Previously, I wrote a post highlighting examples of how the "calories in, calories out" myth does not hold water when it comes to how our bodies treat different calories when they enter our bodies. You can find that post here. While calorie counting is useful, I want to show you just how selecting which calories you consume is just as important if not more important than how many calories you consume.
If you consume 120 calories of starch (glucose) about a half a cup of cooked white rice, the following is how your body metabolizes (breaks down and converts into fat/energy) what it receives:
- 20% or 24 calories of glucose goes to your liver, and the rest will be metabolized by other organs and muscles in the body
- Raises insulin, promoting energy storage into fat cells causing weight gain
- Majority of glucose in liver will be converted into glycogen (liver starch) where it is not harmful. It will keep the liver from releasing this glucose into the bloodstream preventing diabetes
- A small amount will be used by the liver itself for energy for the liver
- Any excess glucose from the liver will be converted to triglycerides, which is generally not a good thing
- When excess glucose binds to a protein, it creates a free radical, which is not a good thing. Antioxidants neutralizes these free radicals
- The take away: a lot of glucose won't make you sick overtime, just fat. However, if you accumulate too much fat around your organs (visceral fat) that can lead to health complications.
If you consume 120 calories of grain alcohol (1.5 oz shot of 80 proof liquor) the following is how your body metabolizes what it receives:
- 10% (12 calories) is metabolized within the stomach and intestine
- 10% (12 calories) is metabolized by the brain and other organs, giving you that intoxicating effect
- Approximately 80% (96 calories) reach the liver, 10x that of regular glucose which is key because the detrimental effects are dose dependent
- When it hits the liver in high dosages, alcohol promotes free radical formation and causes cell damage and aging
- In contrast to glucose, which went to glycogen, ethanol goes straight to mitochondria for energy burning
- Any excess gets turned into via a process called de novo lipogenesis. The lipid build up can lead to liver insulin resistance and inflammation
- If this process continues too much, it leads to alcoholic liver disease
- Alternatively the lipid can exit the liver and go into the skeletal muscle, where it induces insulin resistance and cause heart disease
- Finally, ethanol enhances its own consumption, acting on your brain's reward pathway promoting addiction if it gets out of control
For this example we will use an 8 oz glass of orange juice (just as bad as soda if not worse). Fructose is in nature is always equal parts glucose and sucrose, so for our example, 60 calories will glucose metabolized as I described above, and 60 calories will be fructose.
- All 60 calories of fructose go straight to the liver, along with 12 calories of glucose as described above
- That heavy dose hitting the liver needs triple the energy to metabolize, depleting the liver of ATP, leading to generation of uric acid which can cause gout and high blood pressure
- Excess that the mitochondria in the liver escapes and gets turned into fat
- Drives Maillard reaction 7 times faster than glucose, causing your body to age more rapidly, and driving various degenerative processes like aging, cancer, and cognitive decline
- Inactivates a key messenger of insulin action leading to insulin resistance
- Blood glucose rises, as does insulin resistance, which can eventually lead to diabetes
- The liver insulin resistance means pancreas releases extra insulin, promoting conversion into fat and eventually obesity
- The high insulin can drive the growth of many cancers and block leptin signaling, giving your brain the false sense of "starvation", causing you to eat more
- While data between fructose and dementia are currently correlative and indirect, the data between insulin resistance and dementia show clear causation. High waist circumference is also a marker for insulin resistance.
I don't want this information to alarm you and keep you from enjoying the occasional Cinnabon (mmm... Cinnabon) or margarita. Indeed small amounts of fructose and red wine have been proven to have beneficial effects on the body. The detrimental effects of all of these carbs are dose dependent, with alcohol and sugar being the worse offenders. Be mindful of what and how much you allow yourself to consume, and get plenty of fiber which moderates all of the aforementioned risks. Happy eating!
Dr. Charles Lustig, Fat Chance. Penguin Publishing Group, 2012.