Scientists cite benefits of brown rice

A total of 71 percent ( or 41 million) deaths worldwide were attributed to noncommunicable diseases (NCDs) like cancer, diabetes, and cardiovascular diseases.

In the Philippines, NCDs are responsible for 68 percent of deaths and the probability of dying for those ages 30 and 70, cited by a study published by the Philippine Science Journal in April 2021.

This is because a significant proportion of Filipino adults are exposed to the risk factors for NCDs, particularly an unhealthy diet, composed mainly of refined grains.

An unhealthy diet is associated with metabolic changes that increase the risk of NCDs such as overweight/obesity, high blood pressure, high blood sugar, and dyslipidemia. These are the metabolic risk factors for NCDs.

According to the Expanded National Nutrition Survey, three out of 10 Filipinos are overweight or obese and the trend is increasing, from 31.1 percent in 2015 to 37.2 percent in 2018. Overweight and obese adults have high body fat, which is associated with high blood sugar, dyslipidemia, and high BP.

However, obesity and its related metabolic risk factors of NCDs are largely preventable through a healthy diet for instance. This is the case with rice, the most important staple to more than half of the world's population, especially in Asian countries.

Eating whole grains like brown rice (BR) is a good way to address obesity and its related metabolic risk factors of NCDs but with white rice (WR) deeply embedded in many cultures around the world, including the Philippines, this is quite challenging.

BR has important nutrients present in the bran and germ, which are removed when it undergoes polishing to reveal the white grains. BR is an excellent source of minerals such as iron, zinc, manganese, selenium, and magnesium and contains substantial amounts of vitamins (E and B complex), dietary fiber, unsaturated fats, protein, γ-aminobutyric acid, and other phytochemicals. These minerals, vitamins, and phytonutrients can protect against NCDs.

Scientists from the Philippine Rice Research Institute attest that BR is beneficial to one's health as it contains a lot of vitamins, minerals, and other nutrients.

Although a dietician claimed in her blog that while BR is rich in fiber and magnesium, iron, selenium, and zinc, it does not mean we are getting them all BR is also rich in phytic acid (PA), a carb molecule that has been shown to have antioxidant benefits but it also binds minerals like zinc and iron.

On this point, scientist Rosaly Manaois, of the Rice Chemistry and Food Science Division of PhilRice, said "PA indeed chelates minerals, including calcium, iron, and zinc, inhibiting their absorption in the small intestines. Thus, it is not recommended for vulnerable populations (young children, pregnant and lactating mothers, and others with micronutrient deficiency)."

She adds: "Approaches to reduce the PA in rice are being done, including breeding for low-PA rice and processing techniques, particularly soaking and germination of BR. During germination, the phytase enzyme that hydrolyzes or "degrades" the PA is activated, thus, resulting in improved mineral bioavailability of BR."

Dr. Marissa V. Romero, chief science research specialist of RCFSD, stated that "BR has higher nutrients including minerals but it also contains PA which can chelate minerals. However, based on previous study, since BR has higher mineral content than polished rice despite the presence of PA, the bioavailability of minerals is similar to that of WR."

PhilRice collaborated with the Adventist University of the Philippines in conducting the first randomized controlled investigation on the effects of BR consumption on metabolic risk factors of NCDs in selected overweight and obese Filipino adults.

"More metabolic risk factors were significantly reduced at post-intervention in the BR group [body mass index (BMI), visceral fat (VF), systolic BP (SBP), diastolic BP (DBP), FBS, total cholesterol (TC), and low-density lipoprotein (LDL)] than in the WR group [SBP, DBP, TC, LDL, and triglycerides (TG)]. Most of the parameters in the BR group significantly improved at follow-up including the high-density lipoprotein (HDL). Therefore, the BR-based diet was more effective in improving the metabolic risk factors status than the WR-based diet. Hence, in clinical practice, BR could help ameliorate the metabolic risk factors of NCDs among overweight and obese Filipinos, Romero said citing the study published by the Philippine Journal of Science.

PhilRice promotes BR through its BeRiceponsible campaign, which has involved all sectors to encourage Filipinos to consume it. It is important to make the people fully aware of the benefits of brown rice, not just on health, but also on increasing productivity (because of higher milling yields). The issues on BR, particularly the color, rougher texture compared to WR, shorter shelf life, and higher price need to be fully addressed as well, said Manaois.

Romero said the shift to BR can be done gradually by mixing a small portion of BR to WR at first and subsequently increasing the amount of BR until the complete shift to BR.

Manaois said that since rice is our staple food it is widely available compared with other cereals and grains. Aside from the higher mineral and dietary fiber content, BR also contains some healthy oils, particularly gamma-oryzanol, which has an antioxidant property found only in rice bran.

BR is pricey because of the low supply. "It is not yet readily available because most of the milling facility uses single-pass machines that convert paddy straight to WR. BR also cannot be stored as long as WR due to its shorter shelf-life which makes it more prone to rancidity, explained Romero.

The price of BR could be lowered by increasing the supply in partnership with millers. It also needs to be more available and accessible which is partly addressed by the development and deployment of PhilRice-developed BR machines (portable, village-type, and retrofitted), Romero said.