Fuji Apples and Weight Gain
September 02, 2024Fuji Apples and Weight Gain
It's the ursolic acid. Apples have it, but it is mostly in their peel. The societal cost of obesity keeps rising and attempts to understand how to contain that increasing rise have been stymied because of lack of understanding. Eating "more fruits and vegetables" isn't specific enough for many. This week's paper on Fuji apples is in that line of research. Apples are versatile, long-lasting, and inexpensive. They are now in season and are at their peak of quality and ripeness.
Ursolic acid is found in all apples, to a varying degree. The problem arises with long-term storage. To avoid spoilage very cold (33 degrees) and low oxygen (2-4% vs normal 21%) and high CO2 atmospheres are used, with loss of apple mass reduced dramatically with those strategies. Interestingly enough, it is a robust topic of study as different varieties need different storage strategies. The content of different species of ursolic acid varies as well from 0.45 mg g−1 to 3.52 mg g−1. That's an almost 10-fold variability. The variety called Spartan is the highest, with Cortland the lowest. Ursolic acid makes up some 70% of the antioxidant compounds in apples. The peel has 41% of it, with only 10% of the apple mass.
What is it about ursolic acid that helps with obesity? That's the nugget we are interested in. How is it better than Ozempic (and all the knockoffs), other than the $ 750 per month price tag? That's what this particular research was about. This is one of the many articles beginning to appear investigating the specifics of food contents in their relation to health issues. This particular one was looking at obesity and ursolic acid in apples, Fuji in particular (the dominant apple in Korea where the study was done).
In Korea, the WHO (World Health Organization) recommends that folks eat 400 grams of fruits and vegetables a day. No one does. In America, the FDA is our authority and recommendations are likewise ignored. The average American eats 1/2 a serving of vegetables a day, but only if french fries are included as vegetables. That makes potatoes #1. Pizza with its tomatoes and hamburgers with ketchup make tomatoes the number two vegetable. Possibly not in the best nutritional form. The Chinese and Croatians are the champion vegetable eaters at around 1 kilo per day.
But back to ursolic acid. It appears to lower triglycerides by about 25%. That reduces triglyceride storage, which means less fat gain. Pretty basic first pass. There is no explanation of what metabolic pathway is interrupted or redirected. The conclusion that apples help reduce fat storage because of their ursolic acid content may be a little premature, but the pattern fits.
I suspect the effect of volume of food in a whole apple, the fiber in the peel and apple, and the time spent eating all also play a part. All fruits and vegetables also tip you to a slightly alkaline balance. Who cares. Apples are a great food and if we can talk you into eating more, that's good. If it replaces a hamburger on a white wheat bun, I suspect you are better off.
www.What will Work for me? I'm having fun buying any variety of organic apples I can find. There appear to be more kinds and I want to encourage those farmers willing to diversify and grow new varieties. They just have to be organic. And I wash them as soon as I get home.
References: Food, Molecule, World Pop Review,
Pop Quiz
1. What is it in apples that provides their extra metabolic kick? Answer: Ursolic acid is the 70% active form.
2. Are all apples the same for ursolic acid content? Answer: No, up to a 10-fold difference. If you can find Spartans, they are the best,
3. What does ursolic acid do that appears to be the key benefit? Answer: Inhibits triglyceride accumulation and uptake.
4. Do we know the mechanism of that inhibition? Answer: No, not yet
5. Where is the ursolic acid found in the apple? Answer: Mostly in the peel.