Jamun (Java Plum) Has No Anti-Anaemic Benefits

Often, my friends ask me to opine on some article they read online about the purported health benefits of some exotic fruit, vegetable, or concoction. Most such articles have outrageous claims, with zero scientific proof.

But when many renowned experts and health websites indulge in such fabrication, it is time to point it out.

Many prominent health websites claim that Jamun (Java Plum) fruits are loaded with iron and improve blood haemoglobin and iron levels. Complete nonsense!

In this article, I will discuss why Jamun has no anti-anaemia benefits. More important, I will highlight how the rampant cut-and-paste culture on the internet has made wrong information so pervasive. Caveat emptor—buyer beware!

Jamun, Internet and Anti-Anaemic Properties

Search "Jamun and iron" on the internet and you will see a host of renowned health websites saying 'Jamun is packed with iron and is great for anaemia patients'. Sadly, even a bunch of published research papers claim so.

I decided to dig deeper into this for my chapter on Jamun in my book on the medicinal properties of our superfoods.

I found almost no one offered any substantiation for those claims.

On one website, there was a reference given. But when I eagerly went through that paper, it mentioned a lot of Jamun properties, none of which had anything to do with benefits for anaemia. Interestingly, it said that Jamun has blood-purifying properties, which the website seemed to have interpreted as anti-anaemic benefits. It is a sad commentary on what is happening in today's preventive nutrition world; such blatant misinformation lowers the credibility of all plant and herbal research.

In this article, let us scientifically check if Jamun can indeed help improve anaemic conditions. Most information below is taken from my upcoming book.

Jamun (Java Plum, Black Plum, or Jambolan)

Jamun is a large tree (scientific name Syzygium cumini) native to the Indian subcontinent. Its fruits develop annually by the month of May. As the large oblong berries ripen, their colour changes from green to crimson to deep purple. The ripe fruits are sweet, sour and astringent in taste.

Jamun has antioxidant, anti-inflammatory, antimicrobial, anti-allergic, anticancer, and antidiabetic properties and protects digestive, heart, liver, and oral health (go to the end for references).

Nutrients in Jamun

Jamun fruit flesh has 83% water, 16% carbohydrates, 0.7% proteins, and 0.2% fats. Jamun is a good source of Vitamin C and has some magnesium, too. But iron?

For health benefits, one is advised to consume a hundred grams of Jamun fruit a day. Since the fruit is seasonal, one can instead have four teaspoons (20 mL) of Jamun fruit juice daily. How much iron will you get from that?

A hundred grams of Jamun fruits have 0.19 mg of iron—your body can absorb only a small fraction of this.

• The Indian guidelines advise consuming 19 mg of iron for men and 29 mg for women a day.
• Similarly, the American guidelines recommend 8 mg of iron daily for men and 18 mg for women.

Since women are more likely to be afflicted by anaemia, let us take the number for women. How will 0.19 mg of iron from Jamun cover 29 mg of the daily requirement for women?

You can't consume much more Jamun fruits or juice either—excess intake can lead to constipation, acne breakout, and vomiting.

Some people think that vitamin C in Jamun helps improve iron absorption. While that is true, I will explain later why that won't give much iron either.

Summary

• There is no chance that Jamun can have any anti-anaemic properties.
• Eat Jamun fruits (or drink their juice) for their myriad health benefits but don't consume them under the false hope that they will somehow increase your body's iron and blood haemoglobin.
• Take proper treatment for your anaemia from a medical professional.

I could end the write-up here, but I prefer articles that are less prescriptive ("do this", "don't do that") and more educative ("think this way", "why not that?").

Twenty-five years ago, even I struggled to make sense of conflicting health information and claims. But over the years, I learned how to evaluate each bit of evidence correctly, work with ambiguity in research data, fit pieces of such jigsaw puzzles, draw usable conclusions, and most important, modify my opinions when new information becomes available.

My articles are designed to tell you how to think correctly, not what to do. The data may change; the way to use them should not.

So let us cover a few interesting tidbits about iron intake and Jamun.

India and the USA Have Different Iron Intake Guidelines

Well, there is no conflict here. Let me explain how these numbers are decided.

The authorities first check how much iron our bodies lose every day, through sweat, shedding of skin and cells in the intestines, and blood loss. That number is about 1 mg for men and 1.5 mg for women, the latter being higher due to menstruation (which is why the iron requirement for post-menopausal women is the same as for men). That much iron needs to be replenished daily.

However, iron is notorious for its poor absorption in the body, which absorbs 25%–30% of iron in non-vegetarian food. If the source is vegetarian, such as Jamun fruits, the absorption is just 1%–10%.

For your body to absorb 1 mg of iron, you will need to consume 4 mg of iron from meat or 20 mg from Jamun fruit.

• The Indian diet is largely vegetarian. So the authorities take 8% as the rough number for iron absorption. If you eat 12.5 mg of iron through the Indian diet, your body will absorb 1 mg.
• The typical USA diet has more non-vegetarian components compared to the Indian diet. So the USA guidelines suggest lesser iron intake.
• Incidentally, Australian dietary guidelines suggest 8 mg of iron intake for men and just 9 mg for women.

But there are more issues when suggesting dietary guidelines.

EAR and RDA

There is a difference between the average (or median) need and the worst-case need.

For example, if you take a large group of young Indian women, half of them will need to replenish 1.2 mg or less iron daily. So they should consume 15 mg of iron a day (assuming 8% absorption). This number is called EAR or Estimated Average Requirement.

But if you give that much iron to all Indian women, half of them will develop iron deficiency. So the norm is to ensure that 97.5%—and not 50%—women are covered by the recommendation.

Studies have shown that 97.5% of Indian women need 2.32 mg or less iron daily. So if Indian women consume 29 mg of iron (of which 8% is absorbed, giving them 2.32 mg), 97.5% of them will have their iron needs covered. This number is called RDA or Recommended Dietary Allowance.

The guideline states, "Daily RDA for iron is 29 mg for Indian women".

Obviously, 2.5% of the women will still be iron deficient after consuming 29 mg of it a day. However, upping the guidelines and making the remaining 97.5% of women take more iron just to protect 2.5% of women is not considered a good trade-off.

If the remaining 2.5% of women were to develop cancer—or worse, die—instead of just becoming iron deficient, the authorities would have considered 99% or 99.99% as the cutoff instead of 97.5%.

So I hope you understand that EAR is a reality, but RDA is a tradeoff—nothing sacred about it.

Vitamin C in Jamun

Vitamin C increases the absorption of iron from vegetarian sources. In one study, iron absorption increased from 1% to 7% as the vitamin C given with it was increased from 25 mg to 2000 mg.

We are talking about 14 mg of vitamin C in 100 grams of Jamun fruits. How is that going to make a difference to the iron that one can get from Jamun?

Colour of Jamun Fruits

Some people think that Jamun fruits have a lot of iron because of their crimson colour. But that hue comes mainly from Jamun's antioxidant compounds called anthocyanins, which are antioxidant, anti-cancer, anti-diabetes, anti-microbial, and protective for the heart, brain, and eyes.

Most fruits and vegetables that are purple in colour are rich in anthocyanins.

Most of the information in this article is taken from my upcoming book to be published by Macmillan Publishers in Nov 2023. The links to research and more reading material are given in my original article on my Health Sachet website. (Go to www.healthsachet.com and search for the following article).