Apple vs Guava - Health impact and Nutrition Comparison

Introduction

We’ve all heard about the many benefits that apples have on health. Here, we will talk about how the guava compares to an apple and how exactly the two affect the human organism.

Guava is a common tropical fruit, believed to be native to southern Mexico and Central America. Since then it has spread throughout warm areas of tropical America and later to the rest of the world, in areas with warm climates, such as Spain and Portugal, some Mediterranean countries and India (1). Today India is the largest producer of guavas in the world. Guavas belong to the Myrtaceae family and the Psidium genus. 

Apples, on the other hand, originated in Central Asia and have quickly spread to all corners of the world. Nowadays China is the largest producer of apples (2). Apples are a part of the Rosaceae family and the Malus genus. 

Apples and guavas are often the same size and shape, however you can clearly tell them apart judging by guavas outer rind that is similar to a lemon. 

The most commonly used species of guava, that is often what we think about when we say guava, is the apple guava, scientifically named Psidium gujava. In many parts of the world guava is cheaper than an apple, consequently it gained the nickname “a poor man’s apple”, being cheaper but more nutritious.

Nutrition

Guava fruits contain more calories, more protein and fats. Guava also has a slightly higher concentration of carbohydrates due to its fiber content, even though apples contain more sugar and starch. Both fruits do not contain trans fats.

In a protein quality breakdown, guava’s protein contains all essential amino acids except phenylalanine. Apples lack not only phenylalanine, but also tryptophan, isoleucine, leucine and methionine.

A single serving of apples is one cup full of chopped apples that is equivalent to 125 grams. One serving of a guava is one whole fruit that weighs 55 grams on average. 

Since guava contains more of all macronutrients, between the two, apples are recommended during low calorie, low fats, low carbs and low glycemic index diets.

Vitamins

Guavas have a higher concentration of all vitamins, especially vitamin A and vitamin C, when compared to apples. Guava is also richer in vitamin E, vitamin K and vitamins B1, B2, B3, B5 and B6.

Both fruits do not contain vitamin D, vitamin B9 and vitamin B12.

Minerals

Guava is aslo much richer in all minerals, including iron, calcium, potassium, magnesium, copper, zinc and phosphorus. 

Apples contain a lower concentration of sodium by half.

Health Impacts

Apples have been considered as an essential part of a healthy diet for centuries, consequently sayings have arrised in the language such as “An apple a day keeps the doctor away”. Guavas have also been known to be used in traditional medicine. 

Here we will discuss mechanisms of action of those effects on health.

Cardiovascular Health

Foods rich in vitamin C can lower the risk of heart disease. Guavas are particularly rich in this vitamin. Vitamin C has powerful antioxidant, fibrinolytic properties. It also lowers low density cholesterol and promotes excretion of cholesterol through the bile (3). 

Other studies have found guava fruit and guava leaf tea to have hypoglycemic and hypotensive activities (4). Increased consumption of guava fruit can cause a substantial reduction in blood pressure and blood lipid levels (5). 

Epidemiological evidence suggests that apples, as a rich source of flavonoids, as well as polyphenols, can ameliorate cardiovascular risk factors such as dyslipidemia, endothelial dysfunction and inflammation. Apple consumption is associated with a reduced risk of coronary heart disease and total cardiovascular disease mortality (6).

Diabetes

Multiple studies have found that guava leaf extracts exert antidiabetic, antihyperglycemic and antihyperlipidemic qualities (7). This effect can potentially be explained by the inhibition of protein tyrosine phosphatase 1B (8), that can function as a negative regulator of insulin and leptin signal transduction. Guava leaf teas are overall recommended to patients with type 2 diabetis mellitus (9).

A study has shown that apple juice consumption daily can have significant effects on plasma concentrations of glucose, insulin, gastric inhibitory polypeptide (GIP) and glucagon-like peptide (GLP1), potentially due to its phloridzin and polyphenol content (10). 

Apple polyphenol extracts exhibited an insulin sensitizing effect, activating glucose transport through translocation of glucose transporter 4 (GLUT4), mediated by phosphatidylinositol 3-kinase (PI3K) and peroxisome proliferator-activated receptor-gamma (PPARγ) signaling pathways in muscle cells (11).

Allergies

Both fruits can be the cause of allergies.

Apples are one of the most prevalent and best described allergens among fruits. Allergic reaction to an apple can be expressed in two ways, depending on the allergen type of an apple. The two types of allergens within an apple are heat-labile birch pollen allergens and the heat-stable allergen that is located under the skin of the apple. The birch pollen allergen usually causes milder symptoms, such as the oral allergy syndrome and is more frequent in the cooler regions of the northern hemisphere where the birch commonly grows. The heat-stable allergen cross reacts with peaches, causing severe reactions and is more commonly found in the Mediterranean area (12).

Contrastingly, guava allergies are very uncommon in the medical literature. One study found that children with seasonal asthma attacks have a higher chance of being hypersentisized to many foods, one of them being guava, and that a specific elimination diet may prevent the seasonal provocation (13).

There has also been a report of allergic skin dermatitis caused by guava tea leaves. Guava leaves may contain allergens such as pollen and latex (14).

Cancer

The aqueous extract of guava fruits has been found to inhibit brain derived metastatic prostate cancer, potentially due to its extraordinarily high polyphenol and flavanoid contents. Therefore guavas can potentially be used as part of treatment for such cancers (15). Guava leaf hexane fraction has also induced anticancer activity in human prostate cancer by suppressing AKT/ mammalian target of rapamycin/ ribosomal p70 S6 kinase (16).

Studies have also found a consistent inverse association between apples and risk of various cancers (17). Significant risk reduction was observed in oral cavity and pharynx, larynx, esophagus, colorectal, breast, ovary and prostate cancers (18).

Antimicrobial qualities

Antibiotic resistance is becoming a growing issue in the world, due to the overuse or misuse of antibiotic drugs. The question of finding natural antimicrobial remedies is becoming imperative.

Both apples and guavas have been found to exhibit antimicrobial properties. Ethanolic and methanolic apple axtracts have shown antimicrobial qualities against Staphilococcus aureus and Enteroaggregative eschcherichia coli (EAEC). Guava extracts were effective against Staphylococcus aureus, Enterotoxigenic E. Coli (ETEC), Enterobacter cloacae, Shigella flexineri, Enterococcus faecalis, Klebsiella and Pseudomonas aeruginosa, but not Enteroaggregative E. Coli (EAEC). The methanolic extracts of apple and guava showed slightly larger zones of effectiveness compared to their ethanolic extracts (19).

These findings show great promise for future potential antimicrobial drugs.

Summary

In comparison to apples, guavas contain more protein, fats and carbohydrates, while containing less sugars. Guavas are also richer in all vitamins and minerals. Apples are lower in sodium. Both fruits exhibit antidiabetic, antihypertensive, antihyperlipidemic, anti inflammatory, anticancer and antimicrobial effects.

While guavas are richer in most nutrients than apples, both fruits have many beneficial effects on health and the choice is up to the consumer.

Sources.

1. https://hort.purdue.edu/newcrop/morton/guava.html
2. http://www.fao.org/faostat/en/#data/QC
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3689326/
4. https://pubmed.ncbi.nlm.nih.gov/16395418/
5. https://pubmed.ncbi.nlm.nih.gov/16395418/
6. https://www.researchgate.net/publication/277943255
7. https://pubmed.ncbi.nlm.nih.gov/18819164/
8. https://pubmed.ncbi.nlm.nih.gov/15619559/
9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831039/
10. https://onlinelibrary.wiley.com/doi/abs/10.1002/jsfa.1264
11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4852413/
12. https://farrp.unl.edu/informallfruit
13. https://indianpediatrics.net/apr2005/362.pdf
14. https://www.researchgate.net/publication/12126601
15. https://pubmed.ncbi.nlm.nih.gov/17571972/
16. https://pubmed.ncbi.nlm.nih.gov/22280146/
17. https://pubmed.ncbi.nlm.nih.gov/16091428/
18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3183591/
19. http://article.microbiologicalresearch.com/pdf/ajmr-5-5-2.pdf