Bisher AKIL, MD

Archive for August 23rd, 2016|Daily archive page

Six teaspoon of added sugar, no more!

In General Health, Heart, Kids & teens on August 23, 2016 at 8:00 pm

The American Heart Association now recommends that children limit their added sugar intake to 25 g daily or less, the equivalent of 6 teaspoons of sugar, or 100 calories. On average, children currently consume about 80 g daily.

Some definitions are needed here:

Sugar: Although commonly used more broadly, the US Federal Drug Administration defines the term sugar as a sweet ,crystalline substance, obtained chiefly from the juice of the sugarcane and the sugar beet.

Total Sugars: The term total sugars is used conventionally to describe the monosaccharides: glucose, galactose, and fructose, as well as the disaccharides sucrose, lactose, maltose, and trehalose (sunflower seeds, shiitake/mushroom, oyster). Total sugars include all sugars in a food or beverage from any source, including those naturally occurring (such as fructose in fruit and lactose in milk) and those added to foods.

Naturally occurring Sugars include those that are an innate component of foods (eg, fructose in fruits and vegetables and lactose in milk and other dairy products).

Extrinsic and Intrinsic Sugars terms originated from the UK Department of Health.  Intrinsic sugars are defined as sugars that are present within the cell walls of plants (eg, naturally occurring sugars)  and are always accompanied by other nutrients. Extrinsic sugars are those not located within the cellular structure of a food and are found in fruit juice, honey, and syrups and added to processed foods. The term non- milk extrinsic sugars is used to differentiate lactose- containing extrinsic sugars from all  others  because the metabolic response for the 2 types of sugars differs  substantially.

Free Sugars a term used by the World Health Organization that refers to all monosaccharides and disaccharides added to foods by the manufacturer, cook, and consumer (eg, added sugars) plus sugars naturally present in honey, syrups, and fruit juices (eg, non-milk extrinsic sugars).

The Risk:

  1. Excess weight gain and obesity
  2. Elevated blood pressure and uric acid levels
  3. Dyslipidemia
  4. Nonalcoholic fatty liver disease and
  5. Insulin resistance and diabetes mellitus.

Data source: They  used publicly available data from the most recent cycles of the National health and Nutrition Examination Survey ( NHANES)  (2009–2012) to estimate current levels of added sugars intake. These estimates may be conservatively low because it is well established that self-reported dietary assessments under report. Their analysis demonstrates that US children 2 to 19 years of age consume an average of 80 g added sugar daily . Absolute intake is higher among boys than girls (87 versus 73 g), but there were no differences when intake was assessed in relation to total energy intake (16.1% for both). Added sugars intake increases with age . Intake of free sugars, the combination of added sugars and sugars that occur naturally in honey, syrups, and juices, is 91 g and 18.5% total energy. Foods and beverages each contribute half of the added sugars in children’s diets, 40 g each. The top contributors to added sugars intake include soda, fruit- flavored and sports drinks, and cakes and cookies. Previous research has suggested that most added sugars are consumed at home rather than away from home.

Sobering findings: 

  1. Children consuming 3.5% to 6.8% of calories as sucrose (the lowest consumption group) had lower triglycerides and higher High density lipoprotein(HDL) than higher consumers.
  2. Children consuming no sugar-sweetened- beverages (SSBs) such as sodas,  compared with those consuming an average of 8 oz/d had lower C-reactive protein, smaller waist circumference, and higher HDL cholesterol.
  3. Each additional Sugar- sweetened beverages (SSB) equivalent (≈1 cup or 8 oz) consumed by children daily was associated with a 5% increase in Homeostatic model assessment and insulin resistance (HOMA-IR – , a method used to quantify insulin resistance and beta-cell function) 16-mm increase in systolic blood pressure, a 0.47-cm increase in waist circumference, a 0.90-percentile increase in BMI for age, and a 0.48-mg/dL decrease in HDL concentrations. The low consumers in this analysis consumed a mean of 0.1 oz of SSBs per day.
  4. Adolescents who consumed >10% of their total energy as added sugars had lower HDL levels, higher triglycerides, and higher low-density lipoprotein cholesterol levels than those who consumed less. Overweight or obese adolescents had higher insulin resistance (as assessed with HOMA-IR).

They concluded,  the available evidence found that associations with increased cardio-vascular disease (CVD) risk factors are present at levels far below US children’s current added sugars consumption levels. Current evidence supports the associations of added sugars with increased energy intake, increased adiposity (severe or morbid overweight), increased central adiposity, and increased dyslipidemia (elevation of plasma cholesterol, triglycerides (TGs), or both, or a low high-density lipoprotein level that contributes to the development of atherosclerosis, all of which are demonstrated CVD risk factors. Importantly, the introduction of added sugars during infancy appears to be particularly harmful and should be avoided. Although added sugars can mostly likely be safely consumed in low amounts as part of a healthy diet, little research has been done to establish a threshold between adverse effects an health, making this an important future research topic.

Summary appeared in JWatch, August 23 2016

Citation: published ahead of print

http://dx.doi.org/10.1161/CIR.0000000000000439

Comments: This is my review of the paper. The conclusions are: Children and adolescents should limit their intake of sugar-sweetened beverages (like sodas) to one 8-oz serving per week, or less, and for those under 2 years of age, added sugars should be avoided entirely_BA

 

Virus load is undetectable, but active virus still?

In HIV, Immune System on August 23, 2016 at 4:16 pm

HIV-infected patients taking antiretroviral medications with undetectable viral loads continue to have detectable HIV DNA in CD 4+ cells despite many years of therapy. Previous studies have found that most of that HIV DNA is defective and unable to replicate, a veritable “defective” of proviruses (the genetic material of a virus as incorporated into, and able to replicate with, the genome of a host cell). The current consensus view of the “defective” proviruses is that these are dead-end products that do not give rise to progeny (offspring) virus and thus collectively represent a “graveyard” of viruses.Now, a careful analysis reveals that these defective proviruses may not quite be as “dead” as we thought.

Investigators have now studied HIV DNA proviruses from four patients with undetectable plasma viral loads. As expected, the patients had defective proviruses with deletions or lethal mutations. Surprisingly, when cytoplasmic RNA from these patients was sequenced, the investigators found novel RNA transcripts matching the defective proviruses. These transcripts appeared to be capable of producing viral proteins. Investigators  propose that the proviruses persistently present in combination antiretroviral therapy-treated patients are not defective in a conventional sense, but rather represent incomplete forms of proviruses encoding translationally competent HIV-RNA transcripts. Strategies directed toward curing HIV-1 infection and eliminating the state of persistent immune activation need to include approaches designed to eliminate cells harboring such proviruses.

 

Appeared in JWatch August 5, 2016

Citation(s):Imamichi H et al. Defective HIV-1 proviruses produce novel protein-coding RNA species in HIV-infected patients on combination antiretroviral therapy. Proc Natl Acad Sci U S A 2016 Aug 2; 113:8783. (http://dx.doi.org/10.1073/pnas.1609057113)

 

Comments: this could explain the presence of viral activation ( seen by careful analysis of T-cell panel, mediators, ..etc) in those with undetectable plasma virus load. The question remains, should this be controlled, can it lead to an increase in CD4+ counts in those with undetectable virus load? This is probably one of the biggest clinical hurdles left_BA