Thursday, April 16, 2009

When Are "Facts" not Facts?

I don't usually comment on other blogs. Search on "lactose" and you get almost nothing back for the time and effort you expend. Every once in a while, though, I stumble over a load of such concentrated ignorance that I need to contain it before it spreads further.

The home page of dietblog appears at first glance to be a source of reasonable health information. Closer inspection reveals the hidden truth. Each entry is from anyone who registers and is only as good as the knowledge and opinions of the blogger. That means readers are likely to fall immediately into an abyss of food nonsense.

What caught my eye was a post It's Easy to Eat Right and That's a Fact! by a blogger named ej.
Everything I have said here, and everything else that I'll say on this site is fact, so don't have a go at me because none of this is my opinion - it's fact.

Did somebody wave a red flag?

Here's one of ej's "facts:"
Humans have been consuming fat since the year dot. Therefore our bodies know the fat and it can use the fat accordingly. We find it hard to eat too much fat because our bodies have an 'off switch' for fat - it detects when we have consumed enough fat and we feel full. ... Full fat milk is fine to have in moderation, as lactose is detected by the enzymes in the liver, so the body can deal with it.

What in world could ej possibly have meant by those sentences?

First, our bodies don't have an "off switch" for fat. Fat can, well, make you fat, just as sugar can. All sources of proteins, fats, and carbohydrates are broken down by the body into their components. If they can be used by the body or burned as fuel they will be. If not, they will be stored. As fat.

Lactose is, of course, not fat. It is a sugar. It is not "detected by the enzymes in the liver" whatever that means. Lactose gets digested by the enzymes in the small intestine, specifically the lactase enzyme. Those of us with lactose intolerance make little to no lactase, so we can't digest lactose. It doesn't matter in the tiniest whether that lactose is wrapped in whole milk or skim milk. The body doesn't notice, and the liver never sees it at any time, in any way.

Everybody about ej's approach to sugar is beyond odd. Take these statements:
They say there is a lot of sugar in fruit so it's bad for you. NO. Fruit has natural sugar, yes, but it also has fiber and nutrients in it that counteract the sugar when we eat it, so the sugar is still there, but our body can use it positively.

Here's one thing most of you probably don't know. Our bodies can't detect fructose...

What is the sugar in fruit? Right. It's fructose. Until the past few thousand years, the vast majority of the sugar that an adult human would encounter would be fructose. Natural honey is a physical rather than chemical combination of fructose and glucose. A few vegetables, notably sugar cane and sugar beets, are predominantly sucrose, itself a complex sugar made out of fructose and glucose, but those had limited range compared to fructose-heavy fruits.

BTW, it's fructose, not lactose, that is metabolized by the liver. The Wikipedia page on fructose has a jumble of contradictory and inconsistent statements on fructose digestion, but check Figure 6 Metabolic conversion of fructose to glycogen in the liver. Maybe this is what ej has read about once and misinterpreted. Saying our bodies "can't detect fructose" is sheer nonsense no matter how one interprets it.

No one diet is right, and by that I mean no one type of diet is right. You can lose weight on every type of diet. Empty sugars, which are sugars without good supporting nutrition, the nutrients found mainly in, um, fruit, do contribute to obesity. Too much fat also contributes. Too much food period is a cause of obesity. Cutting calories will help you lose weight when accompanied by an increase in exercise. Eating healthy, sensible foods is a must.

So is understanding a few basics about food, digestion, and nutrition. Everything poor ej doesn't know.

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