Nutrition for healthy ageing

Be your own better judge. When you see a headline, news item or online report about some great new diet or food that will improve memory or prevent an array of ailments, think again.

Unquestionably, new scientific research has enormously increased our understanding of how to maintain health as we age, but never has there been so much information out there promising everything from miracle weight loss, to quick fixes and anti-ageing. Often, it is difficult to distinguish fact from fiction and to identify what is backed up by good science.

• In this regard, scientists look for ‘sufficient evidence’ to make a reasonable judgement about diet and health. There are particular scientific approaches to conduct studies, pool findings and judge their accuracy.

But before we get weighed down in scientific jargon or lessons in statistics, here are some basic tips or questions to consider as you navigate through new discoveries and that next big thing in food, nutrition and health:

1. Who is saying it? If it is a ‘wonder food’, then who is suggesting it is wonderful? ? Is it a credible organisation such as WHO, World Cancer Research Fund (WCRF), or a Government body? Is the recommendation based on a new published research study (bearing in mind that some studies are better than others)?
2. Does it sound too good to be true? I think we all know the answer to that one.
3. Mice or men? Was the study based on animals or humans? You would be surprised how many reported findings, even in the diet/nutrition field, may actually be based on animal work. And, while this kind of science is important and has been the basis of many discoveries, the application to humans cannot be assumed. Further work in humans would naturally be required.
4. Dose matters. Consider if the report states how much or little of this food/nutrient you would need to consume to have the proposed beneficial effect. A portion per day versus a truckload …. and if you did manage to consume the truckload would that pose other (negative) consequences?
5. We eat foods, not single nutrients and so it is our dietary patterns over longer periods of time that influence health.
6. Cause and effect. If consuming a high level of A (e.g. a food) is associated with a low level of B (e.g. a disease) it does not necessarily mean that A caused B. People who eat more of one food may eat less of something else, or do more exercise or have different lifestyles, so the effect may be due to something else. Again, good studies should account or ‘control’ for this, but either way it doesn’t prove ‘causation’.

Because there are so many conflicting messages, in Step 3.11 we have provided some FAQs about nutrition and health.

Maria O’Sullivan is Associate Professor in Human Nutrition at Trinity College Dublin.