Food Synergy: An Operational Concept For Understanding Nutrition, American Journal of Clinical Nutrition, 2009
"Research and practice in nutrition relate to food and its constituents, often as supplements. In food, however, the biological constituents are coordinated. We propose that "thinking food first"' results in more effective nutrition research and policy. The concept of food synergy provides the necessary theoretical underpinning. The evidence for health benefit appears stronger when put together in a synergistic dietary pattern than for individual foods or food constituents. A review of dietary supplementation suggests that although supplements may be beneficial in states of insufficiency, the safe middle ground for consumption likely is food. Also, food provides a buffer during absorption. Constituents delivered by foods taken directly from their biological environment may have different effects from those formulated through technologic processing, but either way health benefits are likely to be determined by the total diet.At what point do questions such as "Where do I get my [nutrient]?" cease being relevant?
The concept of food synergy is based on the proposition that the interrelations between constituents in foods are significant. This significance is dependent on the balance between constituents within the food, how well the constituents survive digestion, and the extent to which they appear biologically active at the cellular level. Many examples are provided of superior effects of whole foods over their isolated constituents. The food synergy concept supports the idea of dietary variety and of selecting nutrient-rich foods. The more we understand about our own biology and that of plants and animals, the better we will be able to discern the combinations of foods, rather than supplements, which best promote health."
I ask this question about some nutrient every day, and have for years. I'm coming to realize its inadequacy. It fails to consider in much depth the vehicle which supplies the nutrient (breakfast cereals seem to be fortified these days with just about any nutrient you could want, but who wants breakfast cereals?), the condition of the person consuming the nutrient, and the interaction among the constituents supplied with the nutrient. Also, it attaches an importance or prestige to the nutrient that might not be justifiable.
On that last point, for example, how important are omega-3 fatty acids for human health? Of course some amount are essential, but this meta-analysis of randomized controlled trials (RCTs, not epidemiological studies but actual intervention trials with control groups) and cohort studies:
Risks And Benefits Of Omega 3 Fats For Mortality, Cardiovascular Disease, And Cancer: Systematic Review, British Medical Journal, 2006
"We found no evidence from RCTs or cohort studies that omega 3 fats have an effect on combined cardiovascular events.There was no strong evidence that taking omega-3 reduced heart attacks, yet this is one reason omega-3 supplements are being promoted.
Neither RCTs nor cohort studies showed significantly increased risks of cancer or stroke with higher intake of omega 3, but there were too few events to rule out important effects."
If there was no substantial risk in supplementing, you might sanction it. But in the case of omega-3, the risks include:
- Fewer immune cells, e.g. natural killer (NK) cells. NK cells recognize tumors and are important against cancers and viral infections.1
- Possible increased risk for cardiac death.3 This was seen in men with angina in the DART-2 trial, primarily those taking fish oil supplements.2 DART-2 was included in the above meta-analysis; its authors said:
"UK guidelines encourage the general public to eat more oily fish, and higher amounts are advised after myocardial infarction. This advice should continue at present but the evidence should be reviewed regularly. It is probably not appropriate to recommend a high intake of omega 3 fats for people who have angina but have not had a myocardial infarction."
"Nutritional interventions are not equally acceptable and should be tailored to the individuals for whom they are intended. Various distinct groups have a raised risk of CHD, and it cannot be assumed that the same nutritional interventions are appropriate to them all. Nutritional supplements do not necessarily have the same effects as the foods from which they are derived."Which leads us back to food synergy. Supplements are useful when a particular good-source food is out of reach ... logistically, economically, culturally, or for reasons of taste or ethics. But I'm more convinced these days that supplements make poor substitutes for food, and may at times be harmful.
2 Lack Of Benefit Of Dietary Advice To Men With Angina: Results Of A Controlled Trial, European Journal of Clinical Nutrition, 2003
3 Secondary Prevention Of CHD In UK Men: The Diet And Reinfarction Trial And Its Sequel, Proceedings of the Nutrition Society, 2007