Open Source Apothecary At Home / The twelve-month course

Unit 11 (November): Heart, joints, and where herbs must defer

The month to learn the arithmetic of risk — and why the best-evidenced thing for a knee is not a pill.

guide

The physiology. The cardiovascular system is a pump and a set of pipes, and the things that damage it — high blood pressure, high LDL, smoking, diabetes, inactivity — are cumulative over decades. This is the system where the arithmetic of risk matters most, because a small reduction sustained over thirty years is worth a great deal, and a large reduction over none is worth nothing.

The arithmetic that must be understood. A plant product that lowers blood pressure by a few points is not equivalent to a drug that lowers it by twenty. For someone with high absolute risk, the difference is measured in heart attacks. That is not a reason to skip the herb; it is a reason never to substitute it.

What has real evidence.

| Target | What works | |---|---| | Blood pressure | Weight, sodium, exercise, potassium-rich diet, alcohol reduction — far more than any herb | | Knee osteoarthritis | Exercise and weight loss — outperform most pills. Curcumin has trials, comparable to NSAIDs in some | | Heart failure | Hawthorn has trials as an adjunct — never a replacement | | Cholesterol | Diet and statins where indicated; garlic and omega-3 move markers inconsistently |

The two safety lessons of the month.

Hawthorn is an adjunct and its users are usually on cardiac drugs — it may add to cardiac glycosides, beta-blockers and vasodilators. Nobody stops heart medication to take hawthorn.

Willow is where aspirin came from, and it carries aspirin's risks plus unpredictability — including the absolute prohibition in anyone under 19 with a fever or viral illness, because of Reye's syndrome.

The best-evidenced thing in this unit is not a herb. For knee osteoarthritis, exercise and weight loss have better evidence than anything in the pharmacopoeia. Saying so is the point.

What the studies found

Growing it

In season

• Hawthorn — berries, fully coloured. Harvest and dry for the winter.
• Rose hips — after the first frost, when they are sweetest
• Willow — bark from pruned branches, never the trunk
• Turmeric, ginger — lift before frost; save rhizome indoors
• Garlic — planted last month; now mulched and waiting

Garden work

• Mulch everything; the ground is going cold
• Dormant-season planting for woody medicinals starts now — bare-root elderberry and hawthorn
• Take hardwood cuttings of willow — they root almost regardless of treatment

Preparation

Project: a joint salve and a heart-support tea

Joint salve

• Calendula and ginger infused oil, with beeswax
• Optional: a 1-2% dilution of a warming essential oil, never neat
• Massage into the joint; movement and strengthening matter more than the salve

Heart-support tea

• Hawthorn leaf, flower and berry, with a little rose hip
• 1 teaspoon per cup, steeped 10-15 minutes
• An adjunct. Nobody stops cardiac medication for this.

The intervention that beats all of it for a knee

• Strengthening and low-impact aerobic exercise, and weight reduction where relevant
• This has better evidence than curcumin, and far better than the salve.

The blood-pressure arithmetic

• Weight, sodium, exercise, alcohol reduction, and a potassium-rich diet
• Check the medication list before any potassium-rich herb — see the potassium gate

Cautions and interactions

• Hawthorn is an adjunct to cardiac care, never a replacement. Never stop heart medication to take it.
• Never give willow bark to anyone under 19 with a fever or a viral illness — Reye's syndrome.
• Willow carries aspirin's risks — GI bleeding, anticoagulant interaction, contraindicated in pregnancy and peptic ulcer.
• High-dose curcumin supplements have caused liver injury, and curcumin adds to anticoagulants.
• Garlic, ginger, turmeric and hawthorn all interact with cardiac or anticoagulant medication.
• Do not self-treat chest pain, palpitations or a swollen ankle with an herb.

When this is not a self-care problem — get help

• Chest pain, breathlessness at rest, fainting or palpitations — emergency care.
• Rapid weight gain with ankle swelling — urgent assessment; possible heart failure decompensation.
• Vomiting and lethargy in a child or teenager given a salicylate during a viral illness — emergency care; possible Reye's syndrome.
• Very high blood pressure with headache, visual disturbance or chest pain — urgent care.

Related

• The twelve-month course
• Heart failure and cardiac support: hawthorn, CoQ10 and the limits
• Blood pressure: the dietary interventions with real numbers
• Exercise and load: the intervention with the best evidence in this section
• Turmeric, curcumin and osteoarthritis
• Hawthorn

Sources

1. Effects of Garlic Supplementation on Cardiovascular Risk Factors in Adults: A Comprehensive Updated Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrition reviews 2026; doi:10.1093/nutrit/nuaf090 PubMed 40580481
2. Comparative Effectiveness of Nutritional Supplements in the Treatment of Knee Osteoarthritis: A Network Meta-Analysis. Nutrients 2025; doi:10.1016/j.joca.2012.04.002 PubMed 40806131
3. Effects of Timing and Types of Protein Supplementation on Improving Muscle Mass, Strength, and Physical Performance in Adults Undergoing Resistance Training: A Network Meta-Analysis. International journal of sport nutrition and exercise metabolism 2024; doi:10.1123/ijsnem.2023-0118 PubMed 38039960
4. The efficacy of curcumin in relieving osteoarthritis: A meta-analysis of meta-analyses. Phytotherapy research : PTR 2024; doi:10.1002/ptr.8153 PubMed 38576215
5. Efficacy and safety of curcumin therapy for knee osteoarthritis: A Bayesian network meta-analysis. Journal of ethnopharmacology 2024; doi:10.1016/j.jep.2023.117493 PubMed 38036015
6. Effects of aged garlic extract on blood pressure in hypertensive patients: A systematic review and meta-analysis of randomized controlled trials. Prostaglandins & other lipid mediators 2024; doi:10.1016/j.prostaglandins.2024.106914 PubMed 39437887