- RELATED RESEARCH -
Source: Harvard Carnivore Diet Study Publication: Current Developments in Nutrition
The Harvard Carnivore Diet Study surveyed 2,029 individuals adhering to a carnivore diet for at least six months. Participants reported significant improvements in health with few adverse effects. The study highlighted positive experiences and high compliance rates among participants, challenging conventional dietary guidelines.
Source: Journal of the American College of Cardiology
This study reevaluates recommendations to limit saturated fatty acid (SFA) intake, finding no substantial evidence that such restrictions reduce cardiovascular disease (CVD) or mortality. The research noted protective effects against stroke and proposes not further limiting SFA-rich foods like whole-fat dairy, dark chocolate, and unprocessed meat, which do not show an increased risk of CVD.
Source: New England Journal of Medicine
This study assessed the effectiveness of a low-carbohydrate, high-protein, high-fat diet versus a conventional low-calorie, high-carbohydrate, low-fat diet on obesity over a year. Findings showed the low-carbohydrate diet led to greater initial weight loss and improvements in certain coronary risk factors, but differences were not significant at the one-year mark. The study highlights challenges of dietary adherence and suggests more extensive studies are needed for long-term safety and efficacy evaluation.
This study investigated the "Spanish Ketogenic Mediterranean Diet" (SKMD), combining Mediterranean diet elements with a ketogenic approach (olive oil, salad, fish, moderate red wine). After 12 weeks on 31 obese participants, significant improvements were found in weight loss, blood pressure, cholesterol levels, and blood glucose. Results suggest SKMD can be effective for weight loss while promoting a healthier cardiovascular profile.
This study assessed the therapeutic effect of a ketogenic diet on type 2 diabetes over three months. Results showed significant reductions in key physiological markers including Hemoglobin A1c, triglycerides, fasting blood glucose, and body mass index. The study utilized MRI images to track changes in adipose tissue volume and introduced a new parameter called "Slope and Offset of Oral Glucose Tolerance Test." Findings suggest the ketogenic diet may be a beneficial non-pharmacological treatment for type 2 diabetes.
Source: PubMed's Cochrane Database Systematic Review
This review evaluated the impact of reducing saturated fat intake on cardiovascular disease, incorporating results from 15 randomized controlled trials involving approximately 59,000 participants. Findings show that lowering dietary saturated fat and replacing it with polyunsaturated fats reduces cardiovascular events by 17%, although there's less clear evidence on all-cause and cardiovascular mortality. Replacing saturated fat with polyunsaturated fats is beneficial, whereas replacing with carbohydrates or proteins is less effective or unclear.
This systematic review and meta-analysis examined the relationship between red and processed meat consumption and coronary heart disease (CHD), stroke, and diabetes mellitus. Findings suggest processed meat consumption is associated with higher risk of CHD and diabetes, while red meat does not show a consistent association. The study emphasizes the need for detailed analysis of meat types and their health impacts due to nutritional differences, particularly sodium and preservatives in processed meats.
Source: Biomedicine & Pharmacotherapy
This study examines the evolutionary aspects of human diets, particularly the omega-6/omega-3 ratio imbalance in contemporary Western diets. Originally, human diets had a balanced ratio of 1:1, whereas modern Western diets exhibit ratios ranging from 15:1 to 16.7:1. This shift over the last 150 years correlates with increased incidences of chronic diseases such as cardiovascular disease, diabetes, and depression. The study highlights the importance of restoring this dietary balance.
Source: Archives de Pédiatrie
This case study reports a 10-month-old infant experiencing failure to thrive, megaloblastic anemia, and delayed psychomotor development due to being exclusively breastfed by a vegan mother. Investigation revealed deficiencies in vitamin B12, K, and D in both mother and child. Subsequent vitamin supplementation led to significant improvements, emphasizing the critical need for monitoring and preventing nutritional deficiencies in vegan mothers and their breastfed children.
Source: Current Developments in Nutrition
A systematic review and meta-analysis of randomized controlled trials examined unprocessed beef consumption effects on CVD risk factors. Findings showed that consuming two servings (approximately 3 ounces each) of unprocessed beef daily had little to no effect on most CVD risk factors, including blood pressure and cholesterol measures. While a slight increase in LDL cholesterol was observed, it was not statistically significant after adjusting for certain variables. These findings suggest unprocessed beef can be included in heart-healthy diets.
Source: CAPFISH-3 Trial (ASCO Publications)
The CAPFISH-3 trial showed that a high omega-3, low omega-6 diet with fish oil significantly reduced Ki-67, a key biomarker for prostate cancer progression, in men on active surveillance. Over one year, the intervention decreased Ki-67 by 15%, while the control group's levels increased by 24%. This supports the potential of dietary strategies in prostate cancer management.
This study found that vegetarians consuming plant-based meat alternatives (PBMAs) had a 42% higher risk of depression compared to non-consumers. No significant differences in sodium, sugar, or saturated fat intake were observed between groups. However, PBMA consumers exhibited higher blood pressure and increased inflammation markers. Conversely, PBMA intake was associated with a 40% reduced risk of irritable bowel syndrome. These findings suggest that while PBMAs can be part of a balanced diet, their association with depression and inflammation warrants further investigation.
The diet-heart hypothesis, introduced in the 1950s, suggested a direct link between saturated fat intake and cardiovascular disease, leading to widespread recommendations to limit these fats. However, over the decades, numerous clinical trials have failed to establish a causal relationship. Recent analyses, including over 20 review papers, have concluded that saturated fats do not significantly impact cardiovascular disease, cardiovascular mortality, or total mortality. Despite emerging evidence, policy changes have been slow due to longstanding biases and potential conflicts of interest.
In 1961, the AHA began advising Americans to limit saturated fat intake, recommending replacement of traditional fats like butter with polyunsaturated vegetable oils such as P&G's Crisco. This shift was significantly influenced by a substantial donation from P&G to the AHA, totaling $20 million in today's dollars. This funding aligned with P&G's commercial interests in promoting vegetable oils over animal fats. Subsequent research has questioned the validity of the diet-heart hypothesis, revealing that early clinical trials did not find a significant link between saturated fat consumption and heart disease.
Sugar Industry and Coronary Heart Disease Research
Studies indicate that the Sugar Research Foundation funded research in the 1960s and 1970s that downplayed sucrose's link to coronary heart disease while promoting fat as the main culprit. This suggests a need for policymakers to rely on more comprehensive studies, including those on added sugars.
This article explores the history of the diet-heart hypothesis, revealing conflicts of interest with the American Heart Association and irregularities in the reviews for the 2015 and 2020 Dietary Guidelines. It includes new insights from FOIA-obtained emails and highlights the ongoing review for the 2025-2030 Dietary Guidelines.
This article challenges the common belief that saturated fat contributes to clogged arteries, suggesting instead that coronary heart disease is a chronic inflammatory condition. It emphasizes that the risk of CHD can be effectively reduced through healthy lifestyle interventions.
Recent evidence challenges the long-standing recommendation to limit saturated fatty acid (SFA) intake. Meta-analyses show no beneficial effects on cardiovascular disease (CVD) or total mortality from reducing SFAs, and even suggest protective effects against stroke. SFAs increase LDL cholesterol, but typically larger, less harmful LDL particles.
Source: Blood biomarker profiles and exceptional longevity study (Swedish AMORIS cohort)
In a 35-year follow-up study analyzing blood samples from over 44,000 Swedes aged 64 to 99, researchers discovered that individuals who lived to 100 had higher levels of total cholesterol and iron, and lower levels of glucose, creatinine, uric acid, and certain liver enzymes, compared to those who didn't reach 100. These findings suggest that specific blood biomarkers, measurable decades before death, may be linked to exceptional longevity.
This study examined the relationship between meat consumption and life expectancy across various countries, finding a positive correlation: populations with higher meat intake tend to have longer life expectancies. This challenges the common belief that higher meat consumption is detrimental to health and suggests meat may play a beneficial role in human longevity.
A personal account of completing five marathons over five consecutive days while adhering to a ketogenic diet and fasting regimen. The final marathon was the official Sydney Marathon on September 17, 2023, completed despite cumulative fatigue and 35°C temperatures. This demonstrates the potential for sustained endurance performance on a ketogenic diet.
A recent study estimates that in 2020, sugar-sweetened beverages were responsible for 2.2 million new type 2 diabetes cases and 1.2 million new cardiovascular disease cases globally, with the highest burdens observed in Latin America, the Caribbean, and sub-Saharan Africa.
Studies suggest that drinking raw, unprocessed cow's milk may lower the risk of asthma, hay fever, and allergies—likely due to its natural bacteria, fatty acids, and proteins. However, because of infection risks, raw milk isn't recommended until the protective mechanisms are fully understood.
A large U.S. population study found an inverse link between total serum cholesterol and cancer risk—especially for lung, pancreatic, bladder, and smoking-related cancers. Individuals with the lowest cholesterol levels had 2-3x higher cancer risk, suggesting cholesterol may play a protective role or reflect early disease processes. Further research is needed.
Research shows that exposure to cold activates brown fat, which burns energy and reduces nutrients available to tumors, effectively starving cancer cells. This "cold-induced thermogenesis" suggests a potential noninvasive way to suppress tumor growth by altering whole-body metabolism.
A long-term Japanese study found that people with higher intakes of animal fat and cholesterol had a 60% lower risk of death from cerebral infarction (ischemic stroke). In populations with low animal food intake, these nutrients may offer protective effects on brain health, though moderation and context remain key.
In this mouse study, diets high in saturated fat almost completely prevented UV-induced skin tumors, while diets rich in polyunsaturated fat promoted tumor formation. The findings suggest that unsaturated fats may fuel cancer progression, whereas saturated fats could offer protective effects during UV exposure.
A Japanese study found that spending two days in forest environments ("Shinrin-yoku") significantly increased natural killer (NK) cell activity—the body's first line of defense against cancer. Participants showed higher levels of anti-cancer proteins such as perforin, granulysin, and granzymes. The findings suggest that forest exposure naturally enhances immune strength and stress resilience.
A 20-year Swedish study of nearly 30,000 women found that those who avoided sun exposure had twice the all-cause mortality rate compared to women with the highest sun exposure. Researchers suggest that moderate sunlight—essential for vitamin D production—supports longevity, and overly strict sun avoidance in low-UV regions may harm overall health.
A global study of 86,000 adults found that people with higher triglyceride levels—from foods like butter, eggs, and red meat—had an 18% lower risk of developing dementia over 12 years. Researchers suggest that normal-to-high triglycerides may support brain energy and function, offering potential clues for new dementia prevention strategies.
This review proposes the "oxidized linoleic acid hypothesis"—arguing that excess omega-6 fats from vegetable and seed oils (like soybean, corn, and sunflower) drive heart disease. When linoleic acid oxidizes inside LDL cholesterol, it creates toxic compounds that damage arteries, trigger inflammation, and accelerate atherosclerosis. Evidence suggests that replacing saturated fats with omega-6 oils may raise cardiovascular mortality, while balancing intake with omega-3 fats could offer protection.
Recent research shows no clear link between saturated fat intake and heart disease, challenging decades of dietary guidelines. Meta-analyses reveal that full-fat dairy and natural saturated fats may even reduce cardiovascular risk, while replacing them with refined carbs can be harmful. Experts emphasize that not all saturated fats act the same—some support vital functions like brain myelination and metabolic balance—suggesting the need to move beyond blanket restrictions.
A global analysis of data from 181 countries found that higher sodium intake was positively associated with life expectancy and inversely linked with all-cause mortality—even after adjusting for income and BMI. Countries consuming more salt had lower death rates and longer healthy lifespans. Researchers caution, however, that the findings are observational and not a basis for new dietary guidelines.
Source: University of California
A study found that high consumption of soybean oil, a common seed oil, has been linked to obesity and diabetes, and potentially to conditions such as autism, Alzheimer's disease, anxiety, and depression.
Research indicated that increased intake of omega-6 fatty acids, prevalent in many seed oils, was associated with a higher risk of non-fatal myocardial infarction and coronary heart disease death.
The Cleveland Clinic notes that while omega-6 fatty acids are essential, excessive consumptions common in Western diets can disrupt the balance between omega-6 and omega-3 fatty acids, potentially leading to increased inflammation in the body.
This double-blind, randomized controlled trial investigated whether substituting saturated fats with linoleic acid-rich vegetable oils would reduce coronary heart disease and mortality by lowering serum cholesterol levels. Findings revealed that although the intervention group experienced a reduction in serum cholesterol, this did not lead to improved survival rates. Unexpectedly, participants who had greater reductions in serum cholesterol exhibited a higher risk of death. These results challenge the traditional diet-heart hypothesis.
This randomized controlled trial assessed the effects of replacing dietary saturated fats with linoleic acid in men aged 30-59 who had experienced a recent coronary event. The study concluded that substituting dietary linoleic acid for saturated fats increased the risks of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials found no evidence of cardiovascular benefit, suggesting that such dietary substitutions may have adverse effects.
These studies indicate that replacing saturated fats with linoleic acid-rich oils like corn oil may not confer the anticipated cardiovascular benefits and could potentially increase mortality risks. These findings have significant implications for dietary guidelines concerning fat intake and heart disease prevention.