Contents
What it is
The apple is the fruit of a tree in the rose family. It originated around the Tian Shan mountains of Central Asia and is now grown across the temperate world. There are thousands of varieties, and they differ widely in sweetness, acidity and crispness — Fuji is the most common in Korea, while sharper varieties hold up better to cooking. Most of the fibre and pigment sits in the skin, so apples are usually washed and eaten unpeeled. Cut surfaces brown quickly, which salt water or lemon juice slows.
Scientific name Malus domestica
An apple's nutrition is concentrated at its surface. Most of the polyphenols, quercetin among them, and a large share of the fibre sit in the skin and just beneath it.
A peeled apple loses more than a third of its fibre and considerably more of its antioxidant capacity. "An apple a day" only works with the skin on.
Key benefits
- Moderate evidence
Pectin moderates cholesterol and blood sugar
Apple's soluble fibre binds bile acids in the gut and increases their excretion, which nudges LDL cholesterol down. It also slows the rate at which sugars are absorbed.[1]
- Nutrition data
It feeds your gut microbes
Pectin reaches the colon and is fermented into short-chain fatty acids. Studies report shifts in gut bacterial composition with regular apple intake.
- Early research
Polyphenols support vascular function
Quercetin and catechins concentrate in the skin. Small trials find improved endothelial function in people eating apples consistently.[2]
- Moderate evidence
High satiety for the calories
In one trial, 58 adults ate a preload of apple, applesauce or apple juice — matched for weight, calories, energy density and even eating rate — then had lunch freely. On the whole-apple day they ate 15% less at lunch (187 kcal), and fullness ranked apple > applesauce > juice. Adding the fibre back into juice did not raise satiety. What made the difference was solid versus not, more than fibre itself.[3]
How to eat it well
- Eat the skin. Scrubbing under running water is enough.
- To stop cut slices browning, dip them briefly in lemon juice or salt water.
- Whole beats juice. Juicing strips out most of the pectin and raises blood sugar faster.
- Cooking keeps the pectin. Baked apple is gentler on a sensitive stomach.
- Seeds contain small amounts of cyanogenic glycosides, so do not deliberately chew them.
How to read the grades
Each benefit carries a label showing how far research on people supports it. Grades differ between items even within the same ingredient.
- Nutrition data
- A fact verifiable from food composition databases or health authorities. This is a different kind of statement from a clinical effect.
- Strong evidence
- Consistently confirmed across randomised controlled trials or meta-analyses.
- Moderate evidence
- Human studies exist, but effect sizes are small or results are mixed.
- Early research
- Cell or animal work, or small preliminary studies.
- Not established
- Commonly claimed, but not confirmed in studies on people.
What to watch out for
- Seeds contain amygdalin, so avoid chewing large quantities of them. A few swallowed whole are not a problem.
- In irritable bowel syndrome, fructose and sorbitol can trigger symptoms.
- With birch pollen allergy, raw apple can cause oral allergy syndrome. Cooking usually resolves it.
- The acidity means brushing immediately after eating can damage enamel — wait 30 minutes.
Nutrition
Approximate values per 100 g edible portion.
- Calories
- 52 kcal3%
- Carbohydrates
- 13.8 g5%
- Fiber
- 2.4 g9%
- Sugars
- 10.4 g
- Protein
- 0.3 g<1%
- Vitamin C
- 4.6 mg5%
- Potassium
- 107 mg2%
Percentages are of the US FDA Daily Value for adults and children 4 and over. National reference intakes differ by sex and age.
Calculate this alongside other ingredients →
Key nutrients
By health concern
Dishes with this ingredient
Compare with
Sources
The databases and health authorities this article's nutrition figures and health statements draw on.
- 1Two apples a day lower serum cholesterol and improve cardiometabolic biomarkers in mildly hypercholesterolemic adults: a randomized, controlled, crossover trialClinical trialKoutsos A, et al. Am J Clin Nutr 2020PMID 31840162
- 2Flavonoid-Rich Apple Improves Endothelial Function in Individuals at Risk for Cardiovascular Disease: A Randomized Controlled Clinical TrialClinical trialBondonno NP, et al. Mol Nutr Food Res 2018PMID 29086478
- 3The effect of fruit in different forms on energy intake and satiety at a mealClinical trialFlood-Obbagy JE, et al. Appetite 2009PMID 19110020
- 4USDA FoodData CentralFood composition database
- 5NIH Office of Dietary SupplementsHealth authority
- 6PubMedResearch literature
