Bumblebees, Neanderthals, Booze
Stay curious and informed with the latest science news in this month's edition of Briefly Science.
I summarise 9 groundbreaking research papers spanning topics from dementia prevention to ancient human evolution.
Learn how Mediterranean diets may reduce dementia risk, discover social learning in bumblebees, and gain insights into the legacy of Neanderthal DNA.
Also featured: a study linking brain structures to high blood pressure's impact on cognition, an investigation into changing online alcohol habits, and more.
With complex academic research presented in clear, relatable language, this newsletter makes cutting-edge scientific discoveries easy to understand for college students and non-experts alike.
Estimated reading time: 9 minutes
1: How a Mediterranean Diet Can Help Lower Your Risk of Dementia
Read the original paper: Mediterranean diet adherence is associated with lower dementia risk, independent of genetic predisposition: findings from the UK Biobank prospective cohort study
Publisher / Publication: BMC Medicine
Authors: Oliver M. Shannon, Janice M. Ranson, Sarah Gregory, Helen Macpherson, Catherine Milte
Published: March 14th, 2023
Dementia is a growing concern and finding ways to prevent it is crucial. Researchers conducted a study using data from the UK Biobank to investigate the relationship between sticking to a Mediterranean diet and the risk of developing dementia. The Mediterranean diet is known for its emphasis on fruits, vegetables, whole grains, beans, and healthy fats like olive oil, while limiting red meat and processed foods.
The study followed over 60,000 participants for an average of 9.1 years. The researchers used two different measures to evaluate adherence to the Mediterranean diet: the Mediterranean Diet Adherence Screener (MEDAS) and the Mediterranean diet Pyramid (PYRAMID) scores. They also examined whether there was an interaction between diet and genetic risk of dementia.
The findings indicated that those who closely followed a Mediterranean diet had a lower risk of developing dementia. Regardless of their genetic predisposition to the condition, individuals with higher adherence to the Mediterranean diet had a reduced risk of dementia.
This research supports the significance of diet in dementia prevention. By adopting a Mediterranean diet, individuals can potentially lower their risk of developing this debilitating condition. It highlights the importance of incorporating more fruits, vegetables, whole grains, and healthy fats into daily meals, while reducing the consumption of red meat and processed foods.
While the study provides valuable insights, it is important to note that it focused on a large sample size and followed participants for an extended period. As a college student, understanding the benefits of a Mediterranean diet in dementia prevention can lead to a healthier and more informed lifestyle choice. In knowing that dietary interventions can play a role in reducing dementia risk, it becomes a personal responsibility to make conscious food choices that align with this evidence.
2: Are Hormonal Birth Control Pills Linked to Breast Cancer? - An In-depth Analysis
Read the original paper: Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case–control study and meta-analysis
Publisher / Publication: PLOS Medicine
Authors: Danielle Fitzpatrick, Kirstin Pirie, Gillian Reeves, Jane Green, Valerie Beral
Published: March 21st, 2023
You may have heard mixed opinions on how hormonal birth control pills can affect breast cancer risk. In this comprehensive UK study, researchers examined the association between different types of hormonal contraceptives and breast cancer risk in premenopausal women.
The study focused on two types of hormonal birth control pills: combined oral contraceptives (which contain both oestrogen and progestagen) and progestagen-only contraceptives. While current or recent use of combined oral contraceptives has been previously linked to a slight increase in breast cancer risk, much less is known about the risks associated with progestagen-only preparations, even though their usage is on the rise.
To get a clearer picture, the researchers meticulously analyzed hormonal contraceptive prescriptions documented in a primary care database. The results of this nested case-control study, encompassing a substantial group of 9,498 women, were then combined with the findings from various other studies, yielding a robust meta-analysis.
The outcome of this investigation sheds light on the potential risks faced by premenopausal women who rely on hormonal contraceptives. By presenting the data in a way that is relatable to your own experiences, we aim to help you make informed decisions about your contraception choices.
The main findings confirm that current or recent use of combined oral contraceptives does indeed carry a small increase in breast cancer risk. However, the study also highlights the scarcity of information surrounding progestagen-only options. This knowledge gap necessitates further research and attention.
By delving into the world of hormonal birth control pills and their relationship to breast cancer, this study provides valuable insight to help you navigate your contraceptive options more effectively. It is important to understand the risks so that you can make an informed choice that aligns with your personal circumstances and health considerations.
3: Bumblebees Learn New Tricks by Watching Others: How Social Learning Shapes their Behaviour
Read the original paper: Bumblebees acquire alternative puzzle-box solutions via social learning
Publisher / Publication: PLOS Biology
Authors: Alice D. Bridges, HaDi MaBouDi, Olga Procenko, Charlotte Lockwood, Yaseen Mohammed
Published: March 7th, 2023
Social insects like bumblebees have always amazed us with their seemingly innate abilities. However, a group of researchers recently discovered that these remarkable creatures are capable of learning from one another. By studying bumblebees, the team developed a clever experiment using puzzle boxes to observe how non-natural foraging behaviours are spread within a population.
Here's how it worked: a bumblebee was trained to open the box using one of two possible techniques, and then placed in a colony with other bumblebees. Astonishingly, the observers quickly learned the demonstrated technique and continued using it, even if they stumbled upon an alternative method. The researchers found that social learning played a crucial role in the proper acquisition of box-opening skills. When no demonstrator was present, some bees spontaneously opened the boxes, but with less proficiency than those who learned from watching their peers.
In another set of experiments, the researchers introduced two equally prevalent behavioural variants. Over time, one variant became dominant through random processes. These findings mirror those observed in primates and birds, suggesting that bumblebees might possess a cultural capacity.
This study challenges the belief that the behavioural repertoire of social insects is purely innate. Bumblebee populations can actually learn and maintain complex, unique foraging behaviours, treating them as "behavioural traditions." It is fascinating to see how bumblebees, with their small brains, can adapt and pass on knowledge to one another.
Understanding the learning abilities of bumblebees not only sheds light on the fascinating world of insect intelligence but also prompts us to rethink the ways we perceive social learning in the animal kingdom. These findings show that even creatures with limited cognitive capabilities have the potential to learn and teach others, much like we humans do.
4: Genetic Research Identifies Brain Structures Linked to Cognitive Impairment from High Blood Pressure
Read the original paper: Genetic analyses identify brain structures related to cognitive impairment associated with elevated blood pressure
Publisher / Publication: European Heart Journal
Authors: Mateusz Siedlinski, Lorenzo Carnevale, Xiaoguang Xu, Daniela Carnevale, Evangelos Evangelou
Published: March 27th, 2023
High blood pressure has long been associated with cognitive decline, but the underlying changes in the brain that link the two have remained a mystery. In this research, scientists sought to uncover the brain structures involved in the impact of elevated blood pressure on cognitive function. Using data from extensive studies and genetic analysis, the researchers aimed to pinpoint these crucial brain regions.
The study integrated data on blood pressure with a vast range of brain measurements derived from magnetic resonance imaging (MRI). Additionally, cognitive function was assessed using fluid intelligence scores. Through careful observations and validation, the researchers compared their findings in the UK Biobank with a separate cohort.
Using a technique called Mendelian randomisation, the researchers also examined genetic data from the UK Biobank, the International Consortium for Blood Pressure, and the COGENT consortium. This analysis allowed them to determine if there was a causal relationship between blood pressure and cognitive function.
The results indicated a potentially negative impact of high systolic blood pressure on cognitive function. The Mendelian randomisation analysis strengthened this finding even further when considering both systolic and diastolic blood pressure. Furthermore, the researchers discovered numerous specific brain structures, represented by 242, 168, and 68 derived phenotypes, that showed significant associations with blood pressure.
Understanding the relationship between blood pressure and cognitive impairment is crucial for developing preventive measures and interventions. By identifying the brain structures involved in cognitive decline caused by high blood pressure, this research opens new avenues for targeted treatments.
This study sheds light on the intricate connection between blood pressure and cognitive function, revealing the potential risks posed by elevated blood pressure on the brain. Such insights are essential for individuals, healthcare professionals, and policymakers alike, as they highlight the importance of monitoring and managing blood pressure levels to preserve cognitive abilities.
5: Unraveling the Legacy of Neanderthals in Our DNA: How Ancient Interbreeding Influences Complex Human Traits
Read the original paper: The lingering effects of Neanderthal introgression on human complex traits
Publisher / Publication: eLife
Authors: Xinzhu Wei, Christopher R Robles, Ali Pazokitoroudi, Andrea Ganna, Alexander Gusev
Published: March 20th, 2023
DOI: 10.7554/eLife.80757
Ever wondered about the lasting impact of our ancient relatives, the Neanderthals, on our modern genetic makeup? A team of researchers has delved into this intriguing question by exploring the intriguing genetic variants that were passed down to us through interbreeding with Neanderthals. These genetic fragments, acquired thousands of years ago, have been proposed to play a surprising role in shaping various aspects of who we are today.
To investigate this further, the researchers harnessed advanced methodologies, meticulously analyzing 235,592 inherited Neanderthal genetic variants alongside a wide range of 96 distinct human traits in approximately 300,000 individuals from the white British population. The outcomes were fascinating. The team found that indeed, these ancient Neanderthal variants contribute significantly to the variation observed in human traits, accounting for about 0.12% of the overall trait diversity on average.
However, it is worth noting that these introgressed Neanderthal variants seem to have undergone selective pressure over time, leading to a significant depletion in their influence compared to our own modern human genetic variants. Interestingly, no elevated heritability was observed across the examined traits, contrary to previous studies.
Notably, the researchers identified a notable 348 independent associations between these Neanderthal genetic fragments and 64 different traits. Intriguingly, a majority of these associations were found to be statistically linked to nearby modern human variants, suggesting that they might be the true causal factors for these trait variations. By employing a specially tailored fine-mapping technique, the team pinpointed 112 key regions across 47 traits harbouring around 4303 unique genetic variants, where the impact of these ancient Neanderthal fragments on our physical makeup is highly probable.
Upon closer examination of these variants, it becomes evident that they exert a substantial influence on important genes related to fundamental aspects of the human body such as the immune system, development, and metabolism.
This groundbreaking research helps shed light on our ancestral connections and offers a fresh perspective on how our complex traits have been shaped by ancient interactions. Understanding the impact of Neanderthal genetic inheritance broadens our knowledge of human evolution and paints a vivid picture of the fascinating interplay among our distant ancestors.
6: Unrealistic Expectations May Hinder the Benefits of Polygenic Scores
Read the original paper: Realistic expectations are key to realising the benefits of polygenic scores
Publisher / Publication: British Medical Journal
Authors: Amit Sud, Rachel H Horton, Aroon D Hingorani, Ioanna Tzoulaki, Clare Turnbull
Published: March 1st, 2023
Polygenic scores have generated significant excitement in the research community, but it is crucial not to overlook other influential factors that have a greater impact and are more amenable to change. This viewpoint, shared by a team of researchers led by Amit Sud and Rachel Horton, highlights the need for realistic expectations when it comes to the potential advantages of polygenic scores.
Polygenic scores, derived from complex genetic information, offer insights into an individual's predisposition to various traits or diseases. However, it is important to acknowledge that their value is not absolute; they are just one piece of the puzzle. Researchers caution against being drawn into excessive enthusiasm around these scores, as they can divert attention from more significant factors that have a broader relevance for everyone.
In our pursuit of improved health and well-being, it is crucial not to lose sight of the bigger picture. Factors such as lifestyle choices, socio-economic conditions, and environmental influences significantly overshadow the impact of genetic predisposition. Instead of fixating solely on polygenic scores, it is essential to channel our efforts towards addressing these modifiable factors that have a more profound effect on our lives.
By underscoring the importance of realistic expectations, this research urges individuals to consider the broader context in which polygenic scores exist. It encourages us to reflect on the multiple factors that shape our lives and emphasizes the need to focus on those that can be modified for a positive outcome. While polygenic scores can provide valuable insights into our genetic makeup, they should not overshadow the importance of addressing more influential factors within our control.
Achieving a comprehensive understanding of our overall health requires a multifaceted approach that integrates genetic knowledge with lifestyle changes, socio-economic considerations, and the creation of environments that promote well-being. This perspective encourages individuals to broaden their horizons, focusing not only on genetic predispositions but also on the areas where they have agency to make meaningful changes.
In conclusion, by maintaining realistic expectations and recognising the primacy of influential factors within our reach, we can harness the true potential of polygenic scores and indeed, our own personal agency, to enhance our health outcomes and overall well-being.
7: Hunter-gatherer mixing with Neolithic farmers in Europe shaped natural selection
Read the original paper: Hunter-gatherer admixture facilitated natural selection in Neolithic European farmers
Publisher / Publication: Cell
Authors: Tom Davy, Dan Ju, Iain Mathieson, Pontus Skoglund
Published: March 23rd, 2023
The intermingling of ancient cultures has left its mark on our genetic heritage, and researchers have discovered intriguing evidence of this through the study of ancient DNA. One particularly fascinating example is the interaction between Neolithic farming groups and Mesolithic hunter-gatherers as they spread across Europe. By analysing the genomes of individuals from this period, scientists can explore how these two groups mixed and adapted genetically. Furthermore, they can identify regions of the genome that resisted interbreeding and may have contributed to the agricultural advancements of Neolithic populations.
In this study, researchers conducted a comprehensive analysis of the DNA from 677 individuals spanning the Mesolithic and Neolithic eras in Europe. Their aim was to uncover any deviations in ancestry within individuals who had mixed genetic backgrounds. Additionally, they investigated whether natural selection had occurred after this mixing by examining deviations from a null distribution throughout the entire genome.
The results revealed fascinating insights. The genomic region associated with SLC24A5, a gene responsible for pigmentation, showed the highest representation of Neolithic ancestry in the genome. Conversely, the major histocompatibility complex (MHC), a crucial locus for immunity, exhibited the highest representation of Mesolithic ancestry. Notably, the MHC also displayed signs of allele frequency deviations that suggest selection occurred following the mixture of these populations.
These findings could suggest that Neolithic populations experienced negative frequency-dependent selection on MHC alleles inherited from their Mesolithic counterparts. Alternatively, it is plausible that Mesolithic alleles were positively selected for and aided Neolithic populations in adapting to pathogens or other environmental factors. Importantly, this research expands upon previous studies that highlight the impact of immune function and pigmentation as targets of adaptation in more recent populations, shedding light on the selection processes that took place during the Stone Age.
Understanding our ancient genetic heritage not only enriches our knowledge of human history but also provides insights into the genetic adaptations that shaped our ancestors' lives. This research offers a captivating glimpse into the complex interplay between hunter-gatherers and early farmers in Europe and how their interactions influenced natural selection.
8: The Impact of Offering More Alcohol-Free Drinks Online: A Study on Changing Alcohol Selection and Online Purchasing Habits
Read the original paper: Impact on alcohol selection and online purchasing of changing the proportion of available non-alcoholic versus alcoholic drinks: A randomised controlled trial
Publisher / Publication: PLOS Medicine
Authors: Natasha Clarke, Anna K. M. Blackwell, Jennifer Ferrar, Katie De-Loyde, Mark A. Pilling
Published: March 30th, 2023
Do you ever wonder if changing the proportion of alcohol-free drinks available online could have an impact on people's alcohol selection and purchasing habits? Well, researchers conducted a study to find out. They wanted to see if offering more non-alcoholic options in an online retail setting could actually reduce the amount of alcohol people buy.
The study involved 737 adults residing in England and Wales who regularly purchased alcohol online. Participants were randomly assigned to different groups and were asked to select drinks in a simulated online supermarket before making actual purchases in an online supermarket. The researchers wanted to see how the proportion of non-alcoholic drinks available (ranging from 25% to 75%) would affect the participants' choices.
The main finding was that increasing the proportion of non-alcoholic drinks had a significant impact. In the group where 75% of the available drinks were non-alcoholic, a higher percentage of participants chose not to select any alcohol at all compared to the group with only 25% non-alcoholic options. This suggests that by simply offering more alcohol-free drinks, people may be more inclined to choose them over alcoholic beverages.
Interestingly, the study also looked at the actual purchasing behavior of the participants. While the data is still being analyzed, this could provide further insights into the potential effects of increasing non-alcoholic options online.
This research is particularly important because it explores a population-level intervention to reduce alcohol consumption. By making non-alcoholic drinks more readily available online, individuals may have an easier time making healthier choices and reducing their alcohol intake.
In conclusion, this study shows that changing the proportion of available non-alcoholic drinks online can have a significant impact on alcohol selection and purchasing habits. It sheds light on the potential benefits of increasing the availability of alcohol-free options and provides valuable insights for policymakers and online retailers alike.
That’s it for this month.
Thanks for reading.
See you in May.
Claudia Brady.