Aerobic power measured by estimated maximal oxygen consumption (mL/kg/min) in vegans compared to omnivores in a meta-analysis of cross-sectional studies
Numerous epidemiological studies carried out over the last 115 years have fairly consistently indicated a benefit of plant-based diets for both stamina and endurance (1). Recently, several cross-sectional studies found that vegans had higher estimated maximal oxygen consumption (mL/kg/min) compared to age-matched omnivores (2 3). Of 3 studies examining this measure, the findings were statistically significant in 2, with the non-significant effect in the remaining study possibly explained by limited statistical power resulting from a small sample size (2 3 4). In a meta-analysis carried out for this review, the difference between vegans and omnivores was found to be highly significant (see the figure above). These findings are likely important as maximal oxygen consumption (VO2 max) is considered a very good marker of aerobic endurance, cardiovascular fitness, and overall health (5). These findings are also consistent with the observations of high levels of aerobic power of plant-based populations, including the highlanders of Papua New Guinea and the Tarahumara of Mexico which have demonstrated a higher VO2 max (mL/kg/min) than even active Inuit hunters (6).
Several factors may help explain a likely benefit of a plant-based diet on fitness and endurance (1). Clinical trials have found that high-quality plant-based diets improve flow-mediated dilatation (FMD), a good predictor of arterial blood flow compared to a Mediterranean diet and animal-rich low-carbohydrate diets (7). Improved blood flow has been hypothesized to improve athletic performance via a number of mechanisms, including increased oxygen and nutrient delivery to the muscles (8). Indeed, it was recently demonstrated in a randomized, placebo-controlled trial that increased arterial blood flow improved performance recovery between bouts of high-intensity exercise (9).
Clinical trials have found that high-quality plant-based diets also improve blood lipids, including Apolipoprotein B (the total number of circulating atherogenic particles, including LDL) compared to commonly recommended therapeutic diets and animal-rich low-carbohydrate diets (10 11). This benefit is partly explained by the effect of substituting animal with plant protein (12). Clinical trials indicate that reducing the concentration of atherogenic blood lipids can greatly improve limb health, as demonstrated by significant reductions in the risk of adverse limb events in those at high-risk (13). In contrast, nomadic pastoralist populations subsisting on minimally processed, low-carbohydrate diets, rich in naturally derived animal foods have been observed to have high rates of limb-related circulatory disorders, in addition to other circulatory disorders including erectile dysfunction (14). In one notable experiment on nonhuman primates, compared to a cholesterol-free diet, feeding of the equivalent of cholesterol from only half a small egg/day in a human diet of 2,000 kcal (0.043mg/kcal) resulted in the development of atherosclerosis in major arterial supplies to the limbs, independent of differences to LDL cholesterol (15). It is important to recognize that amino acids and other nutrients are delivered via the bloodstream and hence require a healthy cardiovascular system for efficient delivery (7).
Numerous epidemiological studies carried out over the last 115 years have fairly consistently indicated a benefit of plant-based diets for both stamina and endurance (1). Recently, several cross-sectional studies found that vegans had higher estimated maximal oxygen consumption (mL/kg/min) compared to age-matched omnivores (2 3). Of 3 studies examining this measure, the findings were statistically significant in 2, with the non-significant effect in the remaining study possibly explained by limited statistical power resulting from a small sample size (2 3 4). In a meta-analysis carried out for this review, the difference between vegans and omnivores was found to be highly significant (see the figure above). These findings are likely important as maximal oxygen consumption (VO2 max) is considered a very good marker of aerobic endurance, cardiovascular fitness, and overall health (5). These findings are also consistent with the observations of high levels of aerobic power of plant-based populations, including the highlanders of Papua New Guinea and the Tarahumara of Mexico which have demonstrated a higher VO2 max (mL/kg/min) than even active Inuit hunters (6).
Several factors may help explain a likely benefit of a plant-based diet on fitness and endurance (1). Clinical trials have found that high-quality plant-based diets improve flow-mediated dilatation (FMD), a good predictor of arterial blood flow compared to a Mediterranean diet and animal-rich low-carbohydrate diets (7). Improved blood flow has been hypothesized to improve athletic performance via a number of mechanisms, including increased oxygen and nutrient delivery to the muscles (8). Indeed, it was recently demonstrated in a randomized, placebo-controlled trial that increased arterial blood flow improved performance recovery between bouts of high-intensity exercise (9).
Clinical trials have found that high-quality plant-based diets also improve blood lipids, including Apolipoprotein B (the total number of circulating atherogenic particles, including LDL) compared to commonly recommended therapeutic diets and animal-rich low-carbohydrate diets (10 11). This benefit is partly explained by the effect of substituting animal with plant protein (12). Clinical trials indicate that reducing the concentration of atherogenic blood lipids can greatly improve limb health, as demonstrated by significant reductions in the risk of adverse limb events in those at high-risk (13). In contrast, nomadic pastoralist populations subsisting on minimally processed, low-carbohydrate diets, rich in naturally derived animal foods have been observed to have high rates of limb-related circulatory disorders, in addition to other circulatory disorders including erectile dysfunction (14). In one notable experiment on nonhuman primates, compared to a cholesterol-free diet, feeding of the equivalent of cholesterol from only half a small egg/day in a human diet of 2,000 kcal (0.043mg/kcal) resulted in the development of atherosclerosis in major arterial supplies to the limbs, independent of differences to LDL cholesterol (15). It is important to recognize that amino acids and other nutrients are delivered via the bloodstream and hence require a healthy cardiovascular system for efficient delivery (7).
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