The Truth about Watermelons…and Benefits

By: Catherine Ebeling 
Co-author of the best-sellers:  The Fat Burning KitchenThe Top 101 Foods that Fight Aging & The Diabetes Fix

Nothing says “Summer” better than a cool, refreshing, sweet, juicy, delicious slice of ripe watermelon—no matter what time of year it is. But I often hear cautions on eating watermelon—that it is high glycemic, full of sugar, mostly water, not very nutritious, etc.

Right? Or wrong?

While watermelons are mostly water—90% or so, they are also full of vitamins A, B6, C, lycopene, antioxidants and minerals. Remember hearing about the lycopene in tomatoes? Watermelon, another red-colored fruit, is FULL of this powerful phytonutrient! In fact, watermelon has some of the highest levels of lycopene of all fruits and veggies. Just one cup of watermelon has 1 and a half times the lycopene of a large fresh tomato. And who eats just one cup of watermelon? I know I don’t!

Because watermelon is one of the best sources of lycopene with more than 6,500 micrograms in less than half a cup, you are getting an army’s worth of inflammation-fighting antioxidant activity! Lycopene from the red flesh of watermelon is very stable, even after the watermelon has been cut and stored in the refrigerator. Lycopene is thought to be even more powerful than its other orange/red colored ally, beta carotene—found in red and orange fruits and veggies.

Cardiovascular Benefits

Lycopene is a powerful natural anti-inflammatory and antioxidant, valued for its role in protecting the cardiovascular system, bone health, and preventing cancer. Along with lycopene, watermelons contain another powerful phytochemical, citrulline, an amino acid. Citrulline gets converted into another important chemical in the body, arginine, or L-arginine. Arginine is used to create nitric oxide, which has powerful benefits on the heart and blood vessels. NO can actually cause blood vessels to relax and open up, lowering blood pressure and helping the body carry more oxygen to parts of the body where it is needed–like muscles, your heart and your brain. A study from Florida State University found that watermelon could make a significant difference in lowering blood pressure–especially in overweight people, by relaxing the blood vessel walls.

Citrulline, when it converts into arginine, can also help prevent excess accumulation of fat in fat cells, because it blocks an enzyme that stores this fat. And because citrulline is a precursor to nitric oxide, it can also help improve erectile dysfunction in men, in a similar way that Viagra works—although you would have to quite a bit of watermelon to get the same effect as Viagra.

As you can see in this article, watermelons are on the list of foods that beat statins for heart health!

It’s All About the Lycopene

Carotenoids are powerful antioxidants, capable of destroying free radicals which attack our bodies and can contribute to chronic disease and aging. In one study of 13,000 adult Americans, low levels of carotenoids were a key predictor of early death. Especially low blood levels of lycopene! Lycopene protects our cardiovascular system, the male reproductive system, and in the skin, it protects and prevents UV damage from the sun.

Several studies have been conducted showing the strong link between levels of lycopene and heart disease. Analyses from the Physicians Health Study showed a 39% decrease in stroke risk in men with the highest blood levels of lycopene. Another study in Finland following 1,000 men for 12 years has had similar results as well.

Lycopene is also responsible for limiting the enzyme responsible for making cholesterol, so eating foods with more lycopene also helps to reduce cholesterol—specifically, LDL cholesterol.  (Side note:  speaking of heart health, did you know that grass fed dairy fat actually contains nutrients that help unclog your arteries)

Anti-Cancer Power

Lycopene is a life-saver in more ways than one! Besides its cardiovascular benefits, lycopene’s antioxidant power extends to anti-cancer effects as well. A 2014 meta-analysis of 10 studies shows dietary lycopene to be protective against ovarian cancers, as well as brain tumors and breast tumors.

And of course, we know about lycopene’s value in fighting prostate cancer. In several studies, higher intakes of foods containing lycopene and a higher serum or plasma concentration of lycopene was associated with a very significant decreased risk of prostate cancer—especially the more lethal kind of prostate cancer. When researchers studied only the men who had had at least one high risk PSA test, the subjects had a 50% decreased risk of lethal prostate cancer.

“Based on these results, we hypothesize that the consumption of a diet rich in lycopene-containing foods reduces the aggressive potential of prostate cancer by inhibiting the neoangiogenesis that occurs in tumor development,” Dr. Giovannucci’s team reported online ahead of print in the Journal of the National Cancer Institute.”

Other studies have shown lycopene’s powerful cancer fighting ability effective against lung cancer, esophageal, stomach, pancreatic, colorectal, and cervical cancers as well.

Extremely Good for Rehydration

Watermelons get their name because they are over 90% water, and that water is full of electrolytes and potassium which helps you stay hydrated or to rehydrate. The perfect fruit to eat on hot summer days, or after a hard, sweaty workout! And that delicious juice can also help prevent muscle soreness—especially if you have watermelon before your intense workout.

Its Not Just the Red Part

While most of us only eat the juicy red flesh of the watermelon, the whole thing is actually edible and chock full of nutrients! From the red center to the stem end, and also the blossom end–including the white part near the rind–are a plethora of impressive antioxidants, flavonoids, lycopene, and vitamin C. Even the green rind is full of nutrients. The rind is full of chlorophyll, and contains even more citrulline than the red flesh. Try throwing your watermelon rinds into the blender with fresh squeezed lime juice for a healthy slushy treat.

It is still best, however, to pick ripest, reddest watermelon you can find. Lycopene content continues to increase all the way up until the time the watermelon is at its reddest and ripest.

And don’t spit out those seeds, unless you are in a watermelon seed-spitting contest! The black watermelon seeds are not only edible, but actually extremely good for you. They are full of iron, zinc, fiber and protein. Seedless watermelons are ok to eat too—they are not genetically modified, only hybrid forms of watermelon bred especially for their no-seed content.

Watermelons also are rich in anti-inflammatory substances including cucurbitacin E, tripterpenoid which help to block the pain and inflammation of certain enzymes, in a similar fashion as NSAID’s like ibuprofen and aspirin.

While being very low in calories (only about 46 calories in a cup), watermelon also contains an impressive variety of other important essential nutrients including:

  • Vitamin A
  • Vitamin C
  • Vitamin B6
  • Potassium
  • Magnesium

The Age Old Question—How Do You Pick the Perfect Watermelon?

It can be a huge gamble finding the perfect, red, sweet watermelon. But—if you know what to look for, there is a real method to finding the best one. Look on the underside of the watermelon for a pale, butter-colored yellow spot—not white or green. This is one of the best indicators of the ripeness of the watermelon. Also pick up a few and choose the one that is heaviest for its size. Many people ‘thump’ the watermelon to check its ripeness too—listen for the best hollow bass sound.

Be aware that watermelons do contain a reasonable quantity of fructose, so be mindful of your sugar intake, and eat watermelon in moderation.  With that said, because watermelons are so filling, and have both high water content AND high fiber content, the old myth that watermelons are high glycemic is not entirely true… This is because the “glycemic load” of a watermelon is actually fairly low since it’s nearly impossible to overeat large quantities of a food that is as filling as watermelon.

So enjoy your watermelon, knowing you’re doing your body good!  Also try my friend Danette’s watermelon & lime juice drink here!

Charnow, (Feb 2014). Lycopene May Decrease Prostate Cancer Risk. Retrieved from
Figueroa, Wong, Kalfon. (2014). Effects of Watermelon Supplementation on Aortic Hemodynamic Responses to the Cold Pressor Test in Obese Hypertensive Adults. American Journal of Hypertension, 2014; DOI: 10.1093/ajh/hpt295
Furhrman, J., MD. How Tomatoes Can Protect You Against Heart Attack and Stroke. Retrieved from
Hak AE, Ma J, Powell CB, et al. (2004). Prospective study of plasma carotenoids and tocopherols in relation to risk of ischemic stroke. Stroke 2004; 35:1584-1588.
Journal of the National Cancer Institute. (Feb 1999). Tomatoes, Tomato-Based Products, Lycopene, and Cancer: Review of the Epidemiologic Literature. Retrieved from
Karppi J, Laukkanen JA, Sivenius J, et al. (2012). Serum lycopene decreases the risk of stroke in men: A population-based follow-up study. Neurology 2012; 79:1540-1547.
Karppi J, Laukkanen JA, Makikallio TH, et al. (2011). Low serum lycopene and beta-carotene increase risk of acute myocardial infarction in men. Eur J Public Health 2011.
Mateljan, G. World’s Healthiest Foods. Retrieved from
Mercola, J., DO. (2014). 6 things you didn’t know about watermelon. Retrieved from
Szalay,J. (October, 2014). Watermelon: Health Benefits, Risks & Nutrition Facts. Retrieved from
Shardell MD, Alley DE, Hicks GE, et al. Low-serum carotenoid concentrations and carotenoid interactions predict mortality in US adults: the Third National Health and Nutrition Examination Survey. Nutr Res 2011; 31:178-189.

About The Watchdog

Mike Geary has been a Certified Nutrition Specialist and Certified Personal Trainer for over 15 years now. He has been studying nutrition and exercise for almost 25 years, ever since being a young teenager. Mike is originally from Pennsylvania, but has fallen in love with mountain life and now resides in the picturesque mountains of Utah. Mike is an avid adventurist and when he’s not spending his time skiing, mountain biking, hiking, or paddleboarding on the lake, he has enjoyed skydiving, whitewater rafting, piloting an Italian fighter plane (seriously), scuba diving, heli-skiing, and traveling all around the world, enjoying learning about different cultures. At the age of 40, Mike now feels healthier, stronger, and more energetic than when he was 20... All because of a healthy lifestyle and great nutrition!

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  1. Dear help desk,

    Pls help me to delete my email from subsciption of your web news, thanks.

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  2. I am very interested in watermelon not I will include in my daily life thanks for all the wonderful information

  3. Hello, I love Watermelon so much and get so disappointed when it stops selling when fall gets here in Manitoba I miss it so much.. I have it for breakfast everyday and a snack at work. I never knew how good it is for you thank-you for this article I can’t wait until Spring until watermelon is back in the stores:)

    • Dear Jacie H,
      Ever tried to freeze the watermelon ?
      It is so full of water, that it freezes very well.
      Make sure that you wash and dry the melon before cutting it up
      into small cubes, include the seeds and the rind, white and the green.
      you can also put it into the grinder/foodprocessor and then make slush size, freeze it in
      small containers, and fill the freezer with them for use during the off season.
      Works like a charm !

      st wash the melon before cutting it up

  4. ” The Nector Of The Gods “

    • I have heard and read somewhere watermelon is not recommended for people with Type 11 diabetes. Anyone shed any light on this.

      • as long as they walk right after eating it, it should be allright; in the article it mentions the fructose in the fruit, but ingesting the natural fiber as it comes from our Creator, better manages the absorption of glucose into the bloodstream..

  5. What about yellow meat watermelon? Does that have any health benefits?

  6. Watermelon is GREAT.

    One possible correction. If I’m not mistaken, citrulline doesn’t convert into arginine. It does something better. It restores spent Nitric Oxide, which is the compound that relaxes our arteries.

  7. I order a book from you and I did not receive please check it

    • Hi Nenita, I’m sorry to hear about that. The help desk will be able to assist with locating your order, please email them at [email protected] and provide them with additional information if available to help them locate your order more quickly such as order #, name of book, price, etc…

  8. Be sure to let your Dr. know that you’re eating watermelon. Their potassium can markedly change medical test findings/diagnosis.

  9. I agree with you 100% I have used water melon to treat my dad who has prostate cancer and he has managed for ten years now without any drug. Please send me that article through email to help others n
    Know the benefits of watermelon.

  10. I had not known the importance of watermelon and yet we grow it in large quantities, not that I have read this article, I will consume this fruit so much with my family, keep researching for other fruits as well

  11. In order to get the benefits and to enjoy having this wonderful summer fruit we need to get a real one with seeds. The artificial unseeded lab experiments are falling apart on their own and weeping clear water. They are not real, safe food to eat. That’s where we need to start learning about the benefits of our foods is to grow real ones.

  12. The seedless watermelons have no taste or they taste like medicine, and the fall apart really easily. After I watched on youtube how the seedless ones are made I quit eating them. But I do love frozen watermelons and frozen grapes for sore throats and in boba drinks.

    • I think that the taste depends on the type of watermelon you pick. I love seedless watermelons. They must be solid inside (test by knocking) and dark green on the outside. The red in the middle is the sweetest part and I don’t worry about sugar anymore either. My mom taught me how to pick them and although she is gone now, I remember how to do it. I never tasted watermelon that tastes lite medicine? Do you smoke? I quit eight years ago, buy I vape. So I’m not getting all of those chemicals they put in the cigs. Good luck and I hope you find better melons.

  13. If you are ever fortunate enough to actually pick a watermelon from the field where it’s grown, here are some hints on how to choose the right one. (1) Choose a well-shaped one that is large compared to the others. Larger ones are more likely to be ripe. (2) While it’s still lying on the ground, thump the melon with your finger. A ripe melon will give off a dull, bass sound. A sharp, higher pitch sound indicates the melon is not ripe. (3) Turn the melon over and look at the surface of the melon that has been in contact with the ground. I f it’s the same color as the rest of the melon,the melon is not ripe. A ripe melon will have this skin a whitish-yellow color. (4) On the stem that connects the melon to the vine, there is a small, spiral-shaped growth about an inch long called the “curl.” Originally the color of the curl is a whitish pale green. When the melon is ripe, the color changes to a light brown. So, in the watermelon field, choose a well-shaped, large melon, that gives a dull bass -sound thump, with a whitish-yellowish bottom, and with a brown curl.

  14. What if eating watermelon produces a fuzzy lip/tight throat feeling?

    Never had issues with melons until I reach my 30’s. I avoid them since I grew my own to test if it happened with an organic melon and it happend with three different varieties.

    • maybe you have an allergy to them. how about cantaloupe or honey dew melons? never heard of that but there’s always one or two?

  15. Hi,
    Thanks for the information but does watermelon really contain Vitamin A or is it beta carotene. From what I understand beta carotene is converted in the body to Vitamin A. Also there are some people who are poor converters of beta carotene. According to one study published by G. Tang in the American Journal of Clinical Nutrition in May 2010, “there is genetic variability in β-carotene metabolism”.
    I am someone who has discovered that I need to take preformed vitamin A. Too much preformed vitamin A can seriously damage your health as it is a fat soluble vitamin and stays in the body as opposed to Vitamin C which is water soluble and is easily eliminated from the body. However my health significantly improved with the introduction of a daily vitamin A capsule.

    • Vitamin A can be toxic unless balanced with vitamin D. Supplemental D can be toxic unless balanced with vitamin A.Take them together, in a ratio of, say 1000 IUs of D to 5000 to 10,000 IUs of A.
      Whatever happened to natural cod liver oil – which also provides omega 3s. Read the labels or call the companies.

  16. I read somewhere ,when we open the melon ,some times you will notice holes on the surface that means that melon got inject ,better to dispose it .The good on with sold surface

    • what? that’s crazy. someone filling your head with garbage. where do you buy your melons? at the store or the local drug cartel? Anyone can inject any piece of fruit. A needle is so tiny you wouldn’t be able to see the hole from it.
      i think that if you purchase your melon from a well known store, you won’t have any holes in any fruits.

  17. Another thing I learned is a lot of people get upset stomachs from certain type of watermelons–if the watermelon has cracks in it after slicing it open— it doesn’t necessary mean it’s overripe. It means that some countries use a hormone to make the watermelon grow faster hence the upset stomach from the hormone.

  18. I have just spent a long time listening to your wonderful presentation only to find much as I would desperately like to purchase your PREBIO THRIVE that you cannot send it to me in Spain

    Please Dr.Grundy is there any other source who ships to Spain.

  19. Why would you bother eating seedless fruit when the seeds in watermelon, grapes and others are so good for you, especially organic? Chewing grape seeds is like getting free grape seed extract which can run a lot of money as a supplement. Chewing the apple, apricot,, cherry seeds is like getting free B17, also expensive in supplements.

  20. as the ol;dest olympin ever2012 and 2016 was 93 in 2016 n plyed againsat young guys and didgreat like watermelo hrd to find orngnic one but use them msometimes thanks for such a great artile am almost 98 two time olym,pian also two time hll of famer in tennisplayed alex olmedo rod laver and other alsohonored in namericn legue baseball at knsas city royls gme with 41000 people and oldest or near oldet surivorof us infantry in world war two in combat but none of thismatters now as i see our country in the midst of virus started in china and am very much for mchange goingm on with the november election going to trump a gret american bill guilfoil vetern in eerthing but peoplem and gret foods as you mmention are very importnt tolong life and also am involved in memory research and thiis a mmust for all people bill g

  21. I love watermelon & eat it all summer! I knew it was good for me, just didn’t know it was this good for me! I even crave it at times! I recently discovered one of my local grocer has bottled watermelon juice! I grabbed a small one to see if it was any good & I loved it too! So that might be available during the winter & can help those of us who crave watermelon in the winter!

    Would it be possible to get this article sent to my email! I want to send it to my sisters & my great-granddaughter!

    Thank you , Mary-Jo Wiese

  22. I love watermelon but if I eat to much it plugs me up…but I eat it anyway…

  23. Don’t forget watermelon’s significant L-Glutathione content!

  24. A doctor once told me that watermelon is the only fruit that doesn’t cleanse or filtrate the water it takes from the where it grows. Have been trying to confirm or dismiss this ever since, but couldn’t get any info either way. Nobody seems to know anything about it. But watermelon experts that write articles about this topic should know, so, hoping you have an answer.

  25. Bonnie Evans Tittle

    I know all the nutritional information about watermelon. I love it. But I am a brittle type 1 diabetic. I have never been able to find out about this and would be great to learn more about it. Thankk you

  26. Good information. Thank you

  27. after reading the article on Watermelon I decided to give juicing up a half watermelon, rind and all per day . First we wash the watermelon then give it a diluted vinegar rinse then rinse then blend it up rind and all. After 1 week of this what do I notice…. i) feel better more balanced ii) going to the bathroom is a more complete experience both with #1 and # 2 ….. I do seem to be urinating harder and longer iii) waking up ready for action (if you get my drift) iv) BP went from long term resting 126/82 to 108/72 ( I test a few times per day)… sure this all could be coincidental and nothing to do with the watermelon but I can honestly say I feel better in myself .. less full and less tired as well… as i say jury is still out if its the watermelon and one week is too short a time frame but i will keep on it and monitor it…. we juice it with one lime each time so the extra Vit C surely helps as well….. BP tests to me are the biggest pointer that something is going on

  28. Especially in Regard to Our Equatorial Climate across here in Africa, the Seed filled WATERMELON is Known, much Welcome and Appreciated by a Large Number of the Population. So for it is Overly Juicy, quite cool and with Medium-Level Sugar, making it delicious and Non-Toxin. Certainly, this is a Ripe Fruit that is welcome by all, Young and Old: so to fight and win Over Weakening bodies, out of the hot Weather climates more-so during the Hot, Summer Season. Yes, Watermelon is a Body Coolant, Healthy and Safe.

  29. Just one more truth about watermelons. Watermelons are very high in fructose, which has a hidden problem, causing a metabolic syndrome. Our cells are too smart to accept fructose, so our livers have to metabolise fructose, and eventually get a fatty liver disease (NAFLD). When you check your blood sugar, the result shows only glucose level. Most doctors don’t know that HbA1c can test only glycation by glucose, while glycation by fructose is 10x higher than by glucose. This is why many people have diabetes, but not correctly diagnosed, and don’t even know that, because HbA1c is below a diagnostic level.
    Watch this 12-min video for an explanation by Dr. Berry, the most honest doctor, who admits that he was ignorant about fructose dangers:

  30. Yes good point made earlier about how “clean” the watermelon is if it doesn’t purify the water it takes in! Some soils/water have toxic elements/compounds in them so these could be taken up by the watermelon and end up in the fruit we eat! That’s why organic is usually a better way if you can get them!! But then how many organic farmers actually test the soil for toxics???

  31. Thank you for this article! I was recently put on a low fodmap diet by a gastroenterologist I was seeing. This diet called for avoiding watermelon which I thought was odd to say the least. After reading this, I feel vindicated and will not be seeing the gastroenterologist anymore (there are other reasons too beside the flawed diet advice). Good health to everyone!

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