Sugar: The Bitter Truth
Dr R H Lustig's lecture Sugar: The Bitter Truth
I think he makes some good points, including the potential for correlation between high-sugar diet and heart disease and the biochemical connection between high fructose intake and fat deposition. But I find some serious problems with his preconceptions about the Japanese diet and his implication that correlation is causation only when it suits his point.
So, points against:
1) The Japanese diet has always contained a small amount of fructose. There are native fruits, but they are traditionally consumed sparingly as a treat. Culturally this was reinforced by valuing the highest quality fruits and moderate consumption. In addition, the vast majority of Japanese people lived in poverty until after the second World War. There was a small business in traditional sweets which catered to the rich in the old days; these are more affordable and widely available but remain somewhat expensive today.
1a) The cultural emphasis on moderation is a big part of Italian health, which was also raised.
2) Ethanol is not a carbohydrate. Carbohydrates have C:O:H atom ratios of 1:1:2. For example, glucose is C6O6H12, which dividing all by 6 gives 1:1:2. Ethanol is 2:1:5. This does not negate his points about how it is metabolized, but carbohydrate is more specific than "contains C, H, and O."
3) When fat and sugar consumption are confounded in the original data on diet and heart disease, it is correct to postulate that sugar may have a role when it was not examined. It is incorrect to discount the original correlation between fat an heart disease on this basis. Diet and metabolic disease are complex, and can have more than one cause.
4) Many of the studies he cites are correlative, not causative studies. The intervention studies appear to actually examine causality, but others do not.
5) His description of the paleolithic diet is not quite right. Cooking is allowed, and the focus is on whole foods, as they could be collected before the agricultural revolution. It's heavy on meats and vegetables, sparing-to-moderate in fruits and nuts, and can include small amounts of specific ancient grains. It's not the diet for me, but it's important to correctly describe special diets. He might as well have said vegetarians only eat salads!
Good points:
1) Metabolic feedback of glucose and lack of this with fructose feedback in satiety. This leads to eating more than we need.
2) Showing the different partition of glucose & fructose into the blood and liver, and liver metabolism of fructose. Fructose is more likely to end up in the fat-deposition pathway, contributing to obesity and cardiovascular disease. There was (to me) a clear description of how liver damage from excessive fructose in the diet parallels damage from chronic alcohol abuse.
3) He had some neat descriptions of different kinds of "bad" LDL cholesterol. These are not differentiated in routine cholesterol tests, but can be by more sophisticated methods. I think they used HPLC for the study in his research lab, but the details on the slides were fuzzy.
4) Lowering kids' sugar consumption via beverages and a "wait 20 minutes to take seconds" is effective in treatment of childhood obesity. Soda availability in schools is apparently a huge contributor to this problem.
5) Whole fruits are OK, as the fructose is bound up with fiber. Refined sugars and high-fructose corn syrup are "the enemy".
6) The "thermodynamics" view of weight loss is inaccurate
In my mind, reducing sugar intake is not a one-size or complete solution for either weight loss or health. I see Lustig's point about the different metabolic pathways and feeling of satiety. It is necessary though to determine and study additional mitigating factors, such as stress, chronic inflammation, and genetic predispositions to higher percent body fat. It is nigh impossible for me to get below 30% body fat without excessive dieting/athletic training. (I'd like to get back near that someday, but I'm arguably not trying hard right now). Also, overeating is overeating, whether it is out of boredom, stress, or the awesomeness of food. At very high caloric intake, thermodynamics are still against us!
The biggest problem that I have is that once again the medical profession sees a problem, calls it a disease, and treats it to make the problem go away without regard for alternative causes, interactions, and the like. "The last person whose research defined the field overlooked my pet point, but now I have the whole story!" seems to be the prevailing attitude among researchers. I would prefer a shift to looking at a diverse sample of healthy people and asking "What makes these people healthy? Can we even define it?"
Overall, I'm most behind Michael Pollan's food philosophy, at least as outlined in The Omnivore's Dilemma (I haven't got to In Defense of Food yet): Eat foods close to what is naturally available, and avoid what is processed into its individual components and reassembled. Stop eating when you feel full. Voila!
I also believe many people have mild food sensitivities that fly under the radar, cause inflammation, and decrease feelings of wellbeing. Because they are not acute, they can be hard to pin down. For my own case, I have identified a few of these things, but often indulge anyway. Why stop eating ice cream, when Lactaid can alleviate the digestive distress? So what if eating dairy makes me smell bad and feel achey, Lactaid or no? I'm honestly better about cutting back on wheat (which is everywhere)!
Which brings up the really key issue: you have to want to make any dietary or lifestyle change! If, like me, you can't be arsed to do anything about a problem, no change will happen. I have been more conscious of the nature of what I eat, but still eat plenty of sweets, don't get enough exercise, and haven't completely cut out dairy and wheat. So no weight loss for me! I'll get around to it, I'm sure.
I think he makes some good points, including the potential for correlation between high-sugar diet and heart disease and the biochemical connection between high fructose intake and fat deposition. But I find some serious problems with his preconceptions about the Japanese diet and his implication that correlation is causation only when it suits his point.
So, points against:
1) The Japanese diet has always contained a small amount of fructose. There are native fruits, but they are traditionally consumed sparingly as a treat. Culturally this was reinforced by valuing the highest quality fruits and moderate consumption. In addition, the vast majority of Japanese people lived in poverty until after the second World War. There was a small business in traditional sweets which catered to the rich in the old days; these are more affordable and widely available but remain somewhat expensive today.
1a) The cultural emphasis on moderation is a big part of Italian health, which was also raised.
2) Ethanol is not a carbohydrate. Carbohydrates have C:O:H atom ratios of 1:1:2. For example, glucose is C6O6H12, which dividing all by 6 gives 1:1:2. Ethanol is 2:1:5. This does not negate his points about how it is metabolized, but carbohydrate is more specific than "contains C, H, and O."
3) When fat and sugar consumption are confounded in the original data on diet and heart disease, it is correct to postulate that sugar may have a role when it was not examined. It is incorrect to discount the original correlation between fat an heart disease on this basis. Diet and metabolic disease are complex, and can have more than one cause.
4) Many of the studies he cites are correlative, not causative studies. The intervention studies appear to actually examine causality, but others do not.
5) His description of the paleolithic diet is not quite right. Cooking is allowed, and the focus is on whole foods, as they could be collected before the agricultural revolution. It's heavy on meats and vegetables, sparing-to-moderate in fruits and nuts, and can include small amounts of specific ancient grains. It's not the diet for me, but it's important to correctly describe special diets. He might as well have said vegetarians only eat salads!
Good points:
1) Metabolic feedback of glucose and lack of this with fructose feedback in satiety. This leads to eating more than we need.
2) Showing the different partition of glucose & fructose into the blood and liver, and liver metabolism of fructose. Fructose is more likely to end up in the fat-deposition pathway, contributing to obesity and cardiovascular disease. There was (to me) a clear description of how liver damage from excessive fructose in the diet parallels damage from chronic alcohol abuse.
3) He had some neat descriptions of different kinds of "bad" LDL cholesterol. These are not differentiated in routine cholesterol tests, but can be by more sophisticated methods. I think they used HPLC for the study in his research lab, but the details on the slides were fuzzy.
4) Lowering kids' sugar consumption via beverages and a "wait 20 minutes to take seconds" is effective in treatment of childhood obesity. Soda availability in schools is apparently a huge contributor to this problem.
5) Whole fruits are OK, as the fructose is bound up with fiber. Refined sugars and high-fructose corn syrup are "the enemy".
6) The "thermodynamics" view of weight loss is inaccurate
In my mind, reducing sugar intake is not a one-size or complete solution for either weight loss or health. I see Lustig's point about the different metabolic pathways and feeling of satiety. It is necessary though to determine and study additional mitigating factors, such as stress, chronic inflammation, and genetic predispositions to higher percent body fat. It is nigh impossible for me to get below 30% body fat without excessive dieting/athletic training. (I'd like to get back near that someday, but I'm arguably not trying hard right now). Also, overeating is overeating, whether it is out of boredom, stress, or the awesomeness of food. At very high caloric intake, thermodynamics are still against us!
The biggest problem that I have is that once again the medical profession sees a problem, calls it a disease, and treats it to make the problem go away without regard for alternative causes, interactions, and the like. "The last person whose research defined the field overlooked my pet point, but now I have the whole story!" seems to be the prevailing attitude among researchers. I would prefer a shift to looking at a diverse sample of healthy people and asking "What makes these people healthy? Can we even define it?"
Overall, I'm most behind Michael Pollan's food philosophy, at least as outlined in The Omnivore's Dilemma (I haven't got to In Defense of Food yet): Eat foods close to what is naturally available, and avoid what is processed into its individual components and reassembled. Stop eating when you feel full. Voila!
I also believe many people have mild food sensitivities that fly under the radar, cause inflammation, and decrease feelings of wellbeing. Because they are not acute, they can be hard to pin down. For my own case, I have identified a few of these things, but often indulge anyway. Why stop eating ice cream, when Lactaid can alleviate the digestive distress? So what if eating dairy makes me smell bad and feel achey, Lactaid or no? I'm honestly better about cutting back on wheat (which is everywhere)!
Which brings up the really key issue: you have to want to make any dietary or lifestyle change! If, like me, you can't be arsed to do anything about a problem, no change will happen. I have been more conscious of the nature of what I eat, but still eat plenty of sweets, don't get enough exercise, and haven't completely cut out dairy and wheat. So no weight loss for me! I'll get around to it, I'm sure.