Tuesday, March 1, 2016

Convenience Foods

Could the increasing use of convenience foods be triggering the increasing incidence of obesity and type 2 diabetes? By convenience foods I don't mean just junk food or fast food or highly processed foods that come in boxes or trays to be heated up in the microwave.

I mean real foods that are sold to consumers cut up or pureed or simply ground, like sausage and hamburger.

A recent study has found high levels of PAMPs, or pathogen-associated molecular patterns, in such foods, whereas fresh whole foods have none or very low levels. For example, PAMP levels in a whole onion are almost undetectable. But PAMPS in onions that you can buy prechopped are high. This makes sense to me, because chopping food greatly increases the surface area on which bacteria can grow. Even if they don't grow enough to make us sick, they could trigger a respose to the PAMPs.

What exactly are PAMPs? They are molecules released by certain bacteria that have patterns that tell our innate immune system to get rid of the bacteria through complex pathways. Some of these pathways involve inflammation. 

When the body produces an inflammatory response, it usually also activates an anti-inflammatory response that is supposed to keep the inflammation from getting out of hand. But if we're constantly triggering new inflammatory responses by snacking on PAMP-containing foods, we'd be in an almost constant state of inflammation.

People used to eat two or three times a day, mostly food freshly prepared from whole ingredients. In today's world, many people snack all day. Even if they're snacking on what are considered healthy real foods, if these foods aren't freshly prepared and contain high levels of PAMPs, the constant snacking could be triggering inflammation all day long. In other words, we would have "chronic inflammation," which has been blamed for myriad health problems.

Because people today mostly work full time and don't have a lot of extra time for chopping onions and tomatoes, the appeal of buying such food is obvious. Food "kits" with various prechopped ingredients ready for a stir fry or a stew are also appealing. The same goes for hamburger. How many people today buy a hunk of beef and grind it right before cooking?

I don't buy prechopped ingredients, but I produce them at home. If a recipe calls for a little onion, I'll slice up a whole onion and save what I don't need immediately in the fridge. I'll puree a whole cauliflower and save it, sometimes for several days. And I love sausage. My fridge is probably brimming with PAMP-containing foods.

Could the constant barrage of PAMPs in today's world be responsible for the increase in chronic conditions like obesity and diabetes?

Eating foods with low levels of PAMPs leads to lower LDL levels and weight loss. I don't think the latter is because of the calories burned chopping onions and tomatoes.

So what can we do about this? The idea that it's the PAMPs that are causing poor health is, after all, only an idea. When we work full time and then have to pick up kids and go home to make dinner, the appeal of prechopped and preground foods is clear. Very few of us have time to grind our own flour (if we eat flour at all). It's unrealistic to expect us to give up convenience completely.

The manufacturers are apparently trying to work out processing methods that would remove the PAMPs. But in the meantime, avoiding prechopped and preground foods when possible could help. So could doing less snacking to give our bodies time to resolve any inflammation triggered by the previous meal. It shouldn't be that hard to take a whole tomato for a salad and slicing it right before eating instead of mixing it all up at home.

Would such changes make a lot of difference to your health? I don't know. But they couldn't hurt.


hboxed macaroni and cheese.


  1. Can't remember who, it was a long time ago, someone was speculating about the increase in "genetic" diseases, namely Crohn's disease. It turned out to increase in different countries alongside the introduction of refrigeration. The thesis was that some currently unidentified infectious agent, possibly a bacillus, was surviving refrigeration and affecting people with a "genetic predisposition" to Crohn's. Said expert claimed that everyone with the predisposition was now getting the actual disease. This turned out to be overoptimistic as the incidence has increased still further.

    Now I wonder if these PAMPS are responsible for the inflammation of the gut lining, along with all the other Diseases Of Civilisation that have a clear inflammatory content. Maybe not a cause but a factor along with all the other proinflammatory changes in our diet and environment.

  2. Interesting. Many of the etiologies we haven't worked out yet may turn out to be multifactorial, which makes finding them more difficult. Plus we're always looking for simple answers.