Wednesday, March 13, 2019

Wisdom Wednesday: Alzheimer's: 'Holy herb' extracts shows promise as future treatment


Yerba santa, a plant with a long history of medicinal use in its native California, contains an active compound that could treat people with Alzheimer's disease one day. This was the conclusion that scientists at the Salk Institute for Biological Studies in La Jolla, CA came to after testing 400 plant extracts with known medicinal properties. Using a new drug-discovery screen, they tested the compounds for their ability to deter the effects of aging on the brain. The initial round of tests yielded several extracts that protected against a type of cell death that occurs in Alzheimer's and other aging-related diseases. Further tests revealed that sterubin, an extract of Eriodictyon californicum, or Yerba santa, was the most able to shield against inflammation and other triggers of brain cell death.

Native tribes of California have long valued Yerba santa, which is the Spanish for "holy herb," very highly as a medicine for respiratory illnesses, fever, infections, bruising, pain, and headaches.

According to a 2018 Alzheimer's Disease International report, dementia affects 50 million people worldwide, two-thirds of whom have Alzheimer's disease. In the U.S., the number of people living with Alzheimer's disease is set to rise from approximately 5.7 million people today to nearly 14 million by 2050.

Monday, March 11, 2019

Vitamin D and Brain Health

New research finds that vitamin D deficiency affects a type of brain "scaffolding" that supports the neurons. This finding could lead to new therapies for the neurological symptoms of mental health conditions such as schizophrenia.

Vitamin D, which people sometimes refer to as the "sunshine vitamin," is necessary for maintaining healthy bones. It also benefits the immune and cardiovascular systems, as well as endocrine function. For instance, research has suggested that insufficient vitamin D may compromise the immune system, raise the risk of hypertension, and negatively affect insulin secretion in people with type 2 diabetes.

Newer studies have focused on the potential link between vitamin D and brain health. For example, a recent study that Medical News Today reported on reinforced the notion that there may be an association between vitamin D deficiency and a higher risk of schizophrenia.

Other studies have shown that depriving middle-aged rodents of vitamin D led them to develop brain damage and perform less well on cognitive tests. Researchers have also found that people who survive sudden cardiac arrest are less likely to recover brain function if they have low levels of vitamin D.

Friday, March 8, 2019

Blueberries May Reduce Cardiovascular Risk By 20 Percent

The phytochemicals that give blueberries their blue color can significantly improve cardiovascular health, finds a new two part study. Dubbed "the silent killer" because it has no visible symptoms in its early stages, hypertension affects approximately 1 in 3 adults in the United States.

The condition puts a strain on the cardiovascular system, which in the long run may contribute to heart failure, stroke, and kidney failure. The National Institutes of Health (NIH) recommend that people with high blood pressure stay in control of the condition by eating healthfully, exercising, not smoking, and maintaining a healthy weight.

But should you eat anything in particular to keep your arteries healthy? In a previous Spotlight feature, we rounded up 16 foods that studies have suggested can improve cardiovascular health. Along with broccoli, spinach, pulses, and fish, berries may also reduce heart disease, due to their antioxidant polyphenols.

New research zooms in on the cardiovascular effects of blueberries and finds that anthocyanins — the phytochemicals that give blueberries their color — mediate the beneficial effects that this fruit has on the cardiovascular system. The lead author of the study is Ana Rodriguez Mateos, Ph.D., from the Department of Nutritional Sciences at King's College London, in the United Kingdom. The researchers published their findings in The Journals of Gerontology: Series A.

Wednesday, March 6, 2019

Wisdom Wednesday: DEXA


The dual-energy X-ray absorptiometry (DEXA) scan uses two low-energy X-ray beams that separates the images into two components, including soft tissue and bone. When determining whether a person has low bone density or whether the condition is getting worse, a DEXA scan tends to be more accurate than a typical X-ray because it can detect even small changes in bone loss. Doctors also consider it more reliable than other methods of calculating body fat percentage, including underwater weighing. Scan results may indicate the severity of bone loss and help doctors determine a person's risk of developing a fracture. When assessing body composition, the results may also help determine a person's level of visceral fat, which the body stores around certain internal organs.

The most common purpose of a DEXA scan is to assess whether a person's bones are weak and or at risk of fracture. It also helps a doctor diagnose osteoporosis. Osteoporosis causes the bones to lose density or become thin. When the bones get thin, they also become fragile, which makes them more susceptible to breaks. Determining whether a person has osteoporosis as early as possible is important to prevent the condition from becoming worse. It also reduces the risk of fractures. A DEXA scan is also a useful diagnostic tool to assess whether or not osteoporosis is getting worse. After the first DEXA scan, a doctor will usually order another scan in a couple of years to determine whether the bone density has changed.

Monday, March 4, 2019

Large Trials Cast Doubt on Low-Dose Aspirin's Benefits

Hello. I'm David Kerr, professor of cancer medicine at the University of Oxford. As many of you know—those who listen to my small rants on Medscape from time to time—I have been conducting a long-distance love affair with aspirin for some time in terms of its cancer-preventive properties.

I have to say that this love affair has been strained somewhat by the recent publication of two important pieces. One was published in the Lancet, written by Peter Rothwell and colleagues, and the other is a report of a combined Australian-US trial in the New England Journal of Medicine.

First, let's discuss Peter's study. Dr. Rothwell and his colleagues suggest that there is not a single dose of aspirin, a one-size fits-all dose, in terms of its cancer- or cardiovascular-preventive properties. They analyzed an enormous dataset from a large series of randomized trials, databases he has been successfully working on for some time. They investigated the benefits and disadvantages of aspirin according to height and weight, predominately weight. They found that the benefits of low-dose aspirin, 75-100 mg daily, in terms of cardiovascular prevention, were relatively confined to those who weigh less than 70 kg.

In the analyzed studies, the vast majority of men, 80% of whom were 70 kg or more, had no obvious benefits from aspirin at all. That's interesting. What was, for me, more worrisome was when they started to look at the disadvantages. They found that subjects taking low-dose aspirin who were under 70 kg had real possibility of harm—an increased incidence of early cancer. This is particularly pronounced in those patients who are more than 70 years old. They concluded that we should further explore the dose of aspirin. The clinical pharmacology of aspirin has been studied since the late 1960s. There is a relationship between pharmacokinetics, steady-state plasma concentrations, weight, and age. As we grow older, liver function deteriorates, and therefore we clear drugs less effectively. This could potentially underlie what is happening. We need more mechanistic work to understand this better.

Friday, March 1, 2019

Interval Training May Be Best for Weight Loss

Interval training may result in greater weight loss than continuous exercise, with sprint interval training (SIT) the most effective, say researchers, who say interval training also may be easier for obese and older individuals to perform.

The findings of Ricardo Borges Viana, MSc, a PhD student in the Faculty of Physical Education and Dance, Federal University of Goiás, Brazil, and colleagues were published online February 14 in the British Journal of Sports Medicine. Senior author Paulo Gentil, PhD, of the same institution, told Medscape Medical News that interval training "seems to promote many physiological changes that might favor long-term weight loss.

The team conducted a systematic review and meta-analysis and compared weight loss with interval training, including both high-intensity interval training (HIIT) and SIT with moderate-intensity continuous training (MOD).

After pooling results from over 1000 individuals, they found both interval training and MOD led to significant reductions in both total body fat percentage and total absolute fat mass.
However, interval training was associated with a reduction in total absolute fat mass that was more than 28% greater than that seen with MOD, with the greatest reductions seen with SIT.
Despite the positive results, the team cautions that "it is important to be aware of the possible risks and caveats associated with higher-intensity training."

For example, they warn that "it might increase the risk of injury and impose higher cardiovascular stress," and the potential discomfort associated with high-intensity training could affect adherence. They also highlight that the "methodological diversity" between protocols used in the studies "makes it difficult to generally recommend that one particular protocol is 'best' for modulating body adiposity."

Wednesday, February 27, 2019

Wisdom Wednesday: Fecal Immunochemical Tests


Performance Characteristics of Fecal Immunochemical Tests for Colorectal Cancer and Advanced Adenomatous Polyps: A Systematic Review and Meta-analysis

Purpose:
To summarize performance characteristics of FITs for CRC and advanced adenomas in average-risk persons undergoing screening colonoscopy (reference standard) and to identify factors affecting these characteristics.

Data Sources:
Ovid MEDLINE, PubMed, Embase, and the Cochrane Library from inception through October 2018; reference lists of studies and reviews.

Study Selection:
Two reviewers independently screened records to identify published English-language prospective or retrospective observational studies that evaluated FIT sensitivity and specificity for colonoscopic findings in asymptomatic, average-risk adults.

Data Extraction:
Two authors independently extracted data and evaluated study quality.

Data Synthesis:
Thirty-one studies (120 255 participants; 18 FITs) were included; all were judged to have low to moderate risk of bias. Performance characteristics depended on the threshold for a positive result. A threshold of 10 µg/g resulted in sensitivity of 0.91 (95% CI, 0.84 to 0.95) and a negative likelihood ratio of 0.10 (CI, 0.06 to 0.19) for CRC, whereas a threshold of greater than 20 µg/g resulted in specificity of 0.95 (CI, 0.94 to 0.96) and a positive likelihood ratio of 15.49 (CI, 9.82 to 22.39). For advanced adenomas, sensitivity was 0.40 (CI, 0.33 to 0.47) and the negative likelihood ratio was 0.67 (CI, 0.57 to 0.78) at 10 µg/g, and specificity was 0.95 (CI, 0.94 to 0.96) and the positive likelihood ratio was 5.86 (CI, 3.77 to 8.97) at greater than 20 µg/g. Studies had low to high heterogeneity, depending on the threshold. Although several FITs had adequate performance, sensitivity and specificity for CRC for 1 qualitative FIT were 0.90 and 0.91, respectively, at its single threshold of 10 µg/g; positive and negative likelihood ratios were 10.13 and 0.11, respectively. Comparison of 3 FITs at 3 thresholds was inconclusive: CIs overlapped, and the comparisons were across rather than within studies.

Limitations:
Only English-language studies were included. Incomplete reporting limited quality assessment of some evidence. Performance characteristics are for 1-time rather than serial testing.

Conclusion:
Single-application FITs have moderate to high sensitivity and specificity for CRC, depending on the positivity threshold. Sensitivity of 1-time testing for advanced adenomas is low, regardless of the threshold.

Primary Funding Source:
Department of Medicine, Indiana University School of Medicine.

My Take:
This is an abstract taken directly from the Annals of Internal Medicine, February 26, 2019. Typically I “dummy it down” a little, but I thought you might find the original abstract interesting. It’s a retrospective study using two independent authors as noted above. Please note how they not only present the data, but also the limitations prior to any conclusions. Finally, they also list the funding. In this case, it appears to be independent of bias.

Bottom Line:
Cologuard is the most popular trade name for this home test. It is available by prescription only but is covered by most insurance. Despite the limitation in testing for advanced adenomas, it is quite accurate in testing for colorectal cancer. I highly recommend you ask your primary care provider to add this test to your annual physical.