cross-posted from: https://lemmy.ml/post/24943429

Human ancestors like Australopithecus – which lived around 3.5 million years ago in southern Africa – ate very little to no meat, according to new research published in the scientific journal Science. This conclusion comes from an analysis of nitrogen isotope isotopes in the fossilized tooth enamel of seven Australopithecus individuals. The data revealed that these early hominins primarily relied on plant-based diets, with little to no evidence of meat consumption.

  • AntiThesis@leminal.space
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    1 day ago

    When consumed in moderation it doesn’t always make the hugest difference, but the the claim that “science against meat is inconclusive” is overselling it. Decades of studies show that reducing meat, particularly red and processed meat, in favor of plant-based proteins consistently leads to better health outcomes.

    Health Outcomes: Cohort studies like Zhong et al. (2018) found that diets lower in red meat significantly reduce cardiovascular and mortality risks (DOI), while Kim et al. (2016)*linked animal protein to increased cardiovascular mortality and plant protein to lower all-cause mortality. (DOI) Similarly, the BMJ (2020) systematic review showed plant protein is associated with reduced all-cause and cardiovascular mortality. (DOI)

    Cancer and Cardiovascular Disease: An umbrella review in PLOS ONE found plant-based diets are systematically linked to lower risks of heart disease and cancer. (DOI)

    RCT Support: Controlled trials also confirm these findings. For example, Zeraatkar et al. (2023) found replacing animal protein with plant-based protein improves cardiovascular markers. (DOI) Twin-pair studies further showed improved metabolic health with plant-based diets. (DOI)

    Nutritional Adequacy: Plant-based diets provide complete nutrition when planned well. Protein blends match whey in muscle synthesis (pubmed), while legumes and grains promote longevity (DOI, DOI).

    • jet@hackertalks.com
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      18 hours ago

      claim that “science against meat is inconclusive” is overselling it.

      https://www.dietdoctor.com/low-carb/skeptical-doctors#cancer

      In brief, the data linking fat to cancer risk are inconsistent, incomplete, and unreliable.

      The most consistent (albeit weak) associations between cancer risk and fat have been found over the years in observational studies looking at red meat and the risk of colorectal cancer. However, two more recent, important papers published in Annals of Internal Medicine make the case that available evidence from randomized controlled trials and observational studies does not support recommendations to lower red meat intake for prevention of cancer or heart disease.

      Strong Evidence - Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials

      Weak Observational - Patterns of Red and Processed Meat Consumption and Risk for Cardiometabolic and Cancer Outcomes: A Systematic Review and Meta-analysis of Cohort Studies

      https://www.dietdoctor.com/low-carb/red-meat#cancer

      While the epidemiological studies reviewed by the committee suggest an association, other studies question the strength of the association.

      large reviews and meta-analyses of observational studies, researchers have found inconsistent results. One very large meta-analysis found that the absolute effects of red meat on cancer risk are extremely low, with the certainty of evidence being low to very low.While some have shown no association of red meat and cancer risk, others have shown a positive association with gastric, esophageal, breast, and prostate cancer. Weak Protective 1 Weak Protective 2 Weak Positive 3 Weak Protective 4 Weak Protective 5

      For those that did show an association, the hazard ratios were quite small, in the range of 1.06 to 1.4. In comparison, cigarette smoking has a hazard ratio greater than 20 for being associated with cancer. Therefore, although these observational studies can suggest an association between red meat and cancer, the very low hazard ratios weaken the assertion that red meat causes cancer.

      I’m happy you have found a diet that works for you, I have not seen compelling non-observational evidence that ASF is dangerous, ESPECIALLY in the context of a low carbohydrate diet. I’m not trying to change your mind, but I wanted to illustrate that different reasonable people reading the literature can come to different conclusions.

      • AntiThesis@leminal.space
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        6 hours ago

        Good prospective cohort studies and meta-analyses of them are some of the best evidence we can possibly get for diet, because doing lifespan-scale human RCTs is completely impractical, especially for diet. The meta analyses you shared still showed an association between reduced meat consumption and reduction of CVD risk, just with low effect size and low statistical confidence, so this is really not strongly contrary to the conclusion that red meat is better to eliminate or reduce.

        I hear the “correlation is not causation” argument loud and clear, but meat is expensive, meat consumption correlates with wealth, and wealth correlates strongly with health and longevity. Diets like the Atkins diet and the Paleo diet have also been relatively popular among health-conscious people since the 70’s. The animal agriculture industry also has enormous incentive to fund studies which show animal products in a positive light. So I really don’t see any strong reason to think that confounding factors/biases would systematically favor low-meat diets rather than high-meat diets. If meat were truly neutral in terms of CVD risk, we would expect to see a near equal number of studies showing that it is protective for CVD as we see studies showing it increases CVD risk, but this is not what we see in practice.

        RCTs measuring CVD biomarkers also pretty consistently show that reducing meat consumption, especially red meat, decreases well-established CVD biomarkers, so, if these results combined don’t convince you, what results would convince you?

        And yes, the evidence for cancer with unprocessed red meat is weaker, but the evidence for CVD risk and CVD biomarkers is pretty consistent across both RCTs and observational studies. The small effect size you mention is consistent with the expected heterogeneous results of some studies, and the fact that the effect size is weaker than something like smoking does not mean the effect does not exist.

        The CVD hazard ratio may be close to 1.11 for red meat, which means just 100g a day increases your risk for CVD by 11% (Red meat consumption, cardiovascular diseases, and diabetes: a systematic review and meta-analysis). In an animal based low carb/carnivore diet you would need to be eating 10x that much (whether or not youre incorporating other animal foods also high in saturated fat), and there’s no compelling reason to expect the results to be better by consuming more of something with demonstrable long term cardiovascular system-damaging effects, whether in the context of an extremely low carbohydrate diet or not. Studies like Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis also show us that a moderate level of carbohydrate consumption give better results than either extreme high carbohydrate or extreme low carbohydrate diets. “There was a U-shaped relationship between carbohydrate intake and mortality in the Atherosclerosis Risk in Communities cohort, a finding that was consistent in the meta-analysis combining these data with those from the other cohorts. When assessing total carbohydrate without regard to specific food source, diets with high (>70%) or low (<40%) percentage of energy from carbohydrates were associated with increased mortality, with minimal risk observed between 50–55%. Low carbohydrate dietary patterns that replaced carbohydrate with animal-derived protein or fat were associated with greater mortality risk, whereas this association was inverse when energy from carbohydrate was replaced with plant-derived protein or fat.“

        What you define as “dangerous,” is somewhat subjective, but if you care about things like minimizing all-cause mortality and heart disease risk (which you probably should, given that CVD is the number 1 killer), then it’s pretty clear that eating ASF in large amounts is suboptimal.