Are we eating apples wrong? An ABC news headline reads, “If you aren’t eating the whole apple, you might be eating it the wrong way, a study finds.” This reporting is based on this study, which is a comparison of the bacterial content of different parts of apples, and comparing organically grown to conventionally grown apples. The study found that there was a different bacterial composition between the conventional and organic apples, and that the core and seeds of the apples contained about 10 times the bacteria as the flesh. The authors also conclude:
“Moreover, organic apples conceivably feature favorable health effects for the consumer, the host plant and the environment in contrast to conventional apples, which were found to harbor potential food-borne pathogens.”
All the usual problems I often complain about are present with this conclusion, starting with the fact that it is absolutely not justified by the actual data. First, this is a small preliminary study, of the sort that the media should not even report on. At best this type of study can generate a hypothesis to be tested. The researchers compared a grand total of four apples each from two orchards, one organic and one conventional. Right there you can probably see the problem.
All the apples were of one cultivar, so we cannot generalize the findings to other cultivars. But even worse, only two orchards were compared. Even if you sampled a thousand apples from each orchard, you are still only comparing two orchards. Elisabeth M Bik, a microbiota researcher, already commented on the study, pointing out that –
For example, the orchards could also have different sun exposures, soil characteristics, age of trees, harvesting techniques and storage conditions, etc. These are all parameters that are not associated with organic vs conventional farming, but that could still have a big impact on the microbiome composition.
Exactly. There are many variables, and absolutely no way for the researchers to isolate the organic farming as the one variable that correlates with the changes they saw. Even worse, and I have no idea why they did this, the organic apples were picked and sampled fresh, while the conventional apples were stored in plastic prior to examination. Why introduce another variable like that? Bacterial populations are certain to change over time after harvesting, and based on storage conditions. So – do I have to say it – this study was not comparing apples to apples while they were comparing apples to apples.
So essentially the results of this study are uninterpretable when it comes to organic vs conventional apple growing.
Further still, the authors try to draw conclusions about the favorable health effects of consuming the bacterial species in the organic apples vs the conventional ones. The problem here is that existing data absolutely do not support any such conclusions. While there is active research into the use of probiotics, this research remains preliminary and the benefits so far have been extremely modest. There are really only two conditions for which there is reasonable evidence of benefit, and even here the benefits are highly limited- antibiotic associated diarrhea (AAD), and irritable bowel syndrome.
Regarding AAD, here is a very recent summary of the research from the NIH:
Both Lactobacillus rhamnosus GG and Saccharomyces boulardii have been shown to reduce the risk of AAD. In a systematic review and meta-analysis of 12 RCTs with a total of 1,499 children and adults, treatment with Lactobacillus rhamnosus GG (4 x 108 to 12 x 1010 CFU) compared with placebo or no additional treatment for 10 days to 3 months reduced the risk of AAD in patients treated with antibiotics from 22.4% to 12.3%. However, when the 445 children and 1,052 adults were evaluated separately, the difference was statistically significant in children only. Although the optimal dose of Lactobacillus rhamnosus GG is unclear, 1 to 2 x 1010 CFU/day reduced AAD risk in children by 71%. Taking probiotics within 2 days of the first antibiotic dose is more effective than starting to take them later.
So basically if you are a hospitalized child and you start high colony count probiotics with lactobacillus within 2 days of starting certain (not all) antibiotics, it may reduce your risk of AAD. Otherwise no benefits for AAD have been statistically significant. For irritable bowel syndrome, the research remains preliminary but meta-analyses show a possible modest benefit. Other potential benefits are being studied but the data is too preliminary to make recommendations.
But, here is the key – there is no evidence, and no plausible mechanism, that healthy subjects routinely taking probiotics is of any general health benefit. Your GI system is colonized with a stable ecosystem of bacteria comprising about 100 species. Adding new bacteria to that ecosystem has little to no effect. That’s actually the point – those bacteria crowd out any new bacteria as a layer of protection against all those millions of bacteria we consume every day in our food.
Therefore, the bottom line is that there is absolutely no reason to think that there is any health difference between consuming different kinds of apples loaded with different species and amounts of bacteria. This study does not alter that conclusion, and the reporting of this study is highly misleading and irresponsible.
And don’t eat the apples seeds. They contain amygdalin, which is converted into cyanide with digestion. For an average weight person, you would have to eat about two cups of ground apples seeds for a fatal dose, but a smaller does can make you sick and cause symptoms like headaches. So there is no risk from a single apple, but keep in mind what some reporting is suggesting – regularly eat apples and consume the core with seeds. As I stated, there is no proven health benefit to this, and the dosage of cyanide from the seeds can start to add up.
In the end this is another poor study that doesn’t really show anything conclusive, but it is presented to promote a narrative, that organic produce is more healthful than conventional produce. Over half a century of research, however, has failed to demonstrate any clear health benefit to organic food, yet that is the number one reason people choose it and pay more for it. Terrible reporting about studies like this is a major reason.
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