Yogurt: Nutrition to support healthy ageing
Dr. Brendan Egan, discusses how appropriate nutrition is central to healthy ageing.
What do we mean by healthy ageing?
Healthy ageing is about growing old in absence of (or at least limiting the extent of) major diseases associated with the Western lifestyle such as heart disease, stroke, cancer and diabetes. Data from the Central Statistics Office suggest that by 2050 there will be almost 1.5 million over 65s (20 to 25% of the projected population), half a million of whom will be over 80 years of age. At the same time, life expectancy in Ireland will rise to 85 years in men and almost 89 years in women. Although we are now living longer as a population, there is a major healthcare burden, both global and personal, associated living longer if these years are in poor health.
However, for a variety of aspects of health and fitness, most of us will have reached our peak by about 35 years of age, and so a proactive approach to healthy ageing should focus on maximising that initial peak, trying to maintain that peak as we enter middle age, and later trying to reduce the inevitable declines that accompany older age. Nutrition and physical activity obviously play key roles in these strategies.
What is the role of nutrition in healthy ageing?
Lifestyle patterns including dietary overindulgence and excess calorie intake resulting in increase risk of cancer, obesity, and type 2 diabetes, should obviously be avoided. Highly-processed refined carbohydrates, most junk food and processed meats are the foods associated with the greatest threat to good health. For positive effects, it is useful to think of nutrition from two perspectives: first, the long-term dietary habits that can reduce the risk of developing certain diseases, or second, how we can alter our nutrition habits as part of therapy for a disease. Examples of the former would be the association of high intakes of processed meat with development of certain cancers, or a diet rich in fibre, fruit and vegetables being protective against these diseases, whereas examples of the latter would be reducing the intake of sugary carbohydrate sources in type 2 diabetes, or increasing protein intake as a means to reduce loss of muscle size and function with ageing.
Yogurt: a nutrition powerhouse to support healthy ageing
Much of the nutrition advice for healthy ageing tends to focus on the intake of protein given a strong link between inadequate protein intake and this loss of muscle with age. As a result, the daily quantity of protein recommended for older adults is 1.2 grams of protein per kilogram of body mass, which is 50% greater than the current EU recommended daily allowance (RDA) for the average adult of 0.83 g/kg.
Yogurt and other forms of dairy are rich in protein and are said to be of higher ‘quality’ in terms of their benefits to muscle size and function. This because dairy is the richest dietary source of an amino acid (or building block of protein) named leucine, which is key to the growth-promoting properties of protein.
In a typical plain natural yogurt, the quantity of protein is generally 4 to 6 grams per 100 grams of yogurt. However, in newer yogurt varieties such as high protein strained Greek-style yogurt, this quantity can be as much as 10 grams per 100 grams of yogurt. Therefore, a medium-sized pot of plain yogurt (125 grams) or high protein yogurt (150 grams) provides ~ 7 and 15 grams of protein respectively. One recommendation is that we should aim for about 20 to 30 g of protein at each meal, so clearly a portion of yogurt accompanying breakfast or lunch, or even as a snack, can serve as an excellent means to meet this guideline.
Protein is just one of many nutrients found in yogurt. Other nutrients present include calcium and conjugated linoleic acid (CLA), and fat-soluble vitamins such as vitamin K2. These are key nutrients thought to support healthy ageing. Perhaps then it is unsurprising that a higher intake of yogurt is also associated with reduced likelihood for type 2 diabetes. For example, a daily serving of yogurt, but not other forms of dairy, is associated with a 28% reduction in diabetes risk. Similarly, while consumption of dairy products is generally better than supplementing with calcium alone for bone health, and yogurt, but not other forms of dairy, have been shown to be protective against hip fracture.
While there is much still to learn, clearly yogurt shows a lot of promise as a food to be consumed regularly as part of any pro-active approach to healthy ageing.