About Herbs

Bottom line: Alfalfa may be effective at reducing cholesterol levels, but there is no evidence that it can treat cancer and it has many side effects. Because it also has a significant estrogenic effect, patients with hormone-sensitive cancers should avoid alfalfa.

Alfalfa contains fiber and a substance called saponins, which are thought to bind with cholesterol in the body and may reduce cholesterol levels. Alfalfa plants also contain phytoestrogens, which act like some human hormones. In fact, alfalfa phytoestrogens caused the growth of estrogen-dependent breast cancer cells. Alfalfa seeds also contain a toxic amino acid, L-canavanine. Levels of this amino acid vary widely across various cultivations of plants, and decrease as the plant matures. It is thought that this amino acid may be responsible for alfalfa's ability to cause a relapse of lupus symptoms in patients who are in remission from the disease, and large levels of L-canavanine from alfalfa supplementation may have additional detrimental effects in humans.

To treat diabetes
Although alfalfa appears to lower blood glucose levels in animals, no studies have tested whether it has any significant effect in patients with diabetes.

To treat high cholesterol
Two very small trials have shown that alfalfa supplements lower cholesterol levels in people with high cholesterol, but larger, controlled trials are necessary to confirm these results.

As a diuretic
This is not backed by experimental evidence.

To treat gastrointestinal disorders
No scientific evidence supports this use.

To treat asthma and hay fever
There are no studies to back this use.

To treat thyroid problems
No scientific evidence supports this use.

To increase lactation
Scientific evidence is lacking for this claim.

To promote menstruation
No scientific evidence supports this use in humans.

High Cholesterol:
This clinical study involved fifteen patients with hyperlipoproteinemia, a disorder that results in high cholesterol and alfalfa. Patients were given 40 grams of alfalfa seeds three times a day for eight weeks. At the end of the study total cholesterol levels and low-density lipoprotein (LDL or "bad" cholesterol) levels had decreased significantly in patients with high LDL without affecting the high-density lipoprotein (HDL or "good" cholesterol) levels. The small size of the study and the absence of a control group limits the validity of the results.

Better, larger studies are necessary to understand the effects of alfalfa on high cholesterol.

You are pregnant or nursing. (Because of its hormonal effects, alfalfa should be avoided during pregnancy and nursing.)

You have lupus. (Patients with systematic lupus erythematosus should avoid alfalfa tablets because they may lead to relapse.)

You have gout. (Due to the high content of purines, alfalfa should be avoided in patients with gout.)

You have hormone-sensitive cancer such as breast, prostate, cervical, or uterine cancers. (Estrogenic effects have been found in alfalfa.)

Buffalo Herb, Lucerne, Purple Medick, Purple Medicle, Purple Medic

The leaves and seeds of this widely used food crop are thought to have diuretic properties and to effectively treat diabetes, thyroid gland malfunction, arthritis, high cholesterol, and peptic ulcers ⁽¹⁾ as well as promote menstruation and lactation ⁽²⁾. Alfalfa is also a popular treatment for asthma and hay fever ⁽²⁾. The herb is claimed to be a source of vitamins A, C, E, and K and of the minerals, calcium, potassium, phosphorus, and iron ⁽³⁾. Small uncontrolled trials show that alfalfa can lower cholesterol levels in humans ^{(4) (5)}. Side effects are mainly gastrointestinal ⁽⁵⁾; however, cases of pancytopenia ⁽³⁾ and systemic lupus erythematosus relapse ⁽⁶⁾ have been reported. L-canavanine, a toxic amino acid contained in alfalfa seeds was shown to affect T cells ⁽⁷⁾. Whether dangerous concentrations of this substance are obtained through supplementation is uncertain ⁽⁸⁾.

Alfalfa sprout extracts exhibit potent estrogenic activity in vitro ⁽⁹⁾; therefore, patients with estrogen-sensitive cancers should avoid alfalfa supplementation. Further, rats fed alfalfa are more susceptible to colon cancer, although similar effects have not been observed in humans ⁽²⁾.

There are two reports of fatalities due to ingestion of alfalfa from contaminated sources ⁽¹⁰⁾, and a fatal case of listeriosis following ingestion of contaminated alfalfa tablets was reported ⁽²⁾. In addition, cases of salmonellosis have been attributed to contaminated alfalfa seeds ⁽¹¹⁾ and sprouts ⁽¹²⁾.

Alfalfa seed and alfalfa sprout are available in many countries and used frequently as animal feed ⁽²⁾.

Foliage:
Carotinoids: lutein
Triterpene saponins: sojasapogenol A-E aglycones medicagenic acid, hederagenin
Isoflavonoids: formononetin glycosides, genistein, daidzein, biochanin A, coumestrol,
Coumarins: coumestrol, 3'-methoxy coumestrol, lucernol, sativol, trifol, medicagol
Triterpenes: sigmasterol, spinasterol
Cyanogenic glycosides

Seeds:
L-canavaine
Betaine: stachydrine, homostacydrine
Trigonelline
Fatty oil
^{(1) (3)}

Saponins contained in this herb act on the cardiovascular, nervous, and digestive systems ⁽¹⁾. The hypocholesterolemic and hemolytic activity of the leaves and sprouts of alfalfa are attributed to a steroidal saponin fraction which along with fiber contained within the plant, binds to cholesterol in vitro. Alkaloids such as stachydrine and l-homo-stachydrine found in the seed are thought responsible for alfalfa's ability to promote menstrual discharge and for its lactogenic activity ⁽²⁾. Extracts from alfalfa preferentially served as agonists for estrogen receptor beta, and alfalfa increased estrogen-dependent MCF-7 breast cancer cell proliferation even more than did estradiol ⁽⁹⁾. The non-protein amino acid constituent, L-canavanine, constitutes 1.5% of the dry weight of alfalfa seeds and alfalfa sprouts. It has been shown to affect human T cells in vitro and induce hematologic and serologic abnormalities characteristic of systemic lupus erythematosus in monkeys ⁽¹³⁾. This mechanism has been proposed as the mechanism by which systemic lupus erythematosus relapse occurs in humans as well ⁽⁷⁾, although some researchers question whether L-canavanine concentrations in alfalfa are sufficiently substantial to cause this effect ⁽⁸⁾.

Alfalfa should be avoided during pregnancy and nursing ⁽¹⁴⁾. Patients with latent systemic lupus erythematosus have relapsed after ingesting alfalfa tablets ⁽⁶⁾. Alfalfa sprouts have been linked to a number of E. coli and Salmonella infections in California and Europe ^{(10) (11) (12)}.

Reported (Oral): Pancytopenia has been associated with ingestion of large amounts of ground alfalfa seeds ⁽³⁾. Increased fecal volume and defecation frequency, loose stools and diarrhea as well as abdominal discomfort and intestinal gas have all been reported in patients on alfalfa supplementation ⁽⁵⁾.

Alfalfa may increase serum urate and urea levels ⁽⁵⁾.

Molgaard J, von Schenck H, Olsson AG. Alfalfa seeds lower low density lipoprotein cholesterol and apolipoprotein B concentrations in patients with type II hyperlipoproteinemia. Atherosclerosis 1987;65:173-9.
Fifteen patients with hyperlipoproteinemia participated in a study of alfalfa seeds and cholesterol. Participants were given 40 grams of heat prepared alfalfa seeds three times daily for eight weeks. At eight weeks, total cholesterol levels and low density lipoprotein levels had decreased significantly without affecting HDL level. Side effects were minor gastrointestinal complaints. The small size of the study and the absence of a control group limit the validity of the results.