Neem for Heart Disease: Does It Work?
Does Neem (Nimba, Azadirachta indica) help with heart disease? Yes, in a specific and focused role. Neem is not a direct cardiotonic in the way Arjuna is, but the Bhavaprakash Nighantu, Varga 3 lists Hridya (cardiac tonic) among Neem's classical actions alongside Raktashodhaka (blood purifier), Pittashamaka (Pitta-pacifying), and Krimighna (anti-microbial). That combination matters for one particular cardiac pattern.
The case is strongest in Pittaja Hridroga and inflammatory cardiac disease where the picture is hot. Classical texts describe this as the angry, burning, red-faced cardiac picture: chest burning, hypertension with flushing, anger-driven angina, type-A personalities with strong ambition. Neem's bitter and astringent taste (Tikta, Kashaya Rasa), cold potency (Sheeta Virya), and Pitta-pacifying action target this profile directly. The Raktashodhaka mechanism, blood purification, also addresses the modern picture of inflammatory atherosclerosis, where chronic low-grade inflammation in the vessel wall drives plaque progression.
Neem is the wrong choice for the cold cardiac patterns. Pure Vataja Hridroga (cold extremities, irregular anxious palpitations, dryness) is aggravated by Neem's cold, dry, light qualities. Kaphaja Hridroga is a better fit only when there is a clearly infected or inflammatory overlay; for plain Kapha sluggishness, Ginger or Garlic are the better warming choices. Read the dosha pattern first, then decide: Neem belongs in the hot-inflammatory cardiac lane, not the cold or sluggish ones.
How Neem Helps with Heart Disease
Neem's cardiac action operates through a different route than the warming cardiotonics. Where Arjuna strengthens muscle and Ginger clears Kapha sludge, Neem works on the inflamed and toxic rakta-dhatu, the blood tissue that classical Ayurveda places at the upstream root of hot cardiac disease.
It cools the inflamed blood
Neem is bitter and astringent in taste (Tikta, Kashaya Rasa), cold in potency (Sheeta Virya), and pungent in post-digestive effect (Katu Vipaka), with light and dry qualities (Laghu, Ruksha Guna). It pacifies Pitta and Kapha while increasing Vata in excess. For the Pittaja Hridroga picture, burning chest, hypertension with red face, anger-flared angina, this profile is exactly the corrective. The bitter taste scrapes inflammatory residue from circulation, the cold potency cools the burning, and the dry quality counters the Kapha-Pitta sticky inflammation that drives atherosclerotic plaque.
Raktashodhaka is the lead mechanism
Bhavaprakash Nighantu names Raktashodhaka (blood purifier) as one of Neem's core actions. In classical pathology, vitiated Rakta is what carries Pitta heat into the cardiac and vascular tissue and inflames it. Neem clears this layer. Modern phytochemistry has identified Nimbidin, Nimbin, Nimbinin, and Azadirachtin as the active compounds, with documented anti-inflammatory and antimicrobial activity that maps onto the modern picture of chronic low-grade inflammation in the vessel wall driving plaque progression. The classical observation that Neem "purifies the blood" and the modern observation that nimbidin reduces inflammatory markers are describing the same thing.
It is the rare cold antimicrobial
Most antimicrobial herbs are hot and pungent and would amplify Pitta. Neem is the rare cold antimicrobial. This matters when cardiac inflammation rides on an infectious or toxin overlay, a picture classical texts call Krimi-aja, and which modern medicine recognises in inflammatory endocarditis and vasculitis. Neem fights the microbial layer without flaring the burning underneath. Its Hridya classification belongs alongside this Pittaghna action, the cardiac tonic effect is downstream of cooling the rakta.
How to Use Neem for Heart Disease
Neem is a precision tool for the inflammatory cardiac pattern, used in short courses rather than indefinitely. The classical caution applies: Neem is cold, light, and dry, so the dose, form, and pairing must protect against Vata aggravation, especially in patients who are already lean, anxious, or depleted.
Best form for this condition
Use Neem leaf powder or capsule for internal cardiac support, not Neem oil (which is for external use). The leaf is the part with the cleanest Hridya and Raktashodhaka profile. For chronic Pittaja Hridroga with elevated inflammatory markers, the bark decoction is a stronger alternative; for milder inflammatory load and mixed Pitta-Kapha pictures, the leaf form is enough.
Dosage and timing
| Form | Dose | Best for | How to take |
|---|---|---|---|
| Neem leaf powder (Nimba churna) | 500 mg to 1 g, once or twice daily | Pittaja Hridroga, inflammatory atherosclerotic load | Warm water after meals; or in honey if bitterness is hard to take |
| Neem leaf capsule (standardised) | 1 capsule, twice daily | Daily prevention in Pitta types, mild elevated CRP | After lunch and dinner with water |
| Neem bark decoction (Kvatha) | 30 to 50 mL, once daily | Heavier inflammatory or infectious cardiac overlay | Short courses only (3 to 4 weeks); morning, after food |
Anupana for cardiac use
For Pittaja Hridroga, take Neem with cool water and a teaspoon of honey, which both buffers the bitter shock and adds Yogavahi (carrier) action for the herb. For mixed Pitta-Kapha pictures, warm water is fine. Pair Neem with Manjishtha for the Rakta-cleansing layer, with Turmeric for compound anti-inflammatory action, or with Arjuna bark powder if direct cardiac tone is also needed. Never pair Neem with warming herbs in this context, the point is to cool the hot picture.
Duration
Run 4 to 6 weeks, then take a 2-week break. Neem is a short-course herb; daily long-term use will deplete shukra-dhatu (reproductive tissue) and aggravate Vata. Stop sooner if you notice dryness, weight loss, fatigue, or cold extremities, all signs that the cold-dry action has gone too far.
Frequently Asked Questions
How long does Neem take to work for heart disease?
Expect 4 to 6 weeks for clear changes in inflammatory markers and chest burning, with the digestive and skin benefits often appearing earlier (within 2 to 3 weeks). Neem is a short-course herb, not a daily long-term tonic; run 4 to 6 weeks, take a 2-week break, then reassess. If inflammatory cardiac markers (CRP, ESR) are not moving by week 6, the pattern likely is not Pittaja and a different herb fits better.
Can I take Neem with statins or blood pressure medications?
Neem is generally well tolerated alongside statins and most antihypertensives, with no major documented interactions at standard culinary or supplemental doses. The caution sits elsewhere. Neem has been associated with reduced fertility and may interfere with diabetic medications by lowering blood sugar, so if you are on insulin, oral hypoglycaemics, or actively trying to conceive, talk to your practitioner before starting. Avoid combining with other strongly bitter or drying herbs simultaneously.
What is the best form of Neem for heart disease?
Neem leaf powder (Nimba churna) or standardised leaf capsules are the right form for cardiac use, 500 mg to 1 g once or twice daily. Neem oil is strictly for external application and should never be taken internally for heart conditions. For heavier inflammatory load, a short course of Neem bark decoction is more potent, but use it under practitioner guidance.
Neem vs Arjuna for heart disease, which is better?
They do different jobs and pair well. Arjuna is the classical lead cardiac tonic, a direct cardiotonic that strengthens heart muscle and stabilises rhythm across all three dosha patterns. Neem is a Pitta-specific blood purifier for the inflammatory cardiac picture. For Pittaja Hridroga with elevated CRP, run both: Arjuna twice daily as the cardiac tone, Neem 500 mg to 1 g daily for 4 to 6 weeks as the inflammatory cleanup. For pure Vataja Hridroga, skip Neem and rely on Arjuna with milk.
Recommended: Start Neem for Heart Disease
If you want to start using Neem for heart disease today, here is the simplest starting point.
The best form for cardiac use is Neem leaf powder (Nimba churna) or a standardised leaf capsule, never Neem oil internally. Take 500 mg to 1 g once or twice daily, after meals, for a focused 4 to 6 week course. Neem is a precision tool for the hot inflammatory cardiac pattern, not a daily long-term tonic.
Kitchen version
Stir 1/4 teaspoon Neem leaf powder into warm water with a teaspoon of honey, after lunch and dinner. The honey buffers the intense bitterness and adds a Yogavahi (carrier) effect for the herb. If the bitterness is still too much, switch to capsules.
Dosha fork
- Pittaja Hridroga (burning chest, hypertension with red face, anger-driven angina, elevated CRP): Neem 500 mg to 1 g daily with cool water and honey. Pair with Manjishtha for compound blood-purification.
- Mixed Pitta-Kapha (cholesterol with mild inflammation): Neem 500 mg daily with warm water; pair with Arjuna for direct cardiac tone.
- Vataja Hridroga (cold extremities, anxious palpitations, dryness): skip Neem; the cold-dry action worsens this pattern. Use Arjuna with milk instead.
Find Neem on Amazon ↗ Arjuna Bark Powder ↗
Safety note: Neem can lower blood sugar and may interfere with diabetic medications; if you are on insulin or oral hypoglycaemics, consult your practitioner before starting. Avoid Neem during pregnancy and when actively trying to conceive.
Safety & Precautions
Neem is a powerful medicine, not a mild daily tonic. Used correctly it is remarkably safe, but it has a handful of specific contraindications that every user should know about. Several of these are well documented in both classical and modern literature.
Do Not Use During Pregnancy
This is the single most important warning. Neem has well-documented anti-fertility and abortifacient effects in both classical Ayurveda and modern animal studies. Neem seed oil in particular has been studied as a contraceptive. Avoid Neem in any form, leaf, bark, oil, or supplement, if you are pregnant or trying to conceive.
Fertility Reduction (Both Sexes)
Neem reduces sperm motility in men and interferes with implantation in women. If you are actively trying to conceive, stop Neem at least 2-3 months beforehand. This same effect is why Neem has been studied as a reversible natural contraceptive.
Blood Sugar Interactions
Neem lowers blood sugar. If you are taking insulin, metformin, sulfonylureas, or other anti-diabetic medication, Neem can push blood sugar too low (hypoglycemia). Use only under medical supervision and monitor your levels closely when adding or stopping Neem.
Never Ingest Neem Seed Oil
Neem leaf preparations are used internally. Neem seed oil is for external use only. Swallowing neem oil, even small amounts, has caused serious poisoning, especially in infants and children, with symptoms including vomiting, seizures, metabolic acidosis, and Reye-like encephalopathy. Keep neem oil locked away from children.
G6PD Deficiency
People with G6PD deficiency should avoid Neem. Some compounds in Neem can trigger hemolytic anemia in this population. If you have not been tested and are of Mediterranean, African, or South Asian heritage, ask your doctor before using Neem.
Vata Aggravation and Depletion
The Bhavaprakasha Nighantu notes that Neem is not ideal for people with high Vata, debility, emaciation, or cold signs. It is cooling, drying, and depleting when overused. People who are already thin, weak, dry, anxious, or convalescing should use Neem sparingly and short-term, ideally paired with a warming, nourishing herb.
Other Cautions
- Children under 2: Avoid all internal Neem. External use of diluted neem oil for lice or skin conditions is acceptable under adult supervision.
- Autoimmune conditions: Neem is an immune modulator. Those on immunosuppressant drugs should consult their physician.
- Surgery: Stop Neem at least two weeks before any scheduled surgery because of its effects on blood sugar and immune response.
- Heart conditions: The Bhavaprakasha notes Neem can be burdensome to the heart in excess, keep doses moderate.
For healthy adults using typical food-level or short-course therapeutic doses, Neem is well tolerated. Most reported adverse events involve neem seed oil ingestion, unusually high doses, or use during pregnancy.
Other Herbs for Heart Disease
See all herbs for heart disease on the Heart Disease page.
▶ Classical Text References (6 sources)
Nimbi Taila – (Neem oil) :ना यु णं न बजं त तं कृ मकु ठकफ णुत ् ॥ ६० ॥ Neem oil – is not very hot (slightly hot) in potency, bitter, anti microbial, useful in skin diseases and mitigates Kapha.
— Astanga Hridaya, Chapter 5: Drava Vigyaniya Drinkables
74 पटोलस तला र टशा गे टाव गुजा अम ृताः वे ा ब ृहतीवासाकु तल तलप णकाः म डूकपण कक टकारवे लकपपटाः नाडीकलायगोिज वावाताकं वन त तकम ् कर रं कु कं न द कुचैला शुकलादनी क ट लं के बुकं शीतं सकोशातकककशम ् त तं पाके कटु ा ह वातलं कफ प तिजत ् Patola, saptala, arista (neem leaves), sharngeshta (angaravalli/bharangi), Avalguja (Bakuchi), amruta (Tinospora), Vetra (shoot of vetra), Brhati (Solanum indicum), vasa (Adhatoda vasica), kutill, tilaparnika (badraka), mandukaparni (Gotu kola), Karkota, karavella
— Astanga Hridaya, Chapter 6: Annaswaroopa Food
Tikta Gana – group of bitters :त तः पदोल ाय ती वालकोशीर च दनम ् भू न ब न ब कटुका तगरा गु व सकम ् न तमाला वरजनी मु त मूवाट पकम पाठापामागकां यायोगुडू चध वयासकम ् प चमल ू ं महा या यौ वशाल अ त वषावचा Patoli, Trayanti – Gentiana kurroa, Valaka, Usira – Vetiveria zizanioides, Chandana – Sandalwood, Bhunimba – The creat (whole plant) – Andrographis paniculata, Nimba – Neem – Azadirachta indica, Katuka – Picrorhiza kurroa, Tagara – Indian Valerian (root) – Valeriana wallichi, Aguru, Vatsaka – Hol
— Astanga Hridaya, Chapter 10: Rasabhediyam Tastes, Their
Tikta Gana – group of bitters :त तः पदोल ाय ती वालकोशीर च दनम ् भू न ब न ब कटुका तगरा गु व सकम ् न तमाला वरजनी मु त मूवाट पकम पाठापामागकां यायोगुडू चध वयासकम ् प चमल ू ं महा या यौ वशाल अ त वषावचा Patoli, Trayanti – Gentiana kurroa, Valaka, Usira – Vetiveria zizanioides, Chandana – Sandalwood, Bhunimba – The creat (whole plant) – Andrographis paniculata, Nimba – Neem – Azadirachta indica, Katuka – Picrorhiza kurroa, Tagara – Indian Valerian (root) – Valeriana wallichi, Aguru, Vatsaka – Hol
— Astanga Hridaya, Chapter 10: Rasabhediyam Tastes, Their
The wound should be fumigated with the smoke of Guggulu, Aguru, Siddhartha, Hingu (Asa foetida), Sarjarasa, Patu (Salt), Sadgrantha(Acorus calamus) or leaves of Nimba (neem), mixed with ghee; Then a wick prepared from paste of Tila, ghee, honey and appropriate drugs should be placed inside the wound and also covered over.
— Astanga Hridaya, Chapter 29: Shastrakarma Vidhi
The wound should be fumigated with the smoke of Guggulu, Aguru, Siddhartha, Hingu (Asa foetida), Sarjarasa, Patu (Salt), Sadgrantha(Acorus calamus) or leaves of Nimba (neem), mixed with ghee; Then a wick prepared from paste of Tila, ghee, honey and appropriate drugs should be placed inside the wound and also covered over.
— Astanga Hridaya, Chapter 29: Shastrakarma Vidhi
Source: Astanga Hridaya, Ch. 5, Ch. 6, Ch. 10, Ch. 10, Ch. 29, Ch. 29
Nimbi Taila – (Neem oil) :ना यु णं न बजं त तं कृ मकु ठकफ णुत ् ॥ ६० ॥ Neem oil – is not very hot (slightly hot) in potency, bitter, anti microbial, useful in skin diseases and mitigates Kapha.
— Astanga Hridaya Sutrasthan, Drava Vigyaniya Drinkables
74 पटोलस तला र टशा गे टाव गुजा अम ृताः वे ा ब ृहतीवासाकु तल तलप णकाः म डूकपण कक टकारवे लकपपटाः नाडीकलायगोिज वावाताकं वन त तकम ् कर रं कु कं न द कुचैला शुकलादनी क ट लं के बुकं शीतं सकोशातकककशम ् त तं पाके कटु ा ह वातलं कफ प तिजत ् Patola, saptala, arista (neem leaves), sharngeshta (angaravalli/bharangi), Avalguja (Bakuchi), amruta (Tinospora), Vetra (shoot of vetra), Brhati (Solanum indicum), vasa (Adhatoda vasica), kutill, tilaparnika (badraka), mandukaparni (Gotu kola), Karkota, karavella
— Astanga Hridaya Sutrasthan, Annaswaroopa Food
Tikta Gana – group of bitters :त तः पदोल ाय ती वालकोशीर च दनम ् भू न ब न ब कटुका तगरा गु व सकम ् न तमाला वरजनी मु त मूवाट पकम पाठापामागकां यायोगुडू चध वयासकम ् प चमल ू ं महा या यौ वशाल अ त वषावचा Patoli, Trayanti – Gentiana kurroa, Valaka, Usira – Vetiveria zizanioides, Chandana – Sandalwood, Bhunimba – The creat (whole plant) – Andrographis paniculata, Nimba – Neem – Azadirachta indica, Katuka – Picrorhiza kurroa, Tagara – Indian Valerian (root) – Valeriana wallichi, Aguru, Vatsaka – Hol
— Astanga Hridaya Sutrasthan, Rasabhediyam Tastes, Their
The wound should be fumigated with the smoke of Guggulu, Aguru, Siddhartha, Hingu (Asa foetida), Sarjarasa, Patu (Salt), Sadgrantha(Acorus calamus) or leaves of Nimba (neem), mixed with ghee;
— Astanga Hridaya Sutrasthan, Shastrakarma Vidhi
Source: Astanga Hridaya Sutrasthan, Drava Vigyaniya Drinkables; Annaswaroopa Food; Rasabhediyam Tastes, Their; Shastrakarma Vidhi
In order to clean the seat of kapha and amashaya, the patient should be given the decoction of pippali, sarsapa (yellow sarson/Indian colza/Brassica campestris) and nimba (neem tree/Margosa/Indian lilac/Azadirachta indica) added with powder of pinditaka (madanaphala/emetic nut/bushy gardenia/Randia dumetorum) and saindhava (rock-salt).
— Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 20: Vomiting Treatment (Chhardi Chikitsa / छर्दिचिकित्सा)
Source: Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 20: Vomiting Treatment (Chhardi Chikitsa / छर्दिचिकित्सा)
Take rāsnā, vāsā, arka, triphalā, vidanga, bark of sigru, mushakaparni, neem, holy basin, nails of vyāghra (shell), durvā, sunflower, katukā, kākamāchi, brihati, kuṣtha, punarnavā, chitraka and dry ginger and make paste with cow’s urine.
— Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 12: Edema Treatment (Shvayathu Chikitsa / श्वयथुचिकित्सा)
In order to clean the seat of kapha and amashaya, the patient should be given the decoction of pippali, sarsapa (yellow sarson/Indian colza/Brassica campestris) and nimba (neem tree/Margosa/Indian lilac/Azadirachta indica) added with powder of pinditaka (madanaphala/emetic nut/bushy gardenia/Randia dumetorum) and saindhava (rock-salt).
— Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 20: Vomiting Treatment (Chhardi Chikitsa / छर्दिचिकित्सा)
The soup which is used for purification of breast milk, should be prepared with tender leaves of neem and vetra, parvala leaves, brinjal and amalaka added with dry zinger (shunthi), pepper, pippali and rock salt.
— Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 30: Gynecological Disorders Treatment (Yonivyapat Chikitsa / योनिव्यापत्चिकित्सा)
Source: Charaka Samhita, Chikitsa Sthana — Therapeutic Principles, Chapter 12: Edema Treatment (Shvayathu Chikitsa / श्वयथुचिकित्सा); Chikitsa Sthana — Therapeutic Principles, Chapter 20: Vomiting Treatment (Chhardi Chikitsa / छर्दिचिकित्सा); Chikitsa Sthana — Therapeutic Principles, Chapter 30: Gynecological Disorders Treatment (Yonivyapat Chikitsa / योनिव्यापत्चिकित्सा)
That which penetrates the subtle channels (Sukshma-chhidra) of the body is called Sukshma (subtle/penetrating), like Saindhava (rock salt), honey, Nimba taila (neem oil), and substances born of Eru (castor).
— Sharangadhara Samhita, Purva Khanda, Chapter 4: Dipana-Pachana Adikathanam (Digestive Actions etc.)
Pathyadi Kvatha: Pathya (Haritaki — Terminalia chebula), Nimba (neem — Azadirachta indica), Nidigdhika (Solanum xanthocarpum), Kiratatikta (Swertia chirayita), Guduchi (Tinospora cordifolia), and Chandana (sandalwood — Santalum album) decoction alleviates Pitta Jvara (fever caused by Pitta).
— Sharangadhara Samhita, Madhyama Khanda, Chapter 1: Svarasadikalpana (Svarasa, Kalka, Kvatha, etc.)
Panchanimba Churna [for Kushtha/skin diseases]: the root, leaves, fruits, flowers, and bark of Nimba (neem — Azadirachta indica) should be collected.
— Sharangadhara Samhita, Madhyama Khanda, Chapter 6: Churnakalpana (Powder Preparations - Extended)
Bibhitaka, Nimba (neem), Gambhari, Shiva, Shelu, Kakini — oil Nasya with each individually surely destroys premature greying.
— Sharangadhara Samhita, Uttara Khanda, Chapter 8: Nasya Vidhi (Nasal Therapy)
Alternatively, the barks of Khadira (Acacia catechu), Arishta (Azadirachta indica/neem), and Jambu (Syzygium cumini/black plum), combined with urine, or Kutaja bark (Holarrhena antidysenterica) with Saindhava (rock salt) as a paste, also destroys Arunshika (scalp dermatitis).
— Sharangadhara Samhita, Uttara Khanda, Chapter 11: Lepa Vidhi (Topical Paste Application)
Source: Sharangadhara Samhita, Purva Khanda, Chapter 4: Dipana-Pachana Adikathanam (Digestive Actions etc.); Madhyama Khanda, Chapter 1: Svarasadikalpana (Svarasa, Kalka, Kvatha, etc.); Madhyama Khanda, Chapter 6: Churnakalpana (Powder Preparations - Extended); Uttara Khanda, Chapter 8: Nasya Vidhi (Nasal Therapy); Uttara Khanda, Chapter 11: Lepa Vidhi (Topical Paste Application)
Then, fumigate the wound area with powders of Guggulu (Commiphora mukul), Aguru (Aquilaria agallocha), Sarja-rasa (Vateria indica resin), Vacha (Acorus calamus), white mustard (Sinapis alba), mixed with salt and Neem (Azadirachta indica) leaves, and anoint the vital points with ghee (18).
— Sushruta Samhita, Sutra Sthana, Chapter 5: Agropaharaniya Adhyaya - Surgical Instruments and Procedures
Post-operative fumigation with antimicrobial herbs (Neem, Guggulu, Vacha are all proven antiseptics).
— Sushruta Samhita, Sutra Sthana, Chapter 5: Agropaharaniya Adhyaya - Surgical Instruments and Procedures
Iron filings, copper dust, neem exudate collyrium, tin, and bronze residue — ground with flower juice.
— Sushruta Samhita, Uttara Tantra, Chapter 12: Raktabhishyanda Pratishedha Adhyaya (Chapter on Treatment of Blood-type Conjunctivitis)
Jasmine flowers, saindhava (rock salt), shringavera (ginger), krisna (black pepper) seeds, and the essence of kitashatru (neem) — this ground preparation with honey should be fearlessly applied as anjana in netra-paka (eye suppuration).
— Sushruta Samhita, Uttara Tantra, Chapter 12: Raktabhishyanda Pratishedha Adhyaya (Chapter on Treatment of Blood-type Conjunctivitis)
Vulture and owl droppings, the skin of a goat and buffalo, neem leaves, and Madhuka (licorice) should be used for fumigation.
— Sushruta Samhita, Uttara Tantra, Chapter 34: Shitaputanapratishedha
Source: Sushruta Samhita, Sutra Sthana, Chapter 5: Agropaharaniya Adhyaya - Surgical Instruments and Procedures; Uttara Tantra, Chapter 12: Raktabhishyanda Pratishedha Adhyaya (Chapter on Treatment of Blood-type Conjunctivitis); Uttara Tantra, Chapter 34: Shitaputanapratishedha
Medical Disclaimer: The information on this page is for educational purposes only and is not intended as medical advice. Ayurvedic treatments should be pursued under the guidance of a qualified practitioner (BAMS/MD Ayurveda). Always consult your healthcare provider before starting any new treatment. Content is sourced from classical Ayurvedic texts and may not reflect the latest medical research.