Beware of the green god

Celery juice may be the latest trend in miracle cures, but does it really have as many health benefits as promised?

Khuen chai, or the so-called Thai celery, is richer in nutrients than Western celery, far right. Khuen chai, for example, has 10 times more vitamic C than Western celery.

When Grammy-award singer Pharrell Williams posted on his Instagram a photo of himself with the "green juice" last September, celery juice started to gain momentum. But later as more celebrities including Selma Blair, Jenna Dewan and even Kim Kardashian jumped on the bandwagon, the drink officially became a serious health trend.

And now celery juice is in vogue in Thailand too with various YouTubers and health influencers unveiling miracle celery juice recipes and formulas that claim to render a number of health benefits, especially weight loss and anti-inflammation. Despite its relatively strong smell and flavour, the drink has become so popular that the hashtag #CeleryJuiceChallenge is trending on various social media platforms.

Assoc Prof Ratchanee Kongkachuichai, director of the Institute of Nutrition under Mahidol University, explained that although celery is full of nutritional value, it does not mean that the leafy vegetable can be consumed without cautionary notes.

"Moderation is still key in the case of celery juice consumption as with other dietary intakes," she said.

In Thailand, there are two main celery varieties: Western celery and khuen chai or the so-called Thai celery (or sometimes called Chinese celery). Although both varieties share the same family of Apiaceae, they are quite different in terms of nutritional volume.

According to Ratchanee, celery -- regardless of variety -- contains 90-95% water. But given that Thai celery has a smaller trunk, its nutritional concentration is higher when compared to Western celery.

"Khuen chai has 10 times more vitamin C than celery," said Ratchanee. "While 100g of khuen chai contains only 33mg of vitamin C, the same amount of celery contains 3.1mg of vitamin C."

The same goes with other nutrients found in celery. While 100g of Western celery has 0.2mg of iron and 40mg of calcium, Thai celery contains 2.7mg and 150mg respectively.

A number of people and celebrities worship celery juice as their magical detox drink. American actress and model Brooke Burke said in an April interview that the green drink is "a really good cleanse and the right way to start your day". As the 48-year-old Dancing With The Stars co-host has been battling with chronic colon inflammation and other gut issues, she is trying to heal her body naturally as she reportedly drinks celery juice every morning.

Ratchanee said that celery juice can indeed help with body detoxification through regular bowel movement, which is a natural way through which the body rids wastes and unwanted elements.

American rapper and songwriter Pharrell Williams posted a photo captioned 'Green Joice' on his Instagram last September.

"Every 100g of celery contains up to 3g of fibre, which is quite a lot. So no wonder it can help detox the body because it stimulates bowel movement."

Set aside its detoxification boosting properties, celery juice is claimed on social media to be a shield against cancer and inflammation, not to mention offering acne-free bright skin, anti-oxidant agents and helping with weight loss among the obese.

Does this mean celery juice is another miraculous cure-all?

Unfortunately, Ratchanee found no scientific proof to support all those promises.

"There is no medical evidences whatsoever to back up the claimed benefits of celery juice," she commented. "Only a few research papers did mention colon cancer and diabetes. But these were just studies on lab animals.

"The benefits of celery juice have never been studied in humans. And when there is no study on humans, people should take it with a grain of salt."

Amid the green drink fever, Ratchanee is most concerned about the when and how of celery juice consumption. The juice, she said, should by no means be considered a substitute for main meals. Neither should it be consumed too close to meal time.

"People who opt for celery juice as a weight loss regimen might replace their main meal with the drink. When that's the case, they will only get a small amount of vitamins, with zero protein, fats, carbohydrates as well as fat-soluble vitamins that they usually get from normal eating. Apparently this can be bad for the body because nutritional deficiency can lead to physical deterioration. Then what's the point of being on a diet if people do not look good thereafter?"

Also if people drink celery juice in the morning, there are chances that they will skip breakfast -- the most important meal of the day.

The nutritional expert therefore recommends celery juice disciples to have a glass either before bedtime or between main meals. Only a maximum of 200ml per day is advised. "The consumption of celery juice prior to bedtime will help stimulate bowel movement when people wake up. But most importantly, the vegetable must not be juiced by means of fibre extraction. Otherwise drinkers will only receive phytochemicals [chemical compounds produced by plants], but not fibre."

Consuming nothing but a single type of vegetable for days could end up detrimental to health, added Ratchanee. Here in the case of celery, a leafy vegetable that is prone to being exposed to insecticides, those who opt for it day after day could end up killing themselves rather than boosting the physical health.

"Too much chemical residue can accumulate inside the body if you opt for the very same kind of vegetable all the time. So instead of benefiting from it, you might end up putting yourself at risk of cancer."

Celery is high in potassium. Especially for khuen chai, 100g of it contains up to 400mg of potassium. People with underlying illnesses especially chronic kidney or heart disease should be extra careful when it comes to celery juice consumption as excessive potassium intake could result in palpitations, abnormal heartbeat, fatigue, nausea, vomiting, chest tightness and even heart failure.

"Despite celery's nutritional benefits, celery juice should not be consumed every day. This is to mainly prevent the body from chemical contamination," Ratchanee warned.

Recently, a number of medical specialists started to come out and warn the public with regard to the consumption of celery juice. Among them was director-general of the Department of Health Dr Panpimol Wipulakorn who said patients with kidney disease should pay special attention to their celery juice intake given that too much potassium can do more harm than good.

As with other health mantras, moderation is the rule of thumb.

"For people who like to drink any fruit or vegetable juice for health benefits, of course they can do it. Just make sure to juice a variety of produce. A mix of various fruits and vegetables in one glass isn't a bad idea. A little bit of ginger in celery juice is recommended too given ginger is proven to help lower blood pressure."

"For the body to properly function, various chemical compounds are necessary and people will get sufficient amount of them only if they don't fail to eat a variety of diets. This is one of the best ways to effectively reduce the risk of cancer and other illnesses."