Dietary Supplements

This paper explores the ethical considerations of promoting substantial dietary changes for brain health despite inconclusive evidence. The authors argue that such interventions, while promising, must include informed consent, balanced communication, and follow-ups to prevent false hope or harm. They highlight that whole-food, plant-based diets have potential neuroprotective effects, yet the complexity of dietary impact on cognition makes causality difficult to establish. Ethical concerns include conflicts of interest, the risk of brain healthism, and the challenge of balancing health goals with other life priorities.

This systematic review and network meta-analysis assessed the effects of various dietary supplements on swimming performance by analyzing 58 randomized controlled trials (RCTs) with a total of 1,014 participants. The study ranked different supplements based on their effectiveness across multiple performance metrics. L-arginine (Arg) was identified as the most effective intervention for improving 100-meter swim time, while beta-alanine (BA) was found to reduce blood lactate levels. Additionally, creatine combined with sodium bicarbonate (Creatine_NaHCO3) significantly increased blood pH, which may help delay fatigue. However, no significant benefits were observed for shorter (50 m) or longer (200 m) distances. The study noted limitations such as small sample sizes and variations in dosage and supplementation timing, which may impact the generalizability of results.

This study investigated whether echinacea, a common herbal remedy, could help treat the common cold. It was a randomized controlled trial with 719 participants aged 12 to 80 years. They were split into four groups: no pills, placebo pills, blinded echinacea pills, and open-label echinacea pills. The primary outcome measured was the severity and duration of cold symptoms.

Results showed that while those who took echinacea had slightly shorter and less severe colds than those in the placebo or no-pill groups, the differences were not statistically significant. There was an average reduction of about 0.53 days in illness duration, but this result was not strong enough to confirm a true effect. The study concluded that this specific echinacea preparation did not significantly alter the course of a common cold.

This study analyzed 42 clinical trials involving 11,305 adults to determine if probiotics can help prevent diarrhea caused by antibiotics. The results showed that taking probiotics alongside antibiotics reduced the risk of diarrhea by 37%. Higher doses and certain probiotic strains (like Lactobacillus acidophilus, Lactobacillus casei, and Saccharomyces boulardii) were more effective. However, the benefits were only significant in people at moderate to high risk of antibiotic-related diarrhea. The study was well-conducted, but many included trials had a moderate risk of bias. The findings suggest probiotics may be a useful preventative measure but are less effective when the baseline risk of diarrhea is low.

This large-scale randomized controlled trial, the VITAL study, examined whether marine-derived omega-3 fatty acid supplementation (1g/day) reduces the risk of cardiovascular disease and cancer in a general population. Over 25,000 participants (men aged ≥50, women aged ≥55) were randomly assigned to either omega-3 supplements or a placebo, with a median follow-up of 5.3 years.

The results showed no significant reduction in major cardiovascular events or invasive cancer rates in the omega-3 group compared to the placebo. However, a lower risk of myocardial infarction (heart attack) was observed, particularly in individuals with lower fish consumption. No excess risks of adverse effects, including bleeding, were detected.

Statistical significance: The study had sufficient power to detect meaningful effects, but findings were mostly null. The minor reduction in myocardial infarction warrants further investigation but does not support widespread omega-3 supplementation for cardiovascular or cancer prevention.

Limitations: The study duration may not have been long enough to capture long-term effects on cancer. The single dose used (1g/day) limits the ability to assess dose-response relationships.

This systematic review and meta-analysis examined the effects of vitamin D supplementation on asthma management, analyzing 20 randomized controlled trials with a total of 2,225 participants (1,155 children, 1,070 adults). The study aimed to determine whether vitamin D reduces asthma exacerbations requiring systemic corticosteroids and improves symptom control. The results showed no significant impact of vitamin D supplementation on reducing exacerbation risk or improving lung function. A single study suggested potential benefits from calcidiol (a form of vitamin D), warranting further research. The study highlights that individuals with severe asthma and profound vitamin D deficiency were underrepresented, limiting conclusions for these subgroups.

This systematic review evaluated the efficacy of vitamin and mineral supplements in preventing cardiovascular disease (CVD) and cancer. Analyzing 84 studies with 739,803 participants, it found that multivitamins slightly reduced cancer incidence but had no effect on CVD or mortality. Beta carotene increased lung cancer risk, particularly in high-risk individuals. Vitamin D, vitamin E, and other supplements showed no significant benefits. Some supplements, like vitamin A and E, were linked to adverse effects like hip fractures and hemorrhagic stroke. The study highlights the limited role of supplementation in disease prevention, especially for well-nourished populations.

The article examines the effectiveness of supplements marketed to improve brain health and cognitive function, particularly among adults over 50. It highlights that many of these products make unproven claims, as they are not required to demonstrate efficacy unless they claim to treat specific diseases like Alzheimer’s.

Key Points:

• Diet vs. Supplements: A healthy diet is linked to reduced cognitive decline, but there's little evidence that isolated nutrients in supplement form provide the same benefits.
• Lack of Strong Evidence: Most "brain-boosting" supplements lack robust research from randomized controlled trials (RCTs), which are the gold standard for proving efficacy.
• Analysis of Popular Ingredients:
  • Omega-3 Fatty Acids: While diets rich in fish are associated with cognitive benefits, omega-3 supplements have not consistently shown the same effects.
  • Ginkgo Biloba: The large-scale GEM study found no significant benefit in preventing cognitive decline.
  • Vitamins: Observational studies suggest possible associations, but RCTs are lacking, making claims about brain health uncertain.
  • Apoaequorin (Prevagen): A protein derived from jellyfish, but it is broken down in digestion and unlikely to have an effect. Most supporting research comes from the product's manufacturer.
  • Ashwagandha: Some small studies suggest potential benefits, but evidence remains insufficient.

This systematic review analyzed the efficacy of dietary supplements and alternative therapies for weight loss by evaluating 315 randomized controlled trials (RCTs) from a pool of 20,504 citations. The study found that the majority of these trials had methodological inconsistencies and high risks of bias. Only 52 (16.5%) of the reviewed studies were classified as high quality, and among these, just 16 (31%) showed significant weight loss differences, ranging from 0.3 to 4.93 kg. The findings suggest that most dietary supplements and alternative weight loss therapies have limited reliable evidence supporting their effectiveness. The authors emphasize the need for more rigorous, well-designed clinical trials.

This meta-review analyzed 33 meta-analyses of randomized controlled trials (RCTs) examining nutrient supplements for mental disorders. Data from 10,951 individuals were included. The strongest evidence supported polyunsaturated fatty acids (PUFAs), particularly eicosapentaenoic acid (EPA), as an adjunct for depression. Folate-based supplements showed promise for depression and schizophrenia, while N-acetylcysteine (NAC) had emerging benefits for mood disorders. Most supplements had good safety profiles. However, many lacked strong evidence, emphasizing the need for targeted research to identify who benefits most.

This review examines the role of vitamins in preventing and managing neurodegenerative diseases like Alzheimer’s, Parkinson’s, ALS, and multiple sclerosis. It highlights the neuroprotective properties of vitamins B, D, E, C, K, and A, which may reduce oxidative stress, inflammation, and cognitive decline. The study draws on existing research but does not include new clinical trials. While some findings support vitamin supplementation for brain health, generalizability remains uncertain due to varying individual metabolism and dietary patterns. The review also discusses EU food law regulations on health claims related to vitamins, emphasizing the need for clearer consumer guidance. The authors call for further research to substantiate these potential benefits.

This review highlights the importance of zinc, an essential trace element, for human health, focusing on its absorption in the intestine and factors affecting bioavailability. Zinc supports various bodily functions, including immune response, enzymatic reactions, and neural signaling. In vitro models like Caco-2 cells have advanced understanding of zinc transport and absorption at the cellular level, revealing how diet, zinc-binding proteins, and intestinal transporters regulate its uptake. This knowledge is vital for addressing deficiencies and improving zinc-related therapies.

This systematic review examined the cognitive effects of dietary supplements on healthy young adults, particularly in military contexts. Tyrosine and caffeine showed the most promise, enhancing attention, vigilance, and memory under stress or sleep deprivation. Omega-3 and flavonoids demonstrated limited but potential benefits for executive function and memory, respectively. The review emphasized methodological weaknesses in many studies and highlighted the need for more robust research to confirm the efficacy of these supplements for cognitive enhancement.

This cohort study evaluated the impact of dietary supplements and nutrient intake on mortality in U.S. adults. It found that dietary supplements did not significantly reduce all-cause, cardiovascular, or cancer-related mortality. Adequate nutrient intake from foods (not supplements), particularly vitamin K, magnesium, and zinc, was associated with reduced mortality risks. However, excess calcium intake from supplements was linked to increased cancer mortality. These findings highlight the importance of meeting nutrient needs through diet rather than supplements.

This review explores how dietary micronutrients and supplements impact cognitive performance, especially for esports players. Vitamins like B-complex, C, and D, and minerals such as zinc, magnesium, and iron support cognitive processes by reducing oxidative stress and inflammation. Specific supplements, including caffeine, creatine, and polyphenols, were highlighted for improving attention, reaction time, and working memory under stress. However, research in esports-specific settings remains limited, emphasizing the need for targeted studies to optimize cognitive and physical performance.

This cohort study analyzed dietary supplement use and its impact on nutrient adequacy in U.S. adults across different socioeconomic groups. Supplements significantly reduced nutrient inadequacies, especially for calcium, vitamin D, and vitamin E. Higher-income groups benefited more, as they used supplements more frequently and had better diets. However, excessive intake of some nutrients, like calcium and zinc, occasionally exceeded safe levels. The findings highlight supplements as a potential tool to address deficiencies, particularly where diets fall short.

The NIH Office of Dietary Supplements' fact sheet provides an overview of dietary supplements, including vitamins, minerals, herbs, amino acids, and enzymes. It emphasizes that while supplements can help individuals meet nutritional needs, they are not substitutes for a balanced diet. The document advises consumers to consult healthcare providers before starting any supplement regimen, as some products can interact with medications or have adverse effects. For brain health and cognitive performance, the fact sheet suggests that obtaining nutrients from a varied diet rich in fruits, vegetables, and whole grains is preferable to relying solely on supplements. This approach ensures the intake of essential nutrients that support cognitive function. The information is credible, sourced from a reputable institution, and aligns with current dietary guidelines.

Dietary supplements are widely used to complement nutrient intake but should not replace a balanced diet. Common supplements include vitamins D and B12, calcium, and omega-3s. While they can help address deficiencies and support health, excess intake can lead to side effects or interfere with medications. Regulation by the FDA ensures safety but not efficacy before marketing. Consumers are advised to consult healthcare providers to determine the necessity, dosage, and risks of supplements.

This study investigated the effects of magnesium-L-threonate (MgT) supplementation on fear extinction and synaptic plasticity in rats. MgT enhanced the retention of fear extinction without erasing or impairing original fear memories. The treatment boosted synaptic plasticity and increased NMDA receptor signaling and BDNF levels in the prefrontal cortex, but not in the amygdala. These findings suggest MgT’s potential as a therapeutic aid for anxiety-related disorders like PTSD, by improving fear extinction through targeted brain region modulation.

This review discusses the widespread use of vitamin and mineral supplements and their limited impact on preventing non-communicable diseases like cardiovascular conditions, cancer, or diabetes in healthy individuals without nutritional deficiencies. While supplements can address deficiencies or maintain nutrient levels, they don't provide added health benefits for most people. Excessive intake of some nutrients, like vitamin A or calcium, can be harmful. The findings emphasize focusing on nutrient intake from whole foods.

This review explores how various nutrients and dietary supplements impact brain function and cognitive performance. Key findings highlight the benefits of omega-3 fatty acids, flavonoids, caffeine, and creatine for improving memory, reaction time, and mood under specific conditions. However, evidence varies depending on population and context, with many studies focusing on athletes, older adults, or individuals under stress. More research is needed to establish consistent effects and optimal doses for general cognitive enhancement.

The NIH article "Should You Take Dietary Supplements?" examines the role of supplements like vitamins, minerals, and botanicals in health maintenance. It emphasizes that while a balanced diet typically provides necessary nutrients, supplements can help fill dietary gaps for some individuals. However, they are not intended to prevent or treat diseases, and their efficacy varies. Potential risks include side effects and interactions with medications. The article advises consulting healthcare providers before starting any supplement regimen to ensure safety and appropriateness. Regarding brain health and cognitive performance, the article does not provide specific evidence supporting the use of dietary supplements for cognitive enhancement. Instead, it underscores the importance of obtaining nutrients through a varied and balanced diet. To promote brain health, lifestyle changes such as consuming a nutrient-rich diet, engaging in regular physical activity, ensuring adequate sleep, and managing stress are recommended. Given the NIH's credibility and the article's emphasis on individualized healthcare consultation, these recommendations are well-founded.

The Harvard Health article "Supplements: A Scorecard" evaluates the efficacy and safety of various dietary supplements commonly used for health maintenance and disease prevention. It emphasizes that, unlike medications, dietary supplements are not strictly regulated by the FDA, allowing manufacturers to market products without providing evidence of purity, potency, safety, or efficacy. The article discusses the limited scientific support for many supplements, noting that while some, like vitamin D, have shown potential benefits, others lack substantial evidence or may pose health risks. It underscores the importance of obtaining nutrients primarily through a balanced diet and advises consulting healthcare professionals before initiating any supplement regimen.Regarding brain health and cognitive performance, the article suggests that the evidence supporting the use of supplements for cognitive enhancement is generally weak. Instead, it recommends lifestyle practices such as consuming a nutrient-rich diet, engaging in regular physical activity, ensuring adequate sleep, and managing stress to promote cognitive well-being. Given Harvard Health's reputable standing and the article's reliance on current scientific research, these recommendations are credible and practical for individuals seeking to improve brain health.

This review highlights the role of zinc in brain function and its potential to address psychiatric disorders like depression and psychosis. Zinc deficiency, linked to stress, poor diet, or genetic factors, can disrupt neurotransmission and neuroplasticity. Zinc supplementation has shown promise as an adjunctive treatment for depression, enhancing the effects of antidepressants, and may help modulate psychotic symptoms by regulating NMDA receptor activity. These findings suggest zinc’s importance in maintaining mental health and as a possible therapeutic tool.

This review examines zinc's dual role as an essential trace element and a potential toxin. Zinc is critical for brain function, immune health, and cellular metabolism, being involved in over 300 enzymes. Zinc deficiency, common due to poor diet or health issues, can impair growth, immunity, and brain development, while excessive zinc intake may disrupt copper metabolism and cause toxicity. In the brain, zinc influences neurotransmission and apoptosis, with imbalances linked to neurodegenerative conditions and cellular damage after injury.

This review explores the role of vitamin D supplementation in multiple sclerosis (MS), a chronic neurological condition. While low vitamin D levels are linked to increased MS risk and activity, clinical trials on supplementation have shown mixed results, with limited impact on reducing relapses or disability progression. High doses appear safe short-term but carry risks of toxicity, including kidney damage and symptoms mimicking MS. More robust research is needed to confirm its therapeutic value and optimal dosage.