Nutritional Benefits of Plant Proteins Taking Root with Consumers
The benefits of protein are far reaching, and consumption of protein supplements has now moved beyond “hardcore” elite athletes and bodybuilders. Mainstream consumers have become more aware of protein’s benefits in supporting active lifestyles, muscle health, weight wellness and cardiometabolic health.
Source: Kerry Primary Research, USA, 2016
With the growing demand for protein, interest in plant proteins is also rising. Multiple factors are contributing to this growth, such as food safety concerns, ethics, environmental concerns, rise in food intolerances, allergies and “free-from” foods, sustainability, increased accessibility of vegetarian and vegan foods and the adoption of proactive approaches to health and wellbeing by consumers. These factors can resonate with all types of consumers, meaning that the increasing number of vegetarian and vegans is not the only place that demand for plant protein is coming from.
It’s also not necessarily about totally replacing meat in the diet. In fact the US animal protein market grew by 5% last year - the fastest increase in 40 years (New Nutrition Business, 2016). It’s about consumers wanting a greater variety of protein beyond animal sources (meat, eggs and dairy) to include more plant sources, an approach often referred to as "flexitarian". The quest for dairy-free and soy-free products is also driving the rise in alternative sources of protein such as pea, pulse, nut and seed, quinoa, rice, hemp, potato, and oat proteins, among others.
Essential Versus Non-Essential Proteins
Amino acids are the building blocks of proteins. In total, there are 20 types of amino acids that the human body uses to synthesize proteins (a process whereby individual cells build their specific proteins). These amino acids are classified as either essential (indispensable) or non-essential (dispensable). Non-essential amino acids can be created by our bodies, while the essential amino acids need to be provided by our diets. For optimal health, our bodies need all of the essential amino acids in the right ratios. Animal protein sources, such as meat, fish, poultry, eggs, and dairy, are considered “complete” sources of protein because they contain all of the essential amino acids in the right proportions to meet the body’s needs. On the other hand, plant-based proteins, such as cereals, legumes, and nuts, are lower in certain essential amino acids. Plant proteins are generally low in methionine, lysine or tryptophan, depending on the source, and higher in non-essential amino acids arginine, glycine, alanine and serine. Cereal proteins, for example, are low in the essential amino acid lysine, while legumes (read our blog ‘Love for Legumes in Dietary Guidance and Product Innovation’) are low in the essential amino acid methionine.
There are some plant proteins, such as soy (read our blog ‘Science Supports Soy for a Healthy Diet) and potato, that are considered to be complete proteins since they contain all of the essential amino acids in the right proportions. When we look at the whole diet rather than a specific food, though, the terms “complete” and “incomplete” protein may be misleading. The Academy of Nutrition and Dietetics (2016) states that protein from a variety of plant foods, eaten during the course of a day, can supply enough of all essential (indispensable) amino acids when calorie requirements are met. After all, our bodies are constantly remodeling our cells and tissues, so as long as enough of the body’s building blocks (amino acids) are provided throughout the day in the right amounts, our bodies receive a “complete” protein source over time. This is why it’s important for different sources of plant proteins to be used in combination to complement their deficient amino acids. For example, combining cereal (low in lysine but contains methionine) and legume (low in methionine but contains lysine) protein sources will ensure our bodies get enough lysine and methionine.
Plant-Based Dietary Recommendations
Many nonprofit and government institutions, such as the American Institute for Cancer Research and the 2015-2020 Dietary Guidelines for Americans (DGA), encourage plant-based diets. Although only 3.3% of adult Americans are vegetarian or vegans, this increases to 6% in younger adults (18-34 y) (AND, 2016). According to the Mintel 2017 Food and Trend “Power of the Plants” report, US consumers perceive plant-based food and beverage products as more natural (68% vs. 41%) and healthy (68% vs. 39%) compared to all US food and drink products.
A well-planned plant-based diet that includes vegetables, fruits, whole grains, legumes, nuts and seeds can provide balanced nutrition to meet individual needs and prevent nutrient deficiencies. A recent report from the USDA Economic Research Services found that 70% of U.S. calories consumed in 2010 were from plant-based foods (Figure 1). According to the DGA, protein needs at all ages, including those for athletes (read our blog: Three Things You Need to Know About Protein for Exercise Performance), can be achieved with a balanced vegetarian diet. Some evidence suggests that protein is used less efficiently with aging, so it is important that older individuals consuming plant-based diets include protein-rich foods such as legumes and soy foods in their diets.
Benefits of High Plant Protein Diets
Proteins are rarely found in isolation; a wide variety of other nutrients come along as co-passengers with protein in plants. These nutrients include fiber, vitamins (e.g. Folate, B12, D), and minerals (e.g. Iron, Zinc, Calcium). As a result, diets high in plant protein, such as the vegetarian diet pattern, are associated with health benefits. Studies suggest that vegetarians tend to have lower body weight, cholesterol and blood pressure levels. As a result, people who consume plant-based diets have been shown to be at lower risk for stroke and heart disease. The host of nutrients and phytonutrients found in plants are also associated with a reduced risk of certain cancers (AND 2016).
Bone and muscle health also stand to benefit. Plant-based diets rich in nutrients like protein, magnesium, potassium, and vitamins K and C can improve bone health, however a plant-based diet low in these nutrients can have the opposite effect. Emerging evidence suggests that plant proteins can also play a role in muscle protein synthesis, especially when combining different plant proteins to provide the body with a balanced amino acid profile.
Plant-based diets are more environmentally sustainable than animal-based diets due to the use of fewer natural resources and less environmental damage caused by their production. Livestock are typically fed with plants rich in protein, so if we consume the plant protein directly instead, we are able to avoid the resource inputs required to raise the livestock. For example, to produce 1 kg protein from kidney beans requires 18 times less land, 10 times less water, 9 times less fuel, 12 times less fertilizer and 10 times less pesticide compared to producing 1 kg protein from beef (AND, 2016). By eating less meat and dairy, the diet-related environment impact can be cut by nearly one-half while also reducing agricultures pressure on the environment (WRI).
What’s the Future for Plant Proteins in Packaged Goods?
Translating the benefits of plant proteins packaged goods that are convenient for consumers can be difficult. Although consumers are becoming more aware of their health and are trying to make better food choices, taste remains the number one purchase driver. When asked to report the three most important factors in choosing a protein product, 72% of consumers selected the flavor of the product and 63% selected the texture of the product (Kerry Primary Research, USA, 2016).
In order to successfully meet the needs of consumers, food and beverage manufacturers need to take this into account along with the need to complement amino acid profiles of different plant proteins to create a complete protein source when creating protein products. By utilizing processing technologies to improve texture, as well as choosing applications that complement the flavor of plant proteins, it is possible to deliver the benefits of plant protein in a way that delivers on the taste expectations of consumers. Specific opportunities include snacking, non-dairy drinks, pre-prepared vegetables and meat alternatives.
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Satya Jonnalagadda, PhD, MBA, RD
Satya Jonnalagadda Ph.D., MBA, RD is currently the Director of Global Nutrition at Kerry. She is responsible for leading Kerry’s nutrition function, strategic nutrition research, internal and external nutrition positioning and scientific communications, while staying abreast of proposed food regulations and identifying new nutrition opportunities. Satya leads the Kerry Health and Nutrition Institute including management of the Scientific Advisory Council.
Orlaigh Matthews, RD
Orlaigh graduated with a BSc in Human Nutrition and Dietetics from Dublin Institute of Technology and Trinity College Dublin. After working as a clinical dietitian specialising in maternal nutrition, senior nutrition and critical care in a Dublin teaching hospital for several years, Orlaigh joined Kerry’s nutrition marketing team as a Market Analyst and has a particular focus on infant nutrition and healthcare nutrition.