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A very interesting, but very preliminary study just came out about breast cancer and walnuts. Could follow up research really show this to be true - that eating walnuts has an anti-breast cancer effect?? Animal studies find that multiple ingredients in walnuts (e.g.alpha linolenic acid, beta-sitosterol, a number of antioxidants such as ellagic acid) reduce the risk of cancer or slow its growth, or even increase tumor cell death. Researchers think this is true for human breast cancer also, and so a study was done looking at "gene expression" of breast cancer tumors. The question asked by the Marshall University (West Virginia) researchers was: Would eating 2 oz (14 halves) of walnuts daily for 2 to 3 weeks have an effect on the breast cancer tumors?

10 post-menopausal women had diagnostic breast cancer tumor biopsies done and then were randomly divided into 2 groups: 1) 5 of the women ate 2 oz of walnuts daily for the 2 to 3 weeks until breast cancer surgery, and 2) the other 5 avoided eating walnuts in the 2 to 3 weeks prior to breast cancer surgery. Otherwise the women ate their normal diets - a Western style diet.

The researchers noted that in the walnut eating group: "gene expression in the tumor was modified in ways expected to slow proliferation, reduce inflammation, reduce metastasis and to increase cancer cell death". The researchers also felt that consuming walnuts would decrease risk for cancer recurrence, and that there may be benefit from walnuts against many cancer types.

The researchers point out that another study published in 2016 (which was a review and analysis of 20 studies) concluded that "nut consumption, including peanuts, was associated with reduced risk of cancer and reduced all-cause mortality" (meaning death from any cause) - which agrees with the results of this study. In the 2016 study the beneficial health effect was for at least 28 grams (1 serving) of nuts per day. Bottom line: Enjoy consuming some nuts daily!

From Medical Xpress: Scientists tie walnuts to gene expressions related to breast cancer

New research from Marshall University links walnut consumption as a contributing factor that could suppress growth and survival of breast cancers.  ...continue reading "Walnuts Have An Effect On Breast Cancer Tumors"

Some good news for women and breast cancer. We are all exposed to endocrine disruptors  around us - such as in personal care items, some household items, some medical devices and medications, plastic raincoats, and vinyl flooring. Phthalates, which are endocrine disruptors, are used as plasticizers in many of these products. We can lower our exposure to phthalates, but can't totally eliminate it. So a big question is: Is exposure to phthalates linked to breast cancer?

Animal and laboratory studies suggest that a number of phthalates have carcinogenic effects (cancer causing), but several retrospective studies of women had mixed results regarding whether higher phthalate levels are associated with breast cancer or not. But now a large study (the Women's Health Initiative) that followed postmenopausal women for 2 decades has found that phthalate levels are not associated with an increased risk of breast cancer.

The 1257 women (average age 62 1/2 years at the start) in the study gave either 2 or 3 urine samples (once a year) during the first 2 or 3 years of the study, and the urine was analyzed for a number of phthalates. Then the women were followed for 19 years. The researchers found some "suggestive associations", but nothing significant. Whew... We can breathe sigh of relief.

However, there are some real problems with the study. While it does not look likely that phthalates have a large effect, smaller associations are possible, which the researchers discuss.

1) One big problem is that phthalates are rapidly metabolized and excreted from the body, so that the levels can vary tremendously from one point in time to another. (Half of phthalate metabolites are excreted in urine within 12 to 24 hours of exposure.) And the researchers did find that "phthalate biomarker concentrations exhibited high within-person variability over a 3 year period".  More urine samples should have been taken from the women - not just one a year for 2 or 3 years. This study did not look at who routinely got exposed to high levels of phthalates and who wasn't. Half of phthalate metabolites are excreted in urine within 12 to 24 hours of exposure. Just having a week with lots of fast food could raise phthalate levels (the chemicals leach in from the packaging). See why only one measurement a year is inadequate?

2) Another big problem is that most of the postmenopausal women - whether with breast cancer or not, were using hormone therapy - in the past or during the study. As the researchers point out: "Because phthalates are far less estrogenic than hormone therapy formulations, it is possible that hormone therapy use may mask any true effect of phthalate exposure on breast cancer risk." 3) And the last big issue to think about is that this study did not look at early life exposures to phthalates, such as during puberty when the breasts are developing. Other studies suggest that exposure to endocrine disrupting chemicals are important during critical periods of life, especially earlier in life (e.g. adolescence). Looking just at phthalate exposure of postmenopausal women may be too late.

According to studies and the CDCalmost everyone in the United States is exposed to phthalates in varying degrees, especially by eating and drinking food and liquid that has come in contact with containers and products containing the chemicals, and by inhaling indoor air that has phthalates in the dust. Adult women tend to have higher exposure to certain phthalates (it's measured in the urine) that are used in soaps, body washes, shampoos, cosmetics, and similar personal care products.  ...continue reading "Breast Cancer and Endocrine Disruptors"

A recently published study was good news for those who eat organic foods. The large French study (about 69,000 people) found a  significantly lower risk of getting cancer (25% lower) in people who ate a lot of organic food - when compared to people who rarely or never ate organic food. The participants in the study were followed for an average of 4.6 years. Cancers with the greatest decreased risk were breast cancer (especially in postmenopausal women) and all lymphomas, especially non-Hodgkin lymphoma.

The researchers summarized the findings as:  "In a population-based cohort study of 68 ,946 French adults, a significant reduction in the risk of cancer was observed among high consumers of organic food." and "...if the findings are confirmed, promoting organic food consumption in the general population could be a promising preventive strategy against cancer." This could be an easy way to cut cancer risk! (Other organic food benefits.)

Of course the pesticide and conventional agriculture industry went nuts attacking the study - this finding goes against their message that pesticides are fine and necessary, don't worry about pesticide residues in food, and that antibiotics and other medicines are safe when given routinely to animals. Unfortunately, research finds that a number of pesticides used in conventional farming are considered carcinogenic (cancer causing), and pesticide residues are found in conventionally grown foods. Eating conventional foods every day results in chronic low-dose pesticide residue exposure. The researchers suspect the pesticide residues in foods is the reason for the higher cancer risk. [Note: those pesticides are not allowed to be used in organic farming.]

What foods did the researchers ask about? They asked people about the consumption of 16 types of labeled organic food products: fruits; vegetables; soy-based products; dairy products; meat and fish; eggs; grains and legumes; bread and cereals; flour; vegetable oils and condiments; ready-to-eat meals; coffee, tea, and herbal tea; wine; biscuits, chocolate, sugar, and marmalade; other foods; and dietary supplements. In other words, all the foods we eat daily.

But what I found really interesting was a review of the study by Dr. Charles Benbrook (Visiting Scholar in the Bloomberg School of Public Health, Johns Hopkins University, and a Visiting Professor at the Univ. of Newcastle in the UK). He correctly points out that the results are big news and a big deal. Excerpts from Environmental Health News:

Charles Benbrook: New study showing organic diets cut cancer risk is a big deal. Let’s treat it that way.      ...continue reading "Lower Cancer Risk By Eating Organic Food?"

There has been a lot of discussion in recent years about whether mammogram screening actually cuts the risk of death, with some studies finding that it does and others that it doesn't (here and here).  It's tricky to figure out because during the last few decades in which more women were screened, there have also been major improvements in breast cancer treatments.

A recent large Danish-Norwegian study came to the conclusion that breast cancer screening (mammograms) does not reduce mortality. Instead, the researchers found that there have been similar reductions in deaths from breast cancer in all women - from both unscreened women and those receiving mammograms (screening) - and this is due to better cancer treatments. From Science Daily:

Breast cancer screening does not reduce mortality

Fewer and fewer women die from breast cancer in recent years but, surprisingly, the decline is just as large in the age groups that are not screened. The decline is therefore due to better treatment and not screening for breast cancer.  ...continue reading "Study Finds Mammogram Screening Doesn’t Reduce Breast Cancer Deaths"

Is the Mediterranean style diet the future in breast cancer prevention? The following study was done in primates, but it makes sense that the results would also be true for humans: that the type of diet eaten influences the breast microbiome. This means the community of microbes that live in the breast. Yes, it's true - studies show that there is a breast microbiome and it varies between those who have breast cancer and those who don't (healthy breasts).

The study looked at macaque monkeys who were fed either a Mediterranean style diet or a Western style diet for 31 months, and then their breast tissue was examined. They found microbial differences in the breast tissue among the 2 groups, including  greater numbers (abundance) of Lactobacillus species in the primates that had been eating the Mediterranean diet.

Lactobacillus species are generally considered beneficial to humans (which is why they are added to many foods and supplements) and studies suggest they may have anti-tumor effects. Some research has found microbial differences between healthy and malignant (cancerous) human  breast tissue  - including lower Lactobacillus numbers or "abundance" in the malignant breast tissue (compared to those with benign breast lesions). Researchers say it suggests that microbial imbalances (dysbiosis) of breast tissue could be a possible driver of breast cancer .

Studies already show that a person's diet influences the gut microbiome. This study shows diet directly influences microbial communities far away from the gut - in the breasts. Unfortunately it is not stated in the study what Lactobacillus species increased in the breast tissue of primates fed a Mediterranean diet. There are many Lactobacillus species, and they are not equal in their effects (as our experiences with Lactobacillus sakei and sinusitis has shown).

Of course more studies are needed, but in the meantime - eat a diet rich in fruits, vegetables, whole grains, legumes (beans), nuts, and seeds. There are many other documented health benefits from a diet rich in those foods (frequently referred to as a Mediterranean diet). The diet is low in processed foods and high in fiber, and rich in "real foods". From Science Daily:

Diet affects the breast microbiome in mammals

Diet influences the composition of microbial populations in the mammary glands of nonhuman primates, researchers report October 2 in the journal Cell Reports. Specifically, a Mediterranean diet increased the abundance of probiotic bacteria previously shown to inhibit tumor growth in animals ...continue reading "Diet And The Breast Microbiome"

A decades long study (from the Harvard T.H. Chan School of Public Health) had results that many women may find reassuring - because there may be something they can do to increase their odds of preventing breast cancer. The study found that women who ate more than 5.5 servings of fruits and vegetables each day had an 11% lower risk of breast cancer than those who ate 2.5 or fewer servings daily.

While the findings support eating a variety of fruits and vegetables, they found that cruciferous (broccoli, cabbage, cauliflower) and yellow/orange vegetables (e.g. winter squash) appear to be especially beneficial in reducing the risk of breast cancer, especially those that are more aggressive tumors. The association between amount of fruits and vegetables eaten daily  and breast cancer appeared to be strongest 8 or more years before cancer diagnosis - meaning fruit and vegetable intake now appears to have effects many years later.

By the way, the researchers found in earlier research that a higher fiber intake (especially during adolescence and early adulthood) was also associated with a lower beast cancer risk. Now let's see if these findings hold up over time in other studies. From Science Daily:

High fruit and vegetable consumption may reduce risk of breast cancer

Women who eat a high amount of fruits and vegetables each day may have a lower risk of breast cancer, especially of aggressive tumors, than those who eat fewer fruits and vegetables, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. In their findings, cruciferous vegetables such as broccoli, and yellow and orange vegetables, had a particularly significant association with lower breast cancer risk.  ...continue reading "Eating Lots of Fruits and Vegetables Associated With a Lower Breast Cancer Risk Years Later"

A recent study published in BMJ (British Medical Journal) found a link between high consumption of ultra-processed food and higher rates overall of cancer, but also a higher risk of breast cancer. Specifically, a 10% increase in the proportion of ultra-processed foods in the diet was associated with a greater than 10% increase of overall cancer and 11% increase of breast cancer during the 6+ years of the study.

Alarmingly (because of the health implications), several surveys (in Europe, the US, Canada, New Zealand, and Brazil) have suggested that ultra-processed food products are now between 25 to 50% of calories eaten every day.

Ultra-processed food is food that is highly processed. It is food that is mass produced and packaged, as well as foods that have manufactured substances in them - such as hydrogenated oils (also contains trans fats), protein isolates, additives, preservatives, artificial or natural flavors, colors, nitrites (in processed meat), titanium dioxide (nanoparticles), etc. The food packaging can leach chemicals such as pthalates (endocrine disruptors). The list goes on and on and on. All of these things in ultra-processed foods may be involved in causing health problems, including cancer. They are typically also poorer nutritionally and higher in salt than unprocessed or minimally processed foods. These ultra-processed foods that are so popular are all around us - in fast food, in mass produced desserts and breads, packaged snacks, soups, cold cuts, margarine, frozen or shelf stable ready to eat meals, instant foods, sodas and drinks, etc.

On the other hand, unprocessed or minimally processed foods are fresh, dried, ground, chilled, frozen, pasteurised, or fermented foods such as fruits, vegetables, legumes (beans), rice, pasta, eggs, meat, fish, or milk. There are also “processed culinary ingredients”  which are salt, vegetable oils, butter, sugar, and other substances extracted from foods and used in kitchens to transform unprocessed or minimally processed foods into "culinary preparations" (meals). The study did NOT find any association with unprocessed, minimally processed, or processed culinary ingredients with cancer. Only with the ultra-processed food. Instead, the study found that higher consumption of “minimally/unprocessed foods” (and lower ultra-processed food) was associated with lower risks of overall cancer and breast cancer.

So an apple is unprocessed, and plain apple sauce made with just apples is minimally processed, while a packaged apple dessert with additives added is ultra-processed. Think of it as "transformed food". Also keep in mind that your beneficial gut microbes like unprocessed or minimally processed food - especially those high in fiber. You know - a diet rich in fruits, vegetables, whole grains, seeds, nuts, legumes (beans).  ...continue reading "Ultra-Processed Food and Risk of Cancer"

This article by academic physician and cancer researcher H. Gilbert Welch about viewing cancers as a barnyard pen of animals (birds, rabbits, and turtles) is a way to explain why some early screening tests haven't really reduced the rate of deaths from certain cancers, such as breast cancer (here and here). Or another way of looking at it is that some cancers are really "bad" and aggressive (birds that have already flown away to distant points at earliest cancer diagnosis), while others are "good" (rabbits or cancers that are slowly spreading and that can be treated, or turtles - that are such slow growing cancers that they would never cause a problem).

Interesting and thought-provoking reading. Excerpts from an editorial by H.Gilbert Welch from Breast Cancer Research and Treatment:

The heterogeneity of cancer

Cancer used to be so simple. It started as a wayward cell that then underwent a stepwise progression: from in situ to local, local to regional and, finally, regional to distant disease. At least, that is what I was taught in medical school…some (gulp) 40 years ago. Narod and Sopik suggest a wildly different paradigm. Local growth and distant metastasis are independent phenomena. Local control of cancer (e.g., efforts to minimize local recurrence) has no effect on its tendency to metastasize. If a cancer is destined to spread to distant sites, it will have already done so.

Call it the “bad cancers are bad” model. Or, alternatively, “good cancers are good.” Oddly enough, in 1955 a cancer surgeon at the Cleveland clinic—George Crile Jr.—foretold this complexity on the pages of Life magazine: In clinical practice to say that a person has cancer gives as little information about the possible course of his disease as to say that he has an infection. There are dangerous infections that may be fatal and there are harmless infections that are self-limited or may disappear. The same is true of cancers. Cancer is not a single entity. It is a broad spectrum of diseases related to each other only in name

..... The conventional model has been that large tumors are more likely to metastasize because they have a large pool of cancer cells to disseminate. Narod and Sopik instead suggest that these tumors became large because they are more aggressive cancers and thus are more likely to metastasize. Large, late-stage, node positive lesions are simply valuable markers for “badness.” The corollary is that small, early-stage, node negative lesions are valuable markers for “goodness.” But not always.

Which brings us to the conundrum of DCIS. It would be simplest if all DCIS was pseudodisease— cancer not destined to ever cause problems for our patients. Most DCIS is pseudodisease, but as Narod documented in earlier work , about 3% of women with DCIS will die from breast cancer in the next 20 years. Over half of these women did not experience an in-breast invasive recurrence prior to death. In other words, bad breast cancers are bad—from the get go.

This phenomenon explains the limited ability of mammography to reduce breast cancer mortality. The lack of value in finding microscopic breast cancers (like DCIS) is one of the least well-recognized findings from the ten randomized trials of mammography. Only one trial addressed this important question, the second Canadian trial ..... Given the finding of no difference in breast cancer mortality between the two groups, the lesson is clear: there is no obvious value to finding breast cancers that are so small they cannot be felt (such as most DCIS).

Overdiagnosis is made possible by cancers at the other end of the spectrum. Overdiagnosis is the detection of cancers that are very good – so good that patients would be better of not having them detected. Overdiagnosis doesn’t limit the ability of mammography to reduce breast cancer mortality—instead it’s a side-effect of the effort.

Such heterogeneity in cancer poses huge challenges for our effort to catch the disease early. It’s been described as the “barnyard pen of cancers” (an analogy that likely originates with Crile). We are trying to catch birds, rabbits, and turtles.

We can’t catch the birds early, because they have already gone—these are the most aggressive cancers, those that have already spread by the time they are detectable. We are able to catch the rabbits—the more slowly progressive cancers— but their earlier detection may not help much, because they weren’t destined to metastasize anyway. And then there are the turtles. There’s no need catch them, because they’re not going anywhere anyway.

H. Gilbert Welch has written extensively about the issue of "overdiagnosis" and resulting  "overtreatment" of cancers. Cancer screening can cause the problem of overdiagnosis (finding small tumors that may never cause problems) and lead to overtreatment (treating unnecessarily, which can cause harm).

But now Welch and coauthor Otis Brawley discuss the issue of how too much screening and diagnostic testing of people thought to be "high risk"  for certain cancers results in more being found - thus the risk factors are "self-fulfilling". And it occurs the most in "scrutiny dependent cancers" - which are cancers that the more you look, the more you find, and the more of what you find is harmless. Many are referred to as slow-growing, indolent, subclinical, or even as precancerous. Prostate cancer, thyroid cancer, breast cancer, melanoma, and  lung cancer are  examples of "scrutiny-dependent" cancers.

Looking so hard and then finding cancer gives a false impression of an increased incidence of some cancers. The authors also said that risk factors in determining  who should be screened should not be cancer diagnosis (e.g. in a family member), but death from cancer. From STAT News:

Too much screening has misled us about real cancer risk factors, experts say

The best-known downside of cancer screening, such as PSA tests for prostate cancer and mammograms for breast cancer, is that they often flag cancers that pose no risk, leading to overdiagnosis and unnecessary, even harmful, treatment. But widespread screening for “scrutiny-dependent” cancers — those for which the harder you look the more you find, and the more of what you find is harmlesscauses another problem, two leading cancer experts argue in a paper published on Monday: increasing the apparent incidence of some cancers. That in turn is misleading doctors and the public about what increases people’s risk of developing cancers — or at least the types of cancer that matter.

“Detecting cancers that would never become apparent is screwing up our understanding of risk factors,” said Dr. H. Gilbert Welch of the Dartmouth Institute for Health Policy and Clinical Practice, co-author of the analysis in Annals of Internal Medicine. The problem is especially clear in prostate, breast, and thyroid cancers, all of which are scrutiny dependent.

Men whose relatives developed prostate cancer are more likely to get PSA and other screening tests, either because they request them or because their physicians, noting their family histories, order them. Men with no such family history are less likely to be screened. .... (More than half of such cancers are so slow-growing that they don’t affect health or longevity.) Men who don’t get screened are less likely to have biopsies and so are less likely to be diagnosed with prostate cancer — not because they develop the disease at a lower rate but because they get screened at a lower rate. What you don’t look for, you don’t find.

“If we biopsied men without a family history of prostate cancer at the same rate that we biopsy men with a family history, we’d find more prostate cancer in them as well,” Welch said. “Family history influences how hard we look for prostate cancer and therefore how much we find. The risk factor becomes a self-fulfilling prophecy.”

2016 study of increased prostate cancer screening in men with a family history of the disease concluded that the risk due to family history has been overestimated by nearly half. “The risk factor of family history is spuriously strengthened because men with a family history are exposed to greater scrutiny,” write Welch and Dr. Otis Brawley, chief medical officer of the American Cancer Society, in the Annals report.

Wealthier, better educated women are, however, more connected to the health care system and therefore get more mammograms, breast ultrasounds, and MRIs. The more scrutiny, the more likely that harmless cases of breast cancer are found. (The idea of “harmless” breast cancer sounds like an oxymoron, but an estimated one-half of breast cancers detected by screening would never cause problems even if undetected and untreated.)

Breast tumors found by imaging are much more likely to be harmless than those discovered by women or their physicians finding a breast lump. Income and education are therefore less likely to be a true risk factor for breast cancer and more likely to be a “risk factor” for undergoing screening. If poorer, less educated women were screened for breast cancer at the same rate as wealthier, better educated women, the socioeconomic risk factor would likely vanish.

Thyroid cancers are also scrutiny dependent, which is why when countries launch screening programs the incidence of the disease skyrockets (but death rates don’t, showing that what’s being found is a false epidemic). 

Welch and Brawley call for less focus on risk factors for developing cancers, since those numbers both determine and reflect who gets screened, and more on risk factors for death from cancer.

Prostate cancer is something that men worry about, especially because it is the most common cancer in men, and because it can take several forms. On one hand, a tumor can be "indolent" or so slow growing that it just needs to be monitored, or sometimes it can be very aggressive and even lead to death. That's why the possibility of a dietary pattern (what a person eats) having an effect on the cancer's progression or aggressiveness is very exciting - if true, it would be something people could do to improve their prostate cancer outcome. Or perhaps even prevent it in the first place. Studies up to this point have been mixed, with no clear results.

A recent large study conducted in Spain found that those men with prostate cancer who had a high adherence to a Mediterranean diet had a lower risk of aggressive prostate cancer, as compared to those following a typical Western diet (large amounts of fatty dairy products, refined grains, processed meat, caloric beverages, sweets, fast food, and sauces) or a Prudent diet (low-fat dairy products, whole grains, fruits, vegetables, and juices). A Mediterranean dietary pattern is rich in fruits and vegetables, and also fish, legumes, boiled potatoes, olives and olive oil, vegetable oils, and a low intake of juices.

The researchers also discussed that there are many similarities with breast cancer and prostate cancer, including risk factors. They found in an earlier study in Spain that eating a Western diet is associated with breast cancer risk, the Prudent diet is not associated with breast cancer, and the Mediterranean diet seems to be protective for breast cancer. From Medical Xpress:

A more complete Mediterranean diet may protect against aggressive prostate cancer

In a new study published in The Journal of Urology, researchers determined that men who followed a Mediterranean diet, rich in fish, boiled potatoes, whole fruits, vegetables, legumes, and olive oil, and low consumption of juices had lower risk of aggressive prostate cancer (PC) than those who followed other dietary patterns like Prudent or Western diets. ..."Our results show that a diet oriented towards the prevention of aggressive tumors in the prostate should probably include important elements of the Mediterranean diet such as fish, legumes, and olive oil, and suggest that a high intake of fruits, vegetables, and whole grains might not be enough."

The authors explored the relationship between the risk of having PC and dietary patterns as part of the MCC-Spain study, a Spanish case-control study that involved 733 patients with histologically confirmed PC and 1,229 healthy men with a mean age of 66 years from seven Spanish regions. Anthropometric, epidemiologic, and dietary data were collected.

Adherence to the three dietary patterns of Western, Prudent, and Mediterranean, which characterize the dietary habits of the Spanish population, was evaluated, The Western [dietary] pattern includes consumption of large amounts of fatty dairy products, refined grains, processed meat, caloric beverages, sweets, fast food, and sauces. The Prudent pattern involves consumption of low-fat dairy products, whole grains, fruits, vegetables, and juices. Finally, the Mediterranean pattern consists of high consumption of fish, boiled potatoes, fruits, vegetables, legumes, and olive oil, and low consumption of juices. The diets were graded according to the degree of adherence to each pattern and assigned to four quartiles from lower to higher adherence within each pattern.

Only a high adherence to Mediterranean dietary pattern appeared to be associated with a lower risk of aggressive PC. Prudent and Mediterranean dietary patterns showed different effects in low and high grade tumors. 

PC was assessed using Gleason scores of tumor aggressiveness (<6 or ?6) and clinical stage (cT1b to cT4). A Gleason score of <6 typically indicates a less aggressive tumor with generally good prognosis. Lower clinical stage (cT1-cT2a) indicates a tumor that has not spread. Results indicated that for more aggressive and more extensive tumors (Gleason >6 and stages cT2b to cT4), only high adherence to the Mediterranean diet showed a statistically significant protective effect. All other dietary patterns and tumor characteristics showed little or no correlation and did not achieve statistical significance. [Original study.]