Day: September 22, 2021

High Fat Dairy Intake not Tied to CVD Risk

Photo by Waldemar Brandt on Unsplash

In a study of countries with high dairy consumption, higher intakes of dairy fat, as measured by bloodstream levels of fatty acids, had a lower risk of cardiovascular disease (CVD) compared to those with low intakes. Higher intakes of dairy fat were not linked to an increased mortality risk.

In a study published in PLoS Medicine, researchers combined results from 4000 Swedish adults with those from 17 similar studies in other countries, creating the most comprehensive evidence to date on the relationship between this more objective measure of dairy fat consumption, risk of  and death.

Dr Matti Marklund from The George Institute for Global Health, Johns Hopkins Bloomberg School of Public Health, and Uppsala University said that with rising dairy consumption around the world, a better understanding of the health impact was needed.

“Many studies have relied on people being able to remember and record the amounts and types of dairy foods they’ve eaten, which is especially difficult given that dairy is commonly used in a variety of foods.

“Instead, we measured blood levels of certain fatty acids, or fat ‘building blocks’ that are found in dairy foods, which gives a more objective measure of dairy fat intake that doesn’t rely on memory or the quality of food databases,” he added.

“We found those with the highest levels actually had the lowest risk of CVD. These relationships are highly interesting, but we need further studies to better understand the full health impact of dairy fats and dairy foods.”

Sweden has one of the world’s highest consumption of dairy. An international team of researchers assessed dairy fat consumption in 4150 Swedish 60-year-olds by measuring blood levels of a particular fatty acid that is mainly found in dairy foods and therefore can be used to reflect intake of dairy fat.

The participants were then followed up for an average of 16 years, recording heart attacks, strokes and other serious circulatory events, and all cause mortality.

After adjustment for other known CVD risk factors including things like age, income, lifestyle, dietary habits, and other diseases, the CVD risk was lowest for those with high levels of the fatty acid (which reflects a high intake of dairy fats). Those with the highest levels had no increased all-cause mortality risk.

These findings highlight the uncertainty of evidence in this area, which is reflected in dietary guidelines, noted  Dr Marklund.

“While some dietary guidelines continue to suggest consumers choose low-fat dairy products, others have moved away from that advice, instead suggesting dairy can be part of a healthy diet with an  emphasis on selecting certain dairy foods — for example, yoghurt rather than butter — or avoiding sweetened dairy products that are loaded with added sugar,” he said.

Combining these results with 17 other studies with a total of almost 43 000 participants from the US, Denmark, and the UK confirmed these findings in other populations.

“While the findings may be partly influenced by factors other than dairy fat, our study does not suggest any harm of dairy fat per se,” Dr. Marklund said.

Lead author Dr Kathy Trieu from The George Institute for Global Health pointed out that consumption of some dairy products, especially fermented products, have been shown to be linked to cardiovascular benefits.

“Increasing evidence suggests that the health impact of dairy foods may be more dependent on the type — such as cheese, yoghurt, milk, and butter — rather than the fat content, which has raised doubts if avoidance of dairy fats overall is beneficial for cardiovascular health,” she said.

“Our study suggests that cutting down on dairy fat or avoiding dairy altogether might not be the best choice for heart health.”

“It is important to remember that although dairy foods can be rich in saturated fat, they are also rich in many other nutrients and can be a part of a healthy diet. However, other fats like those found in seafood, nuts, and non-tropical vegetable oils can have greater health benefits than dairy fats,” Dr Trieu added.

Source: The George Institute for Global Health

SA Daily COVID Vaccination Rate Plummets

Image by Quicknews

The daily COVID vaccination rate in South Africa plunged this week, prompting fears that the vaccination drive may be losing steam. This comes amid criticism around insufficient  information about vaccinations in more remote and impoverished communities.

Just 159 542 doses were administered on 20 September, the lowest weekday total since 13 August, when 147 307 jabs were given, according to government statistics.

That falls short of its target of 300 000 daily doses (which is yet to be obtained), and also the lowest since 18-to-35 year-olds became eligible for vaccines on 1 September.

As of Wednesday, 22 September South Africa has administered 16.56 million doses, but only 8.23 million of the country’s almost 40 million adults are fully vaccinated. Of those fully vaccinated, about 44% are the single-dose Johnson & Johnson vaccines.

To achieve 70% coverage of the adult population by December, a further 18 million adults will need to be vaccinated, noted health minister Dr Joe Phaahla.

In an address to the media on Friday, 17 September, Dr Phaahla said that the government is still focused on adult vaccinations, with the main priority being the 50 and older age group ahead of a possible year-end fourth wave. Dr Phaahla also noted the South African health regulator’s approval of Pfizer’s COVID vaccine for use for children 12 years and older, saying that the policy of vaccination of under 18s would be revisited based on the total number of adults vaccinated by the end of October.

“Even though we know the Pfizer vaccine has been approved [for children], we want to remain focused on the high-risk people as of now.

“If we can reach 70% of the 50+ age group when the next wave comes, our hospitals will not be as overwhelmed as they have been.”

Dr Phaahla added that the government is aware of pressure from schools for vaccinations of children. Other factors to be taken into account are the local government elections on 1 November — a possible super-spreader event — and a surplus vaccine supply to enable targeting under 18s.

“We think it will be very risky to be all over and start just vaccinating people everywhere. Let’s manage the schools,  and keep on pushing the elderly to get vaccinated.”

On Wednesday, 22 September, there were 2967 new COVID cases, with a case positivity rate of 7%. The total number of vaccinations on that day was slightly higher, but only stood at 187 003, short of the government’s goal of 300 000 per day. Of these, 110 847 were fully vaccinated, 45.3% from J&J doses.

Source: BusinessTech

Azithromycin Protects Pregnancies in Countries with Malaria

Photo by Hush Naidoo on Unsplash

A review has found that the common antibiotic azithromycin taken during pregnancy reduces low birth weight and premature births in countries where malaria is endemic.

The systematic review of 14 studies in African and Asia, published in The Lancet EClinicalMedicine, found that azithromycin, reduced low birth weight and prematurity but didn’t lower infant deaths, infections and hospital admissions.

Azithromycin, an inexpensive antibiotic widely used to treat chest and ear infections, has been specifically used in the past in pregnancy to treat STIs and, alongside other antimalarial drugs, to prevent adverse consequences of malaria on maternal and foetal outcomes and caesarean wound infections.

Murdoch Children’s Research Institute (MCRI) researcher Dr Maeve Hume-Nixon said it was not clear whether azithromycin would improve perinatal and neonatal outcomes in non-malaria endemic settings, and the potential harm on stillbirth rates needed further investigation.

Dr Hume-Nixon said these findings emphasised the importance of similar MCRI-led research currently being done in Fiji.

“This review found that there was uncertainty about the potential benefits of this intervention on neonatal deaths, admissions and infections, and potential harmful effects on stillbirth despite biological reasons why this intervention may have benefits for these outcomes,” she said.

“Therefore, results from studies like ours underway in Fiji will help to better understand the effect of this intervention on these outcomes.”

The Bulabula MaPei study is a randomised controlled clinical trial testing if azithromycin given to women in labour, prevents maternal and infant infections.

Globally, infections account for 21% of 2.4 million neonatal deaths per year and 52% of all under-five deaths, disproportionately occurring in low- and middle-income countries.

About five million cases of pregnancy-related infections occur in mothers each year as well, resulting in 75 000 maternal deaths.

MCRI Professor Fiona Russell said the large clinical trials in Africa and Asia, along with the MCRI-led trial in Fiji, were likely to inform global policy related to maternal child health and hopefully benefit infants and mothers around the world.

“Administration of azithromycin during labour may be a cheap and simple intervention that could be used to improve neonatal death rates in low and middle-income countries, alongside strengthening of maternal child health services,” she said. “This study, together with other large clinical trials, will add to evidence for the consideration of new international maternal and child health guidelines.”

Source: Murdoch Childrens Research Institute

Added Salt Found to Suppress Tumours in Mice

Source: Pixabay CC0

new study has found that adding salt to the diet of lab mice can suppress the growth of cancerous tumours.

Dietary salt reduction has been stressed by clinicians for many years, as research has shown that a high-sodium diet can result in inflammation, high blood pressure and an increased heart attack risk. Researchers from the Translational Health Science and Technology Institute wondered if the inflammation resulting from a high-salt diet could also confer positive health benefits, such as fighting cancerous tumours. 

To find out, the researchers fed two groups of mice with implanted melanoma tumours either a normal diet or a high-sodium diet (4.0% sodium chloride above normal diet) and then measured the differences in tumour suppression abilities between the two groups. They found that the mice on the high-sodium diet had an increase in Bifidobacterium probiotics, leading to an increase in natural killer cells that attack cancerous tumors. They also found an increased ability to inhibit PD-1 proteins which have been found to prevent T cells from attacking tumours.

On close examination, it was found that the high-sodium diet caused the gut barrier to be leakier, enabling the movement of Bifidobacteria from the gut to tumour locations. In addition, they found that once the Bifidobacteria arrived at a tumour, crosstalk between them and the immune cells engaged in attacking the tumour improved the success of the attack.

However, the researchers also found that a low-sodium diet worked in conjunction with several cancer-fighting drugs, showing an increased ability to reduce tumour growth. Since the researchers hypothesised that Bifidobacteria were responsible for the tumour immunity of a high-sodium diet, they performed faecal transplants from mice on a high-sodium diet to those on a normal diet and found that it also improved their ability to fight tumour growth.

The study was published in Science Advances.

Source: MedicalXpress

Diabetes Linked to Tuberculosis Risk

Scanning electron micrograph of Mycobacterium tuberculosis bacteria, which cause tuberculosis. Credit: National Institute of Allergy and Infectious Diseases, National Institutes of Health

Diabetes status may play a role in the risk for developing tuberculosis, suggests a new study reported in JAMA Network Open.

Diabetes and tuberculosis are two major problems for South Africa; an estimated 15% of the population 25 and over have type 2 diabetes, and the burden of tuberculosis was 774 per 100k population in 2012.

In the population-based study from Korea, adults with diabetes had a 48% greater risk for developing tuberculosis compared with adults without diabetes.

This increased tuberculosis risk also appeared to be tied to the duration of diabetes, with risk increasing the longer the person had diabetes:

  • New-onset diabetes: aHR 1.32 (95% CI 1.23-1.42)
  • Diabetes duration less than 5 years: aHR 1.45 (95% CI 1.36-1.54)
  • Diabetes duration 5 or more years: aHR 1.57 (95% CI 1.48-1.66)

The tuberculosis risk also seemed to be dependent on blood glucose levels. Individuals with impaired fasting glucose only, that is, blood glucose levels of 100-125 mg/dL but no diabetes diagnosis, did not appear to have an elevated risk of contracting tuberculosis.

However, those with new-onset diabetes in the highest decile of fasting blood glucose levels (202 mg/dL or higher) had a 79% greater risk for tuberculosis than those with lower glucose levels (fasting plasma glucose of 126-128 mg/dL).

The researchers noted that a previous study looking at this association found about a 2.2-fold increased risk of tuberculosis in patients with diabetes, including those with a fasting plasma glucose level over 130 mg/dL.

“Diabetes appears to be associated with increased risk of lower respiratory tract infection, including TB [tuberculosis], and to have a profound adverse effect on TB treatment outcomes,” the researchers explained. “Even though TB is more associated with other immunosuppressive states, such as human immunodeficiency virus infection, because of the greater numbers, diabetes remains an important factor associated with TB incidence at the population level.”

For the cohort study, the researchers drew upon data from the Korean National Health Insurance System database. Only patients without a history of tuberculosis were included. Besides a history of tuberculosis, other exclusion criteria included diagnoses of anaemia, cancer, and end-stage renal disease.

Individuals who had diabetes the longest tended to be older, have obesity, and possess more comorbidities like chronic kidney disease, chronic obstructive pulmonary disease, ischaemic heart disease, stroke, and dyslipidaemia.

During a median follow-up of about 8 years, 0.6% of the cohort were identified.

A study limitation was that fasting plasma glucose levels were only monitored once at baseline, and that changes in glucose level after treatment was over were not taken into consideration.

“Nevertheless, it is likely that patients whose diabetes status progressed as a result of poor glucose control during the follow-up duration would have a higher risk of TB,” the researchers wrote.

The link with tuberculosis was stronger in male patients, they noted: “The exact mechanism for this phenomenon is not fully explainable — testosterone could be a reason.”

Source: MedPage Today