Even for the healthiest, old age brings challenges to both mind and body.
Changes are inevitable and built into the DNA of every cell. The immune system weakens in aging, making the elderly more likely to catch colds, flus, and also deadly infections from germs including Clostridium dificile which are rampant in hospitals. This impaired immunity can even allow disease to take root.
The Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston has been studying how nutrition intersects with aging for over three decades.
A review from the Nutritional Immunology Laboratory there found a critical role for nutrition in preventing infection. Specific to probiotics, beneficial microbes in the colon drop as we age. Old mice produce fewer immune factors than young mice. Probiotics may reverse this: In one study L. bulgaricus and S.thermophilus did the trick; in another it was B. bifidum.
Poor nutrition is common in the elderly whether because of painful teeth, depression, poor absorption or poor menu planning. Malnutrition affects immunity in a big way.
However, probiotics may help restore resistance to infection. One study found that compromised immune responses were improved after consumption of a strain of L. johnsonii for 14 days.
The researchers at Tufts looked at 48 studies and concluded that the elderly yield only as little as one fourth to one half the protective effect of a vaccine as does a young adult getting the same vaccine. Getting a flu vaccine to work better could go a long way in extending immune function in this group.
Extended probiotics supplementation may increase protection:
- For example, nursing home residents showed improved response after 13 weeks of daily supplement of L. casei and S. thermophilus and L. bulgaricus. A shorter period of 7 weeks did not give this protection.
- Tube-fed elderly in the hospital receiving strain s of L. johnsonii and S. thermophilus for 12 weeks had a significantly shorter duration of infection compared to a control group.
- Healthy independent elderly were supplemented with a fermented dairy drink and showed on average 1-1.5 days fewer of all common infectious diseases compared to the placebo group.
- Elderly supplemented with yogurt over several seasons had fewer colds and flu when compared to the placebo group consuming milk.
Foods like yogurt offer many of these needed probiotics. A 2014 study in the American Journal of Clinical Nutrition takes a good look at the use of yogurt in the diets of the elderly.