Intended for healthcare professionals

Rapid response to:


Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review

BMJ 2006; 332 doi: (Published 30 March 2006) Cite this as: BMJ 2006;332:752

Rapid Response:

A little of what you fancy does you good.

Long chain and shorter chain omega 3 fats do not have a clear effect
on total mortality, combined cardiovascular events, or cancer; should we
be surprised? Toxic compounds found in oily fish and fish oils may be a
factor but do we need to invoke methylmercury and the like when it is more
likely to be, as the authors state, ‘that its beneficial effect is limited
to a specific group’?

The decision to expose a patient to any intervention whatsoever
should be based upon two premises: first, that every actual prescription
is a clinical trial (1) and, secondly, that the evidence used should
relate to the best decision for the patient in front of you and not
necessarily that applicable in the group setting which ignores individuals
who are therein subsumed (2).

We are reminded that all clinicians and researchers should ‘first do
no harm’ (3) and this should also resonate without the arena of RCTs.
Prescribing a drug or suggesting any other intervention represents a trade
-off between its benefits and harms, which point I always make to patients
attending my pain clinic, and, increasingly, we are exhorted to
individualise the patient’s treatment and consider the benefit harm ratio;
indeed, the new consent process in respect of surgery, for example,
requires it.

Response by the patient to a medicine or any other intervention is
always (except twins) individual, we are not Sprague-dawley rats.
Treatment options need to be considered with appropriate outcome measures
to enable the better identification of those individuals or groups of
patients who may respond to also avoid denying safe and effective
treatments which should continue to be available for those who may derive
benefit therefrom (2).

For the general public some omega 3 fat is good for health (4) but,
of course, that some is good does not necessarily mean that more is better
and, likewise, in a different context, that if less is good it does not
necessarily mean that even less is better. Acting against the realisation
of all these simple premises are lined up medical practitioners,
epidemiologists, statisticians and the pharmaceutical industry – is it any
wonder that the patient may lose out? When big business, big money and
influence are involved there can be a risk of the eye being taken off the
ball as may have happened in the recent trial disaster (5).

Cholesterol is an integral part of lipid metabolism and homeostasis,
involved in the continuous turnover of cells but what is the right level?
Who can say, but we do know absolutely (and intuitively) that it will be
individual. Statins are, of course, big money and this means a big push
(with mega-dose therapy now proposed) to reduce the level of cholesterol
to one which may, in fact, be bad for many individuals. Peripheral
neuropathy as a recognised complication of use may be just the tip of an
iceberg which may well include chronic pain either exacerbated or de novo
in this association and the beginning of other problems related to
cellular turnover and requiring a patient specific level (6).

We ought to be more concerned that an individual’s inbuilt checks
upon their own intake of dietary constituents (including salt) are being
bypassed by food technology in particular and issues covered up with the
connivance of the pharmaceutical industry rather than properly addressed.

All things in moderation…………

1. Lake APJ. Every Prescription is a clinical trial. Br Med J 2004;
329: 1346.

2. Lake APJ. EBM for the future. J Eval Clin Pract (in press:
accepted 25.01.05).

3. Godlee F. Count the harms. BMJ 2006; 332,

4. BMJ, doi:10.1136/bmj.38798.680185.47 (published 24 March 2006)

5. Goodyear M. Learning from the TGN1412 trial. BMJ 2006; 332: 677-8.

6. Lake APJ. JACK SPRAT WOULD EAT NO FAT. Pain for the future?;595

Competing interests:
None declared

Competing interests: No competing interests

03 April 2006
Alfred P J Lake
Consultant in Anaesthesia and Pain Management
Glan Clwyd Hospital, Rhyl LL18 5UJ.