SCIENCE FRIDAY FOR ATHLETES: APPLE 'CORE' STRENGTHS AND BENEFITS OF ORGANIC

FIJI APPLES BY SCOTT BAUER, USDA https://commons.wikimedia.org/wiki/File:Fuji_apple.jpg (not the apple used in the study)

THE HUGE MEDIA FANFARE GENERATED FROM A NUTRITION STUDY ON INTERMITTENT FASTING a few days ago overshadowed the July 24, 2019 release of results from an Austrian study which examined the potential gut microbiome benefits of apple core eating in conventionally- versus organically-managed apples. Bacteriologically, it seems eating a whole raw apple, including the core, seeds, and little flowery end (calyx), beats the heck out of eating just the yummy flesh and skin.
 
Before reading a “Frontiers News Science” blog piece that discusses the research and quotes the study’s senior author, or the much longer original scientific publication in the journal Frontiers in Microbiology, understanding the differences between the two types of apple-growing “management” systems is helpful.
 
According to the publication, harvested organic apples originated from an orchard “which follows the international ‘demeter’ guidelines of organic farming “using sterile gloves and instruments”.  Harvested conventional apples originated from a conventional orchard and had been cold-stored, short-term in a controlled atmosphere, and “washed and wrapped in polythene sheets for sale.”  During the study all apples were handled in an identical manner.
 
The research showed that highest numbers of bacteria in each type of apple were found in its seeds, the next highest in flesh (pulp), and the least in peel.  Conventionally- and organically- managed apple bacterial numbers were roughly equal, about 100 million in a 240-gram apple.
The blog article reported that by not eating the core, the bacterial number consumed falls to about 10 million, roughly 9-10 times less.
 
The other highlight covered by the Frontiers News Science blog concerned bacterial strain diversity; it was greater in those handled as organic fruit than fruit processed in the conventional manner. Higher diversity, senior author Professor Gabriele Berg of Graz University of Technology was quoted as saying, is “expected to limit overgrowth of any one species, and previous studies have reported a negative correlation between human pathogen abundance and microbiome diversity of fresh produce.”
 
Study results were supportive of this thinking, which showed that “Escherichia-Shigella – a group of bacteria that includes known human pathogens—was found in most of the conventional apple samples”, although in low abundance. This bacterial group was absent in the organic apples.  Conversely, the famously beneficial pro-biotic Lactobacillus microbes were found in organic but not in conventional apples.
 
Important points made by the two sources:
To consume the most bacteria, eat a whole raw apple, including core, which contains seeds

• Apple seeds contain the highest number of bacteria of all the other apple tissues
• Organic apples have twice the number of seeds as conventional apples

To take in the greatest diversity of beneficial microbial strains choose organic apples

• Bacterial strain diversity in organic apples- which includes Lactobacilli- is highest in the fruit’s pulp, next peel and stem, then stem end, followed by seed and calyx end.
• Bacterial strain diversity of conventional apples - which includes the Escherichia-Shigella group-is highest in fruit peel, next stem, then stem end, then fruit pulp. followed by calyx end, and finally seeds.

 
Also mentioned in the blog piece was information concerning possible taste differences between organically- and conventionally-managed produce. Certain bacteria known to synthesize compounds which impart a strawberry flavor were found to be “significantly more abundant in organic apples” in the study, “especially on peel and flesh samples.”
 
The findings from this investigation definitely have been placed in my “Good-To -Know” file, which will likely influence future eating and shopping decisions.  I thought the only food sources of Lactobacilli were dairy and fermented foods but a bit of digging into the topic indicates some species occur in the environment and on plants and may be responsible for fermentation that occurs in spoilage of fruit juices.  [Anyone knowledgeable on the subject, please enlighten us further!]
 
How does this nutrition science relate to athletics and fitness? Apples are a portable carbohydrate/energy source that don’t require special storage.  The fruit’s fiber  and nutrient content make it  Knowing that types of bacteria scientists believe are beneficial to the gut microbiome can be so easily obtained can make a post work-out snack choice easier, especially when packing food is necessary.
 
In the fall, when MacIntosh apples first ripen and come directly from the orchard to store, they are my very favorite fruit.  I’ve eaten the whole apple for years to avoid disposing of the core later; plus, I like the crunch of the seeds.
 
The results of this study also mean that it can be worthwhile to seek out organic apples or at least those offered at established roadside stands and farm market vendors. That the organics may indeed be tastier encourages spending extra on this fruit item.
 
RUN & MOVE HAPPY!
 
NOTES:

1.  The apple used in the research is the modern Austrian “Arlet”, developed in Switzerland in the 1950’s but patented in 1989 as a cross between a Golden Delicious and Ida Red; also known as a “Swiss Gourmet.” It does not seem to be widely available in the United States. Possibly the results reported from the investigation of this particular cultivar in this region of the world will change with apple variety and location.
2. The Lactobacilli bacteria discussed in the original research publication seem to have been identified in samples as Firmicutes (Phylum) by “CLSM in combination with FISH”.  2https://www.frontiersin.org/files/Articles/475179/fmicb-10-01629-HTML-r1/image_m/fmicb-10-01629-g007.jpg

 
https://blog.frontiersin.org/2019/07/24/microbiology-apples-bacteria-organic-microbiome/
 
https://www.frontiersin.org/articles/10.3389/fmicb.2019.01629/

https://www.sciencedaily.com/releases/2019/07/190724090255.htm
 
https://www.sciencedaily.com/releases/2014/03/140310090919.htm
 
https://www.forbes.com/sites/alicegwalton/2019/07/25/the-100-million-bacteria-on-apples-may-be-key-to-their-health-benefits/#44bfb03c1e2f
 
https://www.orangepippin.com/varieties/apples/arlet-swiss-gourmet
 
https://healthyeating.sfgate.com/foods-containing-lactobacillus-bifidobacterium-3728.html
 
https://en.wikipedia.org/wiki/Firmicutes
 
http://www.medibiztv.com/articles/spoilage-of-fruit-juices
 
https://aem.asm.org/content/aem/16/9/1326.full.pdf
 
https://commons.wikimedia.org/wiki/File:Fuji_apple.jpg (not the apple used in the study)
Scott Bauer, USDA ARS [Public domain]