Scientists reviewed dozens of studies comparing how dairy products, plant-based milk alternatives, and hybrid products (made with both) affect the environment. While plant-based options like oat and almond milk often look better when you just count their weight or volume, the picture changes when you consider nutrition. Some plant-based products actually have similar or worse environmental impacts than regular dairy when you account for protein quality and how well your body uses the nutrients. Hybrid products fall somewhere in the middle. The research shows we need better ways to compare these products fairly.
The Quick Take
- What they studied: How much environmental damage different types of milk and dairy products cause, including regular dairy, plant-based alternatives like almond and oat milk, and hybrid products that mix both
- Who participated: This was a review study that looked at many other scientific studies—not a new experiment with people. Researchers analyzed existing life cycle assessment studies that measured environmental impact
- Key finding: Plant-based products appear better for the environment when measured by weight or volume alone, but this advantage shrinks significantly when nutritional value is considered. Some plant-based options may actually be as harmful or more harmful than dairy when you account for how much nutrition your body actually gets from them
- What it means for you: Choosing plant-based milk isn’t automatically the more environmentally friendly choice—it depends on which product you pick and how you measure ‘better.’ The best choice for the planet may depend on your location, what’s available, and how much nutrition you actually need from the product
The Research Details
This was a review study, meaning scientists didn’t do a new experiment themselves. Instead, they carefully looked at many existing studies that measured the environmental impact of different dairy and milk products using a method called Life Cycle Assessment (LCA). This method tracks all the environmental damage a product causes from creation to disposal—like greenhouse gases from cows, water used to grow crops, and land needed for farming.
The researchers focused on studies that followed strict international standards (ISO 14040/14044) to ensure quality. They looked at how different studies measured ’environmental impact,’ which is tricky because some studies count by weight, some by volume, and some by nutrition. They also examined how studies handled different parts of production, like whether they included transportation and packaging waste.
The review examined three main product categories: conventional dairy (milk, cheese, yogurt from cows), plant-based analogs (oat milk, almond milk, soy-based products designed to replace dairy), and hybrid products (mixtures of dairy and plant-based ingredients).
This research matters because many people are switching to plant-based products thinking they’re automatically better for the environment. However, comparing these products fairly is complicated. Different studies measure things differently, making it hard to know which choice is actually best. By reviewing all the studies together and pointing out where they differ, scientists can help people and policymakers make better decisions about food choices and environmental protection.
This review synthesized studies that followed strict international standards for measuring environmental impact, which is good. However, the review found that studies vary widely in their methods, making direct comparisons difficult. The researchers noted that many studies don’t include important factors like nutrition quality, how much food gets wasted, or regional differences in farming practices. This means the conclusions are solid about the general patterns but may not apply equally to all situations.
What the Results Show
When scientists compared products by simple measurements like weight or volume, plant-based alternatives generally showed lower environmental impacts than conventional dairy. This makes sense because raising cows produces methane gas (a greenhouse gas), requires lots of feed crops, and uses significant land.
However, the advantage of plant-based products largely disappeared when researchers accounted for nutritional value. Dairy products are naturally high in protein and contain nutrients that your body absorbs easily. Many plant-based alternatives have less protein or protein that your body doesn’t use as efficiently. When studies adjusted for this nutritional difference—essentially asking ‘how much environmental damage per unit of nutrition?’—some plant-based products performed similarly to or worse than dairy.
Hybrid products (mixing dairy with plant-based ingredients) fell between the two extremes. The more animal-based ingredients they contained, the higher their environmental impact. This suggests that the environmental cost increases proportionally with the amount of dairy included.
A major finding was that how researchers measure and compare these products dramatically affects the conclusions. Different choices about system boundaries, allocation methods, and functional units can flip which product appears more environmentally friendly.
The review identified significant gaps in current research. Most studies don’t adequately account for the consumption stage (how people actually use the products) or the waste stage (what happens to packaging and leftover product). Geographic differences are also important—environmental impact varies greatly depending on where products are made, what energy sources are used, and local farming practices. Studies using local data from specific regions often reach different conclusions than studies using global averages.
This review confirms what some previous research suggested: the ‘plant-based is always better’ narrative is oversimplified. Earlier studies that only counted weight or volume did show plant-based advantages, but newer research incorporating nutrition paints a more nuanced picture. The review shows that the scientific community is moving toward more sophisticated comparisons that account for what your body actually gets from these foods.
The biggest limitation is that existing studies use different methods, making it hard to draw firm conclusions. Many studies don’t include all the environmental factors that matter—like how much food is wasted, transportation impacts, or packaging. The review also notes that nutritional quality comparisons are still developing, so some studies may not accurately reflect how well your body uses nutrients from different products. Additionally, most studies focus on developed countries; results may differ significantly in other regions. The review couldn’t provide a simple ‘winner’ because the answer genuinely depends on which specific products you’re comparing and how you measure environmental impact.
The Bottom Line
Based on this research, there’s no single ‘best’ choice for everyone. If environmental impact is your concern: (1) Consider the specific product, not just the category—some plant-based options are better than others; (2) Account for nutrition—a product that requires you to eat more to get the same nutrition may not be better overall; (3) Look for products made locally with renewable energy when possible; (4) Reduce overall consumption of all dairy and milk products, as this typically has the biggest environmental benefit. Confidence level: Moderate—the research shows clear patterns but acknowledges significant uncertainties.
This research matters for environmentally conscious consumers, people with dietary restrictions, policymakers creating food guidelines, and food companies developing new products. It’s particularly relevant for people in developed countries where food choices are flexible. People with allergies or intolerances who must use alternatives should focus on nutrition rather than environmental impact alone. The findings are less directly applicable to people in food-insecure situations where availability and affordability are primary concerns.
Environmental impact is measured over the entire product lifecycle, so there’s no ’timeline’ for personal benefits like with health interventions. However, if you switch products based on this research, the environmental benefit happens immediately in aggregate—your individual choice contributes to reduced demand for higher-impact products. Widespread adoption of better choices would show measurable environmental benefits over years to decades.
Want to Apply This Research?
- Track the specific dairy and plant-based products you consume weekly, noting the brand and type (e.g., ‘Oatly oat milk,’ ‘Greek yogurt,’ ‘soy-based hybrid yogurt’). This allows users to see their actual consumption patterns and make informed swaps based on their priorities.
- Instead of switching entire product categories, users can experiment with swapping one regular dairy product per week for a plant-based alternative and track how they feel nutritionally and how it affects their environmental footprint. For example: replace cow’s milk with oat milk in coffee, or try a hybrid yogurt. This gradual approach helps identify which swaps work for individual nutrition and taste preferences.
- Create a monthly ‘product impact score’ that combines environmental data with nutritional information for products the user regularly buys. Allow users to compare their current shopping basket against alternatives, showing both environmental impact and nutritional completeness. This helps users make decisions aligned with their personal values and nutritional needs.
This review synthesizes existing research on environmental impacts of dairy and plant-based products but does not constitute medical or nutritional advice. Individual nutritional needs vary significantly based on age, health status, activity level, and dietary restrictions. Before making major dietary changes, especially if you have allergies, intolerances, or medical conditions, consult with a healthcare provider or registered dietitian. Environmental impact varies by region, specific product brand, and production methods—local research may provide more relevant information for your area. This research addresses environmental sustainability, not health benefits or risks of specific products.