cancer risk lower with organic foods; and lots of fast food consumption in US

2 articles: one on the lower incidence of cancer with organic foods. the other a CDC report on the quite high levels of fast food consumption in the US

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A recent population-based prospective cohort study found that those eating more organic foods had a decreased overall risk of cancer (see cancer risk dec with organic food jamaintmed2018 in dropbox, or doi:10.1001/jamainternmed.2018.4357​)

Details:

-- 68,946 participants provided information for 16 products, including the consumption frequency of labeled organic foods, from 2009 to 2016. Study done in France, assessing the large-scale French NutriNet-Sante cohort, a web-based prospective cohort study looking at the association between nutrition and health.

-- 78% female, mean age at baseline 44 years

-- those in the lowest quartile of organic food consumption include: people employed as manual workers, retired, or students; those with less than a high school diploma, those with lower monthly income, those with more physical activity, current smokers, those with higher BMI, and those who eat more processed meat, red meat, less fiber, fewer vegetables/fruits/nuts/legumes/micronutrients/poultry/milk and overall higher energy intake, and those on oral contraceptives

-- follow-up 4.6 years

Results:

-- 1340 first incident cancer cases were identified in follow-up (controlling for age, sex, occupational status, educational level, marital status, monthly income, physical activity, smoking status, alcohol intake, family history of cancer, BMI, height, energy intake, fiber intake, processed meat and red meat intake, and parity (for women)

    -- 459 breast cancers, though only differences in post-menopausal cancers reached statistical significance, with 34% decrease, HR 0.66 (0.45-0.96), p=0.03

    -- 180 prostate cancers, nonsignficant (though there were 60 in quartile 1 decreasing progressively to 28 in quartile 4 which had the highest organic food consumption; not sure what to make of this lack of significance, no comment in paper or supplementary materials)

    -- 135 skin cancers, almost significant 37% decrease, HR 0.63 (0.38-1.05), p=0.06

    -- 99 colorectal cancers, nonsignificant

    -- 47 non-Hodgkin’s lymphomas, marginally significant 86% decrease, HR 0.14 (0.03-0.66), p=0.049

    -- 62 total lymphomas, significant 76% decrease, HR 0.24 (0.09-0.66), p=0.02

-- high organic food scores were inversely related with risk of cancer, with hazard ratio for quartile 4 vs quartile 1: a 25% decreased risk, HR 0.75 (0.63-0.88), p=0.001 for trend.

    -- Absolute risk reduction: 0.6%

    -- hazard ratio for a 5-point increase in cancers (1/2 of the interquartile range of organic food consumption) was 0.92 (0.88-0.96) [ie, an 8% increase with each ½-quartile decrease in organic foods consumed]

--subgroup analysis: subgroups on high organic diet, with the most cancer benefit:

    --women (28% decreased risk, HR 0.72(0.59-0.88)

    --BMI: a graded response, all significant. BMI>30 had 43% decreased risk, HR 0.57 (0.35-0.93); BMI 25-30 had 34% decrease, HR 0.66 (0.48-0.90);  BMI <25 had 19% decrease, HR 0.81 (0.66-0.99)

    --family history: positive fam history of cancer associated with 29% decrease in high organic food diet, HR 0.71 (0.56-0.89)

    --age: those > 44yo had 29% decreased risk, HR 0.71 (0.59-0.86)

    --smoking history: former smokers had 29% decreased risk, HR 0.71 (0.55-0.92)

     --diet: both the lower quality and the medium quality diets were associated with decreased cancer in those on higher organic food diets, with 32% and 26% decreases; HRs of 0.68 (0.49-0.93) and 0.74 (0.55-0.99), respectively

Commentary:

-- one of the benefits of organic foods is they do not allow synthetic fertilizers, pesticides, and genetically modified organisms, and also restrict the use of veterinary medications/antibiotics

-- a European Food Safety Authority report in 2018: 44% of conventional foods had one or more quantifiable pesticide residues, vs 6.5% of organic samples

--there are some important concerns with regard to this study:

    -- there may well be a significant preselection bias. People who eat organic foods may also be more health conscious in many other ways (eg, were there differences in the non-organic foods consumed? quality or quantity of exercise done?), and this may not be accounted for in the modeling for the study.

    -- There are rather large issues about access to organic foods (e.g. in rural areas and the inner cities, in particular), as well as the large differential in cost

    -- these data are derived largely from self-administered questionnaires, which might have an inherent bias. Diet was assessed by three 24-hour records, randomly allocated over 2 weeks.

    --the study had a pretty short time-scale of 4.6 years. A longer study in this young cohort would likely have yielded a higher association with cancer, given its typically slow initial growth.

    -- but, the real overriding issue is with the potential oncogenic effects of environmental toxins/herbicides/insecticides/fungicides/etc. and, this issue is highlighted by the fact that several highly prevalent and potentially fatal cancers are not effectively cured by early detection, including breast (see http://gmodestmedblogs.blogspot.com/2014/01/mammography-concerns-update.html ​ ) and prostate cancers (see http://gmodestmedblogs.blogspot.com/2018/05/psa-screening-recs-from-uspstf.html ). and even if they were, prevention is better than early detection and treatment. For example, in these tumors there may well be a role for environmental compounds with hormonal effects, such as the estrogenic effects of BPA’s or PCBs, etc. And several pesticides (malathion, terbufos, and diazinon) are associated with a 22% increase in non-Hodgkin’s Lymphoma. Unclear what the specific mechanisms are, but likely structural changes in DNA as well as epigenetic changes (see http://gmodestmedblogs.blogspot.com/2018/10/ace-inhibitors-may-inc-lung-cancer-risk.html​ , where i comment on the many social determinants of health)

    -- and, as noted in this last blog, thousands of new chemicals are being introduced by industry yearly, yet extremely few are rigorously tested for health consequences. Most are deferred to industry to monitor and, not so surprisingly, this is not done much (a bit of a conflict of interest)

-- of note, natural pesticides used in the European Union have much lower toxic effects than synthetic pesticides in conventional farming

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the CDC just released a report on fast food consumption in US adults from 2013-16 based on data from the National Health and Nutrition Examination Survey (see https://www.cdc.gov/nchs/products/databriefs/db322.htm​ ).

Findings:

--36.6% of adults consumed fast food on any given day

--The percentage of adults who consumed fast food decreased with age: 44.9% aged 20–39, 37.7% aged 40–59, and 24.1% aged 60 and over (the same pattern for men and women)

-- A higher percentage of non-Hispanic black adults (42%) consumed fast food than non-Hispanic white (38%), non-Hispanic Asian (31%), and Hispanic adults (36%).​

-- The percentage of adults who consumed fast food increased with increasing family income, form 32% with <130% of federal poverty level (FPL) to 36% between 130-350% of FPL to 42% if>350% of FPL.​

-- Among those who consumed fast food, men were more likely than women to eat fast food at lunch, but women were more likely to report eating fast food as a snack​

so, this all really brings up the big-picture social issues commented on in yesterday's blog (see http://gmodestmedblogs.blogspot.com/2018/10/ace-inhibitors-may-inc-lung-cancer-risk.html​ ). we are in a society which regularly puts the profits of the few running large corporations over the health of the population. we are exposed to too many chemicals with unknown (and some even with known) adverse effects on the human body (and also animals, plants...). our whole ecology has changed dramatically to now having pretty polluted water, soil, air etc. And this is all part of our food chain. we are spending lots of time and money figuring out ways to combat the resulting ill health effects. the US, unfortunately, is behind most other countries in identifying this as a problem and trying to figure out solutions. for example, it is pretty remarkable that more than 1/3 of US adults consume fast-food daily, per the CDC. Not surprisingly, obesity (and its attendant consequences) is endemic here. And, often the finger is pointed at the individual with the poor outcomes (“after all, you did eat too many McDonald’s hamburgers…”)

The issue is that our social environment is leading to most of our chronic diseases. The article on organic foods provides some evidence that cancer is a not-so-surprising outcome of environmental toxins. And there are very real effects on us, with the attendant morbidity and mortality. In a more equitable society, there would be fixes to prevent this (perhaps including the natural pesticides used in some European farming). These fixes might be quite expensive, but so is our current solution of high priced health care with medications that are not only remarkably expensive (especially when one enters the realm of oncology drugs) and variably effective, but themselves may create significant morbidity/mortality (including the increasing the psychological morbidity of decreased self-efficacy, dependence, self-esteem, etc). it is pretty clearly important that we move to a more healthy and sustainable future, doing whatever we can to change our current situation.​

As the renowned pathologist Rudolf Virchow wrote in 1879: "Don't crowd diseases (epidemics) point everywhere to deficiencies of society?"​

geoff

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