Why Older People Are Often Under-Nourished

This week I want to talk about the importance of good nutrition for older people, as it's something that we may all have to address at some point in our lives — whether that's caring for someone close to us, or looking after ourselves as we age. But while I've often thought about this topic over the years, until I started researching for this article I hadn't actually realised how bad the situation is in many Western countries, including New Zealand. Take a look at these appalling statistics — a recent study of older adults admitted to hospital in Auckland found that almost 75% were either at risk of malnutrition, or already malnourished on admission. I'm going to repeat that — seventy-five percent.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8308886/

Another study from Massey University found that 37% of older New Zealanders living in the community are at risk of malnutrition, with social isolation and living alone identified as significant risk factors.

https://www.massey.ac.nz/about/news/older-people-living-alone-at-high-risk-of-malnutrition/

Think about the consequences of these statistics for a second — aging adults gradually fading away while those around them putting their increasing tiredness, frailty and gradual loss of brain power down to ‘just getting older’. We need to ask ourselves — how can this happen? How do well-meaning families, caring partners, and dedicated residential facilities end up with older people who are chronically under-nourished? Of course, the answer, as is so often the case, is complicated and has many contributing factors; the rising cost of living, social isolation, reduced appetite, and the poor food habits that people simply get stuck in — I'll be exploring each of these in detail in a future post. But today I want to focus on what I believe is the most urgent and least understood aspect of this crisis, and discuss two of the specific nutritional deficiencies that are driving it, and what can practically be done about them. I’m talking about protein and healthy fats.

The protein and B12 problem

Let me start with something that most people, including most doctors, don't fully appreciate: older people need at least as much protein as younger people, not less. This is because as we age, the body becomes less efficient at using the protein we eat — a process called anabolic resistance — meaning that the same amount of protein that would maintain muscle mass in a forty year old won’t do the same job in a seventy year old.

When protein intake is consistently too low, the consequences start to add up quickly. Muscle mass declines — a condition known as sarcopenia — which reduces strength and mobility, and this in turn reduces appetite further, because people who move less tend to feel less hungry. Reduced mobility and appetite can then mean that cooking is more of a chore than a pleasure, and this in turn can lead to a diet that is high in less nutritious, ultra-processed foods, as they are often perceived as being easier to prepare than meals cooked from scratch.

But there is also another consequence of low protein intake that is less well known, and which I find particularly important: its effect on B12 absorption.

Vitamin B12 is essential for nerve function, red blood cell production, and cognitive health — and deficiency is very common in older people. One of the reasons for this has to do with a compound called intrinsic factor, which is a protein produced by the stomach lining that is essential for B12 absorption. Without enough intrinsic factor, B12 simply cannot be absorbed properly, regardless of how much is consumed. However not only does the production of intrinsic factor decline with age, it is also dependant on the consumption of protein — the less protein you eat, the less intrinsic factor you produce. To make things worse, intrinsic factor is further reduced by low stomach acid, which is increasingly common in older people and actually caused by not eating enough protein.

So the result is a vicious cycle. Low protein intake reduces intrinsic factor production. Reduced intrinsic factor means poor B12 absorption. Low B12 causes fatigue, brain fog, and loss of appetite. And loss of appetite can mean even less protein — and round it goes. A huge number of older people are living somewhere in this cycle without ever being aware of it, because the symptoms — tiredness, mild confusion, low energy — can so easily be attributed to aging itself.

Equally damaging is the tendency to stick to either a low-fat diet, which many older people have been told in the past is the healthiest way to eat, or to one high in seed oils, which will be the case if ultra-processed foods make up a significant part of the diet. Truly healthy traditional fats i.e. those found in butter, lard, beef tallow, ghee, olive oil, full-fat dairy and oily fish — are actually essential for absorbing fat-soluble vitamins A, D, E, and K, all of which play important roles in immune function, bone health, and tissue repair. Removing them from the diet doesn't just reduce calorie intake; it reduces the body's ability to absorb and use the nutrients in our food.

What to do — for older people and those who care for them

Here are some practical suggestions that are easily achievable, but which are also relatively easy on the budget:

Prioritise protein at every meal. This doesn’t mean that you have to spend large sums on gourmet meats — just pick relatively cheaper cuts like lamb shoulder, mince, stewing steak, or offal such as liver or kidneys, and be creative in how you cook it. For example you could add some properly prepared and cooked chickpeas to a lamb casserole, have that the first night and then thin with home-made broth to make a soup that lasts for another couple of meals. Beef, lamb or pork mince make delicious meatballs, which again can be served with broth to increase the protein and spread the cost. Chicken livers make fantastic pâté, which served with a slice of traditionally made sourdough bread is a protein-rich lunch, or go with eggs for breakfast, followed by a bowl of full-fat yoghurt or kefir. Fresh fish has now become pretty expensive, but maybe you know someone who catches it themselves? Or you could choose high-quality tinned fish (always in olive oil), tinned cod-livers, which are delicious mashed on toast, or fresh mussels, which are cost-effective and available in most large supermarkets. Always look for specials, and consider buying in bulk and freezing, either in portions or pre-cooked meals.

N.B. Research suggests that spreading protein intake across the day — rather than having most of it at dinner — is more effective for muscle maintenance in older people. A protein-rich breakfast and lunch matter as much as the evening meal.

 Bring back the butter. Yes, really! A pat of butter on vegetables, stirred through mashed potato (or a mixture of mashed potato and kumara), or spread on good sourdough bread is not a dietary indulgence, but rather a source of fat-soluble vitamins that enable you to better absorb many other nutrients. Butter also contains butyric acid, which has now been linked to improved gut health, and lastly but not least, butter just makes food taste so much better! For older people with a reduced appetite, having food that tastes delicious is incredibly important.

Let me know your thoughts by email, and in the next post I'll be looking at the other factors that contribute to under-nutrition in older people — the increasing cost of living, social isolation, and the bad habits that we all fall into but never question.