Plant-based dairy alternatives: enhancing healthy and sustainable diets

Introduction

This publication investigates the multifaceted aspects of integrating plant-based dairy alternatives (PBDA) into a healthy and sustainable diet, with a particular focus on their environmental, nutritional, and health implications. To provide comprehensive insights into this subject, the research draws upon the expertise of seven accomplished authors from diverse fields, including nutrition, epidemiology and environmental, behavioural, and health sciences. Their collective knowledge contributes to a robust analysis of PBDA's role in promoting a healthy and sustainable European diet. In addition the researchers undertook dietary modelling of an established sustainable dietary plan, replacing dairy with fortified plant-based drinks to establish whether they were better for the environment and impact on the overall diet nutritional quality.(1)

Method

This study encompasses a review of the existing literature, coupled with a modelling exercise aimed at assessing the nutritional adequacy of incorporating PBDA within an established sustainable diet. The primary nutrients under review are those closely associated with PBDA when replacing dairy milk: protein, calcium, iodine, and vitamins D, B2, and B12.

The modelling process involved the nutritional re-evaluation of the EAT Planetary Health Diet (EAT-PHD), using a European dietary analysis software (Nutritics). The data inputs are derived from the EAT-PHD supplementary material, providing a comprehensive breakdown of foods and quantities featured in their original US analysis.(2)

The European nutritional analysis of the EAT-PHD serves as the baseline for the nutritional comparisons. Subsequently, the baseline European EAT-PHD underwent adaptations by replacing the 250ml of dairy milk allocation with 250ml of plant-based drinks (PBD), either soya or oat, fortified with calcium, iodine, and vitamins B12 and D – representative of the average offerings on the European market.(3) No other alterations were introduced.

A nutritional comparison was drawn between the baseline European EAT-PHD (incorporating 250ml dairy milk) and the adaptated versions where dairy milk is replaced with either a fortified soya or oat PBD.

Key findings

Plant-based drinks have a significantly lower environmental footprint than dairy milk

One of the pivotal findings highlighted in this publication centres on the significantly reduced environmental footprint associated with PBD compared to dairy milk. The discussion commences by providing a comprehensive review of current data pertaining to the environmental impact of a 250ml serving of dairy milk versus PBD. Employing European-specific datasets by Poore and Nemecek, PBD including rice, soya, and oat, exhibited markedly lower environmental footprints across multiple metrics: greenhouse gas (GHG) emissions, land use, water withdrawals, and eutrophying potential, in contrast to dairy milk (see figure 1). Although European-specific data for almond PBD were not available, global datasets consistently indicate that almond PBD also showcase a substantially reduced environmental footprint across all key environmental indicators, including water usage, when compared to dairy milk.

Replacing dairy milk with a fortified PBD further reduced the environmental footprint of the EAT-PHD without nutritional compromise

Substituting 250ml of dairy milk with fortified PBD not only maintained the nutritional adequacy of the EAT-PHD but also led to a further reduction in its environmental footprint.

The baseline European EAT-PHD analysis revealed that the macronutrient and vitamin A content surpassed current dietary reference values (DRV) for European adults. However, it also indicated that the baseline EAT-PHD would require some adaption to ensure adequate intakes of some micronutrients; calcium, iodine, riboflavin, and vitamins D and B12, falling short of European adult DRV. This underscores the EAT commission's guidance that the EAT-PHD should serve as a reference diet, subject to adaptation and modification to align with the specific nutrient and health objectives of different nations.

The modelling demonstrated that the substitution of 250ml of dairy milk with a fortified soya PBD enhanced the nutritional profile of the EAT-PHD. Notably, this shift resulted in similar macronutrient values, with reductions of 8% in saturated fat and total sugars. Minimal variance in micronutrient content was observed, except for a 5% decrease in vitamin B12, countered by notable increases of 31% in vitamin D and 85% in iodine content. The extent of these variations may vary among European countries, contingent upon their individual fortification policies for dairy and PBD.

Comparable results were observed when replacing 250ml of dairy milk with a fortified oat PBD. Even in light of concerns surrounding protein intake, substituting dairy milk with PBD low in protein, within the context of a balanced diet, still resulted in protein intakes exceeding DRV by 43-52% for adult females and males.

Moreover, the replacement of the dairy milk allocation with fortified soya or oat PBD led to reductions in GHG emissions, of 9% and 12% respectively.

Nutrient adequacy and health implications

Protein

The authors contend that, given the current issue of protein overconsumption and the availability of more concentrated protein sources, excluding dairy from a balanced and diverse sustainable diet would not result in a shortfall of protein intake. This assertion is supported by the EAT-PHD modelling, which indicates that individuals would still exceed their protein requirements. The authors also argue that, in the context of Western affluent societies following mixed and diverse diets that meet both protein and energy needs, the amino acid profile and quantity of individual foods do not significantly impact overall nitrogen balance in healthy individuals.

Calcium

Approximately 80% of non-organic PBD are fortified with calcium, typically at levels similar to dairy products.(3) The authors emphasise that the slight variation in bioavailability between dairy calcium and the fortifying agents used in PBD is negligible, with a maximum difference of 11mg per 250ml serving. Additionally, the authors highlight that calcium is widely available throughout plant and animal foods.

Vitamin B12

Globally, few individuals adhere strictly to a 100% plant-based diet. Moreover, evidence suggests that individuals who choose PBD continue to consume other dairy and meat products, thereby obtaining vitamin B12 from other animal sources. In the case of a completely plant-based diet, fortified foods, including PBDA, and supplements are typically recommended. The authors suggest that increasing fortification with higher quantities and across a wider range of plant-based foods could be advantageous as populations shift toward more plant-based dietary patterns.

Vitamin D

In the European context, where mandatory vitamin D fortification of dairy is not widespread, PBDA, which are typically fortified, offer an advantage by enhancing vitamin D intake, given its limited dietary sources.

Iodine

For many European countries that primarily feed their cattle on fodder rather than allowing them to graze, dairy milk is a significant source of iodine, alongside fish. Consequently, replacing dairy milk with non-fortified PBDA could put individuals at risk of sub-optimal iodine intakes. Currently, only 11% of PBDA in the European market are fortified with iodine.(3) The authors recommend that manufacturers consider increasing iodine fortification across all PBDA to address this issue.

Riboflavin

Dairy is a major source of riboflavin in European diets, along with grains and meat products. Riboflavin content in European PBDA varies, with around half of non-organic options being fortified.(3) Nevertheless, studies have shown that riboflavin intake is sufficient in European vegan populations, and there are multiple alternative sources that can more than compensate for the riboflavin in dairy milk. These sources include green leafy vegetables, mushrooms, almonds, eggs, cheese, yeast extract, and most fortified breakfast cereals.

Why categorising foods as 'utra-processed' can be contraindacted for optimum health and sustainability

The authors raise concerns about classifying food as ultra-processed, particularly under the NOVA system, when advising on healthy and sustainable diets. While some ultra-processed foods (UPF) can be high in saturated fat, salt, and/or sugars, this classification doesn't apply universally. Foods such as bread, fortified cereals, and PBDA have nutritional profiles associated with promoting health. Importantly, the NOVA system also categorises certain foods with known health and environmental concerns, like full cream mik, fatty meat, lard, and butter, as 'minimally processed,' encouraging their consumption over UPF which contradicts dietary recommendations. Focusing solely on processing level, without considering nutrition or environmental impact, lacks meaningful guidance and contradicts national and international sustainable diet advice. Labelling PBDA as UPF is misleading as, in the main, they have a beneficial nutritional profile and a signficantly lower environmental footprint compared to dairy milk which is classified as 'minimally processed'.

PBDA overcome common barriers to shifting towards a plant-based sustainable diet

PBDA offer a promising solution to a number of obstacles consumers often face when trying to change their dietary habits. PBDA's widespread availability, ease of access, and increasing societal acceptance make them particularly appealing. What's more, their usage similarity to dairy milk means there's no need to acquire new culinary skills, simplifying the transition. Cost is a frequently cited deterrent to dietary change. Nevertheless, despite their relatively higher price point, the PBDA market continues to expand. As PBDA gain a larger share of the dairy market, their prices are anticipated to decrease. Notably, it's worth mentioning that while branded PBDA may be pricier than traditional dairy milk, private-retail brands offer a more cost-competitive option.

In conclusion

The authors emphasise the significance of evaluating PBDA in context of a diverse, healthy and environmentally sustainable diet. Their assessment of current evidence, coupled with their modelling of the EAT-PHD, not only underscores that integrating PBDA into the sustainable EAT-PHD reduces environmental impact without compromising nutritional quality but also highlights PBDA's potential to help individuals overcome common obstacles encountered when transitioning to a more plant-based and sustainable diet.

Read the accompanying publication - New insights: Nutritional profiles of plant-based dairy alternatives in Europe.