Monday, May 21, 2018

Could intermittent fasting diets increase diabetes risk?


Fasting every other day to lose weight impairs the action of sugar-regulating hormone, insulin, which may increase diabetes risk, according to data presented in Barcelona at the European Society of Endocrinology annual meeting, ECE 2018. These findings suggest that fasting-based diets may be associated with long-term health risks and careful consideration should be made before starting such weight loss programmes.
Type-2 diabetes is a growing global epidemic that is often attributed to poor diet and a sedentary lifestyle, so is closely linked to obesity. Blood sugar is partially regulated by the hormone insulin, which is produced by the pancreas, if insulin levels are too low, or the body becomes resistant to its effects, type-2 diabetes results and high blood sugar levels can cause serious health issues, including heart, kidney and eye damage. In addition to medical strategies used to treat type-2 diabetes, patients are also advised to make lifestyle and dietary changes to lose weight. Recently, intermittent fasting diets have gained general popularity for weight loss, however, evidence on their success has been contradictory and there is a lack of knowledge and some debate on their potentially harmful long-term health effects. Previous research has also shown that short-term fasting can produce molecules called free radicals, which are highly reactive chemicals that can cause damage to the body at a cellular and may be associated with impaired organ function, cancer risk and accelerated aging.
In order to investigate whether an intermittent fasting diet could also generate damaging free radicals, Ana Bonassa and colleagues, from the University of Sao Paulo in Brazil, examined the effects of fasting every other day on the body weight, free radical levels and insulin function of normal, adult rats, over a 3-month period. Although the rats' body weight and food intake decreased as expected over the study period, the amount of fat tissue in their abdomen actually increased. Furthermore, the cells of the pancreas that release insulin showed damage, with the presence of increased levels of free radicals and markers of insulin resistance were also detected.
Ana Bonassa comments, "This is the first study to show that, despite weight loss, intermittent fasting diets may actually damage the pancreas and affect insulin function in normal healthy individuals, which could lead to diabetes and serious health issues."
The researchers now plan to investigate how this diet impairs pancreas and insulin function. There are many conflicting reports on the benefits and disadvantages, and many different types of intermittent fasting diets. Although these data were obtained in normal weight rats with positive effects on weight gain and food intake, the results suggest that in the long-term harm may be caused and that more investigation is needed to assess how people may be affected, particularly those with existing metabolic issues.
Ana cautions, "We should consider that overweight or obese people who opt for intermittent fasting diets may already have insulin resistance, so although this diet may lead to early, rapid weight loss, in the long-term there could be potentially serious damaging effects to their health, such as the development of type-2 diabetes."

Exercise to stay young: 4-5 days a week to slow down your heart's aging


Participating in exercise 4-5 days per week is necessary to keep your heart young, according to new research published in The Journal of Physiology. These findings could be an important step to develop exercise strategies to slow down such ageing.

The optimal amount of exercise required to slow down ageing of the heart and blood vessels has long been a matter of vigorous debate. As people age, arteries - which transport blood in and out of the heart - are prone to stiffening, which increases the risk of heart disease. Whilst any form of exercise reduces the overall risk of death from heart problems, this new research shows different sizes of arteries are affected differently by varying amounts of exercise. 2-3 days a week of 30 minutes exercise may be sufficient to minimise stiffening of middle sized arteries, while exercising 4-5 days a week is required to keep the larger central arteries youthful.

The authors performed a cross-sectional examination of 102 people over 60 years old, with a consistently logged lifelong exercise history. Detailed measures of arterial stiffness were collected from all participants, who were then categorised in one of four groups depending on their lifelong exercise history: Sedentary: less than 2 exercise sessions/week; Casual Exercisers: 2-3 exercise sessions per week; Committed Exercisers: 4-5 exercise sessions/week and Masters Athletes: 6-7 exercise sessions per week. (NB: an exercise session was at least 30 minutes).

Upon analysing the results, the research team found that a lifelong history of casual exercise (2-3 times a week) resulted in more youthful middle sized arteries, which supply oxygenated blood to the head and neck. However, people who exercised 4-5 times per week also had more youthful large central arteries, which provide blood to the chest and abdomen, in addition to healthier middle sized ones.

The fact the larger arteries appear to require more frequent exercise to remain youthful will aid the development of long-term exercise programmes. They also enable the research team to now focus on whether or not ageing of the heart can be reversed by exercise training over a long period of time.
The research may have been limited by the fact that individuals were allocated to groups based on past exercise frequency, as opposed to other components of exercise programmes such as intensity, duration or mode, all of which could have large impacts on vascular adaptations. Furthermore, additional, unmeasured factors such as dietary intake and social background could influence arterial compliance indirectly through reduced adherence, or by non-exercise related means.
Benjamin Levine, one of the authors of the study, is excited to investigate this in the future:
"This work is really exciting because it enables us to develop exercise programmes to keep the heart youthful and even turn back time on older hearts and blood vessels. Previous work by our group has shown that waiting until 70 is too late to reverse a heart's ageing, as it is difficult to change cardiovascular structure even with a year of training. Our current work is focussing on two years of training in middle aged men and women, with and without risk factors for heart diseases, to see if we can reverse the ageing of a heart and blood vessels by using the right amount of exercise at the right time".

Improving heart health could prevent frailty in old age


New research has shown that older people with very low heart disease risks also have very little frailty, raising the possibility that frailty could be prevented.

The largest study of its kind, led by the University of Exeter, found that even small reductions in risk factors helped to reduce frailty, as well as dementia, chronic pain, and other disabling conditions of old age.

Many perceive frailty to be an inevitable consequence of ageing - but the study, published in the Journal of Gerontology: Medical Sciences found that severe frailty was 85% less likely in those with near ideal cardiovascular risk factors.

It also found that those with fewer heart disease risk factors were much less likely to have other conditions unrelated to the heart - including chronic pain, incontinence, falls, fractures, and dementia.
Dr João Delgado, of the University of Exeter Medical School, joint lead author of the study, said:

"This study indicates that frailty and other age-related diseases could be prevented and significantly reduced in older adults. Getting our heart risk factors under control could lead to much healthier old ages. Unfortunately, the current obesity epidemic is moving the older population in the wrong direction, however our study underlines how even small reductions in risk are worthwhile." The study analysed data from more than 421,000 people aged 60-69 in both GP medical records and in the UK Biobank research study. Participants were followed up over ten years.

The researchers analysed six factors that could impact on heart health. They looked at uncontrolled high blood pressure, cholesterol and glucose levels, plus being overweight, doing little physical activity and being a current smoker.

Dr Janice Atkins, of the University of Exeter Medical School, joint lead author of the study, said: "A quarter (26%) of participants from UK Biobank, made of predominantly healthy volunteers, had near perfect cardiovascular risk factors compared to only 2.4% of the population via GP records. This highlights the huge potential for improvement in cardiovascular risk factors of the general population in the UK."

It is the first largescale study to show that older people with near-ideal cardiovascular risk factor profiles have better outcomes on a number of factors that are not directly linked to heart-disease.
Dr. George Kuchel, Director of the UConn Center on Aging at UConn Health, co-researcher on the study, said: "Individuals with untreated cardiovascular disease or other common chronic diseases appear to age faster and with more frailty. In the past, we viewed ageing and these common chronic diseases as being both inevitable and unrelated to each other. Now our growing body of scientific evidence on ageing shows what we have previously considered as inevitable might be prevented or delayed through earlier and better recognition and treatment of cardiac disease.

"This overall approach working at the interface of ageing and varied chronic diseases could be transformative in helping adults to maintain function and independence in late life, adding life to their years as opposed to just years to their life."

Dr Ivan Pavlov, Programme Manager for Systems Medicine at the MRC, said: "These findings are relevant to us all because they re-emphasise the importance of a healthy lifestyle for better quality of life in old age. These new results also show that age-related conditions may share common risk factors or mechanisms with cardiovascular diseases. We're living longer so it's crucial that we recognise this by taking care of our bodies and monitoring our risk for disease even earlier in life."

Vascular risk interacts with amyloid levels to increase age-related cognitive decline


Risk factors for heart disease and stroke appear to hasten the risk of cognitive decline in normal older individuals with evidence of very early Alzheimer's-disease-associated changes in the brain. Vascular risk factors increase the risk of cognitive impairment in older individuals and appear to have a negative synergistic effect with levels of brain amyloid-beta, the protein that aggregates into neurotoxic plaques in the brains of individuals with Alzheimer's disease. In their report published in JAMA Neurology, a team of Massachusetts General Hospital (MGH) investigators describes finding that the combination of increased vascular risk and higher brain amyloid levels predicted even faster cognitive decline in clinically normal older individuals than would be expected based on the independent effects of both factors.

"Our findings suggest that having vascular risk factors like diabetes, smoking, and high blood pressure may accelerate the rate of cognitive decline in normal older adults, and that the effect of vascular risk on decline is magnified in people with higher brain amyloid levels," says Jennifer Rabin, PhD, a clinical and research fellow in the MGH Department of Psychiatry, lead author of the paper. "Our findings support the rationale behind targeting modifiable vascular risk factors either alone or in combination with amyloid-lowering therapies to delay cognitive decline. Measures of vascular risk also may be able to complement existing biomarkers in identifying people at the greatest risk of cognitive decline."

Alzheimer's disease and cerebrovascular disease are probably the two most common causes of cognitive impairment in the elderly, but even though they often co-occur in individual patients, they are typically viewed as independent contributors. While the presence of amyloid plaques in the brain is considered a hallmark of Alzheimer's disease, some individuals with elevated amyloid levels never develop cognitive impairment. This has led to a search for additional markers beyond brain amyloid to help identify those at increased risk for cognitive decline.

The current study was designed to investigate whether the effects of increased brain amyloid and of vascular risk on cognitive decline are merely additive, reflecting a simple combination of the risks independently contributed by each factor, or synergistic, in which interaction of the two produces an even higher level of risk. Another goal was determining whether vascular risk remained a powerful predictor of cognitive decline, even when investigators also considered other cutting-edge measures of brain health derived from PET scans and MRIs.

The study analyzed data from 223 participants in the Harvard Aging Brain Study, an ongoing study of cognitively normal individuals ages 50 to 90 designed to improve understanding of brain changes affecting memory and cognition that occur with aging. Upon enrollment in the study, participants receive standard imaging biomarker studies, including PET scans with a compound that reveals amyloid deposits in the brain. Assessment of vascular risk is determined by the Framingham cardiovascular risk score, which is based on factors such as hypertension, body mass index, and histories of diabetes or smoking. Participants also receive standard tests of memory, attention and language, which are repeated at annual follow-up visits.

The results showed that both elevated brain amyloid levels and higher vascular risk, as measured upon study enrollment, were associated with more rapid cognitive decline, with the most rapid changes seen in participants with elevations in both factors. The extent of the interaction between the two measures suggested a synergistic, rather than simply an additive effect. Vascular risk remained a consistently strong predictor of cognitive decline, even after controlling for other biomarkers; and while the study did not directly compare the contributions of brain amyloid levels and vascular risk to the rate of cognitive decline, the predictive power of both factors was statistically similar.

Senior and corresponding author Jasmeer Chhatwal, MD, PhD, of the MGH Department of Neurology, says, "Recent findings suggest elevated brain amyloid is necessary but perhaps not sufficient on its own to predict imminent cognitive decline. Therefore, we need to find additional, complementary measures to identify individuals at the highest risk for cognitive decline, as these are the people we want to enroll in Alzheimer's-disease-prevention clinical trials. Remarkably, vascular risk appears to be useful in identifying risk of cognitive decline above and beyond a full slate of MRI and PET measures of brain health. Perhaps more importantly, we can reduce vascular risk factors through medical treatments and lifestyle interventions, and reducing these vascular risk factors might reduce memory loss over time - especially in people with high brain amyloid."

Friday, May 18, 2018

Keep saying yes to fish twice a week for heart health American



A new scientific advisory reaffirms the American Heart Association's recommendation to eat fish- especially those rich in Omega-3 fatty acids twice a week to help reduce the risk of heart failure, coronary heart disease, cardiac arrest and the most common type of stroke (ischemic). The advisory is published in the American Heart Association's journal Circulation.

"Since the last advisory on eating fish was issued by the Association in 2002, scientific studies have further established the beneficial effects of eating seafood rich in Omega-3 fatty acids, especially when it replaces less healthy foods such as meats that are high in artery-clogging saturated fat," said Eric B. Rimm, Sc.D., chair of the American Heart Association writing group and professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health in Boston.

The Association recommends eating two 3.5-ounce servings of non-fried fish, or about ¾ cup of flaked fish every week. Emphasis should be placed on eating oily fish like salmon, mackerel, herring, lake trout, sardines or albacore tuna, which are all high in omega-3 fatty acids.

The advisory was written by a panel of nutrition experts, who also reviewed studies about mercury in fish. Mercury is found in most seafood but is prevalent in large fish such as shark, swordfish, tilefish, king mackerel, bigeye tuna, marlin and orange roughy. The writing group concluded that while mercury contamination may be associated with serious neurological problems in newborns, existing scientific research finds that mercury contamination does not have adverse effects on heart disease risk in adults, and the benefits of eating fish substantially outweigh any risks associated with mercury contamination, especially if a variety of seafood is consumed.


The importance of environmentally sustainable fish farming techniques and other topics are also briefly discussed in the advisory. A previously published American Heart Association advisory on Omega-3 fish oil supplements noted that the supplements are not recommended for the general public to prevent clinical cardiovascular disease because of a lack of scientific evidence regarding any effect on cardiovascular risk.



Male depression may lower pregnancy chances among infertile couples


Among couples being treated for infertility, depression in the male partner was linked to lower pregnancy chances, while depression in the female partner was not found to influence the rate of live birth, according to a study funded by the National Institutes of Health.

The study, which appears in Fertility and Sterility, also linked a class of antidepressants known as non-selective serotonin reuptake inhibitors (non-SSRIs) to a higher risk of early pregnancy loss among females being treated for infertility. SSRIs, another class of antidepressants, were not linked to pregnancy loss. Neither depression in the female partner nor use of any other class of antidepressant were linked to lower pregnancy rates.

"Our study provides infertility patients and their physicians with new information to consider when making treatment decisions," said study author Esther Eisenberg, M.D., of the Fertility and Infertility Branch at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), which funded the study.

Citing previous studies, the authors noted that 41 percent of women seeking fertility treatments have symptoms of depression. In addition, a study of men seeking IVF treatments found that nearly 50 percent experienced depression. The authors conducted the current study to evaluate the potential influence of depression in couples seeking non-IVF treatments.

The researchers combined data from two previous studies funded by NICHD's Reproductive Medicine Network. One study compared the effectiveness of two ovulation-inducing drugs for establishment of pregnancy and live birth in women with polycystic ovary syndrome.

The other study compared the effectiveness of three ovulation-inducing drugs at achieving pregnancy and live birth in couples with unexplained infertility. In each study, men and women responded to a questionnaire designed to screen for depression. Only the women were asked whether they were taking any antidepressants.

From the two studies, the researchers analyzed data for 1,650 women and 1,608 men. Among the women, 5.96 percent were rated as having active major depression, compared to 2.28 percent of the men.

Women using non-SSRIs were roughly 3.5 times as likely to have a first trimester pregnancy loss, compared to those not using antidepressants. Couples in which the male partner had major depression were 60 percent less likely to conceive and have a live birth than those in which the male partner did not have major depression.

The study did not include couples who underwent in vitro fertilization because the authors thought that this procedure could potentially overcome some possible effects of depression, such as reduced sexual desire and lower sperm quality.

Biotin supplements caused misleading test results, almost led to unnecessary procedure


A new case report in the Journal of the Endocrine Society documents how a patient's use of a common biotin supplement, also known as vitamin B7, caused her to have clinically misleading test results, which prompted numerous consultations and unnecessary radiographic and laboratory testing.

The patient in the case report took a 5000 mcg dose of biotin daily. Biotin supplements in that dosage are commonly sold over-the-counter, without a prescription, in many grocery and drug stores for about $8-$20 a bottle. They are marketed as being good for healthy hair, skin and nails, but there is no scientific evidence to support this claim.

In this patient's case, "The negative clinical impact included weeks of psychological distress concerning the possibilities of hypercortisolemia or a testosterone-producing tumor. Most significantly, these abnormal test results nearly resulted in an unnecessary invasive procedure for a complex patient with a hypercoagulable state," the case report says. Hypercortisolemia is a condition involving a prolonged excess of cortisol -- a steroid hormone -- in blood.

Maya Styner, MD, associate professor of endocrinology and metabolism in the department of medicine, is the case report's corresponding author.

"The literature is lacking with regard to biotin interference with serum cortisol and testosterone immunoassays, as in our case-report," Styner said. "Patients are ingesting supplements in a higher frequency, and higher doses, and therefore this case is timely and relevant from both a clinical and basic-science perspective."


She added, "Our manuscript is a product of a collaboration between endocrinology, reproductive endocrinology/gynecology and clinical chemistry at UNC and at the Mayo Clinic. This collaboration enabled us to ascertain the underlying diagnosis and perform relevant research-based biotin quantification in our patient's sample."