Everyone tells us to eat healthy, to exercise, to sleep well, to live a life without stress to live a long and happy life. Almost all of the science to date either support these conclusions or are inconclusive (read: authors found no significant difference). Nothing so far (that I know of) refutes any of the common knowledge, common sense, government-endorsed advice in the opening sentence.

A no-brainer, right?

Finally, an article (Food: The Omnivore’s Labyrinth) from the top tier journal Nature talks about the flip side of things and in layman’s language, hints at the difficulties behind doing scientific research as well as translating research results from the cellular to the organismal level.

Consider the follow excerpts from said article:

Despite much research over the past 40 years, it’s still not clear what to eat — or not eat —to help prevent cancer.

In the mid-1970s, epidemiological studies suggested that people who ate more fruits and vegetables were at lower risk of several cancers.

A high-fat diet was thought to lead to an increased risk of breast cancer, until it wasn’t. Early studies of dietary fibre suggested that higher consumption could decrease chances of colon cancer, but that didn’t pan out either.

So what was it? Was it just that those studies were not done well? Or is it the case that the situation from the past to the present (a difference of one to four decades) is drastically different?

The author, Sarah DeWeerdt, outlines seven factors that explain why scientists appear to be backtracking over their claims from year to year.

  1. All vegetables are not created equal.
  2. All heads of broccoli are not created equal.
  3. Human genomes vary.
  4. Human microbiomes vary.
  5. Timing is everything.
  6. Some phytonutrients are difficult to access.
  7. The whole (diet) is greater than the sum of its parts.

I particularly enjoyed her discussion of points 2 and 7. The idea that the nutritional profile of an apple or a head of broccoli is different from that of its neighbor can be a startling idea to the lay public but really, it makes perfect, rational sense. And the idea that what else you consume along with a selected vegetable affects your body’s absorption and ability to utilize those phytonutrients is a relatively new idea that is only starting to make slow headway in scientific research (slow, but interesting headway, simply  because the results become exponentially much more difficult to analyze).

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