E

very year, Muslims celebrate a whole month of fasting called Ramadhan. In Islam, a Muslim refrains from food, drink, sex and tobacco from pre-dawn (imsak) until dusk (maghrib). This period involves a shift in the pattern of intake from daytime to the hours of darkness.

Every adult man and woman should assume this ritual as a religious obligation, except for the sick, women who are menstruating, pregnant women, breastfeeding mothers and the elderly. Many Muslims also know that fasting is a healthy ritual, but how do they know?

If fasting is conducted like a calorie-restricted diet program, Muslims can acquire several advantages for their own health. Ruqian Wan, from the Laboratory of Neurosciences at the Gerontology Research Center, National Institute on Aging, Baltimore, stated that intermittent fasting improves glucose metabolism, as indicated by lower basal levels of circulating glucose and insulin, but maintains glucose and insulin responses to stress. Wan also concluded that improvements in cardiovascular risk factors and cardiovascular and neuroendocrine stress adaptation occur in response to intermittent fasting.

In term of hypertension, Alan Goldhamer said that almost 90 percent of subjects achieved blood pressure less than 140/90 mmHg (millimeters of mercury) by the end of the treatment program.

During this research, the average reduction in blood pressure was 37/13 mmHg, with the greatest decrease observed in subjects with the most severe hypertension.

Patients with stage 3 of hypertension (those with systolic blood pressure greater than 180 mmHg, diastolic blood pressure greater than 110 mmHg, or both) had an average reduction of 60/17 mmHg at the conclusion of treatment.

Fasting may boost the immune system in several ways, such as elevating macrophage activity; increasing cell-mediated immunity in the form of lymphocytes; increasing immunoglobulin levels; increasing neutrophil bactericidal activity; increasing the breakdown of monocytes and bacterial functions; and enhancing natural killer cell activity.For people who perform fasting for religious reasons, their stress and depression levels may well be reduced.

At the same time, their immune systems will be increased. And all this can be explained by the psycho-humoral-neuro-immunology paradigm.

A study published in the Journal of the American Medical Association, in March 2007, maintained that fasting also regulates insulin and glucose levels by lowering the concentration of insulin, and substances which are related to insulin, such as insulin-like growth factor 1 (IGF-1).

Plasma insulin concentration while fasting decreases by 65 percent and plasma glucose concentration also significantly declined among the calorie-restricted group.

Plasma insulin levels and plasma glucose levels — while fasting — are used as tests to predict diabetes. Researchers also found that excessive calorie restrictions cause malnutrition and can lead to anemia, muscle wasting, weakness, dizziness, lethargy, fatigue, nausea, diarrhea, constipation, gallstones, irritability and depression.

Two very prominent theories of aging are the free radical theory and the glycation theory, both of which can explain how calorie restrictions can work. With high amounts of energy available, mitochondria do not operate very efficiently and generate more superoxide.

With a calorie restriction program on fasting, energy is conserved and there is less free radical generation.

A calorie restricted organism will have less fat and require less energy to support weight, which also means there does not need to be as much glucose in the bloodstream.

Less blood glucose means less glycation of adjacent proteins and less fat to oxidize in the bloodstream that can cause sticky blockages resulting in atherosclerosis.

Type 2 diabetics are people with insulin insensitivities caused by long-term exposure to high blood glucose. Obesity leads to type 2 diabetes. Type 2 diabetes and uncontrolled type 1 diabetes behave in much the same way as “accelerated aging”, due to the above effects. There may even be a continuum between calorie restrictions and the metabolic syndrome.

A small-scale study in the US, at the Washington University’s School of Medicine in St. Louis, studied the effects following a calorie-restricted diet of 10-25 percent less calorie intake than the average western diet. Body mass index (BMI) was significantly lower in the calorie-restricted group when compared with the control group.

It was found that the calorie-restricted group had remarkably low triglyceride levels. In fact, they were as low as the lowest 5 percent of Americans in their 20s. This is more remarkable when it is noted that the calorie-restricted individuals were actually aged between 35 and 82 years of age.

It was also found that the average total cholesterol and LDL (bad) cholesterol levels for calorie-restricted individuals were the equivalent of those found in the lowest 10 percent of normal people in their age group, while the average HDL (good) cholesterol levels for calorie-restricted individuals were very high — in the 85th to 90th percentile range for normal middle-aged US men.

A 2009 research paper showed that a calorie restricted diet can improve memory function in normal to overweight elderly people. The diet also resulted in decreased insulin levels and reduced signs of inflammation. Scientists believe memory improvement during that experiment was caused by the lower insulin levels, because high insulin levels are usually associated with reduced memory and cognitive functions.

However, that relation seems to be age specific since in another study, when analyzing people older than 65, those who were underweight had a higher dementia risk than normal or overweight people, while the latter group had a lower risk regarding the other two conditions.

Fasting can be dangerous, however, when the body is not able to perform gluconeogenesis (the production of glucose). If the body is not in ketosis (burning fat for energy), then the brain and vital organs (which can burn either glucose or ketones), need 800 calories a day to obtain ample glucose.

If fewer than 800 calories a day are consumed, the brain and vital organs are deprived of the necessary glucose, which can cause damage and, in some cases, death. Ideally these diets should be supervised by healthcare practitioners who are experienced with therapeutic fasts.

So, do fasting with careful calorie restrictions, and stay healthy.

The writer graduated from the School of Medicine at the University of Indonesia, Jakarta.