentary behavior increases risk of certain cancers

Physical inactivity has been linked with diabetes, obesity, and cardiovascular disease, but it can also increase the risk of certain cancers, according to a study published June 16 in the JNCI: Journal of the National Cancer Institute.

To assess the relationship between TV viewing time, recreational sitting time, occupational sitting time, and total sitting time with the risk of various cancers, Daniela Schmid, Ph.D., M.Sc., and Michael F. Leitzmann, M.D., Dr.P.H., of the Department of Epidemiology and Preventive Medicine, University of Regensburg, Germany, conducted a meta-analysis of 43 observational studies, including over 4 million individuals and 68,936 cancer cases

When the highest levels of sedentary behavior were compared to the lowest, the researchers found a statistically significantly higher risk for three types of cancer -- colon, endometrial, and lung. Moreover, the risk increased with each 2-hour increase in sitting time, 8% for colon cancer, 10% for endometrial cancer, and 6% for lung cancer, although the last was borderline statistically significant. The effect also seemed to be independent of physical activity, suggesting that large amounts of time spent sitting can still be detrimental to those who are otherwise physically active. TV viewing time showed the strongest relationship with colon and endometrial cancer, possibly, the authors write, because TV watching is often associated with drinking sweetened beverages, and eating junk foods.

The researchers write "That sedentariness has a detrimental impact on cancer even among physically active persons implies that limiting the time spent sedentary may play an important role in preventing cancer…."