Asparagus Aerial

In alternative medicine, asparagus extract is typically used in "irrigation therapy" to detoxify the bladder and urinary tract. Asparagus is especially high in the flavonoid quercetin which is known to have antibacterial, antiviral, and anti-inflammatory properties.

Asparagus is rich in antioxidants such as vitamin E, vitamin C, and polyphenols that help neutralize free radicals that cause damage to cells. Asparagus is also rich in vitamin K (which plays a role in blood clotting), folate (needed to sustain a healthy pregnancy), and an amino acid called asparagine (essential to normal brain development).

Proponents believe that asparagus extract can prevent or treat a host of unrelated health conditions, including:

Chronic fatigue syndrome
Deep vein thrombosis
High blood pressure
High cholesterol
Joint pain
Kidney stones
Liver disease
Metabolic syndrome
Neural tube defects
Pulmonary embolism
Skin wrinkles
Urinary tract infections
Certainly with regards to digestive health, the insoluble fiber found in asparagus (thought to prevent constipation and reduce the risk of colon cancer) is all but missing in asparagus extract.

This shouldn't suggest that asparagus extract is without health benefits; it is simply that clinical studies investigating asparagus extract are sorely lacking. Here is what some of the current research says:

High Cholesterol
A number of studies have concluded that asparagus extract may help reduce cholesterol levels that contribute to heart disease,

According to a 2011 study published in Phytotherapy Research in 2011, mice fed a high-fat diet supplemented with asparagus extract experienced a significant decrease in "bad" LDL cholesterol and increase in "good" HDL cholesterol after eight weeks.

The effect was attributed to a substance called n-butanol, which the researchers say improves liver function and increases the organ's ability to produce and clear cholesterol. Further research is needed to see if similar results can be achieved in humans.
Asparagus extract may help fight diabetes, suggests a 2012 study from the British Journal of Nutrition. In tests conducted on rats with chemically induced diabetes, scientists found that asparagus extract helped normalize blood glucose levels and improve insulin secretion. Higher doses conferred to better results.

The effect was attributed in part to the trace element chromium which insulin uses to transport glucose through the body. Human research is needed to further evidence this effect.
As far-fetched as it may seem, asparagus extract may help relieve the symptoms of stress, suggests a 2014 study in the Journal of Food Science. According to the investigators, mice subjected to sleep deprivation had normal levels of stress biomarkers in blood tests (such as cortisol and lipid peroxide) after having been given a proprietary asparagus extract product. Untreated mice showed high elevations of all of these biomarkers.

The scientists also tested the extract on a small group of humans who were given a daily 150-milligram dose for seven days. At the end of the trial period, the subjects experienced significant increases in a protein called HSP70, which tempers the effect of cortisol and other stress hormones.

By doing so, asparagus extract may help mitigate the physiological impact of stress, such as high blood pressure, fatigue, and mental "fog." The study does not suggest that asparagus can either reduce stress or deliver "calming" psychoactive effects. Further research is needed.

Breast Cancer
When buying asparagus extract, the two ingredients often highlighted on the product label are asparagine and glutamine. This is because asparagine is thought to enhance athletic performance and improve brain function, while glutamine is considered one of the body’s more potent anticarcinogens. Sadly, these two compounds appear to have contradictory effects insofar as cancer is concerned.

According to a 2018 study in Nature, the asparagine actually shields cancer cells from the effects of glutamine and promotes rather than inhibits the spread of breast cancer. The investigator found that exposing breast cancer cells to increasing concentrations of asparagine in the test tube triggered metastasis (the spread of cancer), while the restriction of asparagine reduced the metastatic risk.

The scientist concluded that the risk was not only associated with the intake of asparagine through foods like asparagus but through asparagine-rich supplements and extracts.