Wednesday, 5 September 2012

Quality Over Quantity

There was an excerpt on the World Service the other day about the effects of calorie restriction on longevity.  The long and the short of the discussion was that what mattered was food quality.  The analysts mooted that restricting calories on an UNHEALTHY diet makes you live longer. 

Stephan posted on the same research and made exactly this point:
  • "In 2009, researchers at the University of Wisconsin published preliminary results from the first primate calorie restriction experiment (3).  The analysis suggested that restricted macaques suffered fewer "age-related deaths".  Many people, including myself, found this somewhat questionable since total deaths from all causes were not significantly different (the experiment is ongoing, so there may eventually be a significant difference).  Also, the diet was appalling-- a refined feed made of sugar, isolated starch and other purified ingredients.  Animals in both groups died of gastrointestinal ailments.  The restricted group was protected from obesity, diabetes and cardiovascular disease, and they certainly looked much better.  Eating less of a poor diet seems to protect against disease, and may or may not extend life.

    Today, a new study was published that casts further doubt on the idea that calorie restriction extends lifespan in mammals, including primates (4).  Researchers from the National Institute on Ageing placed macaques on an unrefined (whole food based) diet for 26 years, with or without 30 percent calorie restriction.  They did this in two experiments, one starting with young monkeys and one starting with older monkeys.  Both experiments showed that calorie restriction does not extend lifespan under these conditions, although it does prevent obesity and cancer, and apparently maintains a youthful appearance."
This is perhaps more interesting than the idea that CR might extend/shorten life; that food quality (FQ) can extend/shorten life.  This is the kind of message that healthy eating initiatives should push!  Paleo makes a push toward FQ and it is broadly way harder to overeat on high quality food than it is processed food.  If we push FQ, appropriate CR may well follow as a consequence.

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