The body of evidence about plant (and nut) protein and health continues to grow, with new local and international research papers regularly published.

Body of evidence

Dietary intake of plant- and animal-derived protein and incident cardiovascular diseases: The pan-European EPIC-CVD case-cohort study. (Zheng et al, 2024).
This case-cohort study investigated the associations of plant- and animal-derived protein intake with risk of total CVD, plus CAD and stroke. It included 16,244 CVD cases (10,784 CAD and 6,423 stroke) and 15,141 sub-cohort participants, from seven European countries. Overall, there was no association between plant-derived or animal-derived protein intake with total CVD or with CAD or stroke incidence, but the replacement of protein from red meat, processed meat or dairy with plant-derived protein might be associated with a lower risk of fatal stroke.

Impact of plant protein intakes on nutrient adequacy in the US. (Fulgoni et al, 2024).
This study, using NHANES 2013–2018 data of 19,493 US-based participants, investigated the impact on nutrient adequacy of increasing quartiles of dietary plant protein. Among the findings, for adults aged 19-50 years, with increasing quartiles of plant protein, the adequacy decreased for protein, choline, selenium, vitamin B12, and zinc, and increased for copper, folate, iron, magnesium, thiamin, and vitamin C. The findings suggest that diets of mixed protein sources (both animal and plant) are the most nutritionally adequate.

Dietary protein intake in midlife in relation to healthy aging – results from the prospective Nurses’ Health Study cohort. (Ardisson Korat et al, 2024).
The findings from this large, prospective study, involving 48,762 female nurses, suggest that long-term dietary protein intake, and especially plant protein, may be related to higher odds of healthy aging. Among the findings, plant protein was associated with higher odds of the absence of physical function limitations, and good mental status. Substitution analyses found significant positive associations for the isocaloric replacement of animal or dairy protein, carbohydrate, or fat with plant protein.

Partial substitutions of animal with plant protein foods in Canadian diets have synergies and trade-offs among nutrition, health, and climate outcomes. (Auclair et al, 2024).
This research used a combination of data to assess the impact (on nutrition, health and climate outcomes) of partially substituting red and processed meat or dairy with plant protein foods in Canadian diets. The substitutions resulted in minor changes to the percentage of the population below requirements for nutrients of concern, but increased calcium inadequacy (by up to 14% when dairy was replaced). Replacing red and processed meat or dairy increased life expectancy by up to 8.7 months or 7.6 months, respectively. Diet-related greenhouse gas emissions decreased by up to 25% for red and processed meat, and by up to 5% for dairy replacements.

Modelling the replacement of red and processed meat with plant-based alternatives and the estimated effect on insulin sensitivity in a cohort of Australian adults. (Goode et al, 2023).
This Australian modelling study found regularly replacing one serve of red meat (65g of cooked meat) each day with one serve of plant foods (such as 30g nuts, or 75g legumes), may result in higher insulin sensitivity – which typically predicts lower type 2 diabetes risk. It involved 783 participants from the long-running ‘Childhood Determinants of Adult Health’ cohort study. The study authors say their findings support prioritising plant-based sources of protein, which are vastly under-consumed in Australia.

Substitution of animal-based with plant-based foods on cardiometabolic health and all-cause mortality: A systematic review and meta-analysis of prospective studies. (Neuenschwander et al, 2023).
This systematic review and meta-analysis of prospective cohort studies involved 37 publications (24 cohorts). The findings suggest that shifting from a diet high in animal-based foods, especially red and processed meat, to plant-based foods (eg. nuts, legumes, and whole grains) is associated with a lower risk of all-cause mortality, cardiovascular disease, and type 2 diabetes. Among the findings, replacing red meat (50g/day) with nuts (10-50g/day), and swapping processed meat (50g/day) for nuts (28-50g/day), was linked with a reduced risk of death from any cause, with a moderate certainty of evidence.

Evaluation of protein adequacy from plant-based dietary scenarios in simulation studies: A narrative review. (Soh et al, 2023).
This review provides a summary of dietary models simulating plant-based diets and outlines the main nutritional outcomes for protein, when animal proteins are substituted with plant proteins.  Among the findings, protein intake from plant-based diet simulations was lower than from diets with animal-sourced foods, but still met country-specific nutrient requirements. And protein adequacy was generally dependent on the choice of substitution – with legumes, nuts and seeds providing greater protein intake and quality than cereals.

Red meat intake and risk of type 2 diabetes in a prospective cohort study of United States females and males. (Gu et al, 2023).
This study included 216,695 participants (81% females) from the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study (HPFS). Over 5,483,981 person-years of follow-up, there were 22,761 cases of type 2 diabetes. Among the findings, replacing one serving per day of total red meat with nuts and legumes was linked with a 30% lower risk of type 2 diabetes (HR = 0.70, 95% CI: 0.66, 0.74). The researchers say this emphasizes the importance of different alternative sources of protein for type 2 diabetes prevention.

Differences in all-cause mortality risk associated with animal and plant dietary protein sources consumption. (Haghighatdoost, 2023)
This prospective cohort study examined the associations of dietary protein sources with all-cause mortality risk. A total of 5,431 participants, aged ≥ 35 years, were followed for a median of 11.3 years. It found higher intakes of plant proteins and animal proteins were associated with a decreased and increased risk of mortality, respectively. Among specific major protein sources, higher intakes of nuts and fish were associated with a 27% and 21% lower risk of all-cause mortality, respectively.

Association of major dietary protein sources with all‐cause and cause‐specific mortality: Prospective cohort study. (Sun et al, 2021).
This prospective cohort study followed more than 102,000 post-menopausal women (aged 50 to 79 years old at the start of the study) for an average of 18 years. The women were enrolled in the well-regarded Women’s Health Initiative. It found eating more plant protein, and substituting animal protein with plant protein, was linked with a lower risk of all-cause mortality, cardiovascular disease (CVD) and dementia. Among the key findings was that substituting total red meat, eggs and dairy products with nuts was associated with a lower risk of death from all causes.

Association between plant and animal protein intake and overall and cause-specific mortality. (Huang et al, 2020).
This prospective cohort study analysed data from 416,104 men and women in the US National Institutes of Health–AARP Diet and Health Study, from 1995 to 2011. It found that higher plant protein intake was associated with lower risk of overall and cardiovascular disease mortality. And participants who replaced 3% of dietary energy intake from animal protein with an equal amount of plant protein had a 10% lower risk of death from any cause.

Effects of plant protein and animal protein on lipid profile, body weight and body mass index on patients with hypercholesterolemia: A systematic review and meta-analysis. (Zhao et al, 2020).
This meta-analysis of intervention trials included 32 studies, involving a total 1,562 participants with hypercholesterolemia. It found that, compared with consumption of animal protein, plant protein significantly reduced total cholesterol (TC), triglycerides, LDL-cholesterol, VLDL-cholesterol, TC/LDL-cholesterol ratio, LDL-cholesterol/HDL-cholesterol ratio, and increased HDL-cholesterol levels, but had no effect on body weight.

Association of plant protein intake with risk of incident CKD: A UK Biobank study. (Young Heo et al, 2023).
In this large, prospective cohort study, greater dietary plant protein intake was linked with a lower risk of chronic kidney disease (CKD). It involved 117,809 adults, without CKD at the start of the study, who were tracked for an average (median) of 9.9 years. Participants were grouped into quartiles, based on their plant protein intake. Compared with those who consumed the least plant protein (the lowest quartile), the adjusted hazard ratios for the second, third, and highest quartiles of plant protein intake were 0.90, 0.83, and 0.82, respectively.

Believe it or ‘nut’: Why it is time to set the record straight on nut protein quality: Pistachio (Pistacia vera L.) focus. (Derbyshire et al, 2023).
The review considers the evolution of protein quality concepts, and explains the protein science related to pistachios. Pistachio nuts are a plant-based complete protein, providing all nine essential amino acids. They have a Protein Digestibility-Corrected Amino Acid Score (PDCAAS) of 73% and 81%, for raw and roasted pistachios, respectively. The researchers suggest that, in the future, more than the PDCAAS needs to be measured, due to the limitations around this method, including that it is not reflective of total ileal digestibility, and does not apply health or environmental indices.