large cucumbers in baskets at farmer's market

9 Health Benefits of Cucumber You Weren’t Expecting

[toc]Where does the saying cool as a cucumber come from?

It means a person who’s cool, calm, and collected. Its origin has to do with the temperature of a cucumber. Because they’re 96% water, they maintain a cooler temperature than the ambient air.

In a room with 80°F air, the inside of the cucumber will only reach around 72°F. Even if it’s been in that room all day.

The reason it stays cool is because of heat capacity. That’s a scientific measurement for the amount of energy needed to raise the temperature of a substance by 1°C.

Water has a heat capacity 4x higher than air. Since cucumbers are almost entirely water, their temperature will be lower than the surrounding air. (1)

But wait, that’s only one of the bizarre benefits.

There may be some uncommon medical uses for this common fruit.

Yes, botanically it’s a fruit. Though we’ll keep calling it a veggie as to not confuse people.

9 cucumber health benefits

1. Hydrates better than water

attractive athletic man resting from exercise and drinking water bottleTemperature aside, they’re cool for another reason; staying hydrated.

Cucumbers have the highest water content of any natural solid food. Bananas are 75% by weight. Green grapes are 82.7%. Apples are 86.2%. Among the fruits and vegetables with the highest water content, none beat cucumbers, which are 96.5%. That’s even more than watermelon and iceberg lettuce. (2)

So how do they hydrate better than water, which is obviously highest at 100% when pure?

Because it takes more than just water to re-hydrate.

We need electrolytes. Those are certain minerals, including potassium, which cucumbers happen to have a lot of; 442 mg in an average 8.25″ long specimen, according to the USDA. (3)

There’s also a decent amount of calcium, phosphorus, and magnesium, all of which serve as electrolytes, too.

Water-rich fruits and vegetables such as this can hydrate better than water, and even some sports drinks, after an intense workout. That’s according to a study by the University of Aberdeen Medical School in Scotland. (4)

In short, the juice in this vegetable is closer to that of the electrolyte-loaded water in your body.

Turns out eating may be better than drinking for hydration.

2. Anti-inflammatory

Research carried out by the University of Nigeria and published in the British Journal of Pharmaceutical Research reports that the anti-inflammatory benefits of cucumber may rival a popular pain medication.

In the study, rodents were divided into groups and given one of the following treatments:

  • Saline water
  • Diclofenac, which is a nonsteroidal anti-inflammatory drug (NSAID). This active ingredient is also sold under the brands Voltaren, Cambia, and Solaraze.
  • Whole cucumber
  • Nothing (control group)

Carrageenan was used to trigger inflammation on their paws. This is common agent for doing so in research (that’s why you shouldn’t drink almond milk that uses it).

bar graphs showing levels of swelling with cucumber extract vs. NSAID medication

By the 3rd hour, the anti-inflammatory effects of the high-dosage cucumber group were comparable to the pain medication.

Although not tested in humans, this suggests potential for muscle and joint pain relief from sports injuries, osteoarthritis, etc. (5)

3. Antioxidants

fresh cucumbers hanging on vine of plant in gardenDo cucumbers have antioxidants?

There are antioxidants in cucumber but they’re not a rich source. With peel intact, their ORAC value is 232. Without peel, it’s 140. These numbers are comparable to other fruits and vegetables with low antioxidant activity, like watermelon and green peas.

Still, that’s better than water and soda which contain zero.

Because of their sugar, drinks like Pepsi and Gatorade will actually have a prooxidant effect in the body, meaning they cause oxidative stress.

Okay none of that is unexpected, but what comes next is.

Lotus roots have an ORAC of 2,177, which is about 9x higher than cucumbers with skin. Despite this, they seem to have comparable antioxidant activity in the human body.

That’s according to a clinical study which measured markers of antioxidant activity in healthy men and women who were age 60 and above. This may be due to additive or synergistic effects from eating vegetables. (6)

4. Good for weight loss

The average cucumber is 45 calories, according to the USDA. That’s for one that’s 8.25″ long and weighs 301g (10.6 oz). It also contains about 6% of your daily value for fiber (1.5g).

That takes up a lot of space in your stomach, while contributing very few calories.

A meta-analysis of 13 different clinical trials involving over 3,600 people found that eating high water and low calorie foods such as this correlate with body weight reduction. (7)

So none of this is surprising, but there’s one more reason why cucumbers might help you blast that belly fat…

In a randomized, double-blinded, and placebo controlled clinical trial, consuming 500 mg daily of cucumber seeds correlated with a BMI reduction, in a statistically significant manner (P <0.001).

500 mg isn’t much. That’s how much powder fits inside of a standard capsule supplement. Since cholesterol was the focus of the study, this secondary finding was totally unexpected.

The clinical results suggest eating cucumbers are good for weight loss, due to an unknown compound in the seeds which might offer an anti-obesity benefit. (8)

5. Excellent source of vitamin K

With 49.4 mcg of vitamin K, the average cucumber provides 62% of your daily value.

This essential nutrient plays an important role in blood clotting and bone health.

6. May lower blood sugar

diabetic man pricking finger for blood glucose testCucumber seeds aren’t given much thought. They’re small, soft, and aren’t that noticeable when you chew this food.

Maybe we should start thinking about them more because in some countries they have used them for diabetes treatment, as part of alternative medicine.

This purported advantage hasn’t been tested in humans formally, but rodent research suggests it might be for real.

When normal and diabetic rats were given cucumber seed extract for 9 days, they had lower blood sugar that was statistically significant. The results were almost as good as those treated with glibenclamide, which is an antidiabetic drug sold under the brand Glynase.

They believe this is happening because the seeds act as euglycemic agents. Those increase cells’ sensitivity to insulin. (9)

7. May lower cholesterol

In a randomized, double-blinded, and placebo-controlled trial involving 47 people, a 500 mg cucumber seed supplement was taken for 6 weeks, to measure effects on:

  • LDL cholesterol (the bad kind)
  • HDL cholesterol (the good kind)
  • total cholesterol
  • triglycerides

Those 24 patients taking the seed supplement experienced lower LDL, total cholesterol, and triglycerides. Their good HDL cholesterol actually went up.

As an added bonus, their BMI went down! This was the same study mentioned above, which suggests they may help you lose weight in more ways than one.

How many seeds are in a cucumber? At least several dozen. When dry, 1 gram worth equals 30-45 seeds.

That would mean to eat 500 mg (1/2 gram) of seeds, probably half of one vegetable would do the job.

8. May brighten skin

female face covered with cucumber slices during spa facialExtracts of cucumber leaves, stems, roots, and fruits (vegetables) were tested on cultured skin cells in the lab. They found that compounds in the leaves decreased tyrosinase gene expression.

In plain English, lower expression equals lower melanin (pigment) production.

Based on the results, these Japanese scientists suggested the plant may be useful for skin whitening of age spots, blemishes, and so forth when topically applied. (10)

Everyone is familiar with the practice of putting sliced cucumber on your eyelids at the spa. Perhaps they should start doing so with leaves, to lighten those dark circles and under eye bags!

9. Used in cancer research

Might those lacto-fermented bread and butter pickles be a cancer fighter?

It’s far too early to say, but researchers out of India report that a novel isolate found in fermented cucumbers displays anti-cancer activity against the most studied cervical cell line (HeLa) and a colon cancer line (HT29) in lab research. (11)

The Department of Urology at UPenn reports that a compound known as cucurbitacin B (CuB) inhibits the growth of various cancers in the lab. It’s found in cucumbers and some other veggies.

They isolated the cucurbitacin B and tested it on prostate cancer cells. It reduced growth through several known pathways (Caspase 3/7 activation, PARP cleavage, and others).

Next, they tested it on living mice fostering human cancer.

That’s possible using what’s called xenografts, in specialized mice which are designed to not reject the human cells.

graphs showing cucumber for cancer treatment in mice

“A 79% reduction in tumor size (accompanied by marked in situ apoptosis) was observed in the CuB-treated group (with no noticeable toxicity) vs. controls at day 31. Strikingly, mechanistic investigations demonstrated that CuB drove dose-dependent inhibition of ATP citrate lyase phosphorylation (ACLY; an important enzyme for cancer metabolism) both in vitro and in the CuB-chemopreventive mouse model.”

In plain English, the prostate tumor growth was suppressed, without there being toxicity from the cucumber treatment. (12)

Side effects

You have to look hard to find something wrong about this food.

Cucumbers are gluten free, low calorie, and virtually fat-free. Unlike beans and onions, they’re not known for causing gas or bloating.

Craving cucumbers while pregnant is relatively common and it’s safe to eat them, as well as drink cucumber water. There’s not data to suggest potential health risks are greater with cucumbers versus other common vegetables and fruits during pregnancy and breastfeeding.

Possible side effects of cucumbers can include:

Allergic reaction

Theoretically you can be allergic to any food and this one is no exception.

Only a few case studies exist which document an allergy to cucumbers. Contact dermatitis and typical oral allergy syndrome (OAS) have been reported but they’re extremely rare. (13) (14) (15)

Bacterial food poisoning

Not through fault of the plant, but rather the sewage runoff from nearby livestock farms have resulted in occassional outbreaks of Salmonella and E. coli. (16) (17)

You can’t really blame cucumbers, because the guilty culprits are the cattle, pigs, and other animals whose defecation contaminates the groundwater.

Heavy metal contamination

Increased exposure to lead (Australian grown), chromium and Nickel (Saudi Arabian), and others have been reported in some samples. This has to do with contaminated soil and there isn’t evidence to suggest cucumbers have an increased propensity for sucking up heavy metals, like the green tea leaves of matcha do. (18) (19)

Increased nitrate exposure

During the winter months and throughout the year in certain regions, you may only have greenhouse grown cucumbers available.

The average nitrate concentration in greenhouse-grown has measured up to 2.7 times higher than the World Health Organization’s standard limit. (20)

Even organic cucumbers can have nitrate, because nitrogen comes from the ground and when it comes in contact with oxygen, it oxidizes and creates nitrates. Greenhouses may trap these nitrates and hence, the higher concentrations when grown inside them.

Consumption of wax

supermarket produce shelves of fresh colored bell peppers, cucumbers, and hot chili peppersThe cucumbers you buy at the grocery store are among the most waxed pieces of produce. Carnauba wax (which comes from a palm tree), beeswax, petroleum waxes, and shallac (from beetles) are all considered food grade and may be used on their skin.

Even organic cucumbers use wax, though it can’t be petroleum derived.

The beetle wax is non-vegan and frankly, disgusting no matter what your diet is. Likewise for other waxes, as most people would prefer non-shiny skin versus eating these!

Farmers markets and growing them in your own backyard are the best ways to avoid them. When you buy from the store you can peel the skin, but know that most of the antioxidants, vitamins and minerals will be lost in the process.

To remove the wax while keeping the skin, on Amazon you can get this all-natural veggie wash spray. It’s citrus-based.

What are cucumbers good for?

It’s not what they have, but what they don’t have which is their best benefit; calories. With almost none, cucumbers are a guilt-free food that you can snack on ‘til you’re stuffed.

What they do have in high amounts is vitamin K and electrolytes.

Although not proven, research suggests cucumbers may be good for arthritis, blood sugar, cholesterol, skin lightening, and cancer. Who would have thought such unusual benefits might come from this common vegetable, which is actually the 4th most consumed in the world.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.