Alfalfa has been used as a medicinal plant for at least 4000 years and is still popular today. It has been a valued herb in both Chinese and Indian medicine for millennia. What makes it so enduring? Read on to find out what the buzz is all about.
What is Alfalfa?
Alfalfa (Medicago sativa) is the most commonly grown legume in the world. It originated in Asia, but today the U.S. is the biggest producer. Its name is rooted in an Arabic phrase meaning the “father of all foods” and its traditional use spans thousands of years .
Alfalfa has become all the buzz among health-conscious consumers nowadays. You’ll hardly find a health food store without alfalfa sprouts or powder. But you might be surprised to hear that the majority of produced alfalfa goes to the food industry, which uses it as animal feed .
Before it made its way into Western food stores and farms, alfalfa was used for a long list of health ailments in the East. Traditionally, it is believed to be a remedy for improving memory, breastfeeding, kidney problems, and arthritis. It is a valued herb in traditional Chinese medicine (TCM) and traditional Indian medicine (Ayurveda) .
Besides being a great source of vitamin K, alfalfa is also rich in phytonutrients. The antioxidants in alfalfa come in different varieties and include :
- Flavonoids: quercetin, myricetin, luteolin, apigenin
- Phenolic acids: coumaric acid, ferulic acid, salicylic acid, caffeic acid
- Phytoestrogens: coumestrol, formononetin, daidzein
The importance of antioxidants for health can hardly be overstated. Systemic inflammation and oxidative stress are involved in virtually every chronic disease. The polyphenols in alfalfa and other foods may help by countering inflammation and free radical damage [2, 3, 4].
In both cell and rat studies, alfalfa reduced markers of oxidative stress. It reduced free radical production, limited DNA damage and boosted the antioxidant glutathione. It also protected the liver from damage [5, 6].
Alfalfa extract has shown brain-protective effects in rats. The extract limited brain cell death due to a lack of oxygen (hypoxia). It also boosted antioxidants inside cells, including glutathione and superoxide dismutase (SOD) .
100 grams (3 cups) of raw alfalfa sprouts provides :
- 23 calories
- 4 grams of protein
- 0.7 grams of fat
- 2.1 grams of carbohydrates
- 1.9 grams of fiber
The sprouts are about 93% water, which explains their low calorie and macronutrient count.
Alfalfa is a good source of the following vitamins and minerals (per 100 grams) :
- Lowers cholesterol
- Reduces symptoms of menopause
- Rich in nutrients
- May improve diabetes
- May lower inflammation
- May protect the heart
- Few human studies
- Seeds may be contaminated
- Drug interactions are possible
- May cause or worsen autoimmunity (rare)
- Unsafe in pregnancy
- Contains lectins and other antinutrients
Alfalfa is considered safe to consume as food, but supplements have not been approved by the FDA for medical use and generally lack solid clinical research. Regulations set manufacturing standards for them but don’t guarantee that they’re safe or effective. Speak with your doctor before supplementing.
The following purported benefits are only supported by limited, low-quality clinical studies. There is insufficient evidence to support the use of alfalfa for any of the below-listed uses. Remember to speak with a doctor before using alfalfa for health reasons, and never use it in place of something your doctor recommends or prescribes.
In a clinical trial of 15 people with high blood fat levels, alfalfa seeds reduced both total and LDL cholesterol. The seeds also reduced apolipoprotein B, a marker of heart disease. A high dosage used: 40 g of alfalfa seeds 3 times daily for 8 weeks .
In a pilot trial, alfalfa seeds reduced total cholesterol levels in the blood. The seeds also reduced the absorption of cholesterol from food and increased bile acid elimination with the stool. It’s hard to draw conclusions from this study; it’s over 3 decades old, included only 3 volunteers, and lasted 3 weeks .
Two rat studies confirmed that alfalfa reduces the absorption of cholesterol from food. But if compounds called saponins were removed, cholesterol absorption went back to normal. Thus, these saponins are likely responsible for its cholesterol-lowering effect [11, 12].
In one clinical trial, a combination of alfalfa and sage reduced hot flashes and night sweats in 30 menopausal women .
The positive effect on menopausal symptoms is usually attributed to phytoestrogens. There are 3 main types of phytoestrogens:
- Isoflavones (e.g. genistein, daidzein, formononetin)
- Coumestans (e.g. coumestrol)
Alfalfa is a rich source of the second group (coumestrol). It also contains phytoestrogens from the first group. According to numerous epidemiological studies, phytoestrogens improve symptoms of menopause by mimicking the effects of estrogen [15, 16, 17].
One cell study demonstrated alfalfa’s estrogenic effects and its ability to target estrogen receptors .
No clinical evidence supports the use of alfalfa for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
Alfalfa is traditionally considered an anti-diabetic plant, and there is some research to back this up. In diabetic rats, alfalfa water extract significantly reduced blood glucose. It also lowered LDL cholesterol and triglycerides. The extract also countered liver damage and reduced the liver enzymes ALT and AST .
In a mouse study, adding alfalfa to the animals’ diet both lowered blood sugar. The water extract raised insulin release. Interestingly, it increased sugar storage too, somewhat mimicking the action of insulin. This might be helpful for some type 1 diabetics and those with advanced type 2 diabetes .
Lipopolysaccharide (LPS) is a toxin produced by Gram-negative bacteria (such as E. Coli) that causes inflammation. In people with leaky gut, this toxin can cross into the bloodstream. In both test tubes and mice, alfalfa extracts reduced inflammation induced by LPS. They reduced several markers of inflammation (including NF-kB, IL-1, IL-6, and TNF-alpha) [21, 22].
LPS strongly contributes to autoimmune arthritis. As mentioned, LPS can migrate from the gut into the blood. There it primes the body for an autoimmune inflammatory response, which can make mild symptoms turn into a full-blown disease. Since alfalfa reduces inflammation from LPS, it may be helpful for leaky gut and arthritis. However, clinical trials to confirm this are lacking [26, 27, 28, 29, 30].
High cholesterol may cause arteries to harden and clog. As discussed, alfalfa can lower cholesterol levels. A few animal studies have confirmed that alfalfa indeed prevents clogged arteries, even when in animals that eat lots of cholesterol [31, 32].
Additionally, flavonoid antioxidants in alfalfa may protect the heart by:
- Lowering cholesterol and blood pressure
- Improving the flexibility of blood vessels
- Countering systemic inflammation and oxidative stress
One review concluded that for every 100 mg of flavonoids a person eats, their risk of stroke may drop by as much as 9%. It is unclear to what extent the specific flavonoids in antioxidants may be helpful for this purpose [33, 34, 35].
Alfalfa is “generally recognized as safe” (GRAS) by the FDA. However, certain people may wish to avoid it for various reasons. To avoid adverse effects or unexpected interactions, talk to your doctor before using alfalfa for health purposes or making significant changes to your diet.
Alfalfa is potentially unsafe during pregnancy, as it may stimulate the uterus. No data exists on the safety of alfalfa in nursing. Since we do not know which byproducts of alfalfa are passed on to the baby through breast milk, nursing women should avoid it [36, 37].
Alfalfa can be an immune stimulant. It should be avoided if you have an autoimmune disorder or a family history of autoimmune disorders.
Even more worryingly, alfalfa has been reported to cause (or reactivate) lupus in a few rare cases. It is suspected that the amino acid l-canavanine is the trigger, since it is toxic to animals. L-canavanine is mainly present in the seeds of alfalfa [38, 39, 40].
Alfalfa seeds are sometimes contaminated with bacteria. There have been several cases of people becoming ill after eating raw alfalfa sprouts. For this reason, anyone with a weaker immune system should avoid them – including children, the elderly, and people taking immune-suppressing drugs [41, 42, 43].
We don’t know if alfalfa contains enough of these compounds to cause sunlight sensitivity in humans, but it is something to be on the lookout for if you are taking alfalfa supplements.
As with all non-organic crops, pesticide levels in alfalfa are a concern. U.S. farmers traditionally used herbicides such as 2,4-DB and paraquat on alfalfa, but are increasingly shifting to glyphosate. This is due to the introduction of genetically modified, herbicide-tolerant seeds. Look for organic alfalfa if you want to avoid these pesticides .
Alfalfa is a legume and contains lectins, which are mainly concentrated in the seeds. Normally, sprouting seeds helps to break down lectins. But in the case of alfalfa, it seems sprouting actually increases the lectin content. Alfalfa contains other antinutrients as well. If you have food sensitivities and/or autoimmune issues, you might be better off avoiding alfalfa .
Alfalfa may interact with certain drugs. These include :
- Warfarin. Alfalfa contains high amounts of vitamin K, which aids in blood clotting. People taking blood thinners should avoid it.
- Birth control pills & estrogen. Alfalfa contains phytoestrogens that may interfere with the estrogen in these medicines.
- Drugs that increase sunlight sensitivity. Alfalfa may increase sensitivity to sunlight. Be careful if you take any medications that increase sunlight sensitivity.
- Immunosuppressants. Alfalfa stimulates the immune system. Avoid it if you are on medications to suppress your immune system.
Few human studies on alfalfa exist, most of which are low-quality. A higher level of evidence supports its benefits for lowering cholesterol and improving menopausal symptoms.
In animal studies, alfalfa improved diabetes, lowered inflammation and protected the heart, but these findings may not translate to humans.
You can easily grow your own alfalfa sprouts at home. All you need is some alfalfa seeds, water, a jar, and a breathable lid to cover it. The lid can be from gauze, cheesecloth, a pantyhose or a screw-on lid with holes. Follow these steps:
- Put 1-2 tablespoons alfalfa seeds in a jar and cover with about an inch of water
- Cover with a breathable lid and soak overnight (8-12 hours)
- Drain and rinse thoroughly
- Continue to rinse 2-3 times daily
- On the 3rd day, move the jar to a place with indirect sunlight
- Continue to rinse 2-3 times daily
- On the 6th day, the sprouts should be ready
Various alfalfa supplements are also available, in case you’re not a fan of sprouting or would prefer to get a consistent daily dose. Some of these include:
- Raw alfalfa herb
- Cut alfalfa leaves
- Powdered alfalfa leaves or juice
- Alfalfa liquid extracts
- Alfalfa tablets and capsules
There is no safe and effective dose of alfalfa or its extracts because no sufficiently powered study has been conducted to find one. For lowering of cholesterol, a very high dose of 120 g/day of heat-treated alfalfa seeds as been used, split up into 3 doses over the day.
The British Herbal Medical Association recommends :
- Dried aerial parts (i.e. leaves/whole herb): 5-10 g, 3 times daily
- Infusion: 5-10 g, 3 times daily
- Liquid extracts: 5-10 g, 3 times daily
Raw, unprocessed honey is naturally antiseptic and antibacterial .
Alfalfa honey is prebiotic, meaning that it may encourage the growth of beneficial gut bacteria. In one study, alfalfa honey enhanced the growth of five human Bifidobacterium species, including B. longum, B. adolescentis, B. breve, B. bifidum, and B. infantis .
Alfalfa honey retains many of the antioxidant compounds from the plant. But this is the case with many other honey types. Alfalfa honey probably offers similar benefits, but it’s unlikely to be superior.
The exact active compounds in alfalfa honey will vary from one manufacturer and geographical location to the next.
One analysis compared alfalfa and clover honey: clover had 19 antioxidant phenolic compounds, while alfalfa had only 14. Only clover honey contained genistein, quercetin, and caffeic acid. Others, such as daidzin, were up to 10 times more concentrated in clover honey. Gallic acid was found in only alfalfa honey and not in clover .
Alfalfa is an ancient herb that has been used medicinally for millennia. It is a rich source of vitamin K, flavonoids, and phytoestrogens. It is most often used to lower cholesterol and blood sugar, fight oxidative stress, and ease menopausal symptoms.
The use of alfalfa is not entirely risk-free, as the herb has strong immune-stimulant potential. The seeds contain lectins and may be contaminated with bacteria. Always heat the seeds before use, or avoid them entirely. Alfalfa shouldn’t be used in pregnant or breastfeeding women. Also, avoid it if you suffer from an autoimmune disorder or take prescription drugs.