Wednesday, May 9, 2012

Lustig Via Mercola on Fructose
In general, one would do well to be sceptical about the idea that any one substance causes anything.  However, the data and the models that support the premise that fructose has a unique and potent role in human illness are significant and worth consideration.  Further, fructose restriction is easy and deprives the human of nothing it needs.  From the link above:

The obesity epidemic threatens not only the health and longevity of a clear majority of people, it also adds a tremendous burden to our health care system. The eight primary diseases related to metabolic dysfunction account for a staggering 75 percent of the healthcare costs in the US.

What are these diseases? Diabetes, non-alcoholic fatty liver disease, hypertension, polycystic ovarian syndrome (aka PCOS), dislipidemia, cancer, cardio vascular diseases, and dementia. I think you could easily attribute the autoimmune spectrum to the same causes, though that is conjecture.

I've been looking for these stats for a long time:
The four diseases listed … are conventionally associated with metabolic syndrome. However, as stated by Dr. Lustig, … other diseases fall within this scope as well. He also explains that while obesity is associated with metabolic syndrome and all of these diseases, obesity is not the CAUSE of them; it is simply a marker. Rather, the underlying cause is metabolic dysfunction, and excessive sugar/fructose consumption is a primary driver of that.

According to Dr. Lustig, 20 percent of obese people have perfectly normal metabolic functioning, and the excess weight will not affect their overall lifespan. Ditto for 60 percent of normal-weight people. However, the MAJORITY of obese people—about 80 percent of them—do not have normal metabolic function, and 40 percent of normal-weight people also suffer from metabolic dysfunction, and are therefore prone to these obesity-related diseases.
In other words, some non-obese people have the same metabolic diseases as the obese, and some obese people don't have the metabolic derrangement, and therefore are not sick, just heavy.
This stat is just plain frightening:
The average American consumes 1/3 of a pound of sugar a day. That's five ounces or 150 grams, half of which is fructose, which is 300 percent more than the amount that will trigger biochemical havoc.
But the stat is also a reason for hope, because the implication is that sugar restriction alone may help a significant number of people to stop or reverse their metabolic injury.

As I’ve blogged about several times, and as more and more folks know, fructose is metabolized differently from glucose. The metabolism of fructose by the liver provides several problems, and accelerates all of the cycles that contribute to metabolic syndrome. And as the article reports, it is suspected that fructose short circuits what we understand as the big drivers in appetite control. Fructose does not drive blood glucose levels higher, and therefore does not stimulate insulin. Insulin’s effect on ghrelin is thought to supress hunger. Fructose also contributes to leptin resistance, meaning it biases the metabolic system towards fat accumulation. Because the majority of fructose is metabolized into fat, in a body that is already in metabolic derrangement, often the fructose derived fat contributes to fatty liver, accelerating the metabolic derrangement. Symptoms include abdominal obesity, high triglycerides, low HDL, and often high blood pressure (and other symptoms like gout, more about which will follow).

As Dr. M reports, this process Over time leads to insulin resistance, which is not only an underlying factor of type 2 diabetes and heart disease, but also many cancers.

Thus he recommends two simple but potent tools to reverse the course of a population wide disease:
Severely restricting carbohydrates (sugars, fructose, and grains), and increasing healthy fat consumption.

How pervasive is fructose consumption?
Fructose is the NUMBER ONE source of calories in the US ... even most infant formulas contain the sugar equivalent of one can of Coca-Cola, which helps explain how six-month old babies can be obese.

So the witch’s brew for obesity would require that one eat many carbohydrates per day (via processed foods including breads, cereals, bagels, waffles, pasta, rice, potatoes, etc), combined with sugar, of which ~50% is fructose. The fructose pummels the liver and leptin signaling, while the glucose overloads the body with blood sugars, resulting in the insulin cascade of fat accumulation, inflammation, and eventually, insulin resistance (also accelerated by fructose’s impact on the liver) progressing to metabolic syndrome progressing to diabetes.

Dr. M recommends total fructose consumption of 25g/day or less for the healthy who wish to remain that way. He presents other detailed recommendations for how to think about fruit consumption and fructose, and what you might be able to tolerate if you already suffer from some metabolic injury.

Are you sick of seeing all the adds for gout medication (the guy toting around the jar full of green gunk)? This is why that product is in such demand:
High uric acid, in particular, is a potent marker for fructose toxicity, so if your levels are above 4 mg/dl for men, 3.5 mg/dl for women ... then you would be wise to avoid all forms of fructose until your levels have normalized—just as you would with high insulin levels.

See Dr. M’s article for a detailed list of how much fructose common fruits contain. 

But this isn't all of the bad news for fructose ingestion - other problems include the fact that fructose is a powerful glycating agent and thus produces a disproportionate quantity of advanced glycation end products (AGEs), which are associated with rapid aging in animals and diabetics.  Fructose has also been shown to strongly support the growth of some cancers, either as a powerful fuel in itself, or by accelerating metabolic derrangment, resulting in higher levels of blood sugar, insulin, and insulin like growth factor 1, all of which help cancers thrive (many cancers derive energy from fermentation, which requires large quantities of sugar). 

While paleo man would not have been likely to have access to the incredible variety of fruits that you and I do by virtue of selective hybridization and world wide exchange of what used to be seasonally available fruits, it seems likely to me that fruit played a potent role in the seasonal cycle of human fertility. Thumbnail version (lengthy discussions of this topic available at spring and summer fruits helped paleo man fatten up for the winter, while hormonal shifts associated with longer days stimulated higher outputs of reproductive hormones.  That made it common for paleo man to get busy with paleo woman in the late summer, after which paleo progeny would find their way into the world in the spring – when paleo mom would be able to get enough calories, and dietary diversity, to nourish said progeny in style, and without overmuch worry about the cold.

The power of fructose to help humans fatten has been turned on its head by the invention of what we call “corn”, and our ability to use “corn” to make very inexpensive sweeteners. In 1970, fructose was estimated to provide 5% of calories, and is now estimated at 30% of the population’s calories. It seems likely that change was not an improvement for health and wellbeing, and the dollar costs in the provision of health care have been staggering.  Eat meat, vegetables, nuts and seeds, little fruit or starch, no sugar no wheat.  That the government set its sights on fat instead of sugar and carbohydrates as the culprits for the obesity epidemic was a monumental mis-interpretation of the available evidence.  I leave it to you to draw your own conclusions about the consequences.

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