The importance of hydration lies in its role in allowing the body to perform our internal processes effectively and efficiently.

Water is involved in a number of essential functions in the body.  For example, it helps maintain our body temperature and acts as a primary material for our cells (the building blocks of our bodies).  This means that staying hydrated is essential for our bodies to do their job to ensure that we can keep ourselves going¹.

The Function of Water in the Body

Water maintains our body temperature, helps transport signals to our brain, flushes out waste and helps deliver vital oxygen around the body.  This, along with many other actions, is why water plays such a big part in our everyday lives.

Up to 60% of the human body is composed of water.  This water is shared between our different organs (most organs contain up to 70% water).

The brain and kidneys contain the highest percentage of water compared to other organs within the body.  By ensuring that we are hydrated we can assist with the function of these vital organs².

The composition of water in our bodies changes with age.  Research shows that the bodies of older people consist of approximately 55% water, whereas the water composition of infants lies at about 75%³.

As we age, the decrease in fluid composition of our bodies can cause issues such as urinary tract infections and constipation.  Older people may be less aware that they aren’t getting enough fluids, and this can exacerbate issues with hypohydration, which we will explain in the following section.

Dehydration vs. Hypohydration

Simply put, dehydration is the process of losing water, whilst hypohydration is the end result, when the body is in a water deficit⁴.  This means that the body is losing more fluids than it is taking in.

The signs of hypohydration are more noticeable than the signs of other nutrient deficiencies.  Hypohydration is the uncompensated loss of water from the body, and this is when the body provides signals that fluid replenishment by drinking liquids is needed.

Hypohydration’s Impact on Focus, Mood and Memory

Even mildly hypohydrated individuals (1-2% fluid loss) have shown impairments in cognitive performance.  This means not being fully hydrated can affect short-term memory, ability to focus on tasks or on mood⁵.

For example, a study conducted in school-age children found that children with better habitual hydration showed better cognitive flexibility than children who were less hydrated and providing a water intervention led to improved task-switching capabilities^6,7.

Hydration and the Gut

Hydration status can also impact bowel movements.  Bowel issues such as diarrhoea can cause our body to lose water via loose stools.  Patients that suffer from chronic diarrhoea can also lose important electrolytes in the process.

When we are re-hydrating post-diarrhoea, electrolytes that have been lost must be replenished.  The WHO have created an Oral Rehydration Formula containing different substances such as glucose and sodium to help with this, which is often used when children have diarrhoea⁸.

How the Body Hydrates Itself

The body always wants to be a constant state of physiological balance.  This is known as homeostasis.

When the body senses that the fluid balance is off, a deficit for example, it moves stored water outside of the cells to regain an equilibrium.

Similarly, if the body feels that it is overhydrated, the opposite occurs and the kidneys help excrete the excess water.  The kidneys play an important role in maintaining the fluid balance of the body by producing concentrated urine when we are dehydrated to conserve water (that is why we have dark urine when we are dehydrated).

The body also tries to re-hydrate itself by sending signals to the brain to indicate that feeling of thirst.

How Hydration Changes Through Ageing

Dehydration is the most common fluid complication amongst the elderly.

This is a result of a diminished thirst sensation, decreased muscle mass (therefore giving a decreased body fluid composition) and older adults have less of an ability to produce more concentrated urine to preserve low fluid levels in the body.

Along with have a reduced thirst sensation some older people have trouble swallowing, therefore thicker fluids may be required to hydrate themselves.

Many older adults with swallowing issues do not enjoy the texture of thickened liquids and this could contribute to a reduction in fluid consumption for these groups^9-11.

Role of Electrolytes in Hydration

Electrolytes also play an important role in hydration and they can be found in foods and beverages, so nutrition can play a role in hydration status as well.

Electrolytes are substances that break down into positive or negative charges when dissolved in water.  Some examples of electrolytes include sodium, potassium and chloride.

These electrolytes work together to create channels of communication within the body to conduct actions such as nerve impulses and muscle contraction^12,13. Sodium and potassium have a positive charge whilst chloride has a negative charge.

Sodium and chloride are found in the fluid outside of cells and potassium is found in the fluid within cells.  Chloride works hand in hand with sodium to transport substances in and out of cells.

As sodium is positive and chloride is negative, the charges cancel each other out to ensure that a neutral charge is maintained, this is known as charge neutrality¹⁴. Both sodium and chloride can often be found in savoury foods containing salt.  The chemical name for salt is sodium chloride.

Often excess salt consumption is discouraged as it plays a role in high blood pressure, but sodium and chloride play crucial roles in fluid balance.  This is because the regulation of salt and water balance in the body is highly inter-connected.

Water is known to follow salt; this can contribute to the regulation of blood pressure and thus fluid balance¹⁵.

Another nutrient that plays a role in fluid balance is potassium.  Potassium is often found in fruits and leafy green vegetables.

Potassium and sodium work together to help us transport fluid where it is needed the most¹⁶.

Beverages to Help Hydration

Recommendations are to drink approximately 6-8 glasses of water per day to maintain good hydration.  Water is a solid choice to maintain hydration, but all beverage consumption can contribute to good hydration.

Teas and coffees can also help with hydration.  Although previously thought to exacerbate dehydration because of the diuretic effect of caffeine, these alternative options have been shown to ultimately push toward a more hydrated state¹⁷.

Fortified milk can be useful as a hydrating solution as it contains vitamins and minerals such as Vitamin D and calcium.

Hydration and Activity

Also, to note that depending on the activity, more or less fluid may need to be taken. T hose that play soccer or rugby might have a higher risk of hypohydration as the alternate pauses can sometimes interfere with the opportunity to rehydrate.

When sweating a lot during activity, sports drinks may be a more suitable choice to rehydrate as the electrolytes within them can help the body retain fluid and give us energy.

Post activity, milk can also be a good rehydration choice as along with the hydration properties, the protein found in milk can contribute to building and retaining muscle.  It is always important to continue to rehydrate yourself when carrying out physical activity¹⁸.

Conclusion

Staying hydrated is very important for overall health and well-being.  Hydration is key to maintain all of the bodies process and we must not take it for granted.

Protein Quality Opportunities

Over the past decade, protein quality has come under intense scrutiny.  Due to growing consumer focus on health and rising interest in proactive—versus reactive—nutrition, proteins have moved well beyond specialised nutrition and are now thriving in the general wellness space.

In the last five years (2017-2021), the number of food and beverage global product launches with a ‘high/source of protein’ claim grew by 9%, according to Innova Market Insights.

Alongside the focus on health and wellness, consumers are more focused on sustainability, driving the growth of plant-based protein food and beverage.

With the pool of protein sources diversifying, parameters such as protein source and protein quality are becoming more important for consumers in their daily product choices.

Therefore, there is an opportunity for food and beverage manufacturers to meet consumers’ needs by investing in protein quality while formulating protein food and beverage.

Protein Quality Differs Depending on Food Source

Protein quality is a growing driver for consumers when purchasing protein products.

With the increased popularity of plant-based food alternatives in the market, it is important to recognise that not all proteins are created equal.  Certain protein sources are better suited to meet our nutritional and physiological requirements than others.

There are several parameters to rank the nutritional quality of these different protein sources and consumers are becoming more familiar with them.

Protein Amino Acid Composition

Amino acids (AAs) are the building blocks of proteins. Proteins are composed of 20 common AAs, 9 of which (Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Leucine and Lysine) are categorised as essential amino acids (EAAs) or indispensable amino acids (IAAs).

Arginine and Histidine are classified as conditionally essential as they are required in populations with specific physiological needs (growth, pregnancy, disease recovery, etc.).

EAAs cannot be synthesised by the body; therefore, these must be consumed in adequate amounts in the diet to prevent nutritional deficiencies (Lopez and Mohiuddin, 2022).  Some proteins naturally contain adequate levels of EAAs, this is very often the case with animal-derived sources such as egg or milk.

However, many plant proteins are deficient in one or more EAAs. For example, rice is deficient in Lysine and pea in Tryptophan.

The AA profile of a protein source varies based on a number of factors, including crop variety, seasonality, protein extraction method and further processing (e.g., protein hydrolysis, heat treatment, etc.).

For this reason, EAA composition can differ significantly depending on the starting ingredient, i.e., bean/grain, flour, protein concentrate or protein isolate.

Protein Digestibility

Another factor that affects protein quality is digestibility.  During digestion protein is broken down by the gastrointestinal enzymes into peptides and AAs.

AAs are responsible for important physiological functions such as hormone or neurotransmitter production, muscle protein synthesis as well as various cellular processes (Lopez and Mohiuddin, 2022; Boye et al., 2012).

The body is not capable of absorbing intact proteins (i.e. how proteins exist natively in food) and must break them down to absorb them.  Therefore, protein digestibility is an important factor to take into consideration since it can directly affect the nutritional value of proteins.

In general, animal proteins are easier to digest than plant proteins.  The reason for lower digestibility of plant proteins is linked to the presence of anti-nutritional factors in plants (e.g., protease inhibitors, phytic acid, tannins, lectins, etc.).

These anti-nutritional factors can hinder protein digestibility and consequently reduce their bioavailability.  Antinutritional factor levels may be reduced during protein extraction from plants following fractionation and heat inactivation.

It has been reported that plant protein isolates, the ingredient with the highest protein purity, contain low levels of antinutritional factors (Nosworthy, 2017).  For this reason, isolation of plant protein is a means to improving protein digestibility.

Other processing methods can be used to improve plant protein digestibility, such as soaking, boiling, microwaving, fermentation, or hydrolysis (Boye et al., 2012).

Consumers Raising Awareness on Protein Quality

The COVID-19 pandemic accelerated consumer’s interest in their overall health and wellness.  They were actively seeking information and tools to increase their understanding of health, its link with food and beverage, as well as functional attributes and nutritional benefits that their food can provide them with.

Proteins are perceived not only as a critical macronutrient, but also as a supporter of overall health, muscle health and exercise, weight management, energy and even immune health.

Kerry undertook a global consumer research ‘The Protein Mindset’ where they surveyed more than 6,300 consumers across 12 countries within North America, Europe, Latin America and the Asia-Pacific region to examine wellness consumer attitudes, perceptions and preferences about dairy and plant protein-fortified food and beverage.

What the research highlighted is that while taste is still the primary driver of purchase for protein-fortified food and beverage, the quality of protein is the second most important driver.

This gives a very good indicator that consumers are putting more importance on protein quality than ever before.  However, protein quality is a wide subject that comprises many parameters, it is important to go further and understand what ‘protein quality’ means to consumers.

While protein quality is at the top of the list of important purchase criteria, other protein quality specificities such as ‘source of protein used’, ‘protein type used in product’ were also highly ranked.

However, other more technical protein quality specificities such as the Protein Digestibility Corrected Amino Acid Score (PDCAAS) and EAA profile were taking a comparatively lower ranking.  This is due to PDCAAS and EAA not being automatically linked to ‘protein quality’.

However, technical terms such as PDCAAS or EAA are being increasingly explained and commonly used in nutrition focused social media platforms which is highlighting that protein quality is a hot topic and consumers are getting increasingly familiar with it.

The research also highlighted that Asian consumers and younger generations (millennials and gen Z) were the most familiar with protein quality specificities.

On the market there have been more product launches that are communicating on protein quality by putting on back claims such as ‘complete essential amino-acid profile’, ‘high protein quality’ and ‘complete protein’ or mention of PDCAAS.

This is an excellent strategy to stand out in a product offering that is getting more and more busy as protein mainstreaming keeps increasing.

Measuring Protein Quality

PDCAAS

Multiple methods have been developed by the scientific community to assess the nutritional quality of proteins (for review, see Boye et al., 2012).

A common nutritional score used in the food industry is the PDCAAS, recommended by the FAO/WHO 1991 Expert Consultation.  This score takes into consideration the level of limiting EAAs in the protein as well as protein digestibility (Equation 1).

Casein is used as the reference protein.  The EAA requirements for a target population of children aged 2-5 years are recommended in the FAO/WHO 1991 report.

PDCAAS varies between 0 and 1, it can also be expressed as a %, ranging between 0-100 %.  In instances where a protein yields a score > 1, it is recommended that the PDCAAS should be reported as 1.

Proteins having a PDCAAS of 1 are classified as nutritionally complete since they are not lacking EAAs.

Initially, PDCAAS determination involved in vivo animal studies (rat).  However, in recent years, an in vitro kit based on a patented method (Plank, 2017) using Medallion’s Animal-Safe Accurate Protein (ASAP) procedure was introduced by Megazyme to determine the protein digestibility.

PDCAAS is used to calculate the % Daily value (DV) in the USA and the Protein Efficiency Ratio (PER) in Canada (Marinangeli et al., 2018).  Nutritional protein claims can be made based on DV or PER of foods as follows:

‘Good source of Protein’ for DV of protein for Reference Amount Customarily Consumed (RACC) ≥ 10% or PER ≥ 20;

‘Excellent source of Protein’ for DV of protein for RACC ≥ 20% or PER ≥ 40.

DIAAS (Digestible Indispensable Amino Acid Score)

In 2013, the FAO made the new recommendation of substituting PDCAAS with the Digestible Indispensable Amino Acid Score (DIAAS).

DIAAS, which was developed by the team of Prof. Moughan in the Riddet Institute (NZ), has been positioned as a superior method to quantify the nutritive value of proteins more accurately.

The DIAA ratio is calculated for each IAA relative to the reference IAA and its true ileal digestibility (Equation 2).

The reference AA scoring pattern (AA requirements/protein requirements for maintenance and growth) used is for children aged between 6 months to 3 years.  The DIAAS corresponds to the lowest DIAA ratio.

With DIAAy ratio, the Digestible Indispensable Amino Acid ratio for AA residue y; SID, the true ileal digestibility of Indispensable AA residue y.

DIAAS assesses the ileal digestibility of proteins using animal (pig) testing.  Pigs have a digestion that is similar to humans, which makes them a good model for digestibility determination.

DIAAS determines the amount of EAAs actually absorbed by the body, through the small intestine instead of theoretical calculation based on residual EAAs in feces as per the PDCAAS method.  In addition, DIAAS values for single foods are not truncated to 1.

Therefore, DIAAS is positioned as more adequate to rank the nutritional quality of proteins.  The DIAAS value can be used to categorise protein quality (FAO, 2013):

• ‘High in protein’ for DIAAS value ≥1.00;
• ‘Source of protein’ for DIAAS between 0.75-0.99;
• No protein nutritional quality claim for DIAAS <0.75

Opportunity – Protein Nutritional Optimisation Strategies

As outlined earlier, not all protein sources are able to deliver all the EAAs in sufficient amounts and differences in digestibility exist.

Consumers are also getting more familiar with protein quality. Several strategies are used by the food industry to manufacture protein ingredients and foods with a complete nutritional profile.

These strategies rely on knowledge of protein composition, a good understanding of how to complement different protein sources and/or enhance protein digestibility.

Combining Plant Proteins

The most common way to optimise EAA profile in protein formulations is by combining different plant protein sources in a complimentary fashion.  The plant protein combination is informed by the limiting EAA in each protein source.

In early studies, Methionine, Lysine, Tryptophan and Threonine have been identified as the most common EAAs lacking in dietary proteins (Pieniaźek et al., 1975; Chardigny et al., 2016).

Most plant proteins are reported as uncomplete in terms of their ability to provide EAAs.  However, there are a few exceptions, such as soy, potato and canola, which have a balanced EAA profile.

With numerous plant protein ingredients displaying uncomplete EAA profile, it is common practice to combine complementary plant proteins to improve the EAA profile in the view of increasing their DIAAS or PDCAAS value (Gorissen et al., 2018; Herreman et al., 2020).  An enhanced DIAAS/PDCAAS value can be achieved by combining pulses (which are generally limited in sulfur-containing AA (Methionine/Cysteine) or Tryptophan) with cereal/grains (generally limited in Lysine). 

Food Formulation with Hybrid Proteins

A few examples of products formulated with hybrid proteins have been available on the market for several years.

However, these were not positioned as hybrid products as the main objective of combining protein sources was to achieve a cost saving.  These products, which are fortified with a blend of dairy and plant protein, include mostly protein bars and nutritional beverages.

There is an opportunity for food companies to better communicate on the hybrid positioning of these products and the benefits of hybrid formulations.

The rise in vegan food product launches is driven by the increasing number of consumers embracing a flexitarian diet.  These consumers are eating animal-derived products, therefore, formulations combining plant and animal proteins are still consistent with the dietary choices of flexitarians.

The nutritional objective of hybrid food is to allow consumers to increase their intake in plant proteins while reducing animal proteins in their diet (Alves & Tavares, 2019).

Combining both animal and plant protein is an excellent strategy to improve the nutritional quality of a protein product as animal proteins are often complete and deliver all EAAs.  However, there are to date only limited numbers of hybrid food launches on the marketplace.

Recent products were launched, mostly in the dairy alternative area by companies such as Premier Nutrition (Creamy Shake with oat and dairy), Live Real Farms (dairy and almond beverage), Bel (Margot brand combining milk and pulses) and Triballat (Paquerette brand blending dairy and various plant beverages).

Nutritional Fortification of Foods 

AA supplementation of foods is not a novel practice.  It has been employed mostly for bioactive properties of selected free AAs or AA blends (e.g., L-carnitine, Branched Chain Amino Acids – BCAAs).

More recently, we are witnessing a shift whereby AA fortification of foods is used as a means to enhance their nutritional profile.

Products formulated with free AA are found in nutritional beverage applications.

Combination of Intact and Hydrolysed Proteins

Protein hydrolysis can be leveraged to further improve protein digestibility, which may result in a better PDCAAS value.

Protein hydrolysates have been used for many years in the formulation of specialised nutrition products (e.g., enteral nutrition, infant formulae, hypoallergenic products, foods for medicinal purposes, etc.).

The food industry has since investigated their broader incorporation into products for the general population as they can be used as fast digestible proteins (Potier and Tomé, 2018).

Beyond Dairy and Plant Proteins

Novel alternative proteins are emerging on the protein ingredient market. These sources originate from mycoproteins, algae, yeast and edible insects.

They generally have an interesting sustainability positioning.  In addition, diversification of protein sources could help alleviate the pressure on supply for conventional proteins linked to the popularity of vegan products.

Nowadays, these alternative protein options are niche since they are not manufactured at a very large scale.  In addition, research on these ingredients is still in its infancy and significant work is required to better understand their nutritional profile and potential health concerns such as allergenicity and toxicity which are very much unknown.

Conclusion

With consumers integrating more plant-based protein options in their diet, protein quality is becoming an important subject matter for consumers and might become in the future a important tool of product differentiation in a crowded market.

However, more education is required regarding the different parameters linked to protein quality such as EAA profile, PDCAAS and DIAAS.

This is an opportunity for protein food and beverage manufacturers to develop formulas with improved nutritional and digestibility quality while educating consumers about protein quality and how this is linked to optimal nutrition and health.

Many strategies are available to deliver better protein quality and with the increasing number of new protein sources introduced on the market the protein quality will be a key tool for consumers to choose between these different sources.

Using protein quality parameters will support consumers making an informed choice for foods with good nutritional quality.

In the article “Active Ageing – Why is Protein So Important?”, we showed how greater protein intakes at ages 50+ can fight the natural loss of muscle mass that comes with ageing, helping people keep active lifestyles later into life than if they didn’t consume adequate protein. Although plant proteins are seen as key to the future of the planet, they may have some limitations for supporting muscle health as we age. How can we improve plant proteins to maximize benefits for healthy ageing?

A study by Houston et al. (2008) showed that ageing adults who had a daily protein intake of 1.1 grams of protein per kilogram of body weight (around 88g per day for an 80kg male) lost 40% less muscle over the course of three years when compared to those who were consuming 0.8g/kg BW (around 64g per day for an 80kg male).

Let’s look at the science of plant proteins and muscle health, and how plant proteins could be optimised for active ageing.

Not all proteins are the same when it comes to healthy ageing

Plant proteins are often missing important amino acids or can be harder to digest

Most plant-based proteins are lower in certain essential amino acids than animal-based proteins and can also be harder to digest. This is reflected in the figure below, which uses a score called PDCAAS to represent the amino acid content of different proteins relative to the needs of the human body. Protein quality can also be measured using a score called DIAAS, which measures the amount of amino acids absorbed by the small intestine after protein is consumed.

What this chart shows is that consuming the same amount of whey protein compared to wheat protein will not result in the same amount of amino acids being absorbed into the body. In this example, the whey protein would provide all of the necessary amino acids for adequate muscle maintenance, whereas consuming the same amount of wheat protein would result in a lack of some of the amino acids the body needs.

When it comes to active ageing, this means plant proteins may be less efficient at activating muscle growth and repair and this must be considered when making recommendations for active ageing. For example, this article discusses the importance of leucine in activating muscle growth and repair. However, wheat protein has 37% less leucine than the same amount of whey protein (Herreman et al., 2020).

Plant proteins can be limited in their ability to stimulate muscle growth and repair in older individuals

The limited effectiveness of  plant proteins to stimulate the muscle protein synthesis system, when compared to animal-derived protein, was shown by Gorissen et al. (2016) in a study where the ability of 35g of whey, casein, or wheat protein to stimulate muscle protein synthesis was measured in 60 healthy older men (70 -72 years old).

The results from the study, shown in the figure above, show that 35g of wheat protein had little to no impact on muscle protein synthesis beyond the baseline rate (i.e., resting rate before a meal).The subjects who consumed whey or casein proteins (which are animal derived) showed an increase in muscle synthetic response. The higher response to the consumption of the animal-derived whey and casein proteins is attributable to the greater content of essential amino acids, and higher overall digestibility which is reflected directly in their protein quality values: wheat=0.48, whey=0.85 and casein=1.17, as measured by DIAAS (Herreman et al., 2020).

The participants needed to eat almost twice as much wheat protein (60g) to see the same response in muscle protein synthesis as 35g of whey or casein. This would be a difficult amount of protein to eat in one sitting, especially in older individuals where diminished appetite is common. Another consideration is the environmental impact of growing the quantity of plant protein required to maintain this increased level of consumption which could counteract some of the benefits attributed to switching from animal protein to plant protein.

How can we improve the ability of plant proteins to support muscle health during ageing?

Choose the right protein source

Plant proteins with high protein quality scores are a good place to start when it comes to active ageing. Soy protein has a DIAAS value of 0.9, which is higher than most other plant sources. Soy protein has been shown to efficiently meet the body’s need to form new muscle but some negative perceptions around soy’s role in health, many of which are unwarranted, has led some consumers to stop consuming soy protein and search for other alternatives.

Pea protein (DIAAS value of 0.71) and rice protein (DIAAS value of 0.47) have become more prevalent and application of these ingredients is increasing over recent years. Emerging plant proteins of nutritional interest also include potato (DIAAS value of 1), pseudo-cereals (such as quinoa, amaranth and buckwheat), legumes (lentils, chickpeas and lupin) and oilseeds (canola, rapeseed and hemp) due to their levels of essential amino acids (Herreman et al., 2020; Martínez-Villaluenga et al., 2020). Mostly, methionine, cysteine, lysine and leucine are four essential amino acids that cause low DIAAS values for plant proteins and, therefore, limit their nutritional quality (Lonnie et al., 2018).  Much scientific research has been conducted in this area to identify plant protein sources that are more nutritionally complete and have similar levels of these essential amino acids to that of soy and animal-derived proteins.

An alternative to finding a single source of plant protein which can act as complete source of nutrition for the healthy growth and maintenance of muscle in ageing individuals is to modify the physical, chemical or functional nature of plant proteins to optimise the effect they have on muscle growth and repair.

Improve digestibility via processing

One of the major limitations preventing plant proteins from having a high protein quality score is their limited digestibility and bioavailability. Within plants, proteins are usually encased in fibre-rich husks or layers that are very difficult for the body to digest, limiting our access to the protein when we eat it. Additionally, plants contain a range of bio-compounds, termed phytochemicals, which slow or inhibit protein digestion (Lonnie et al., 2018).

Physical processes such as cooking (i.e. heating), extrusion, drying, and enzymatic hydrolysis have all been shown to increase the digestibility of numerous plant proteins (Sá et al., 2019). For example, processing a soy flour into a soy protein isolate increases the PDCAAS score from 0.86 to 1.0. These processes can degrade the bio-compounds that limit digestibility or change the structure of the proteins to make them more accessible to the digestive enzymes in the intestine. These physical processing treatments (i.e. heating, wet fractionation, dry fractionation, drying, etc.,) are commonly used in the enrichment and isolation of plant proteins to produce protein-rich flours (e.g. protein concentrates or isolates), which results in the a large improvement in digestibility.

Blend different plant proteins together to improve amino acid profiles

Since many plant proteins are lacking in just a few essential amino acids, such as cereals being low in lysine and legumes being low in methionine, different plant protein sources can be blended to account for the other’s “amino acid weakness” so to speak. The right blend of rice and pea protein will have sufficient amounts of both lysine and methionine, creating a “complete” protein that is more efficient, gram for gram, at delivering amino acids to our muscles than either protein alone.

Plant-animal protein blends are also a possibility, since the plant-based market has expanded beyond vegans and vegetarians to flexitarians or those just looking to eat more plant-based foods. Blends of plant and animal proteins have already seen some use to enhance the functionality (e.g. solubility, taste, texture) of plant proteins in foods and beverages. A series of studies have tested the ability of milk protein, soy protein and a milk-soy protein blend to stimulate protein synthesis after exercise in both older men and young adults. Results from these studies showed that the muscle protein synthesis rates were higher and remained higher for a longer period of time for the milk-soy protein blend (Borack et al., 2016; Reidy et al., 2014, 2013), suggesting possible health benefits in consuming a plant-animal blend of protein. More research would be needed to fully understand how different protein blends interact and their potential health benefits.

Increase leucine content of plant protein

As mentioned earlier, the amino acid leucine has an important role in activating muscle growth and repair. Many plant proteins contain around 20-30% less leucine than animal proteins, although there are a few plants high in leucine, such as corn, soy, and potato (Herreman et al., 2020).  It stands to reason, then, that adding leucine to plant proteins or breeding plants to contain higher levels of leucine might improve their ability to promote active ageing.

A study by Wall et al. (2013) found that the addition of crystalline leucine (2.5g) to a 20g serving of casein had a greater effect on protein synthesis compared to the consumption of 20g of casein alone. Although this study used animal-sourced protein, it shows that addition of leucine can help overcome the reduced sensitivity of the mTOR system (responsible for initiating muscle growth and repair) that is seen during ageing. A study done in mice found that adding leucine to a wheat protein to match the leucine content typically found in whey protein led to a similar ability to stimulate muscle growth compared to whey (Norton et al., 2012).

Conclusion

To promote active ageing it is key that not only the right quantity of protein is consumed but the quality of the protein should also be considered. There are actionable strategies such as processing, protein blending, or targeting leucine content that can improve the ability of plant proteins to promote active ageing while also addressing growing concerns over the environmental impact of animal proteins.

Read Part 2 of this article: Active Ageing – How Can We Optimise Plant Proteins?

Although the average global life expectancy is now over 70 years, the focus for many people today is not “how old can I live to be?” Instead, the most important question has become “will I be able to do the things I want to do when I am older?” Retaining muscle mass is key for active ageing because it allows us to do the day-to-day activities we want to do, as well as protects us from falls and the associated injuries that can result.

Protein’s role in muscle health might be more than you think

Leucine and insulin are “switches” that activate protein synthesis

Most people think of protein, or the amino acids in protein, as the “building blocks” that our body uses to make muscle, but some amino acids have unique roles in metabolism. Scientists have shown that there is a metabolic “switch”, called mTOR, that signals new muscle production when it’s activated. Think of it as the body’s way to regulate creation or upkeep of muscle by promoting growth mainly when fuel or building blocks are plentiful (protein-rich food), or when the body senses an external need for muscle growth or repair (exercise).

Leucine, an essential amino acid that we must get through our diet, plays an important role in turning this “switch” on. When present alongside insulin, which is a hormone that has a key role in telling the body that fuel is plentiful, leucine will activate the mTOR “switch” to allow for creation of new and upkeep of existing muscle protein (Columbus et al., 2015; Ham et al., 2014).

Our ability to activate muscle growth and repair decreases as we age, leading to a loss in strength and ability to perform physical activities

It has been shown that as we age, our ability to stimulate this mTOR complex is reduced which, in turn, reduces our ability to repair and replace protein in muscle tissue. This is thought to be because of a concept called anabolic resistance, which refers to a decreased sensitivity to insulin throughout the body as we get older (Yoon, 2017).

This helps explain why muscle mass gradually starts to decrease as we get older. After the age of 50, approximately 1% of muscle mass is lost annually.

We lose up to 40% of the cross-sectional area of our muscles between the ages of 20 and 60 years; this continues each year thereafter as a result of developing resistance to protein synthesis stimulation (Vandervoot 2002).

A loss of between 30-50% of our total muscle mass by the age of 80 often translates into a severely reduced ability to perform day-to-day activities like climbing stairs, standing, or walking.

Increased protein intake can counteract age-related muscle loss

Increased protein intake may be able to counteract this decreased insulin sensitivity that comes with ageing, which is called anabolic resistance. For young children and adults (< 30 years), the mTOR complex is mostly stimulated by insulin, meaning less leucine (and thus protein) is required to be consumed in each meal (approx. 1g leucine per meal). As individuals age, the sensitivity of the mTOR complex to insulin reduces and this means that more leucine (2.5g per meal) is required to sufficiently stimulate muscle protein synthesis. This means older adults need to consume more protein than younger adults and children to maintain muscle mass (Yoon, 2017).   According to a study by Moore et al. in 2014, older adults need 68% more protein to maximize protein synthesis (i.e. activate mTOR).

The dietary recommendation for protein intake from the World Health Organisation is 0.8g per kilogram of body weight (BW) per day, which is equivalent to around 64g per day for the average male and 55g per day for the average female. This amount is thought to meet the requirements of healthy adults, but there is scientific debate about whether this recommendation should be greater in older adults.

In a study by Campbell et al. (2001), 10 healthy male individuals, aged between 55-70, were fed the Recommended Daily Allowance (RDA) for protein (0.8g/kg BW) over a 14 week period and the results showed that all subjects, bar one, displayed a loss of muscle in their mid-thigh muscle zones. It was concluded that the RDA may not be adequate for the metabolic and physiological need of virtually all ageing people.

How much more protein is needed?

As a result of studies like the one mentioned, groups such as the European Society for Clinical Nutrition and Metabolism (ESPEN) and the International PROT-AGE Study Group have proposed new recommended requirements for protein intake (Bauer et al., 2013; Deutz et al., 2014). They concluded that for healthy individuals over the age of 65 the recommended dietary protein intake should be increased to 1.0 – 1.2g protein/kg BW.

This would be an increase of 25-50% in the total amount of protein needed in a day for older adults, equivalent to daily intakes 80-93g per day for the average male and 69-83g per day for the average female.

Results from clinical studies have supported these higher recommendations with one such study by Houston et al. (2008) showing that ageing adults who had a daily protein intake of 1.1g protein/kg BW lost 40% less muscle over the course of three years when compared to those who were consuming the RDA value of 0.8g/kg BW.

Opportunity: increase both protein intake and frequency

Despite needing more protein at ages 50+, people generally tend to consume less protein as they age. For example, in the United States, men over 70 years old tend to eat around 20% less protein per day than males who are 19-50 years old.

To help people stay active and independent as they age there’s an opportunity for the food and beverage industry to find ways to add protein into the diets of healthy agers. The amount of leucine needed to activate muscle growth and repair is thought to be equivalent to around 25-30g of high quality protein at a single eating occasion.

This means planning meals, or creating foods and beverages, with 25-30g of protein if they are meant to be consumed alone (e.g. meal replacement beverages), or 10-15g of protein if they are intended to be consumed at a meal or with other foods, is one way to improve muscle health. Choosing flavors and language that appeal specifically to active agers is also important.

Turn the “switch” on multiple times per day – opportunities for breakfast, snacks, and lunch

The more times the mTOR “switch” is activated per day via consuming protein, the more likely we are to grow or retain our muscle mass (Layman 2009). Many people consume low amounts of protein early in the day, such as at breakfast, mid-morning, and lunch, and consume a protein-heavy evening meal. This means that muscle growth is likely to be only activated once per day. By shifting  protein toward the early parts of the day, we can activate this “switch” more times per day, leading to a greater retention of muscle through diet alone.

For some people, this doesn’t necessarily mean consuming more total protein in a day is required. Instead,  it can be effective to redistribute protein intake to be more equal across the dayparts. Adding protein to breakfast foods and mid-morning snacks is a great way to promote more protein intake throughout the day. This could include fortifying common breakfast foods like oatmeal, cereals, yoghurts, etc., or creating new foods or beverages to consume alongside a meal.

This article is the first in a 3-part series covering the impact of social isolation on older adults, addressing the key challenges with solutions for maintaining holistic well-being.

‘Deconditioning’ and the Potential of Muscle Mass Loss

For many people, staying at home may lead to a reduction in time spent walking and engaging in other physical activities. Even relatively short periods (~2 weeks) of very low physical activity / low daily step count (<2,000 – 3,000 steps per day) are known to adversely affect skeletal muscle health (1, 2).

This is of particular concern among older adults who are already at high risk of muscle mass and strength loss.

Unlike younger adults who “bounce back” relatively easily from transient periods of inactivity, recovery in older adults is slow and may be incomplete (1, 2).

As such, these periods of inactivity may have long lasting negative effects on physical function and mobility. Fortunately, simple measures can be taken to minimise the deterioration in muscle health.

Nutrition and Maintaining Muscle Mass for Older Adults

What we eat can help us to maintain our muscle health while remaining at home, especially when combined with resistance exercise.

Protein-rich foods combined with a balanced diet of whole grains, fruits, and vegetables can be an important part of staying healthy and maintaining mobility.

Protein Power

Compared to younger adults, older adults are less efficient at using the protein they eat (found in foods like milk, yoghurt, fish, eggs, meat, beans, nuts) to build new muscle (3).  This means that older adults need more protein in their diets than younger ones and not eating enough protein can contribute to muscle loss.

Expert groups recommend that healthy older adults should consume 1.0 – 1.2 g of protein per kilogram of body weight per day to help preserve muscle (4, 5).

It is particularly important to ensure that older adults continue to consume adequate amounts of protein while isolating.

Some tips include:

• Prioritise protein – as physical activity levels fall during social distancing, the number of calories we burn per day decreases and appetite may also decline.  Prioritising protein-rich foods can help maintain a similar protein intake as before social distancing was introduced.
• Choose high quality sources – higher quality protein sources (e.g. milk, yoghurt, fish, eggs, meat, poultry) are better at stimulating muscle growth compared to lower quality protein sources (6).  Getting a moderate-size serving of high quality protein (25-30 grams) at each meal can improve muscle retention.
• Boost breakfast – breakfast tends to be low in protein, so breakfast foods are an opportunity to boost daily protein intake.  Making porridge with milk rather than water, adding Greek yoghurt to muesli or a smoothie, making an omelette or scrambled eggs, or drinking a glass of milk alongside your meal are all common ways of boosting protein at breakfast.
• Pair protein with exercise – the exercise will make muscles more efficient at using the protein from the meal to build new muscle (7).
• Pre-bed protein – consume a protein-rich snack (e.g. Greek yogurt, cottage cheese) before bed to boost muscle building rates overnight (8).

Calories Count

Studies indicate that consuming either too few or too many calories over several weeks can worsen muscle loss during periods of inactivity (9, 10).

It is normal for people to have a slightly lower appetite when they are less active than usual at home.  However, if appetite drops considerably and results in weight loss, this may accelerate muscle loss.

Small, nourishing snacks frequently throughout the day to give a constant source of protein (e.g. milky drinks, yoghurts, crackers and cheese, custard) and add extra calories to meals (e.g. add milk, skimmed milk powder or cream to soups and mashed potatoes, use full fat dairy products) are two ways to prevent appetite-related weight and muscle loss.

Alternatively, some people may find that, despite decreased activity levels, they are eating more than usual due to boredom or stress. In this case, eating plenty of fruit and vegetables which are low in calories and high in fibre can people stay full.

Prioritising protein-rich foods as discussed above and reducing intake of high-calorie, low protein foods (e.g. biscuits, chocolate, crisps, sweets, butter) can help reduce risk of weight gain.

Physical Activity to Maintain Muscle Mass

Use it or Lose it

The best way to protect muscles against the adverse effects of inactivity is to keep using them.

Resistance exercise, defined as exercising muscles against an external force (e.g. weights, resistance bands, our own body weight), is by far the most potent strategy to maintain muscle mass and strength.

Research has shown that incorporating resistance exercise during periods of reduced activity can attenuate or even abolish the decline in muscle mass (11, 12) and strength (12, 13).

Importantly, even relatively low amounts of resistance exercise appear to be effective once performed regularly (e.g. every other day) (12).

Although most older people may not have access to resistance training equipment at home, body weight exercises can be performed (e.g. sit-to-stands, wall push ups, leg extensions from a chair).

It is important for people to check with their doctor to find out if they have any contra-indications to exercise or if there are any reasons to modify their workout.

Reduce Sedentary Time – Exercise “Snacks”

Engaging in physical tasks around the house each day like gardening, active chores (e.g. sweeping, hoovering) or even walking around while on the telephone can help to minimise inactivity while staying at home, thus reducing the detrimental effect on muscle.

People can also break up prolonged periods of sitting with “exercise snacks”.

Exercise snacks are short bursts of exercise spread throughout the day (e.g. briskly climbing the stairs during ad breaks on TV).

A recent study reported that performing brisk stair climbing (approximately 20 seconds of climbing per “snack”) three times per day, three days per week, improved fitness and leg power in sedentary people (14).

Therefore, exercise snacks like these may help to reduce declines in fitness that occur during periods of inactivity.

Stay on Track

Staying motivated can be difficult, especially when we are isolated at home and separated from loved ones.

To maintain muscle health it is important to keep up the exercise and healthy eating for the duration of isolation.  Some tips to help stay motivated include:

• Set goals about when and where to do the exercise (15)
• Choose activities you enjoy (16)
• Monitor your exercise using diaries or apps or ask a friend or family member to monitor you (15)
• Plan your protein-rich meals for the week ahead and make a shopping list
• Keep a stock of protein-rich foods (e.g. tinned fish, freeze extra poultry, meat and fish)
• Experiment with new protein-rich recipes to keep things interesting

Did you know older adults need much more protein than younger adults to achieve the same rate of muscle growth?

Maintaining muscle mass as we age is key for staying active and independent, and is one of the main considerations for ‘healthy ageing’.

This webinar reviews the state of the science on protein for ageing, and looks at other emerging scientific evidence on plant-based diets, cognition, and more to find creative ways to address needs of healthy agers through product formulation.

Umami is one the primary tastes, but unfortunately the way many people have learned about it is through the negative perception of monosodium glutamate (MSG), the prototypical stimulus of umami taste.

The questions ‘what does MSG do to your body?’ and ‘why is MSG bad for your health’ top the list of MSG-related internet searches, and ‘MSG-free’ claims are becoming more common.

Despite the negative perception of MSG, which is likely undeserved, we are beginning to see a rise in popularity of umami as a flavor.

What many people don’t know is that MSG isn’t the only source of umami flavor.  In fact, foods we eat every day contain this flavor, like mushrooms, tomatoes, or aged cheese.

Our bodies have developed complex machinery to sense umami flavor in food, but why?

In this white paper, we break down the complexities of questions like:

• What is MSG and umami flavor? How do our bodies sense it?
• Where is umami found naturally?
• Why does umami flavor exist in food?

Download the full white paper for free here.

Read on…download the full paper for free here.

New research studies show that rising carbon levels may impact the nutrition of crops globally.

Carbon dioxide is one of just a few resources plants need to grow, along with water and sunlight. As CO2 levels increase in our atmosphere due to global warming, plants will see an abundance of this resource, which can have an impact on how plants grow.

A recent study in the journal Environmental Health Perspective found that rising CO2 levels lead to a decrease in protein content of crops like wheat and rice, which use a type of photosynthesis that is impacted by elevated CO2 levels. Protein deficiency is one of the most common deficiencies in the world, so this decrease in protein content could be especially concerning on developing countries where the bulk of protein intake comes from staple crops like wheat or rice. The study found that protein content of crops which use alternative photosynthesis, like legumes, maize, and sorghum, were not impacted by the elevated CO2 levels, meaning the effects of elevated CO2 levels could be specific to different countries based on which staple crop is most commonly eaten.

Another study in the journal GeoHealth found that elevated CO2 levels can also impact iron content of crops. This impact was seen across many different crops, unlike the protein findings above, meaning the decrease in iron intake would not be isolated to specific countries.Iron deficiency is the most common micronutrient deficiency worldwide, and can have severe impacts on health, so a decrease in iron content of staple crops could lead to even more individuals being put at risk for deficiency.

These findings could have implications for nutrition and may suggest fortification strategies may need to change in the future.

Snacking has become an established part of everyday routine around the world with a growing number of people eating frequently throughout the day instead of sticking to a set schedule or menu.

People snack for many reasons and often it’s not because they’re hungry.  Some are bored, fatigued, or stressed.

Others prefer the smaller size of snacks compared to large meals or they may eat one or more snacks because they don’t have time for a meal.

Snacks bring pleasure with their many different flavours and textures.  Interestingly, a lot of people name nutrition as the top reason for eating snacks.

The term snack can refer not only to the act of eating between meals but also to the types of foods eaten.

Traditional snack foods – crunchy or chewy foods that are high in nutrients to limit such as fat, salt and/or sugar and low in fibre, protein, vitamins and other good-for-you and better-for-you nutrients – do not have a particularly good nutrition reputation.

That is changing as the market grows for traditional snacks with a more healthful profile.

Whether snacking is good or bad depends on several factors, including the types of foods a person chooses.

Fruits, vegetables, cheese, yogurt, or other nutrient-dense foods are preferable to energy-dense, nutrient-poor cakes, cookies, or chips.

Healthy snacks can help by filling in key nutrients such as protein, fibre and calcium that might fall short in main meals alone e.g. an older person or convalescent with a reduced appetite.

Snacks with higher percentages of calories from fruit and nuts, for example, have been shown to improve diet quality while calories from desserts, sweets and sugar-sweetened beverages have the opposite effect.

Snack calories matter.  Snacking can offer a benefit to those who cannot meet their calorie needs in three meals alone, including young children, older adults and athletes.

People who get enough calories from meals, however, can exceed their daily calorie needs if they are also consuming calorie-dense snacks.

Snacking does not have a consistent relationship with body weight in adults or children.  There is conflicting data to support the theory that snacking leads to higher total body fat.

The type of foods chosen and level of calorie contribution from snacks may matter.

Replacing traditional snack foods with nutrient-dense choices such as fruits, vegetables, low-sugar dairy foods and some snack bars could increase nutrient intake without negatively impacting calories.

For those snacking out of hunger, satiating snack foods are highly desirable.  Some snack foods are more filling than others.

Yogurt, for example, has been shown to suppress hunger and dampen appetite for the following meal.

Other high-volume, low-energy-dense foods such as broth-based soups, salads, cereal with lower fat milk, can also satisfy hunger.

Protein, whether in dairy products, meat snacks such as jerky, or higher protein snack bars, can be more filling than sugars and refined carbohydrates.

Consumer demands are continuously evolving and they are now looking for snack foods that are natural, “free from” artificial colours and flavours, preservative-free and non-GMO.

Snackers also look for fibre, protein, whole grains and “energy” and often look to dips, meat snacks, refrigerated dairy products, fresh fruits and vegetables and nuts for healthier snack options.

The industry is responding with a growing number of better-for-you snack foods that are lower in total and saturated fat, sodium and/or sugars; have no trans fat or artificial ingredients; and have higher levels of protein, fibre and other nutrients.

The smartest way to snack is to focus on good-for-you snack choices:

• • Include fruits and vegetables, whole grains and lean animal and plant proteins, along with lower-fat dairy products and nuts and seeds.
  • Choose foods with a high nutrient density and low calorie density.
  • Fill in nutrition gaps with snack foods high in calcium, fibre, protein and/or vitamins and minerals.
  • Limit foods that are high in fat, highly salted, sugary and low in healthful nutrients.
  • Limit night time snacking, including snacking in front of a screen.
  • Plan ahead for healthy snacks on-the-go.