Sunday, March 25, 2018

First the fat, then it was the salt and now it’s our sugar.



Cut back on your sugar and carbohydrates? Increase the fat in your diet? Ten years ago fat was the killer in our diet and carbohydrates the answer to preventing heart disease, the bane of our fast food society.

Dr. Atkins (of Atkins Diet fame) was one of the first to suggest that sugar, not fat was the reason for our epidemic of obesity. A recent review of 23 studies in 2017 supported this claim with the observation that study participants on a low carbohydrate diet often lost 2-3 times as much weight as the low fat groups. 

And even more interesting, many of the low carbohydrate group lost weight without any calorie restriction. 

The appetite suppressing effects of dietary fat were associated with an unexpected reduction in participants’ total daily calories. This “fat effect” is why we often take a trip to the refrigerator within a few hours of a chinese meal (generally low fat) and can find ourselves skipping that early lunch after a breakfast of bacon and eggs (high fat).

Then there were the studies showing that excess sugar increased the risk for heart attacks and strokes. In 2014 the Journal of the American Medical Association published a study showing that that North Americans who ate 25 percent of their calories as sugar had a fatal heart attack rate 2.75 times that of those who ate less than ten percent as sugar calories.

A meal high in sugar--or a sugared drink--leads to a rapid rise in blood sugar. Unless that extra sugar is used by exercising muscles (one of the reasons a good walk after dinner is a healthy habit), it is converted almost immediately to a type of fat called triglycerides.
These in turn cause fatty deposits in the lining of blood vessels and are the reason for the increased risk for a stroke or heart attack.

Even cancer has been linked to a high sugar diet. Rapidly growing cancer cells get almost all of their energy from sugar in a process that is oxygen-independent, while normal cells get their energy from fats, protein, and sugar in a process that is dependent on oxygen.

This observation led to speculation that the occasional cancerous cell (resulting from a spontaneous mutation) would have a better chance of survival in the presence of a high blood sugar. The theory is supported by a recent study showing an increased risk of colon cancer recurrence in patients with higher total daily carbohydrate diets.

Why has it taken so long for this to be sorted out? That is a story in itself and a great example of why industry funded research should always be suspect.

In the 1940s there was an ongoing argument in the medical literature on the role of fats versus sugar as the major risk factor for heart disease. To quote from an online blog by Dr. Mirkin, “... in 1965, John Hickson of the Sugar Research Foundation (now the Sugar Association) wrote to Harvard researchers asking them to write an article showing that sugar was safe and healthful. He paid them $6,500 and asked them to review only the research papers favorable to the sugar industry.”

This was the first step in a cascade of events that demonized fat and promoted sugar as heart healthy. And it has taken 50 years for the real facts to come to light.

But the wheel turns and we are now coming back around to our grandmother’s advice to eat a balanced diet. The healthiest approach is not an artificially low fat versus low sugar diet, but instead about eating a balanced diet—a bit of meat, occasional fish, a side of pasta, and several portions of fruit and vegetables. And getting rid of that sugar bowl in the kitchen and on the table.

It won’t be easy. Evidence from PET scans shows the same brain activity changes with the over consumption of sugar that we see in drug or tobacco addiction. And when you talk to someone who has tried to limit the sugar in their diet, their story reminds you of the withdrawal symptoms described by smokers and alcoholics. That is several weeks of withdrawal symptoms with a long term residual urge to have that piece of candy or sugared cereal. 

But in their next breath the successful will just as quickly tell you how much better they feel. So to keep you and your family healthy, it is time to think about taking that sugar bowl off the table….and then out of the kitchen.



References
https://www.ncbi.nlm.nih.gov/pubmed/23136358   
Dietary glycemic load and cancer recurrence and survival in patients
with stage III colon cancer: findings from CALGB 89803.






1 comment:

  1. This comment has been removed by a blog administrator.

    ReplyDelete