Saturday, April 10, 2010

Food Vs. Nutrients (With An Example Of Omega-3)

I like this concept, "food synergy":

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.

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."
At what point do questions such as "Where do I get my [nutrient]?" cease being relevant?

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.

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."
There was no strong evidence that taking omega-3 reduced heart attacks, yet this is one reason omega-3 supplements are being promoted.

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."
From Reference 3:
"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.
1 Can Omega-3 Fatty Acids (Fish Oil) Predispose Someone To Cancer?
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


Melissa said...

If you are doing veganism maybe you should consider getting your b-12, DHA...and many other great things from oysters

preserve said...

This is a widespread problem that goes beyond nutrition.

Lame as it sounds, this topic is the premise of Avatar.

RB said...

Michael Pollan doesn't use the term "food synergy". However, he does talk about how all the constituents of food act together. Their is to much focus on individual nutrients and not enough on how complete foods contribute to a healthy diet. Michael Pollan also likes to point out how cultures figured out what foods works together to promote a healthy diets without knowing about nutrients. I am glad science is finally beginning to take a holistic approach to food and nutrition.

Dr. Mel said...

Oysters---ummm..... Other seafood, yes, if necessary. I do eat sardines about once a week. Actually like fish/shellfish/etc if I can source them from clean waters.
Love the comparison w/ Avatar. Loved the movie and its implications of all things interconnected, despite the predictable story.

Alright, one more specific question then I'll shut up--is it harmful to add a tsp. or so of flax seed oil to a salad that will be dressed w/ olive oil and vinegar? If it's kept properly refrigerated, is flax oil harmful? I know the whole seeds generally go right thru you, and the ground seeds (and oil, if not refrigerated) go rancid *just like that*! So, I'm just asking.

Dr. Mel said...

Btw, great post, Bix!

caulfieldkid said...


The last I remember, you were still taking vitamins/supplements (correct me if I'm wrong). Are you still choosing to do so? If so, how are you determining what to take and how much?

To be fair (or in order to use the iterated prisoner's dilemma strategy), I'm still refraining from using vitamins or supplements. I did take them for a good while, but eventually found the argumentation for consuming them too unconvincing. I also began to question the precision and or contamination of their processing.

Ever the skeptic,

Bix said...

Do I still take vitamins? Hardly any, and never more than the DRI/RDA, not that that's a magic number. I'm a recovering vitaminhead. But, as you said, the argument for consuming them is too unconvincing these days.

I used to take all that calcium, 1200-1500 mg, until I learned we absorb more when we eat less. Which is true for other vitamins too. And taking one mineral at a high dose interferes with mineral balances, like calcium:magnesium, and reduces absorption of other minerals that compete for entry. Oil-based caps deliver cheap fats, often from omega-6 rich soybean oil. Most of the filler in pills is genetically engineered. And the antioxidants ... vitamin C, selenium ... actually interfere with the body's signaling pathways (free radicals are sometimes good) and are linked to insulin resistance and weight gain. There's the contamination issue. It just doesn't make sense to supplement if you can avoid it.

I have some pills/capsules left over that I crush into pieces and sprinkle here and there just to use them up ... as I develop better eating habits. It's. Hard. I'm always cooking. Or buying, putting away, cleaning, cutting ... washing dishes. Eating well is about cooking (or having someone cook for you). That's the secret, if there is one. If I ate chocolate cake and coffee for breakfast, 2 slices of pizza for lunch, and pork chops, biscuits and gravy for dinner, I'd take vitamins.

Once in a while I input a few days of typical food into NutritionData or Cron-O-Meter to see if I'm low on anything. In the past I would have supplemented. Now I try, I try!, to fix it with food.