For the protection of our patients, the staff will wear mask in the office.
For Telehealth follow-up and new consultations please contact us Here
1-818-812-7222 Office Hours: Monday and Wednesay 8:00 AM to 5:00 PM
10 Congress St., Suite #405
Pasadena, CA 91105

Blog

Absorption of Minerals and Metals

January 12, 2009 6:42 am

The vast bulk of mineral absorption occurs in the small intestine. The best-studied mechanisms of absorption are clearly for calcium and iron, deficiencies of which are significant health problems throughout the world.

Minerals are clearly required for health, but most also are quite toxic when present at higher than normal concentrations. Thus, there is a physiologic challenge of supporting efficient but limited absorption. In many cases intestinal absorption is a key regulatory step in mineral homeostasis.

Calcium

The quantity of calcium absorbed in the intestine is controlled by how much calcium has been in the diet during recent periods of time. Calcium is absorbed by two distinct mechanism, and their relative magnitude of importance is set by dietary calcium “history”:.

absorption-of-minerals-and-metals-01
Cellular Iron Absorption
  1. Active, transcellular absorption occurs only in the duodenum when calcium intake has been low. This process involves import of calcium into the enterocyte, transport across the cell, and export into extracellular fluid and blood. Calcium enters the intestinal epithelial cells through voltage insensitive channels and is pumped out of the cell via a calcium- ATPase.The rate limiting step in transcellular calcium absorption is transport across the epithelial cell, which is greatly enhanced by the carrier protein calbindin, the synthesis of which is totally dependent on vitamin D.
  2. Passive, paracellular absorption occurs in the jejunum and ileum, and, to a much lesser extent, in the colon when dietary calcium levels have been moderate or high. In this case, ionized calcium diffuses through tight junctions into the basolateral spaces around enterocytes, and hence into blood. Such transport depends on having higher concentrations of free calcium in the intestinal lumen than in blood. Additional Calcium information here.

Phosphorus

Phosphorus is predominantly absorbed as inorganic phosphate in the upper small intestine. Phosphate is transported into the epithelial cells by contransport with sodium, and expression of this (or these) transporters is enhanced by vitamin D.

Iron

Iron homeostasis is regulated at the level of intestinal absorption, and it is important that adequate but not excessive quantities of iron be absorbed from the diet. Inadequate absorption can lead to iron-deficiency disorders such as anemia. On the other hand, excessive iron is toxic because mammals do not have a physiologic pathway for its elimination. Iron is absorbed by villus enterocytes in the proximal duodenum. Efficient absorption requires an acidic environment, and antacids or other conditions that interfere with gastric acid secretion can interfere with iron absorption.

Ferric iron (Fe+++) in the duodenal lumen is reduced to its ferrous form through the action of a brush border ferrireductase. Iron is the co-transported with a proton into the enterocyte via the divalent metal transporter DMT-1. This transporter is not specific for iron, and also transports many divalent metal ions.

absorption-of-minerals-and-metals-02

Once inside the enterocyte, iron follows one of two major pathways. Which path is taken depends on a complex programming of the cell based on both dietary and systemic iron loads:

  1. Iron abundance states: iron within the enterocyte is trapped by incorporation into ferritin and hence, not transported into blood. When the enterocyte dies and is shed, this iron is lost.
  2. Iron limiting states: iron is exported out of the enterocyte via a transporter (ferroportin) located in the basolateral membrane. It then binds to the iron-carrier transferrin for transport throughout the body.

Iron in the form of heme, from ingestion of hemoglobin or myoglobin, is also readily absorbed. In this case, it appears that intact heme is take up by the small intestinal enterocyte by endocytosis. Once inside the enterocyte, iron is liberated and essentially follows the same pathway for export as absorbed inorganic iron. Some heme may be transported intact into the circulation. Additional Iron information here.

Copper

There appear to be two processes responsible for copper absorption – a rapid, low capacity system and a slower, high capacity system, which may be similar to the two processes seen with calcium absorption. Many of the molecular details of copper absorption remain to be elucidated. Inactivating mutations in the gene encoding an intracellular copper ATPase have been shown responsible for the failure of intestinal copper absorption in Menkes disease. A number of dietary factors have been shown to influence copper absorption. For example, excessive dietary intake of either zinc or olybdenum can induce secondary copper deficiency states. Additional Copper information here.

Zinc

Zinc homeostasis is largely regulated by its uptake and loss through the small intestine. Although a number of zinc transporters and binding proteins have been identified in villus epithelial cells, a detailed picture of the molecules involved in zinc absorption is not yet in hand. Intestinal excretion of zinc occurs via shedding of epithelial cells and in pancreatic and biliary secretions. A number of nutritional factors have been identified that modulate zinc absorption. Certain animal proteins in the diet enhance zinc absorption. Phytates from dietary plant material (including cereal grains, corn, rice) chelate zinc and inhibit its absorption. Subsistence on phytate-rich diets is thought responsible for a considerable fraction of human zinc deficiencies. Additional Zinc Information here

Trans-Fatty Acids

January 07, 2009 9:34 pm

As I am sure you have all heard in the media, the largest group of US population that is getting larger is the youngest member of the society.

There are some common sense reasons why our children are becoming overweight. These include excess calories, sedentary lifestyle (being in front of computer, and video games.) Children however can easily be taught healthy habits. It is much easier to avoid the disease of the obesity, rather than try to correct it later in life. I am not discounting the genetic predisposition to obesity which may be present in some cases.

Looking over some of our very first newsletters I came across the following list that I believe is worthwhile sharing again.

Teaching Kids to Eat Right and Get Moving
Studies cite sedentary pastimes and poor eating habits as the main factors behind childhood obesity. Experts see prevention as the remedy. Much of the latest research on childhood obesity is focused on prevention and intervention: breaking children of their bond to television, guiding them toward more physical
activity and improving their eating habits. Nurturing Good Habits: For a child, family eating patterns and parental pressures can make the difference between a healthy body and a sensible outlook on meals or a lifetime of bad eating habits. Experts recommend that parents establish good habits and pass them on to their kids.

  • Don’t restrict eating by making certain foods off-limits
  • Don’t tell children to clean their plates.
  • Don’t put children on a diet unless recommended by an experienced health professional who realizes that obesity is not all about overeating and lack of activity.
  • Don’t use food to regulate moods-reward children with love, attention and parental time.
  • DO realize that three meals a day works for adults, but children need healthy snacks too.
  • DO try to serve meals to the whole family that meet heart-healthy guidelines-<30% fat.
  • DO try to introduce healthy foods to children—they may learn to love it!
  • DO become educated about the food types, their nutritional values as well as portion sizes.
  • DO make exercise a part of daily life— walk to and from school with them if you can.
  • DO limit television viewing, playing video games, surfing the internet, and being on the computer. They will find fun active things to do.
  • DO join your children outdoors for fresh air. Once outside stress seems to release easier.
  • DO down at dinner with your family— conversations will happen!

Food should be healthy, and be valuable and nutritional. Our children will mimic what we do on daily basis. By making the same changes in our life style, we will set example for our children to follow.

“My hair is thin. My hair is falling out. My hair is dry and brittle. I just run out of energy…..”These are some of the most common reasons bariatric surgery patients come to see me. Typically they are eating between 2 and 4 of the vending machine peanut butter crackers for one meal and a few noodles at the other meal. Many times they just simply aren’t hungry, and this is a welcome feeling for them. Well, thinner is greater, but thinner hair isn’t usually as well received.

The hair problem is reflective of protein malnutrition, (and possibly vitamin deficiency if the patient is not taking their vitamin mineral supplement as directed.) This can happen several year’s post –op when patients simply stop paying attention to their intake.

Here are some of our suggestions for quick and easy protein:

  • Purchase low fat peanut butter and low fat crackers and keep handy in
    your car or desk at work.
  • Try hard-boiled eggs—coloring them is helpful in keeping track of each
    batch’s freshness.
  • Low fat cheese is a possibility.Watch the portion size.
  • Skim milk (or 1% milk) is a great source of protein. Add 1/3 cup of nonfat dry milk powder to 1 cup of milk—this will give you twice the protein. Lactose intolerant? Try Lactaid milk, Lactaid tablets to help
    with the gas, cramping, or diarrhea.
  • Beans and bean soup. If gas is a problem try BEANO—this is an enzyme sold over the counter in the drugstore.
  • Sliced or shaved deli meat, Teriyaki turkey jerky, sliced almonds are quick protein sources.
  • Remember to try and get 80 grams of protein/day.

Trans-fatty acids occur in semi artificial fats created by pumping hydrogen through liquid fats. This process adds hydrogen atoms and alters the molecular bonds of fatty acids that are liquid at room temperature. This process was first used to produce margarine, which has the texture of butter. It gives the “crunch” in cookies, and most importantly (for manufacturers)
prolongs the shelf life.

One of the many problem with these acids is that they increase LDL (low density lipoproteins) and lower the HDL (high density lipoproteins) that are good for you. Studies conducted by scientists in the last 25 years confirm that two percent increase in consumption of trans-fatty acids double the risk of developing heart disease.

As much as 25 to 50 percent of the fat in baby biscuits, cookies, chips, croissants and fish sticks contain appreciable amounts of trans-fatty acids.

Many of the major fast food chains have now committed to removing Trans fats rom their menu. Enjoy your dinner.

Biphosphonates are they good for you?

January 04, 2009 7:03 am

Cases of esophageal cancer in patients who had been taking oral bisphosphonate drugs for osteoporosis have been reported by an official from the Food and Drug Administration (FDA) in the January 1 issue of the New England Journal of Medicine.

Twenty-three cases (of which 8 were fatal) have been reported in the United States, all of them in association with alendronate (Fosamax, Merck), which was cited as the suspect drug in 21 cases and as a concomitant drug in 2 cases. These reports were received by the FDA in the 12-year period between October 1995 (when alendronate was launched in the United States) and mid-May 2008. No reports were received about esophageal cancer and any of the other oral bisphosphonate products.

A further 31 cases (6 fatal) have reported in Europe and Japan, with lendronate as the suspected drug in 21 cases. Of the remainder, 6 cases were associated with risedronate (Actonel, Procter & Gamble/Sanofi- Aventis), ibandronate (Boniva, Roche/ GlaxoSmithKli ne), etidronate (Didronel, Procter & Gamble), or a combination of these, and 4 cases cited bisphosphonates as concomitant drugs.

Writing in a letter to the journal, Diane Wysowski, PhD, from the FDA, gives few further details but points out that 4 of the patients had Barrett’s esophagus, which is a precursor of esophageal adenocarcinoma. “Physicians should avoid prescribing oral bisphosphonates to patients with Barrett’s esophagus,” she writes.

Dr. Wysowski also points out that esophagitis has been associated with oral bisphosphonates, usually when the drugs are not taken according to directions. “Crystalline material similar to ground alendronate tablets has been found in patients with erosive esophagitis, and persistent mucosal abnormalities have been noted in some of these patients, suggesting a potential for carcinogenic effects,” she writes.

Merck said in a statement that data from its clinical trials and postmarketing reports do not suggest any association between alendronate and esophageal cancer. The company pointed out that alendronate has been marketed for 13 years, during which time more than 150 million prescriptions have been written in the United States alone. Merck also noted that its clinical database includes more than 17,000 patients, of whom about 3000 osteoporosis patients took alendronate for 3 to 5 years and about 800 patients took alendronate for 8 to 10 years.

N Engl J Med. 2009;1360:89
Thank you VICKI BLACKBURN for sharing this information .

What are Biphosphonates?

These drugs are usually prescribed to prevent or treat Osteoperosis, and also to long time steroid users (cancer patients) to prevent bone loss. It is also prescribed to patients suffering from Paget’s Disease. Bisphosphonates are antiresorptive medications, which means they slow or stop the natural process that dissolves bone tissue. Fosamax, a member of this particular group of medications, has recently been linked to a condition called Osteocrenosis of the Jaw (ONJ). Individuals taking Bisphosphonates are also advised to avoid any unnecessary unvasive dental procedures (cleanings are OK).

Biphosphonates have been advocated strongly for treatment or prevention of osteoporosis. It has become evident that there are significant risk associated with this class of medication.

We strongly suggest that patients discuss these with the prescribing physician before taking this class of medication. When it comes to weight loss surgery and Biphosphonates, it is imperative that the patient has a normal serum Ca, PTH, Alk. Phos, before starting on this class of medication.

Fat consumption after Duodenal Switch – Olive Oil

December 30, 2008 9:24 pm


 

Good quality extra-virgin olive oil contains health relevant chemicals, phytochemicals’, that can trigger cancer cell death. New research sheds more light on the suspected association between olive oil-rich Mediterranean diets and reductions in breast cancer risk.

A team of researchers set out to investigate which parts of olive oil were most active against cancer. Their findings revealed for the first time that all the major complex phenols present in extra-virgin olive oil drastically suppress over expression of the cancer gene HER2 in human breast cancer cells.

Extra-virgin olive oil is the oil that results from pressing olives without the use of heat or chemical treatments. It contains phytochemicals that are otherwise lost in the refining process. Menendez and colleagues separated the oil into fractions and tested these against breast cancer cells in lab experiments. All the fractions containing the major extra-virgin phytochemical polyphenols (lignans and secoiridoids) were found to effectively inhibit HER2.

Although these findings provide new insights on the mechanisms by which good quality oil, i.e. polyphenol-rich extra-virgin olive oil, might contribute to a lowering of breast cancer risk in a HER2- dependent manner, extreme caution must be applied when applying the lab results to the human situation. As the authors point out, “The active phytochemicals (i.e. lignans and secoiridoids) exhibited tumoricidal effects against cultured breast cancer cells at concentrations that are unlikely to be achieved in real life by consuming olive oil”.

Nevertheless, and according to the authors, “These findings, together with the fact that that humans have safely been ingesting significant amounts of lignans and secoiridoids as long as they have been consuming olives and extra-virgin oil, strongly suggest that these polyphenols might provide an excellent and safe platform for the design of new anti breast-cancer drugs”.


The addition of moderate amount of fat in to your diet, after Duodenal Switch operation will result in loose bowel movement. By reducing the fat absorptive capacity in the small bowel after surgery, more fat is found in the colon. This results in loose bowel movements. In some patients who have had problem with constipation before surgery, and continue to have the same problem after DS, addition of some fat can be helpful. Excessive amount of fat however, will create problem.

Generally, olive oil is extracted by pressing or crushing olives. Olive oil comes in different varieties, depending on the amount of processing involved. Varieties include:

  • Extra virgin – considered the best, least processed, comprising the oil from the first pressing of the olives.
  • Virgin – from the second pressing.
  • Pure – undergoes some processing, such as filtering and refining.
  • Extra light – undergoes considerable processing and only retains a very mild olive flavor.

When buying olive oil you will want to obtain a high quality EXTRA VIRGIN oil. The oil that comes from the first “pressing” of the olive, is extracted without using heat (a cold press) or chemicals, and has no “off” flavors is awarded “extra virgin” status. The less the olive oil is handled, the closer to its natural state, the better the oil. If the olive oil meets all the criteria, it can be designated as “extra virgin”.

What is pure and light olive oil? “Pure” olive oil is made by adding a little extra virgin olive oil to refined olive oil. It is a lesser grade oil that is also labeled as just “olive oil” in the U.S.

“Light” olive oil is a marketing concept and not a classification of olive oil grades. It is completely unregulated by any certification organizations and therefore has no real precedent to what its content should be. Sometimes, the olive oil is cut with other vegetable oils.

Bariatric Surgery Before Pregnancy

December 05, 2008 10:56 am

Newsmaker
This year has gone by very fast. One of the most significant changes that have taken place is the deployment of our electronic medical record system. We are on schedule to have the medical records of our new patients on a secured server stored electronically. This has been a on-going project and now we are aiming for a January 2009 complete deployment.
Ara Keshishian, MD, FACS

Calcium And Vitamin D May Not Be The Only Protection Against Bone Loss Diets that are high in protein and cereal grains produce an excess of acid in the body which may increase calcium excretion and weaken bones, according to a new study.

The study found that increasing the alkali content of the diet, with a pill or through a diet rich in fruits and vegetables has the opposite effect and strengthens skeletal health. “Heredity, diet, and other lifestyle factors contribute to the problem of bone loss and fractures,” said Bess Dawson-Hughes, M.D., of Tufts University in Boston, Mass. and lead author of the study. “When it comes to dietary concerns regarding bone health, calcium and vitamin D have received the most attention, but there is increasing evidence that the acid/base balance of the diet is also important.”

Average older adults consume diets that, when metabolized, add acid to the body, said Dr.Dawson-Hughes. With aging, we become less able to excrete the acid. One way the body may counteract the acid from our diets is through bone resorption, a process by which bones are broken down to release minerals such as calcium, phosphates, and alkaline (basic) salts into the blood. Unfortunately, increased bone resorption leads to declines in bone mass and increases in fracture risk.

“When fruits and vegetables are metabolized they add bicarbonate, an alkaline compound, to the body,” said Dr. Dawson Hughes. “Our study found that bicarbonate had a favorable effect on bone resorption and calcium excretion. This suggests that increasing the alkali content of the diet may attenuate bone loss in healthy older adults.”

In this study, 171 men and women aged 50 and older were randomized to receive placebo or doses of either: potassium bicarbonate, sodium bicarbonate, or potassium chloride for three months. Researchers found that subjects taking bicarbonate had significant reductions in calcium excretion, signaling a decrease in bone resorption.

“In this study, we demonstrated that adding alkali in pill form reduced bone resorption and reduced the losses of calcium in the urine over a three month period,” said Dr. Dawson- Hughes. “This intervention warrants further investigation as a safe and well tolerated supplement to reduce bone loss and fracture risk in older men and women.”

Other researchers working on the study include Susan Harris, Nancy Palermo, Helen Rasmussen, and Gerard Dallal of Tufts University in Boston, Mass., and Carmen Castaneda-Sceppa of Northeastern University in Boston, Mass.

Bariatric Surgery Before Pregnancy Benefits Moms, Babies

Women who get pregnant after having weight-loss surgery have a lower risk of maternal and newborn complications than pregnant women who are obese, according to U.S. researchers who analyzed 75 studies.

Data from those studies showed that bariatric surgery in the United States increased by 800% between 1998 and 2005 (from 12,480 to 113,500). Women accounted for 83% of procedures among patients ages 18 to 45. Between 2003 and 2005, more than 50,000 women in this age group had inpatient bariatric surgery each year, which accounted for 49% of all bariatric surgeries.

The review authors found that pregnant women who’d had bariatric surgery had lower maternal complication rates than obese women, including gestational diabetes (0% vs. 22.1%) and preeclampsia (0% vs. 3.1%). In addition, maternal weight gain was reduced in women who’d had bariatric surgery.

Newborn outcomes among women who’d had laparoscopic adjustable band surgery were similar or better than outcomes among obese women: premature delivery, 7.7% vs. 7.1%; low birth weight, 7.7% vs. 10.6%; overly large body (macrosomia), 7.7% vs. 14.6%.

The findings were published in the Nov. 19 issue of the Journal of the American Medical Association.

“Research is needed to better delineate the extent to which surgery and subsequent weight loss improve fertility and pregnancy outcomes,” the review authors wrote. “Optimizing success for contraception and producing healthy neonates following surgery will require a multidisciplinary effort by surgeons, primary care physicians, reproductive fertility specialists, obstetricians, and patients.”

Having bariatric surgery during childbearing years may change a woman’s fertility following weight loss, alter nutritional requirements during pregnancy, or impact contraception, the researchers noted. — Robert Preidt

Source: Journal of the American Medical Association, news release, Nov. 18, 2008

Completely Novel Action Of Insulin Unveiled

October 27, 2008 9:26 pm



A Ph.D. student at Sydney’s Garvan Institute of Medical Research has uncovered an important piece in the puzzle of how insulin works, a problem that has plagued researchers for more than 50 years. The research brings scientists one step closer to explaining exactly how insulin prompts fat and muscle cells to absorb glucose.

“Since the 1920s, when Banting and Best discovered insulin, scientists have been battling to discover how it actually works,” said Professor David James, head of Garvan’s Diabetes Program. “Then along comes Freddy Yip, doing his PhD, who unveils a completely novel action of insulin, one which we believe plays a fundamental role in glucose uptake, a process that is defective in Type 2 diabetes.” There are two processes involved in Type 2 diabetes: insufficient production of insulin in the pancreas after a meal and faulty uptake and storage of glucose in fat and muscle cells, or ‘insulin resistance’.

Freddy’s finding focuses on the intersection between these two processes. “In the cell we have seriesof motor proteins that have the ability to move other molecules from one place to another along intracellular rail road tracks,” he explained. “I have discovered that insulin activates a specific kind of motor protein known as Myo1c, which in turn performs a critical role in glucose uptake.” Insulin controls glucose uptake into our fat cells by moving glucose transporter proteins from inside the cell to the surface membrane so that they can pump glucose into the cell. Myo1c aids in this process by helping the
transporters slide into the surface membrane.

In healthy people, around 80% of the glucose transporters migrate to the cell membrane after a meal, allowing plenty of glucose into the cell. In people with Type 2 diabetes, however, that figure drops to around 10%. Freddy Yip believes his study will create a strong foundation for future diabetes research. “We knew before that Myo1c was somehow involved in the regulation of glucose transport. My research indicates that Myo1c is a major target of insulin action and helps to accelerate the delivery of transporters to the membrane,” he said. “We think there may be blockages in the signal between insulin and myo1c in people who develop insulin resistance. If we’re correct, it should be possible to target that pathway for development of new therapies.”

Professor James sees the finding as a welcome milestone on a very long road of discovery. “While we’re certainly not saying we’ve found a way to cure diabetes, we are saying we’ve found a pretty significant clue.”

There is a common concern that some oral agents or insulin can cause weight gain.

  1. Regulates the liver from releasing too much glucose (I like to say that insulin leans up against the door of the liver and only lets a little glucose out at a time).
  2. Acts as a “doorman, or key” to open the doors of the cells and allow glucose to enter the cells.
  3. Acts as a storage promoter, to store extra glucose back into the liver, along with the muscles, while the excess is stored as fat.


So as a person without diabetes, whenever I overeat, my pancreas automatically releases extra insulin to take care of my extra food intake; if I don’t exercise it off, that excess food gets stored as fat and I gain weight. Remember Rhoda on the Mary Tyler Moore Show? To paraphrase her comment, she said “don’t bother giving me that candy bar-just apply it directly to my hips, since that’s where it will eventually end up!”

In contrast, with diabetes, if you don’t have enough insulin, then when you overeat, not all the food can enter the cells (to store in the liver and muscles, with the excess stored as fat); some of the glucose from your food just piles up in the blood, and gets urinated out-what I call a “false” weight loss/weight control.


If your diabetes were out of control for awhile, you were losing weight without trying; then as your blood glucose improved from taking diabetes medication, this would mean that instead of urinating out your food/calories, you were now able to retain your food and use it as energy (as well as store the excess in muscle and fat). The long-term studies proving that good diabetes control matters (i.e. the DCCT and UKPDS) also showed that people gained weight as their control improved. Despite the fact that losing weight and exercising are the keys to decreasing the risk of developing type 2 diabetes or to controlling diabetes and decreasing the risk of heart disease, experts have also agreed
that:

  1. controlling glucose is important, even if it means gaining some desirable weight (the average weight gain in the DCCT was 10 pounds);
  2. certain diabetes medications may not cause as much weight gain as others;
  3. careful meal planning and exercise can help to limit the weight gain.


True, if you are overeating and/or not exercising enough, and are thus requiring more oral agents or insulin, then you will gain weight because the diabetes medication is supporting your excess food intake. In the April, 2002 issue of Diabetes Forecast, Sheldon Gottlieb, MD addressed the issue of diabetes medication and weight gain, and commented that some people use insulin as a “carbohydrate credit card.” I hope you get my point that in this instance, the diabetes medication itself did not cause weight gain, but rather the excess calories did.

These drugs (trade names Actos® and Avandia®), which are used in treating insulin resistance, also are associated with weight gain. They interact with a receptor in tissue that may convert it into fat cells, although how this occurs is not yet well understood. Despite the weight gain, this class of drugs is associated with improved cardiovascular function. To limit the weight gain, the drug Metformin (trade name Glucophage®) is often added.

Generally, we tend to say that people might be prone to gain more weight on insulin, rather than on oral agents. But in addition to the issues discussed above, another common reason for weight gain is often related to the actual insulin regimen one is oni. e. if you take pre-mixed, intermediate, or long-acting insulin twice daily, you are forced to eat on time, to avoid skipping meals, and to anticipate exercise by taking an extra snack or decreasing your insulin, etc.-and this restricted regimen makes it harder to control weight. Often, using a rapid-acting insulin with each meal, with a bedtime dose of Lantus or NPH, or using an insulin pump, combined with careful diet and exercise, will allow you more flexibility in your lifestyle and an easier time controlling weight.

How Fatty Foods Curb Hunger

October 20, 2008 12:19 am



Fatty foods may not be the healthiest diet choice, but those rich in unsaturated fats – such as avocados, nuts and olive oil – have been found to play a pivotal role in sending this important message to your brain: stop eating, you’re full.

A new study by UC Irvine pharmacologists shows that these fats trigger production of a compound in the small intestine that curbs hunger pangs. This discovery, the researchers say, points toward new approaches to treating obesity and other eating disorders. Daniele Piomelli, the Louise Turner
Arnold Chair in Neurosciences, and his colleagues have studied how a fat-derived compound called oleoylethanolamide regulates hunger and body weight. In their current work, which appears in the Oct. 8 issue of Cell Metabolism, they found that an unsaturated fatty acid called oleic acid stimulates production of OEA, which in turn decreases appetite.

Oleic acid is transformed into OEA by cells in the upper region of the small intestine. OEA then finds itsway to nerve endings that carry the hunger-curbing message to the brain. There, it activates a brain circuit that increases feelings of fullness. In previous studies, Piomelli found that increasing OEA levels can reduce appetite, produce weight loss and lower blood cholesterol and triglyceride levels. Piomelli believes OEA could be used in a variety of drugs because it is a key to the way the body naturally handles fatty foods and regulates eating and body weight. “We are excited to find that OEA activates cell receptors that already have been the focus of successful drug development,” he said. “This gives us hope for a new class of anti-obesity drugs based on the savvy use of natural appetitecontrolling mechanisms.”

Nearly 30 percent of Americans are obese, according to the Centers for
Disease Control and Prevention, which has declared obesity an epidemic disease. The occurrence of obesity has risen by almost 60 percent since 1991, and it greatly increases the risk of premature death, diabetes, heart disease, stroke and some cancers.

Piomelli’s study colleagues include Jin Fu and Giuseppe Astarita of UCI; Gary Schwartz and Xiaosong Li of Yeshiva University; and Silvana Gaetani, Patrizia Campolongo and Vincenzo Cuomo of the University of Rome. The National Institutes of Health, New York Obesity Research Center, the Skirball Institute of Biomolecular Medicine and the Italian Ministry of Research supported the study.


Eating almonds significantly decreased levels of two biomarkers for oxidative stress in a group of 27 male and female volunteers with elevated cholesterol. The study was conducted by scientists funded by the Agricultural Research Service, the Almond Board of California, and the Canada Research Chair Endowment.

Coauthor Jeffrey Blumberg is director of the Antioxidants Research Laboratory at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass. He and colleagues reported the findings from this study in the Journal of Nutrition. HNRCA scientists analyzed blood and urine samples from the subjects who had consumed three different dietary treatments, consisting of the same amount of calories each, for one month. The study was a cross-over, randomized clinical trial, so eachsubject received each treatment in random order.

Treatments consisted of a “full dose” of almonds, defined as 73 grams daily (about 2.5 ounces), a “halfdose” of almonds plus a half-dose of muffins, and a full-dose of muffins as a control. The subjects consumed a low-fat background diet and were counseled on strategies to maintain weight and to consistently follow their usual exercise routines throughout each test phase.

The researchers wanted to investigate possible antioxidant effects from eating almonds. The team found that when the volunteers ate the full dose of almonds, their concentration of two biomarkers of oxidative stress– plasma malondialdehyde (MDA) and urinary isoprostanes–were significantly lowered. MDA decreased by nearly 19 percent compared to the start of the study in the full-dose almond group. Isoprostane decreased by 27 percent in both the almond groups when compared to the control period, suggesting a possible threshold effect for that biomarker. While this study helps to show the antioxidant benefit of eating almonds, further research is needed to shed light on the individual contributions of vitamin E and polyphenolic constituents, such as flavonoids, found in almonds and other tree nuts. The study did not demonstrate a minimum amount of dietary almonds that would result in a biological effect.

Flatulence – ‘Rotten Egg’ Gas

October 13, 2008 9:12 pm



Anyone with a nose knows the rotten-egg odor of hydrogen sulfide, a gas generated by bacteria living in the human colon. Now an international team of scientists has discovered that cells inside the blood vessels of mice — as well as in people, no doubt — naturally make the gassy stuff, and that it controls blood pressure.

Having discovered that hydrogen sulfide, or H2S, is produced in the thin, endothelial lining of blood vessels, the researchers, including scientists from Johns Hopkins, now report in Science that H2S regulates blood pressure by relaxing blood vessels. As the newest member of a family of so-called gasotransmitters, this messenger molecule is akin in function, if not form, to chemical signals like nitric oxide, dopamine and acetylcholine that relay signals between nerve cells and excite or put the brakes on mind-brain activities.

“Now that we know hydrogen sulfide’s role in regulating blood pressure, it may be possible to design drug therapies that enhance its formation as an lternative to the current methods of treatment for hypertension,” says Johns Hopkins
neuroscientist Solomon H. Snyder, M.D., a co-author of the paper. Conducting their investigations using mice missing a gene for an enzyme known as CSE, long suspected as responsible for making H2S, the researchers first measured
hydrogen sulfide levels in a variety of tissues in the CSE-deficient mice and compared them to normal mice. They found that the gas was largely depleted in the cardiovascular systems of the altered mice, engineered by Rui Wang, M.D., Ph.D., of Lakehead University in Ontario, and Lingyun Wu, M.D., Ph.D., of the University of Saskatchewan, Canada. By contrast, normal mice had higher levels — clear evidence that hydrogen sulfide is normally made by mammalian tissues using CSE. Next, the scientists applied tiny cuffs to the tails of the mice and measured their blood pressure, noting spikes of about 20 percent, comparable to serious hypertension in humans.

Finally, the team tested how blood vessels of CSE-deficient mice responded to the chemical neurotransmitter methacholine, known to relax normal blood vessels. The blood vessels of the altered mice relaxed hardly at all, indicating that hydrogen sulfide was largely responsible for relaxation. Because gasotransmitters are highly conserved in mammals, the findings of the research are believed to have broad applications to human physiology and disease.

“In terms of relaxing blood vessels, it looks like hydrogen sulfide might be as important as nitric oxide,” Snyder says, referring to the first gasotransmitter that two decades ago was discovered to regulate blood pressure.

Just because these two gas molecules perform similar functions, doesn’t mean they’re redundant, says Wang, the paper’s principal author. “Nature has added on layer upon layer of complexity to provide a better and tighter control of body function — in this case, of blood pressure.”

Studying gaseous messengers can be tricky, explains Snyder, an authority on nitric oxide (NO) whose lab in 1990 discovered that the enzyme triggering NO production is activated by a protein mechanism known as calcium-calmodulin. “When a nerve fires, it releases a bit of neurotransmitter. Then it fires again, very quickly, and releases more of the neurotransmitter, which is always in reserve and at the ready in large storage pools called vesicles. However, gasses can’t be stored; they diffuse. So every time there’s a nerve impulse, an enzyme must be activated to make it,” he says.”

Although CSE, the enzyme that activates hydrogen sulfide, was characterized more than half a century ago, the new work is the first to reveal that it is activated in the same way as the nitric oxide-forming enzyme, thus establishing how hydrogen sulfide regulates blood pressure by relaxing blood vessels. “It’s difficult to overestimate the biological importance of hydrogen sulfide or its implications in hypertension as well as diabetes and neurodegenerative diseases,” Wang says. “In fact, most human diseases probably have something to do with gasotransmitters.”

The research was supported by grants from the U.S. Public Health Service and the Canadian Institutes of Health Research as well as a Research Scientist Award.

Authors on the paper are Guangdong Yang, Lingyun Wu, Bo Jiang, Wei Yang, Jiansong Qi, Kun Cao, Qinghe Meng, all of the University of Saskatchewan, Canada; Wang of the University of Saskatchewan and Lakehead University, Canada; Shengming Zhang of Lakehead University, Canada; and Asif K. Mustafa, Weitong Mu and Snyder, all of Hopkins.

Sugar vs. Sugar Alcohol

October 01, 2008 10:00 pm


 

Sugar alcohols are carbohydrates which are also called “polyols.” Part of their chemical structure resembles sugar, and part of it resembles alcohol — hence the confusing name. Examples of common sugar alcohols are maltitol, sorbitol, isomalt, and xylitol.

Sugar alcohols occur naturally in plants. Some of them are extracted from plants (sorbitol from corn syrup and mannitol from seaweed), but they are mostly manufactured from sugars and starches.

Sugar alcohols are like sugar in some ways, but they are not completely absorbed by the body. Because of this, the blood sugar impact of sugar alcohols is less and they provide fewer calories per gram. Additionally, sugar alcohols don’t promote tooth decay as sugars do, so are often used to sweeten chewing gum. One, xylitol, actually inhibits bacterial growth in the mouth.

It’s important to note, however, that the different types of sugar alcohols act very differently in the body (see chart below).

 
Sugar Alcohol Calories/Gram Sweetness
Compared
to Sucrose
Sources
Sorbitol 2.6 50% to
70%
Sugar-free hard and soft candies, chewing gum, flavored jam and jelly spreads, frozen foods, and baked goods
Mannitol 1.6 50% to
70%
Chewing gum, hard and soft candies, flavored jam and jelly spreads, confections, and frostings
Xylitol 2.4 100% Chewing gum, hard candies, and pharmaceutical products
Erythritol 0.2 60% to
80%
Confectionery and baked products, chewing gum, and some beverages
Isomalt 2.0 45% to
65%
Hard and soft candies, ice cream, toffee, fudge, lollipops, wafers, and chewing gum
Lactitol 2.0 30% to
40%
Chocolate, cookies and cakes, hard and soft candies, and frozen dairy desserts
Hydrogenated
starch
hydrolysates
(HSH)
3.0 25% to
50%
Sugar-free foods and candies, and low-calorie foods
Maltitol 2.1 90% Sugar-free chocolate, hard candies, chewing gum, baked goods, and ice cream

The names of the individual sugar alcohols will be on the ingredient list of any product that contains them. They will be included in the amount of carbohydrate on the label, either in the total or on a separate line for sugar alcohols. If the product is labeled “sugar-free” or “no added sugar,” the manufacturer must show the sugar alcohol count separately. As I indicated above, sugar-free does not mean sugar alcohol free.

Though sugar alcohols have fewer calories than sugar, most of them aren’t as sweet, so more must be used to get the same sweetening effect. Still, there is a range of sweetness and impact on blood sugar among the sugar alcohols.

 

The presence of Sugar Alcohol is sugar free food is the dietary version of the Enron Accounting. The label may suggest there is no calories from Sugar, thus Sugar Free label, yet is contains calories from Sugar Alcohol. This is usually listed separately and usually in fine print. By Paying close attention to the ingredients of food purchased, patients can avoid some of the common problems that we see in the office. Inadequate weight loss, weight regain, gas , bloating etc.