Protein is one of the basic elements that the body needs to build and repair muscles and tissues. It is also involved in the production of enzymes and hormones, supports immunity and a number of vital and nervous functions.
The importance of protein increases with age, when the body gradually begins to lose part of its muscle mass and strength, which makes obtaining a sufficient amount of it an important factor in maintaining movement, balance, and the ability to rely on oneself.
But the relationship between protein and aging seems more complex, as studies have begun in recent years to examine the effect of the amount of protein and the quality of the amino acids it contains on metabolic processes, cell growth, inflammation, and biological aging.
Some research indicates that reducing protein or limiting certain amino acids may be linked to benefits in cellular repair processes and longevity, while other studies confirm the danger of protein deficiency, especially in the elderly, due to its effect on muscles, movement, and the ability to recover from diseases.
Between the desire to slow down aging and the need to protect muscle mass, the question arises about the appropriate amount of protein, who can benefit from reducing it, and who may be harmed by it.
Reduced protein and longevity
In this context, a recent scientific review published in the journal Cell Press Blue on August 17, 2026 indicated that restricting total dietary protein or limiting certain essential amino acids may help improve health and prolong life, similar to some of the benefits associated with calorie restriction.
The review included an analysis of more than 350 scientific studies that addressed the effects of protein restriction and some essential amino acids, such as isoleucine and methionine, on health and aging.
The results showed that reducing protein consumption was associated with a number of positive health effects, including increasing the body’s energy consumption, burning more calories, reducing body fat levels, and improving insulin regulation.
It has also been associated with increased levels of the hormone fibroblast growth factor (FGF21), which is a hormone associated with protecting the body from some of the changes associated with aging.
The review also showed that low-protein diets helped inhibit the mTORC1 pathway and activate the GCN2 pathway, which are two of the most important cellular sensors of nutrients that contribute to regulating cell growth and their response to stress.
According to the researchers, these changes may prompt cells to focus more on repair and maintenance processes rather than continuous growth, and also enhance the process of autophagy, which is a natural mechanism through which cells get rid of damaged and accumulated components.
The review also showed that reducing protein was associated with a decrease in the number of senescent cells, which are damaged cells that stop dividing but do not die, and are associated with chronic inflammation and deterioration that accompanies aging.
Amino acids
The review identified 3 essential amino acids whose reduction may be linked to potential benefits related to longevity: isoleucine, valine, and methionine.
The researchers also pointed out that reducing some non-essential amino acids, such as tyrosine and cysteine, may provide additional health benefits. But this does not mean that reducing all amino acids is beneficial, as the review indicated that some other acids, such as glycine, serine, and proline, may have a beneficial role when provided in sufficient quantities.
Commenting on the results of the review, Dr. Mohamed Hassan, a lecturer at the Faculty of Medicine at Cairo University and a consultant in therapeutic nutrition and medical drugs, says that there is no contradiction between studies that confirm the importance of protein intake and those that examine the benefits of reducing it in order to achieve healthy aging.
He explains that aging is naturally accompanied by a decline in muscle mass, which makes obtaining a sufficient amount of protein important, in conjunction with practicing resistance exercises, especially for the elderly.
Dr. Hassan points out that studies that recommended reducing or restricting the consumption of acids such as isoleucine, methionine, and valine; With the aim of improving metabolism and prolonging lifespan, its results cannot be generalized to all humans. This is due to the fact that a large part of these studies were conducted on animals, and therefore their results cannot be treated as direct nutritional recommendations for humans.
He emphasizes that the quantity and type of protein are very important factors, and that a balance between animal and plant sources is necessary to obtain the nutritional benefits of each.
Elderly food
For her part, Dr. Rania Ahmed Bassiouni, a researcher in the Department of Nutrition and Food Sciences at the Food Industry and Nutrition Research Institute at the National Research Center in Cairo, says that the food of the elderly deserves special attention in terms of type, quantity, and the extent of its ability to meet the body’s needs.
She adds that one of the most important goals of elderly nutrition is to maintain muscle mass and strength. This has a direct impact on movement, balance, and the ability to rely on oneself, and this can be supported by obtaining an appropriate amount of protein, in addition to physical activity and muscle-strengthening exercises.
Bassiouni confirms that it is not recommended to reduce protein in the elderly under the pretext of anti-aging without evaluating the needs of each person, and there is no guaranteed benefit from excessive consumption, as it is currently known that adequate protein supports health with age. Its direct effect on the speed of biological aging is still under research.
Protein deficiency or excess?
Dr. Rania Bassiouni believes that persistent protein deficiency represents the most immediate danger for the elderly, especially for those who suffer from poor appetite or weight loss. Over time, the body may lose part of its muscle mass and strength, movement becomes more difficult, and the risk of falling and the need to help others in daily activities increases.
It may also take a longer period to recover from the disease, especially if the elderly person does not also get enough calories. But the solution does not lie in increasing protein without taking it into account, but rather in determining the appropriate amount according to the needs of each case.
A person with kidney failure, for example, needs an amount commensurate with the stage of the disease and his nutritional status. Because excess may harm it, while severe restriction may lead to malnutrition and further muscle weakness.
Therefore, the needs of each elderly person are determined according to kidney function, comorbidities, and activity level, while monitoring weight, appetite, and muscle strength.
How much protein do elderly people need?
Dr. Rania Bassiouni stresses that not all elderly people need the same amount of protein, as it depends on their health condition, the adequacy of the diet, and the level of activity.
A healthy person usually needs about 1-1.2 grams of protein per kilogram of body weight per day, and this amount may increase during illness or recovery.
Having a chronic disease does not alone mean the need to increase or reduce protein. A diabetic or heart patient, as long as his kidney functions are healthy, does not need to reduce protein just because he has the disease.
The most important thing in these cases is to choose appropriate sources, such as beans, lentils, fish, low-fat poultry, and unsweetened dairy products, while limiting processed meats, salt, and saturated fats. The rest of the diet components should also be adjusted according to the health condition, especially the amount of calories and carbohydrates in diabetics.
The picture is different for people with kidney failure, as it is usually recommended in the middle and advanced stages of the disease, for those not undergoing dialysis, an amount of approximately 0.8 grams of protein per kilogram of body weight per day.
Does protein protect the brain?
Regarding the relationship between protein intake, brain function, and Alzheimer’s prevention, Dr. Rania Bassiouni says that protein plays a role in supporting brain functions. It provides the body with amino acids that are involved in building and repairing tissues, and the formation of some substances responsible for communication between nerve cells.
But increasing the amount of protein in food does not necessarily mean stronger memory or protection against dementia.
Some follow-up studies have indicated that people who eat protein, especially from plant sources such as beans, lentils, and chickpeas, recorded less decline in memory and mental abilities.
However, this result cannot be attributed to protein alone, as people may be more active or follow a better diet in general, and other studies have not found a clear benefit of increasing protein intake, so diets rich in it or its supplements cannot be considered a proven means of preventing Alzheimer’s and other types of dementia.
The priority remains for the elderly person to meet his nutritional needs through a variety of meals, in addition to discovering and treating any nutritional deficiency.
Vitamin B12 and memory
Bassiouni draws attention to the importance of vitamin B12 for the elderly. Because its deficiency may affect the nerves and mental abilities. This deficiency may occur in some elderly people as a result of poor absorption of the vitamin, and here treatment and compensation for the deficiency becomes necessary.
Taking vitamin B12 supplements without a deficiency does not mean providing additional memory protection.
A model for a balanced nutritional day
The researcher in the Department of Nutrition and Food Science proposes a model for a nutritional day for the elderly that combines animal and vegetable protein, and includes:
- Breakfast:
4 tablespoons of fava beans, ground in a blender to make swallowing easier, with a teaspoon of olive oil, a little lemon and cumin, a well-boiled egg, and a quarter to half of my loaf according to the size and needs of the elderly person, in addition to slices of cucumber and tomato or soft vegetables when there is difficulty chewing.
- the lunch:
100-120 grams of grilled mackerel after cooking, with the spines carefully removed, 7 tablespoons of cooked rice, and a medium plate of well-chopped salad. Salad can be replaced with well-cooked vegetables if there are problems with swallowing.
- dinner:
80 grams of low-salt cottage cheese, with a teaspoon of olive oil, and a quarter to half of my loaf, depending on the size of the loaf and the needs of the elderly person, in addition to leafy vegetables such as arugula and lettuce.
These meals combine plant and animal protein, which helps maintain muscles and their strength. It also provides calcium from dairy products, and vitamin D from mackerel to support bone health, in addition to vitamin B12, which is important for nerves and blood cell formation.
It also provides iron and folate, which contribute to the formation of blood cells, while fish provides the body with omega-3 acids, and olive oil provides unsaturated fats, as part of a dietary pattern that supports heart health.
Vegetables, fruits, and beans also provide the body with fiber, which helps in regular bowel movement, in addition to potassium and magnesium, which are involved in muscle and nerve functions.
Vegetables and fruits, depending on their types, provide vitamin C, which helps absorb plant iron, vitamin A compounds that are important for vision and immunity, and vitamin K, which contributes to normal clotting and bone health.
As for bread and rice, they provide the energy needed for daily activity, although the adequacy of these meals remains linked to their quantities, the needs of the elderly person, and his health condition.