The saying you are what you eat is increasingly proven true as nutritional research illustrates the importance of following a balanced diet to support the body’s natural processes. This week’s Nutrition News assesses three new articles and studies that provide further weight to the theory that nutrition is vital in leading a healthy lifestyle.

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Junk food could be impacting your sleep

In a first of its kind study, conducted at Uppsala University, researchers have examined the impact of junk food on sleep patterns. Research has been conducted in the past evaluating the nutrients that hold sleep support properties and there has been evidence of what we eat affecting our sleep but this is the first study to illustrate that an unhealthy diet has a direct impact on sleep quality when compared to a healthy diet.

The investigation, which was reported by Science Daily in the article Junk food may impair our deep sleep, focused on healthy participants who consumed both a healthier and an unhealthier diet in a randomised order. The findings revealed that, after consuming the unhealthier diet, the quality of deep sleep deteriorated compared to when the participants followed the healthier diet.

Jonathan Cedernaes, a Physician and Associate Professor in Medical Cell Biology at Uppsala University, explains the motivation behind the study: “Both poor diet and poor sleep increase the risk of several public health conditions” therefore understanding the potential relationship between different diets and sleep changes is crucial.

The study involved 15 healthy young men who participated in two sessions. Both diets provided the same number of calories adjusted to each individual's requirements. The unhealthier diet consisted of higher sugar and saturated fat content, as well as more processed food items. Each diet was followed for a week, and participants' sleep, activity, and meal schedules were meticulously monitored.

During the study sessions, participants underwent several days of monitoring in a sleep laboratory. The researchers discovered that while the participants slept for the same duration regardless of the diet, deep sleep showed reduced slow-wave activity after the consumption of junk food compared to the healthier diet. This effect persisted even after the participants switched to the identical diet.

The researchers emphasise the need for further investigation into the long-lasting effects of an unhealthy diet on sleep and its potential impact on functions regulated by deep sleep, such as memory. It is also worth considering the limitations of the research in which just a small handful of same sex participants were evaluated. Additionally, the researchers are curious about identifying specific substances in unhealthy diets that contribute to the shallower deep sleep observed in the study.

These findings highlight the dynamic nature of sleep and provide valuable insights into the relationship between diet and sleep quality. The findings underscore the importance of maintaining a healthy diet to promote restorative sleep and suggest that diet may play a more significant role in conditions such as insomnia and aging, where similar changes in sleep patterns occur.

A plant-based diet for a healthy heart?

A review of four decades of data conducted by researchers in Denmark, and reported by the BBC in the article Plant-based diets good for the heart,  has shown that vegetarian and vegan diets contribute to supporting heart health by reducing levels of cholesterol and fats in the blood that increase the risk of heart attacks. High levels of bad cholesterol can lead to the buildup of fatty deposits in blood vessels, which can eventually result in heart attacks or strokes.

The study analysed 30 trials since 1982 involving nearly 2,400 participants from around the world. The results indicated that vegetarian and vegan diets were associated with significant reductions in bad cholesterol (10%), total cholesterol (7%), and apolipoprotein B (14%), the main protein in bad cholesterol.

Although longer-term studies would be needed to observe the effects of these diets on heart health over several years or decades, the researchers used data from statin trials to estimate that maintaining a plant-based diet for 15 years could potentially reduce the risk of cardiovascular disease by as much as 20%.

While vegetarian and vegan diets were shown to have positive effects on heart health, the researchers cautioned that individuals should not discontinue any prescribed medications for heart disease without medical advice. It is also important to note that not all plant-based diets are equally healthy, as some may include refined carbohydrates and processed foods high in fat and salt. The study emphasised the importance of a "plant-based" diet that consists of vegetables, fruits, nuts, pulses (e.g., chickpeas), and whole grains.

Experts also highlighted that meat and other animal-based products can provide important nutrients, and diets should be broad and varied to ensure an adequate intake of essential micronutrients. The quality of the plant-based diet is essential, as highly processed vegan foods may differ significantly from traditional vegan diets and may not offer the same health benefits. Ultimately, maintaining a balanced diet that includes a variety of plant-based foods can support overall health and offer heart support.

Consuming flavanols for memory support

A study led by researchers from Columbia University and Brigham and Women's Hospital/Harvard has revealed that a diet low in flavanols, which are nutrients found in certain fruits and vegetables, contributes to age-related memory loss. The study, which was reported by Healthline in its article  Eating Foods With Flavanols May Help Boost Your Memory, demonstrated that the intake of flavanols among older adults correlated with scores on memory tests designed to detect normal aging-related memory decline. Furthermore, replenishing these bioactive dietary components in mildly flavanol-deficient adults over the age of 60 resulted in improved performance on these memory tests, suggesting that flavanols could be a key nutrient in cognitive and memory support.

The study's co-leader, Dr. Adam Brickman, emphasised the significance of the findings, stating that the improvement observed in participants with low-flavanol diets was substantial and suggested the potential use of flavanol-rich diets or supplements to support cognitive function in older adults. This research adds weight to the emerging notion that the ageing brain requires specific nutrients for optimal health, just as the developing brain necessitates particular nutrients for proper development.

The study built upon over 15 years of research linking age-related memory loss to changes in a specific brain region called the dentate gyrus, which is located within the hippocampus and plays a vital role in learning new memories. Flavanols, a subgroup of flavonoids, which are a type of plant compound known as polyphenols are known for their antioxidant and anti-inflammatory properties. They were found to improve the function of this brain region, where previous studies also demonstrated that flavanols, particularly a bioactive substance called epicatechin, supported memory by promoting the growth of neurons and blood vessels in the hippocampus.

The researchers conducted a large-scale trial involving more than 3,500 healthy older adults who were randomly assigned to receive a daily flavanol supplement or a placebo for three years. The results showed that memory scores improved slightly for the entire group taking the flavanol supplement. However, participants who reported consuming a poorer diet and had lower baseline levels of flavanols experienced a significant increase in memory scores compared to those in the placebo group.

The study's findings suggest that flavanol deficiency is a driving factor behind age-related memory decline, as flavanol consumption correlated with memory performance, and flavanol supplements improved memory in flavanol-deficient adults. The researchers noted that flavanols had no effect on individuals without flavanol deficiency. Future clinical trials are needed to confirm the impact of flavanols on memory and to explore the restoration of flavanol levels in individuals with severe flavanol deficiency.

Overall, the study highlights the importance of incorporating flavanol-rich foods into the diets of older adults to potentially mitigate age-related memory loss and support a normal ageing brain. Identifying and addressing specific nutrient requirements for optimal brain health in ageing individuals is a significant step forward in understanding cognitive decline and developing potential interventions.

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Alison Astill-Smith author Alison is Director and Founder of Metabolics who writes about Metabolics updates, events and natural healthcare. Her experience and passion for natural supplements and healthcare comes from her years of experience as a practising osteopath, having founded Metabolics in her search for high quality, natural products in her own work. Alison has been a qualified and practising Osteopath since 1981 and regularly gives seminars on a range of healthcare subjects to the wider practitioner community helping share her knowledge and experience.