04 February 2013

Ian Gawler Blog: Do supplements shorten lifespan?

Could taking a daily multivitamin and multimineral pill shorten your life? Not many in the public would seem to think so given that these pills are the most common form of supplements taken in the world. Yet several large studies from 5 to 10 years ago were pretty clear; such pills could take up to 7 or 8 years off your life!

Now a new study from Melbourne throws new light on the question – a must read for health practitioners and people generally. But first

Thought for the day
Dream the impossible. 
Know that you are born in this world to do something wonderful and unique. 
Do not let this opportunity pass by. 
Give yourself the freedom to dream and think big.
                                                                Ravi Shankar

The right question to begin with is why take a generalised multivitamin/multimineral supplement at all? For most the answer would seem to start with their knowledge that the quality of our food has been degraded by commercial growing practices. Then there is the environmental pollution we all face, coupled with the stresses and strains of a modern, busy life. Fast food, junk food, eating in a rush, eating what happens to be there. Lots of concerns, and then the hope that extra vitamins and minerals taken via a pill will at least compensate, maybe even be good for us.

Seems like a reasonable proposition. But then in 2003 large meta-analyses (the collated results of many individual studies) began to be published and continued to appear over the next 5 years with findings that showed a shorter life span was associated with popping these particular pills.

Needless to say there was a big discussion. Advocates of supplementation came out strongly, claiming the individual studies had a range of flaws. Poor sample selection was discussed, the health of those studied and synthetic vitamins were blamed (chemically produced vitamins rather than naturally derived versions). 

At the centre of it all, Vitamins A and E seemed to be the main culprits, but to my knowledge no manufacturer has come forward and offered to produce a multivitamin/mineral supplement without A and E. Of course, some people may well benefit from specific supplements such as selenium, iodine, iron, magnesium, vitamins D and B12 etc; but that is where specific advice from a doctor trained in nutritional medicine or a good naturopath comes into their own and may well need to be consulted.

In 2009, with a good deal of input from my colleague Prof George Jelinek, I co-authored a discussion paper focussed on the key articles available at the time, (to view, click here) and concluded the following:

1. Food is the best source of human nutrition. 

2. People eating a healthy diet and living a healthy lifestyle are rarely likely to need nutritional supplements. 

3. There is strong evidence that taking supplements of vitamins E and A shortens life. 

4. More research is needed in this field. 

5. There may be a case for a multivitamin/mineral supplement that does not contain vitamins E or A.

In the new edition of You Can Conquer Cancer, which includes recommendations on food and supplements for people who are basically healthy, as well as for those with cancer, I commented further:

“I know of no studies being published regarding the long-term use of Vitamins A and E by people affected by cancer, and maybe they are OK short term, but the caution (for those who are well and take them long-term) needs to be stated”.

However, what we do know (as reported in a July 2012 blog), is that a study in 2011 found that for women with breast cancer who consistently used multivitamins before and after diagnosis and ate more fruits and vegetables, as well as being more physically active had better overall survival. As well, these researchers concluded multivitamin use along with the practice of other health-promoting behaviours may be beneficial in improving breast cancer outcomes in select groups of survivors. Since that blog, more research relating to cancer has come to light, so next week I will update that specific area.

But now we have a new, large meta-analysis involving twenty-one studies which generated a total pooled sample of 91,074 people. The people studied were all independently living adults (not having cancer), their average age was 62 years, a general supplement was taken daily, and the average duration of supplementation was 43 months (so not a very long time for this type of trial). 

The results?
Across all the studies examined, there was no demonstrable effect of multivitamin-multimineral supplementation on all-cause mortality. However, there was a trend for a reduced risk of all-cause mortality across primary prevention trials. Multivitamin-multimineral supplementation had no effect on the risk of dying due to vascular causes or cancer. 

The Conclusion? The researchers state: multivitamin-multimineral treatment has no effect on mortality risk.

So what to do?
If you are well, stick with point one and two from Plan A above, – as much as possible, rely upon good food – it needs to be organic to qualify – and a healthy lifestyle. If travelling or under stress, a general supplement may make sense until things are back in balance again. 

If you are recovering from injury or illness, a high quality general supplement from natural sources may make sense, but food is still number one. Good supplements will never make up for bad food. And juices are a great way to add extra nutrients to your diet from natural, well balanced sources. 

1. The reference for this latest article:  McPherson H et al;  Multivitamin-multimineral supplementation and mortality: a meta-analysis of randomized controlled trials.  Am J Clin Nutr February 2013 97: 437-444

2. You Can Conquer Cancer. The new edition has an extra chapter on nutrition and much more detail on the whys and hows of healthy eating – for wellness or for recovery.

3. CDs Eating well, Being well: Details the Wellness Diet 

Eating for Recovery: Details recommendations for those with cancer. This Cd builds on the previous one, so people with cancer are advised to study both.


Multivitamins and cancer

Lord Maurice Saatchi, co-founder of the famous advertising agency Saatchi and Saatchi, recently supported his beloved wife through a tough and fatal cancer. Now he wants the English laws regarding cancer research to be changed to allow for more sensible experimentation in cancer research. Citing the lack of progress in this field, and the tough treatments he saw his wife endure unsuccessfully, he is a powerful advocate for a new approach. Not for the faint hearted, but a compelling interview on the BBC, December 2012. For a transcript or to view the interview – link here.


  1. I think this can be a case of looking at something and coming to the wrong conclusion - having done this myself I come to this possible position o0n this issue - people who don't feel all that great try and make themselves feel better by taking supplements they feel they might need - ergo they are more likely to be the people who become ill - the opposite is also true - if you feel 100% you are far less likely to take supplements - were these studies all completely controlled or were some based on asking people who had become ill whether they took a supplement and what kind and for how long ?

  2. Julia you raise a good point and these "confounding" issues are what makes this type of research challenging to do in the first place and then challenging to interpret. I think the take home message for me remains to aim to rely on a healthy lifestyle and good, organic food, take a multivitamin occassionly to cover any deficits in B12, iron etc, watch the Vit D levels and probably take a supplement of that regularly as so many people are low, and then when under stress, travelling or recovering from injury or illness consider more regular supplements.

  3. Thank you .
    The marketing of multivitamins is as ubiquitous as it is for alcohol.
    Better to leave them alone.

  4. H Ian
    How refreshing it is to be reminded of an alternative view regarding taking multivitamins. As always you newsletters are like a light in the marketing wildness .

  5. Thanks for this informative post, Dr. Ian. I have always been apprehensive about multi-vitamins and supplements - there just doesn't seem to be as many tests done as with prescribed medicine.