Research Fast Five for January 2021

Cardiology

Not surprisingly, eating fried food is now unquestionably linked to an increased risk of major heart disease and stroke, according to a pooled analysis of data published online in the journal Heart. The researchers concluded that the risk increases with each additional 114 g serving per week. 

The researchers pooled data from 17 studies with 562,445 participants and 37,727 major cardiovascular events such as heart attacks or stroke to assess cardiovascular disease risk.
They also pooled the data from six studies involving a total of 754,873 participants and 85,906 deaths over roughly a decade to determine the link between fried food consumption and deaths from heart disease, as well as all-cause mortality. 

Compared to those with the lowest weekly intake of fried food consumption, the highest intake was associated with a 28% higher risk of major cardiovascular events, a 22% increase in the risk of coronary heart disease, and a 37% heightened risk of heart failure.

For each increase of 114 g fried food per week
Major cardiovascular eventsIncrease 3%
Coronary heart diseaseIncrease 2% 
Heart failure Increase 12%

Interestingly, the researchers found no associations for deaths from cardiovascular disease or all-cause mortality and fried food consumption. However, this might be explained by the relatively small size of the review. 

One weakness of the analysis was that several studies only included one type of fried food, such as only snack foods or fried potatoes. All of the studies also relied on participants’ recall of food intake, a measurement that is well-known to be unreliable. 

Fried foods increase overall caloric intake, consumption of trans fatty acids, ingestion of chemical by-products believed to cause inflammation, and sodium consumption. Furthermore, meals including fried foods are often served with sugary drinks. 

Pei Qin, Ming Zhang, Minghui Han, Dechen Liu, Xinping Luo, Lidan Xu, Yunhong Zeng, Qing Chen, Tieqiang Wang, Xiaoliang Chen, Qionggui Zhou, Quanman Li, Ranran Qie, Xiaoyan Wu, Yang Li, Yanyan Zhang, Yuying Wu, Dongsheng Hu, Fulan Hu. Fried-food consumption and risk of cardiovascular disease and all-cause mortality: a meta-analysis of observational studies. Heart, 2021; heartjnl-2020-317883 DOI: 10.1136/heartjnl-2020-317883

Endocrinology

A randomized clinical trial of 60 participants determined that metabolic surgery (gastric bypass or biliopancreatic diversion) is more effective than medications and lifestyle modification in the long-term treatment of severe type 2 diabetes. More than a third (37.5%) of the participants remained “cured” of their diabetes for the 10-year trial period. All participants had advanced disease and poorly controlled blood glucose with more than five years of disease history at the beginning of the trial. Surgery has also proven to improve overall metabolic control and kidney function, lower cardiovascular risk, and improve patients’ quality of life more than conventional medical treatment. The use of medications for diabetes, high blood pressure, and dyslipidemia is also reduced following surgery. 

Of the three groups, the participants who underwent biliopancreatic diversion had a higher incidence of serious adverse events. The Roux-en-Y gastric bypass was associated with a lower risk of serious adverse events. 

This was the first trial to show that surgery should be considered for patients with advanced, severe type 2 diabetes and obesity. 

Geltrude Mingrone, Simona Panunzi, Andrea De Gaetano, Caterina Guidone, Amerigo Iaconelli, Esmeralda Capristo, Ghassan Chamseddine, Stefan R Bornstein, Francesco Rubino. Metabolic surgery versus conventional medical therapy in patients with type 2 diabetes: 10-year follow-up of an open-label, single-centre, randomised controlled trial. The Lancet, 2021; 397 (10271): 293 DOI: 10.1016/S0140-6736(20)32649-0

Gastrointestinal

Gastroesophageal reflux disease (GERD) affects approximately 30% of the US population and is generally treated with medication. Findings from the Nurses’ Health Study, which asked 43,000 women between the ages of 42 and 62 about their GERD symptoms from 2005 to 2017, show that five diet and lifestyle factors have a significant impact on GERD symptomology:

  1. Maintaining a normal body weight.
  2. Not smoking
  3. Moderate-to-vigorous physical activity for at least 30 minutes daily.
  4. Limiting coffee, tea, and soda to two cups a day
  5. Eating a “prudent” diet.

The researchers discerned that adhering to all five lifestyle factors reduced GERD symptoms overall by 37%. Even among women who also used traditional treatments (proton pump inhibitors and H2 receptor antagonists), adhering to the guidelines reduced symptoms. 

The researchers were especially interested in the effect of physical activity on GERD and hypothesize that exercise helps with stomach acid clearance. 

Raaj S. Mehta, Long H. Nguyen, Wenjie Ma, Kyle Staller, Mingyang Song, Andrew T. Chan. Association of Diet and Lifestyle With the Risk of Gastroesophageal Reflux Disease Symptoms in US Women. JAMA Internal Medicine, 2021; DOI: 10.1001/jamainternmed.2020.7238

Musculoscelatal

Although commonly prescribed for such, it appears that antidepressant drugs are relatively ineffective for both back and osteoarthritis pain. Most clinical practice guidelines currently recommend the use of antidepressants for long-term back pain, as well as for hip and knee osteoarthritis. However, the findings from this analysis of 33 randomized controlled trials involving more than 5,000 adults show that the improvement is, at best, minimal. 

Serotonin-norepinephrine reuptake inhibitors (SNRIs) reduced back pain after three months, but only by 5.3 points (of 100 possible points) on the pain scale compared to a placebo, an amount unlikely to be considered a clinical improvement by most patients. For osteoarthritis, SNRIs reduced pain by an average of 9.7 points compared with the placebo; this reduction could be worthwhile for some patients. 

Tricyclic antidepressants (TCAs) were ineffective for back pain and related disability. However, both TCAs and SNRIs might reduce discomfort among people with sciatica, but the evidence was weak. 

The researchers acknowledged the possibility of missed trials and pointed out a low number of studies spread across six different classes of antidepressants. They conclude, “Large, definitive randomized trials that are free of industry ties are urgently needed to resolve uncertainties about the efficacy of antidepressants for sciatica and osteoarthritis highlighted by this review.”

SNRIs currently on the marketTCAs currently on the market
atomoxetine (Strattera)

desvenlafaxine (Pristiq, Khedezla)

duloxetine (Cymbalta, Irenka)

levomilnacipran (Fetzima)

milnacipran (Savella)

venlafaxine (Effexor XR)
amitripyline (Elavil)

clomipramine (Anafranil)

doxepin (Sinequan)

Imipramine (Tofranil)

trimipramine (Surmontil)

amaxapine desipramine (Norpramin)

nortryptiline (Pamelor, Aventyl)

proptriptyline (Vivactil)

Giovanni E Ferreira, Andrew J McLachlan, Chung-Wei Christine Lin, Joshua R Zadro, Christina Abdel-Shaheed, Mary O’Keeffe, Chris G Maher. Efficacy and safety of antidepressants for the treatment of back pain and osteoarthritis: systematic review and meta-analysis. BMJ, 2021; m4825 DOI: 10.1136/bmj.m4825

Respiratory Disease

New research suggests that consuming more omega-3 fatty acids in childhood may reduce the chances of developing asthma for children with a particular common gene variant. 

Data from a large UK birth cohort, Children of the 90s, which recruited pregnant women in the early 1990s and have followed their offspring since, was used for this research. They reviewed the association between intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish at seven years of age (self-reported) and compared it to the incidence of new cases of asthma between the ages of 11 and 14. 

The association was only seen among the children who carried a common variant in the fatty acid desaturase (FADS) gene, associated with lower omega-3 fatty acid levels in the blood and present in more than half of the children. A higher dietary intake was associated with a 51% lower risk of asthma in these children when researchers compared those in the top quartile of omega-3 intake to those in the bottom. 

Mohammad Talaei, Emmanouela Sdona, Philip C. Calder, Louise R. Jones, Pauline M. Emmett, Raquel Granell, Anna Bergström, Erik Melén, Seif O. Shaheen. Intake of n-3 polyunsaturated fatty acids in childhood, FADS genotype, and incident asthma. European Respiratory Journal, 2021 DOI: 10.1183/13993003.03633-2020