Wednesday, June 3, 2015

Trans Fat "Ban" Overdue

Removing partially hydrogenated oil from the food supply is a major win for America!  However, claiming that the ban is on "trans fats" is technically incorrect.  Small amounts of natural trans fats are found in dairy and these will not be banned.  The "ban" is on partially hydrogenated fats, which are lab produced fat chemical seriously contributing to heart disease risk.  The Federal Food and Drugs Act of 1906 determines a food is adulterated if it "contain any added poisonous or other added deleterious ingredient which may render such article injurious to health."  For decades, science has indicated that added trans fats are not safe, so now the FDA will finally STOP designating this man-made substance as a safe additive for the US food supply.  It's about time!


Harvard School of Public Health article explaining the history/health risks of artificial trans fats


And don't worry, the food manufacturers will reformulate refrigerator cookie dough and microwave popcorn with another unhealthy solid fat, so junk food will remain readily available...

Tuesday, March 10, 2015

Limiting Fructose Helps At-Risk Kids Cut Liver Fat

When scientists replaced sugars with complex carbohydrates and fruits in obese kids' diets, they saw dramatic drops in liver fat in only 10 days, even though the kids did not lose any weight. High amounts
of liver fat increase risk for conditions like Type 2 diabetes and heart disease.
Because of the chemical structure of fructose, it is much more likely to be turned into fat in the liver--BOTH regular cane sugar and high fructose corn syrup contain approximately 50% fructose. There is no convincing evidence that either type of sugar is better or worse than the other for health. There is evidence that replacing these sugars with starchy foods, especially whole grains, does improve health and reduce liver fat.
In a study we conducted at GW a few years back, nearly 40% of DC high school students surveyed indicated they would choose to drink soda, rather than water (n=405; unpublished).

https://clinicaltrials.gov/ct2/show/NCT01200043
http://www.medpagetoday.com/MeetingCoverage/ENDO/50396

Wednesday, February 11, 2015

Cholesterol Exonerated!

A single cholesterol molecule
According to the Washington Post, Americans' greatest frenemy dietary component may no longer be included on the 'to be avoided' list in the 2015 Dietary Guidelines, the nutrition document guiding America's food and nutrition policies and programs.
'Blood cholesterol' is a misnomer--'cholesterol' in your blood are particles that contain cholesterol*, but also fats, proteins, and other molecules. 'Blood cholesterol' particles are made mostly in the liver and do not come directly from the diet. If your liver is a factory producing proteins and lipids (fat, cholesterol, etc.), 'blood cholesterol(s)' are like boxes shipping these food molecules to other parts of your body. Your liver is likely to make a lot of 'blood cholesterol' particles after eating too much sugar, white starches, artificial trans fats, and excessive Calories from any source.
Your 'total cholesterol' number is the sum of VLDL, LDL, and HDL plus some less common particles:
video
VLDL (Very Low Density Lipoprotein)- Extra Calories from any kind of food are often turned into fat in the liver. The VLDL packs up these little pieces of fat and moves them into to fat cells elsewhere, often your butt and hips ladies. This sounds bad, but it's really good. In extreme cases, storing fat in the liver leads to cirrhosis and liver failure. Yikes!
LDL (Low Density Lipoprotein)- After the VLDL gives fat to your butt, it gets more dense and turns into a LDL. LDL is called the 'bad' cholesterol. The video above is a graphic of an LDL, where cholesterol molecules are in the center.  But LDL is only bad when there's too much of it**, promoting blocked arteries over time. Otherwise, LDL is kind-of useful. The actual cholesterol molecule in LDL can be dropped off to the gonads to make testosterone or estrogen, and who doesn't love sex hormones?
HDL (High Density Lipoprotein)- HDL picks up excess cholesterol and fat throughout the body and higher amounts are associated with less clogged arteries and heart disease. So some call it 'good cholesterol'
BASICALLY:
(1) Americans eat too much of their top 10 food choices, mostly crap: (ordered most to least consumed according to the 2010 Dietary Guidelines): 1) starchy dessert; 2) yeast breads; 3) chicken dishes; 4) soda; 5) alcohol; 6) pizza; 7) tacos; 8) pasta; 9) beef dishes; and 10) dairy desserts ---->; THEN
(2) After digestion, the liver receives these foods as simple sugars, fats and amino acids. The liver can and will turn excessive Calories from any source into fat. The liver packs these fats into VLDL. VLDL is released into the blood and gives fat to your butt, love handles, etc. ----> THEN
(3) The VLDL gets more dense and is changed to an LDL ---> THEN
(4) Eating too much over the years (especially white starch and trans fats), promotes chronic inflammation, too much LDL in the blood, and build up of plaque in the arteries ---> THEN
(5) 1 in 4 Americans dies of heart disease, often way too early

The take home message is simple, be active, don't eat more food than you need, and don't eat a typical American diet of cookies, white bread, fried chicken, soda, beer, pizza, tacos, pasta, hamburgers, and ice cream.
I am the food police, but it's out of love.
--
* The cholesterol added to blood cholesterol' particles is mostly made in the liver, and less from the diet.
**LDL in the blood is affected by diet, but also heavily influenced by genetics. An extreme case is familial hypercholesterolemia. LDL are moved out of the blood and into the liver by special proteins. When the genetic code for these proteins is messed up, the LDL can't be removed from the blood. People with this condition have super high blood LDL.
In case you're real nerdy and want to read a lot of dense academic papers about lipoprotein particles and American eating patterns, here are some references:
http://www.jlr.org/content/25/13/1570.full.pdf
http://www.ncbi.nlm.nih.gov/pubmed/14748713
http://www.health.gov/dietarygu…/…/dietaryguidelines2010.pdf

Thursday, July 24, 2014

UTMB Researchers Show that Brown Fat Affects Glucose Metabolism in Humans



Research first-authored by Maria Chondronikola, a registered dietitian, shows that brown adipose is an anti-diabetic tissue in humans. The principal investigator of this ground-breaking research is Dr. Labros Sidossis, will teach a course on obesity in my Master of Science/Dietetic Internship program in the Fall 2014 semester.  


Uncoupling proteins allow hydrogen to cross the membrane without
making ATP; this causes the energy to be lost as heat.
Brown fat cells are different from white fat cells because they are rich in mitochondria containing a lot of uncoupling proteins (UCP).   When our bodies use food for energy, the food energy is used to make a proton gradient in the mitochondria to transfer food energy to ATP, the molecule our bodies use to do work. Uncoupling proteins disrupt the gradients in brown fat cells and allow food energy escape as heat.  In other words, brown fat cells allows us to 'burn calories' to make heat instead of storing energy in the body.

Babies have relatively more brown adipose tissue than adult humans.  Brown fat is found in adults in some areas around the neck and a few other places. Scientists activate
The middle row shows brown fat activation 
with cold exposure on a PET can in 
research performed by Virtanen and others.
brown fat in research by exposing subjects to just the right amount of cold, promoting 'non-shivering thermogenesis.' Adults seem to have more brown fat when they are lean, younger, and female, while older people and those with diabetes or a high BMI tend to have less brown fat.  It seems that aging probably causes a loss of brown fat. The causal relationships between brown fat and obesity and diabetes still need to be determined.  Emerging research shows that exercise and dietary compounds, like capsaicin, may activate brown fat in the short term.

The research done at UTMB is new because scientists matched subjects for factors like age and overall body fat content and separated groups into brown fat + and brown fat -.  The scientists exposed all the research subjects to a cold environment, but only brown fat positive (+) showed increased calorie burning, sugar storage, and insulin sensitivity with cold exposure.  More research needs to be done to see if nutrition, exercise training or other interventions can promote greater brown fat content or activity for the long term.

References

The presence of UCP1 demonstrates that metabolically active adipose tissue in the neck of adult humans truly represents brown adipose tissue




Friday, July 18, 2014

Effects of Extended-Release Niacin with Laropiprant in High-Risk Patients — NEJM

Another major study shows that supplemental niacin (vitamin B3) promotes poorer outcomes in those who have CVD, despite lowering LDL ('bad cholesterol') and raising HDL ('good cholesterol') concentrations.  If you have family members taking niacin for cardiovascular benefits, I would advise them to stop, particularly if the person also has blood sugar problems.

Another study showing similar results is here: http://www.bmj.com/content/342/bmj.d3400

The recommended amount of niacin to consume each day for healthy adults is 14mg for women and 16mg for men.  Many multivitamin supplements exceed this number several-fold.  See the link below for good food sources of niacin:

https://drive.google.com/file/d/0B6qfyK7joFMpejdaeGU1YWpOdTA/edit?usp=sharing

Effects of Extended-Release Niacin with Laropiprant in High-Risk Patients — NEJM