Blood-Thinning Herbs

Q: I have antiphospholipid syndrome and have been advised to take 75 mg of aspirin daily to thin my blood. Is there an alternative blood-thinner? I already take borage oil for rheumatoid arthritis and have read that this has blood thinning properties. Is this correct? – Elaine, via e-mail

A: Antiphospholipid syndrome (APS) is an autoimmune disorder of unknown cause, although possible triggers for it may lie in its frequent association with other autoimmune or rheumatic conditions such as systemic lupus erythematosus (SLE) or rheumatoid arthritis – as in your case.

Normally, the body produces antibodies that fight bacteria, viruses and other causes of infection. But the antibodies made by people with APS attack the body instead. Since, in some cases, it comes with no symptoms, a blood test is one way to know for sure whether you carry these antibodies.

Problems associated with APS include an increased risk of complications during pregnancy, and a predisposition to blood clots (thrombosis). Anticoagulant therapy is often necessary to reduce these risks.

Low-dose aspirin, such as you’ve been recommended, is commonly prescribed by the medical community for APS, especially to women of childbearing age – but it is neither the only treatment nor the best one.

A line of antithrombotic defense often offered for APS is warfarin (Coumadin), an anticoagulant with a raft of potential complications. Although it is more effective than aspirin, it’s not often used because of the risk of haemorrhage, and the fact that patients taking the drug need frequent monitoring (Am J Geriatr Cardiol, 2005; 14: 81-6). Indeed, the average annual rate of fatal, or major or minor, bleeding during warfarin therapy is approximately five times that seen without warfarin therapy (Am J Med, 1993; 95: 315-28).

Perhaps for this reason, a new class of anticoagulants is on trial, including the direct thrombin inhibitor ximelagatran (Exanta). Shown to cause less bleeding than warfarin, it is, however, linked to severe liver damage that could even lead to death (Drug Saf, 2005; 28: 351-70), one reason it has not been approved by the US Food and Drug Administration (FDA).

So, we’re back to aspirin. Despite being referred to as a blood-thinner, aspirin works by inhibiting narrowing of blood vessels and platelet aggregation (clumping), which can lead to blood clots. However, aspirin on its own does not always provide enough antithrombotic effect. In short, patients taking aspirin are not likely to be fully protected against arterial blood clots (Thromb J, 2004; 2: 1).

The side-effects of aspirin are well known and include asthma, tinnitus, gastrointestinal bleeding and kidney failure (see WDDTY’s Arthritis Manual, which can be ordered online at http://www.wddty.co.uk or by calling 0870 444 9866). What’s more, the latest research shows that, over time, people with coronary heart disease taking 100 mg/day or less of aspirin are likely to develop resistance to aspirin (Am J Med, 2005; 118: 723-7).

Given all these negatives, it’s understandable that you seek an alternative to aspirin. More important, the borage seed oil you’re taking for your rheumatoid arthritis is not recommended in conjunction with either aspirin or warfarin.

The components in gamma-linolenic acid (GLA) – an omega-6 essential fatty acid found in many plant-derived oils such as borage, evening primrose and blackcurrant – enhance the action of anticoagulants and platelet inhibitors (Lipids, 1978; 14: 174-80). This, in turn, will increase the possibility of bleeding.

So, indeed, what you’ve heard is correct. GLA has not only been proven to reduce the pain of arthritis, but it can also help to protect against atherosclerotic (hardening of the arteries) and other heart diseases by effectively lowering blood levels of cholesterol and triglycerides (fats contributing to heart disease) while raising levels of ‘good’ HDL cholesterol (Ann Intern Med, 1993; 119: 867-73; Prostagl Leukotr Essent Fatty Acids, 1994; 51: 311-6). These were the findings of one small-scale study in which hyperlipidaemic patients – at high risk of atherosclerosis and other cardiovascular diseases – were given 3 g/day of GLA supplementation for four months. Their blood was ‘thinned’ by 45 per cent and bleeding time increased by 40 per cent (Prostagl Leukotr Essent Fatty Acids, 1994; 51: 311-6).

You’re on the right track with borage seed oil – it can provide relief from your joint pain while, at the same time, protecting you against the blood clots and heart diseases often seen in people who have APS. (Don’t forget that you can substitute evening primrose or blackcurrant oils for borage seed oil – the effect is the same.)

Other herbs to avoid taking as they are also anticoagulants include garlic, Ginkgo biloba and ginger (Ann Ital Med Int, 2000; 15: 139-43).

Garlic can prevent blood from clotting and reduce blood viscosity (‘thickness’) (Indian Heart J, 2004 ; 56: 176).

Ginkgo biloba can bring on spontaneous and increased bleeding, taken on its own and combined with anticoagulant drugs (J Cardiovasc Nurs, 2002; 16: 64-70; Am Surg, 2001; 67: 33-5).

Powdered ginger at high doses (a single 4- or 10-g dose) was found to reduce platelet aggregation (J Cardiovasc Nurs, 2002; 16: 64-70), although lower doses appear to have no such effects.

A number of other herbal remedies are thought to have blood-thinning effects – feverfew, danshen, dong quai and horse chestnut, to name but a few. Even onions have antiplatelet actions, dilate blood vessels and thin the blood (Arzneim Forsch, 2000; 50: 795-801).

Finally, you may wish to supplement your diet with omega-3 fatty acids, found in fish and flaxseed oils, as they are known to prevent arterial disease.