Celery is crunchy with a distinctive taste and a talent for livening up soups. But could celery also protect you from high blood pressure?
According to the National Heart, Lung and Blood Institute at the National Institutes of Health, 50 million Americans suffer from high blood pressure. High blood pressure is called the ‘silent killer’ because although most people don’t realize they have it, it’s a major risk factor for developing heart attack or stroke. Heart disease and stroke are the first and third leading causes of death in the US (figures from the Centers for Disease Control and Prevention state 616,067 people die from heart disease and 135,952 from stroke each year) so it’ s important to keep an eye on your blood pressure.
What is high blood pressure?
Blood pressure measures the pressure of blood in your arteries and it is scored using two figures. The top number is systolic blood pressure, the pressure in your arteries when the heart contracts. The bottom number is the diastolic blood pressure, your resting blood pressure between heart beats. High blood pressure is categorized as 140/90 mmHg or above each time it is taken. Having high blood pressure, or hypertension, over a long period of time damages your arteries and puts a strain on your heart, leading to increased risk of heart disease and stroke.
How Does Celery Help?
There are many methods of lowering blood pressure, both natural and pharmaceutical, but in 1992 a study from the University Of Chicago Medical Center discovered one surprising weapon in the fight against hypertension --celery.
Dr. William Elliott and Quang T. Le found celery had properties that lowered blood pressure. Mr. Le was prompted to investigate the vegetable when his father, who suffered from high blood pressure, ate a quarter-pound of celery a day and found this lowered his blood pressure from 158 over 96 to 118 over 82.
This significant drop in blood pressure was replicated in the University Of Chicago Medical Center study. The researchers reported that a small amount of celery extract, equivalent to four celery stalks, lowered blood pressure in rats by 12 to 14 percent and lowered cholesterol by around 7 percent. Elliott and Le found it was an active chemical in celery that lowered blood pressure and that this chemical worked by relaxing the smooth muscles that line blood vessels and by lowering stress hormones in the blood. Stress hormones cause blood vessels to constrict, raising blood pressure. This active ingredient is called 3-n-butylpthalide, or phthalides.
Does Celery Really Work?
Celery has been used for medicinal purposes since the birth of medicine itself, with Hippocrates prescribing the vegetable as a tonic for those suffering from nervous tension. Celery is also popular in Chinese medicine but it has only recently been tested by Western scientists.
Following the University of Chicago study, a 1997 study from the National University of Singapore found further evidence of celery’s blood pressure lowering powers when they studied the blood vessel relaxation effects of 3-n- butylphthalide in spontaneously hypertensive rats (SHR). Authors Tsi and Tan looked at the rats over 13 days and found phthalides administered at high daily doses of 2 mg and 4 mg didn't reduce blood pressure over time. However, phthalides in lower doses of 0.5 mg a day did decrease systolic blood pressure. Whether these results were due to tolerance being built up in the body at high doses or another element of the study which wasn’t functioning properly is unclear.
Celery contains high levels of the flavonoid called apigenin. A 2006 report by Raquel Soares and Isabel Azevedo from the University of Porto, Portugal, in the American Journal of Pathology demonstrated that apigenin fights cellular oxidative stress and acts as an anti-inflammatory agent. When oxidative stress occurs within arteries, it makes the blood vessel less flexible and unable to properly relax, increasing blood pressure.
Here's the news. Apigenin was found only in celery and a few other vegetables: Chinese cabbage, bell pepper, garlic, belimbi fruit, French peas, snake gourd, guava, wolfberry leaves, daun turi and kadok, according to a University of Putra Malaysia study.
From these studies it appears that celery can lower blood pressure. But the exact amount of celery needed to achieve the drop in blood pressure found in animals cannot be determined until clinical trials are conducted on humans using celery itself.
Celery Is High In Salt, So Is it Dangerous to Use Celery to Lower Blood Pressure?
How Much Celery Should You Eat to Lower Blood Pressure?
Elliott and Le in the original study warned that phthalides' effectiveness had yet to be proved and, until then, they cautioned against overeating celery.
Celery is high in salt (one stalk contains 32mg of sodium) and lowering blood pressure is not usually equated with eating high-sodium foods.
Do the sodium risks outweigh the phthalides benefits in celery? The U.S. Food and Drug Administration's recommended daily intake of sodium is 2,400 mg, the equivalent of about 48 stalks of celery. Since 4 stalks of celery, the amount tested in the study, only make up around 8 percent of your daily intake ,you’ll be safe to eat this amount in addition to following a healthy, low-salt diet.
What Else Can Celery Do?
As well as lowering blood pressure, celery has also been shown to lower cholesterol. In addition to the 7 percent drop in cholesterol levels found in the University Of Chicago Medical Center study, a 1996 study from the National University of Singapore found celery extract reduced LDL (bad) cholesterol in rats. However, when 3-n-butylphthalide on its own was given to rats, there was no significant change, leading researchers to believe “the effect of celery extract on serum cholesterol levels… could be attributed to chemical constituents other than 3-n-butylphthalide.” Further studies are needed to fully demonstrate which compounds in celery have an effect on cholesterol.
Celery is a good source of Vitamin C (3.1mg per 100g), dietary fiber (1.6g per 100g), potassium, folate, molybdenum, manganese and Vitamin B6. You can add celery to soups to give it a salty flavor without increasing the sodium content of your meal, or juice it for a healthy drink mixed with tomatoes or other vegetables. While further studies are needed to prove celery’s exact actions in lowering blood pressure and cholesterol, it can be a real benefit to your diet when eaten in moderation.