Guest post by Paul Fairbairn, BSc (hons) in Sport and Exercise Science & Nutrition MSc student – The truth about our food…
Nutrition confusion in the press
Often we are told about how important or how detrimental one specific nutrient is for our health. All it takes is a simple google search to pick up on some articles championing or demonising specific nutrients, here are just a few examples
“Could taking vitamin B save YOUR memory?”
“Are you hooked on fish oil yet? The natural wonder drug proven to treat a range of conditions”
“Revealed, your body on sugar: From weakening the immune system to triggering thrush, this terrifying tool reveals exactly how the white stuff harms our health”
“Is this the surprise reason you’re always tired? How vitamin D can give you more energy and lower blood pressure”
These types of headlines are certainly interesting and are usually based on some kind of research or experiment. However, whether that research is significant, being interpreted correctly or is of a good quality is another matter in itself.
But let’s look at these types of headlines in detail and investigate the very simplistic way in which they claim that nutrient X causes/prevents health condition B and the truth about our food.
Nutrient Interactions
These types of headlines are often unhelpful, mainly because nutrition and the human body isn’t quite as simple as these headlines make out. Additionally when we eat a food or a meal we don’t consume one single nutrient, in fact, we consume a whole spectrum of nutrients, combined. In this way many nutrients interact with each other to meet the requirements for the human body – and focusing on one nutrient in isolation, may not have much of an effect. Of course this is different if there is risk of deficiency and if your health care professional is advising you take a supplement to improve your health, it’s likely to be for a very good reason (e.g. low vitamin D levels).
In the human body we only know of a few specific nutrient interactions, there are likely to be many more which we don’t yet have the science to prove yet. Some of the ones we are more aware of include:
- Iron absorption is enhanced by vitamin C (Teucher & Cori, 2004)
- Vitamin D regulates calcium absorption and usage within the body (Sunyecz, 2008).
- When large amounts of omega-3 fatty acids are consumed it increases the need for vitamin E as vitamin E protects the fatty acids from being damaged in the body (Raederstorff et al., 2015).
And some slightly more complex nutrient interactions…
- Calcium and magnesium are quite often mentioned within the same breath and are often combined together in supplemental form. They both belong to the same family on the periodic table, and their similarities lead to them competing with each other in the body. There is some evidence that altering the ratio of intake between these two key nutrients may have a greater effect than taking two in isolation (Dai et al., 2013).
- There was a large study looking at the effects of B vitamins on brain degeneration in older adults. One group received B vitamin supplements the other a placebo. In the group who received the B vitamins, only those who had high levels of omega-3 fatty acids had a benefit whereby their brains shrunk less than those who did not take the B vitamins or had lower omega-3 levels (Jerneren et al., 2015). This has led to the theory that there may be an interaction between B vitamins and omega 3 fatty acids, with regards to brain health.
These interactions make an already difficult subject to study and interpret much more difficult, as, accounting for all these interactions (alongside other factors) in studies is very hard to do. (Read here for Charlotte’s blog on why dietary advice is so confusing.) For example let’s say we are running a study trying to find out if giving a vitamin D supplement can prevent osteoporosis. For this study we would need to also consider the calcium intake of all our participants because we know these two interact and that interaction has an effect on bone health. This is fine because we know this interaction exists, but what if we didn’t..?
Evidence Based Nutrition
This is why it’s important to make recommendations based on the most up to date and high quality evidence, because it should account for all the other factors they may influence the outcome. It is also why we shouldn’t rely on the intake of a single nutrient to keep us healthy, we need to be consuming a wide spectrum of all the nutrients on offer.
However, to try and make this more simple and practical here is some useful advice to take away with you…
Making Nutrition Advice Simple (and Realistic – SR…)
There is no doubt that individual nutrients serve a number of purposes in the body, and nutrition research is constantly discovering new and exciting functions for nutrients and how they can impact our health. It is very easy to get bogged down in the finite details of nutrition, and often the answer is actually a bit simpler. It’s important to look at the bigger picture and not just focus on the minutia. Focusing purely on one nutrient would be like going to see the Mona Lisa and staring at her finger nails.
With perhaps the exception of vitamin D, which is synthesised from exposure to sunlight, all the nutrients you need can be easily derived from food. Unless specifically recommended by a health care professional, it would be advisable to try and meet your nutrient requirements from a varied diet than from single nutrient supplements. A diet rich in fruits, vegetables, whole grains, dairy, meat and fish will provide you with a variety of essential vitamins and minerals.
This doesn’t necessarily mean supplements are bad, they can be incredibly useful especially if you’re low in a specific nutrient, if you’re taking a multivitamin as a safeguard to boost levels or if you’re trying to get pregnant for example. However, as most supplements will say on the back of the packet, they need to be consumed in the context of a balanced diet. If you haven’t got the foundations right, you might be just wasting your money!
References
Dai, Qi et al. “Modifying Effect Of Calcium/Magnesium Intake Ratio And Mortality: A Population-Based Cohort Study”. BMJ Open 3.2 (2013): e002111. Web.
Jerneren, F. et al. “Brain Atrophy In Cognitively Impaired Elderly: The Importance Of Long-Chain -3 Fatty Acids And B Vitamin Status In A Randomized Controlled Trial”. American Journal of Clinical Nutrition 102.1 (2015): 215-221. Web.
Raederstorff, Daniel et al. “Vitamin E Function And Requirements In Relation To PUFA”. British Journal of Nutrition 114.08 (2015): 1113-1122. Web.
Teucher, Olivares, and Cori. “Enhancers Of Iron Absorption: Ascorbic Acid And Other Organic Acids”.International Journal for Vitamin and Nutrition Research 74.6 (2004): 403-419. Web.
Sunyecz, J. A. (2008). The use of calcium and vitamin D in the management of osteoporosis. Therapeutics and Clinical Risk Management, 4(4), 827–836.
To help with busting the myths I’m taking part in a Expert Nutrition Panel Debate at the end of September. Sign up and read more here about our Nutrition, Health and Wellness Debunked