A new study found that increasing the consumption of fruits, specifically pineapples, may help boost the immune system.
Among the Top 10 leading causes of deaths in children in the Philippines, however, five are caused by viral and bacterial infections-diseases that may have been prevented had the children developed stronger immune systems.
The reason, according to a press forum spearheaded by Del Monte Phils. Inc., may be linked to decreased fruit consumption by young Filipinos.
According to the 7th National Nutrition Survey conducted by the Food and Nutrition Research Institute, fruit consumption in school-aged children in the Philippines has decreased by as much as 50 per cent since 1978.
"That's probably because we don't consider fruits as ulam. When we think of food we think of fish, meat and poultry," said Dr. Leonora N. Panlasigui, dean of the School of Nutrition at the Philippine Women's University (PWU).
Panlasigui, along with coauthors Mavil May C. Cervo, Luisito O. Llido and Erniel B. Barrios, conducted a nine-week random, controlled test that examined the effects of canned pineapple consumption on the immunomodulation, nutritional status and physical health of 98 schoolchildren, ages 7 to 8.
The School of Nutrition of the PWU, Clinical Nutrition Services of St. Luke's Medical Center and School of Statistics of the University of the Philippines Diliman jointly conducted the clinical study in 2014.
The children, carefully selected grade-schoolers from Ma. Guerrero Elementary School in Paco, Manila, underwent weekly physical examinations, blood examination and extraction, and were also given journals to record any stomach discomfort.
While Del Monte supplied the canned pineapples, the authors declared that Del Monte Phils. Inc. had no role in study design, execution, data analysis or interpretation.
The schoolchildren were divided into three groups: One group was not provided with pineapples; the second had a serving (one canned pineapples, 140 grams) a day; and the third, two servings.
Nutrition and immunity
The study, published in the Journal of Nutrition and Metabolism in November 2014, established the relationship between macro- and micronutrient deficiencies and immunity. If a child is malnourished, for example, she/he is more prone to pneumonia, diarrhoea, measles and malaria, and vice versa. A sick child's resistance to infection, therefore, is decreased when the nutritional status is also affected.
There are two categories of the immune system: innate and adaptive.
The white blood cells are the body's first line of defence, the innate immune system. They are akin to an army of soldiers on standby to combat viral and bacterial infections within hours of detecting an antigen in the body.
The adaptive immunity, on the other hand, is more of an antigen-specific response, triggered only when the innate immune system has failed to overwhelm the infection. Hence, without a healthy innate immune system, the adaptive immune system will not be able to function as efficiently since it is dependent on the prior activation and participation of the innate immune system.
Panlasigui said the study revealed that canned pineapple consumption has a distinct effect on both the innate and adaptive categories of the immune system. Children who consumed pineapples, she continued, significantly increased their body's granulocytes. Granulocytes make up 60 per cent of the white blood cells.
Granulocytes play an important role in the immune system. They are capable of killing certain tumour cells and are cytotoxic (a killing agent) for both viruses and bacteria, while sparing normal cells.
Data collected from the study found that granulocytes increased by 0.77-26.61 per cent for normal weight subjects and 14.95-34.55 per cent for underweight. Intake of a can or two of pineapples, Panlasigui said, may shorten the duration and incidence of infection, and may increase the production of granulocytes.
"Children who incorporated a canned pineapple a day in their diet demonstrated a recovery time from infection in two to five weeks, while those who consumed two canned pineapples demonstrated a recovery in two to four weeks. Both groups showed increased levels of granulocytes," she said.
But what about all the sugar contained in a can?
Fructose is a sugar that will not make your blood sugar increase as much dramatically. It gradually increases the blood sugar but not as much as sucrose does. Still, 17 g of sugar in a can of pineapple, or more if the child consumes two servings, is acceptable for growing children," Panlasigui said.
Fresh pineapples, however, contain higher amounts of nutrients than their canned counterpart. Panlasigui said that while the canned pineapple still contains all the nutrients found in fresh pineapples, albeit in lesser values, what it provides is convenience and longer shelf life.
Panlasigui also cannot verify as yet if other fruits have a similar effect on the body's production of granulocytes. The study conducted was limited only to pineapples, she said.