To fast, or not to fast, that is the question

Whether 'tis nobler in the mind to suffer

The slings and arrows of outrageous fortune,

Or to take arms against a sea of troubles

And by opposing end them.

There is always a trade-off between being adventurous and adopting a more conservative approach to innovation.  The theory of diffusion of innovation comes to mind.  The vast majority of people are not innovators or early adopters - innovators are quite rare. 

We often wrongly assume that deferring a decision whether we should introduce something new into our lives (i.e. our making a decision to maintain the status quo) is a safe choice.  To "wait and see" does not necessarily mean to "play it safe".

Imagine that you are a smoker living in 1920s Germany and you read that doctor Fritz Lickint claims that smoking causes cancer.  Not only many doctors you know are smokers and consider smoking safe, but some even say that smoking actually improves health, and you (and many other smokers you know) agree with them.  You love smoking and decide you do not want to quit till there is a scientific consensus (if ever) that smoking really not only does not improve health but actually causes cancer.  Decades pass.  To escape the war you emigrate to America.  In the 1960s, the United States Surgeon General's Report on Smoking and Health is published and you finally have your consensus: smoking tobacco does cause cancer and many other diseases.  You have been killing yourself for the last forty years!

Or an alternative ending: Considering all that smoking, maybe you are already dead when the report comes out...

Why am writing this?  Why the title?  Well, I have just had a discussion about fasting & LCHF lifestyle and the existing research on their short-term and long-term effects in humans.  Over the years, I stumbled upon quite a lot of studies, in both animials and humans, that show many potential benefits of both fasting and ketogenic / LCHF lifestyle (e.g. anti-carcinogenic, neuroprotective, cardioprotective, anti-aging, anti-inflammatory).  Unfortunately, most available data comes from short-term studies and there is scarcity of long-term studies (which, in case of medical research, is quite typical).

Ultimately, everyone has to do their own research, carefully weight pros and cons, and make their own decisions.  We should never stop challenging our preconceptions and the status quo.  Inaction, a choice not to change anything, is not automatically a safer choice.

Nutrition: omega-6 to omega-3 ratio

It has been claimed that human beings evolved on a diet that had a ratio of omega-6 to omega-3 fatty acids (FA) of about 1:1; whereas today, Western diets have a ratio of 10:1 to 20–25:1, indicating that Western diets are deficient in omega-3 FA (e.g. DOI:10.1007/s12035-010-8162-0).  There is tentative evidence of omega-3 FA lowering inflammation levels in humans while omega-6 FA and their metabolites may have proinflammatory effect (but see 1).  Because of all the above, some hypothesise that the "unnaturaly" high ratio of n6:n3 is the reason why modern diets are correlated with many inflammatory disorders (e.g. cancer, atherosclerosis, and ischemic heart disease).

Many health and nutrition gurus and professionals advise that, in order to improve our health, we should eat X instead of Y because Y has a terrible omega-6 FA to omega-3 FA ratio.  To give just a couple of examples:

• I have stumbled upon advice from Dr Michael Greger (MD) of NutritionFacts.org that we should eat walnuts because they have a good n6:n3 ratio of c. 4:1
• Thomas DeLauer advised his viewers not to eat almonds because of their high omega-6 FA and phytic acid (see 2) content.  At the same time he recommended pecans.

Pecans contain almost twice as much n-6 as almonds. Walnuts are even worse in this respect as they contain around three times as much omega-6.
It seems obvious that ratios of n6:n3 in individual products are not important (unless one follows a monotrophic (or close to monotrophic) diet which one should not).  What is important is the ratio of your cumulative daily intake of both FA groups. If you ingest x grams of almonds (n6:n3 ratio of c. 2000:1) you still get three times less n-6 than if you ingest x grams of walnuts (which boast of a much "better" n6:n3 ratio of c. 4:1). It seems reasonable that what you should do is just enjoy your almonds, walnuts, pecans or whatever else you might fancy and add some ground flaxseeds into your diet to bring the daily n6:n3 ratio closer to 1:1 ;).


Footnotes:

1. Omega-6 FA are still essential for the human body to function.  Moreover, there is also evidence of their anti-inflammatory effect so to consider them just proinflammatory is one-sided.
2. "Studies examining the effects of phytic acid demonstrate that it is important in regulating vital cellular functions. Both in vivo and in vitro experiments have demonstrated striking anticancer (preventive as well as therapeutic) effects of phytic acid. Research shows anti-carcinogenic effects, albeit to a lesser extent and it acts in inhibiting cancer. In addition to reduction in cell proliferation, phytic acid increases differentiation of malignant cells often resulting in reversion to the normal phenotype." (DOI: 10.1046/j.1365-2621.2002.00620.x)