AWA: Academic Writing at Auckland

Doufu, also known as tofu or bean curd, is a traditional Chinese food that is consumed in many parts of the world. The purpose of this essay is to discuss the importance of doufu to me, the history of doufu and its role within the Chinese culture, the changes in doufu consumption among the Chinese since its discovery up till the modern context, and finally the impact of doufu on the diet and health of the Chinese population.

Doufu is a type of soy product that is made by adding a coagulant (most commonly calcium sulfate) to soymilk, transferring the mixture through a cheese cloth, and then pressing the resulting curds with a small weight to form blocks (Asia Recipe, 2011). Doufu is an important food to me for several reasons. First, it gave me a sense of responsibility from a very young age. When my mother used to come home with the shopping, the first thing I did for her was take the doufu out of the container it was purchased in, put it into our own container, and then immerse it in water to ensure its freshness. This was actually a difficult task, as the doufu blocks were fragile and broke to pieces if it was not handled with care. So, whenever I did this for my mother, I felt like I was doing my part to help her out.

Secondly, doufu is a very versatile food, as it can be boiled, baked, fried, marinated, and so on (Hui Chan Liu, pers.com). Furthermore, it can be added to other foods, such as soups, stir-fries, and many more. When doufu is added to other foods, it absorbs the flavours of the foods it is cooked with. So, doufu can have a variety of flavours depending on what it is cooked with (Hui Chan Liu, pers.com). Due to this, I never get sick of doufu and I always enjoy eating it.

There are many theories regarding the origin of doufu. Some argue that doufu preparation was borrowed from the Buddhist monks or dairying tribes of India, while others argue it was adapted from the Mongolian cheese-making process (Asia Recipe, 2011). Nonetheless, the most popular theory argues that doufu was developed around 164BC by Liu An, a prince of the Han dynasty (China Daily, 2011; Eating China, 2011). Lui An wanted to achieve immortality, or longevity at the least, so he went into the mountains to create immortal pills. However, he accidentally created a tender, white substance by adding gypsum (calcium sulfate) to bean juice. Surprising, the substance smelled appealing and after Lui An convinced the local peasants to taste it, it was found to be delicious. The material was then named doufu and Lui An was dubbed the inventor (China Daily, 2011; Eating China, 2011). As a result of the discovery, Lui An’s town, Huianan, held a doufu festival every September 15^th to celebrate the event (China Daily, 2011).

It is important to note that historical evidence is scarce, so the theories may be nothing more than speculation. However, a stone mural that was unearthed from a Han dynasty tomb in 1960 contains images of a kitchen scene depicting the preparation of doufu, which provides support that doufu originated during the Han dynasty (Needham, 1995). Therefore, the Lui An theory seems to be the most plausible.

As a result of the Lui An theory, Chinese beliefs regarding the role of doufu has been shaped by the stories about Lui An. For example, Sun Taya of the Yuan dynasty wrote that Lui An grew younger, sprouted wings, and flew to heaven after eating doufu. Consequently, doufu in Chinese culture has been regarded as a food that promotes a healthy, long life (Asia Recipe, 2011). However, doufu also plays an important role during certain Chinese events. Since doufu sounds like the Chinese word for happiness and fortune, which are xingfu and caifu respectively, the Chinese believe that having doufu at the dinner table during Chinese new year brings good luck to the family (Hui Chan Liu, pers.com). Moreover, doufu is often taken as a food offering to the graves of deceased family members, as the Chinese believed that the spirits lost their jaws and doufu was soft enough for them to eat. Thus, doufu is also a sign of respect to the deceased in Chinese culture (Hui Chan Liu, pers.com).

After its discovery, doufu rapidly spread beyond Huianan. A major factor that precipitated the initial spread was Buddhism, a philosophy and religion originating around 600BC in India (Patil, 2009). Many schools of Buddhism frowned upon meat eating and encouraged their followers to practice vegetarianism (Patil, 2009). Therefore, when doufu was discovered in 164BC, it was readily accepted among Buddhists because it provided a source of protein to those who followed a vegetarian diet (Wikipedia, 2011). So, as Buddhism spread around China, the consumption of doufu spread with it (Wikipedia, 2011).

However, doufu consumption continued to spread around ancient China even after Buddhism was introduced. The second phase of the spread was precipitated by Chinese celebrities and scholars who popularised doufu and standardised the production technique. For example, Su Dongpo and Lu You, writers of the Song Dynasty, wrote about their liking for doufu and documented the preparation of the doufu dishes they had invented (China Daily, 2011).  More importantly, writers of the Qing Dynasty recorded the story of Emperor Kangxi granting doufu to his high officials instead of gold or jade, which highlighted the value of doufu (China Daily, 2011). Therefore, the stories and writings of celebrities and scholars further facilitated the spread of doufu consumption around ancient China. As the doufu culture spread, people in different areas infused their own flavours and developed their own doufu dishes to suit their tastes. Some doufu dishes that developed include mapo doufu (prepared with chilli sauce), douhua (prepared with sweet syrup), and many more (Hui Chan Liu, pers.com). By the 1800s, doufu was commonly consumed in China (Golbitz, 1995). Eventually, doufu was introduced to other parts of Asia and the West around the 1700s and 1980s respectively (Golbitz, 1995).

Although doufu was already commonly consumed in China around the 1800s, consumption frequency continued to increase up till the modern context. The increase is likely to have coincided with the increase in soy production. Over the previous four decades, the Chinese government placed much importance on nutrition to prevent malnutrition among undeveloped areas and non-communicable diseases among more developed areas (Food and Agriculture Organisation of the United States, 2009). Since soy products were advocated by the government as a healthy food, soybean production expanded in China. As soy production increased, doufu consumption also increased (Li & Fund Research Centre, 2005).

Likewise, the frequency of doufu consumption among Chinese migrants living in Western countries may have also increased up till the modern context. A main contributing factor is the increased media hype regarding the health benefits of soy products, such as doufu, although the evidence supporting such claims are inconclusive (discussed later) (Willet, 2001). Another contributing factor is the innovations in doufu processing, such as packaging and pasteurisation, which have extended the self-life of doufu (Golbitz, 1995). Furthermore, adding doufu to Western dishes expanded the ways in which doufu could be eaten. For example, doufu has been added to burgers, spaghetti, and so on (Clark, 2003). Therefore, the uptake of doufu by Western countries has increased doufu consumption among Chinese migrants.

Today, doufu is the most commonly consumed soy product among the Chinese (FAOUS, 2009). One study of 1,188 Chinese women estimated that the average soy intake was 36.7 grams per day, with doufu making up most of the intake (Liu et al., 2004). Therefore, doufu has had a big impact on the Chinese diet- it has cemented soy as a staple food in the Chinese cuisine as it is consumed almost everyday by Chinese peoples (Liu et al., 2004).

As already mentioned, the media tends to advocate doufu as a healthy food. Such claims have some truth, as doufu provides a range of nutrients. First, doufu provides a rich source of protein. In fact, the role of doufu in China has been likened to the role of meat and dairy products in Western countries, as it provides a source of protein to a population that rarely consumes dairy products and has little arable land that cannot be wasted on growing animals (FAOUS, 2009). Other important nutrients that doufu provides include unsaturated fat, calcium, iron, and phytoestrogens (Willet, 2001). The nutritional value of doufu is derived from its principal ingredient: soybeans (Willet, 2001).

Over the years, there has been much research into the health effects of soy foods, such as doufu. One popular area of study is the effect of soy on menopausal symptoms, particularly hot flushes. Epidemiological evidence has shown that Chinese and Japanese women are one third less likely than Caucasian women to experience hot flushes (Gold et al., 2000). The lower rates of hot flushes among Asian women have largely been attributed to their diet, particularly the high consumption of soy products (Gold et al., 2000). In a review of 19 studies, researchers found that soy consumption was inversely associated with the frequency of hot flushes (Messina & Hughes, 2003). However, evidence is inconclusive, as other studies find no relationship between soy intake and menopausal symptoms (St Germain, Peterson, Robinson, & Alekel, 2001). Therefore, soy may relieve menopausal symptoms, but more evidence is required.

On the other hand, some studies have shown that soy may increases the risk of menopausal-related diseases, such as breast cancer. In a study of Japanese women, researchers found that high doufu intake was associated with an increased risk of breast cancer. However, the study was inconsistent, as high intake of miso soup (another soy product) reduced the risk of breast cancer (Yamamoto, Sobue, Kobayashi, Sasaki, & Tsugane, 2003). These contradictions are also found in the literature. Some studies have found that soy intake reduces the risk of breast cancer. For example, in a meta-analysis of 18 studies, high soy intake was associated with a decreased risk of breast cancer compared to low soy intake among all the studies (Trock, Hilakivi-Clarke, & Clarke, 2006). However, other studies have found no association between soy intake and breast cancer risk, while some have reported that soy intake potentially increases the risk of breast cancer (Tamir et al., 2000). Therefore, more evidence is required on the effects of soy on breast cancer risk.

The effect of soy on cardiovascular health is another widely studied topic. Many researchers believe that the lower rates of cardiovascular diseases among Asian countries compared to Western countries may be related to the high consumption of soy protein, which contributes about 20-60% of the protein intake per day (Barnes, 1998). In a meta-analysis of 38 studies, 34 of the studies reported that replacing animal protein with soy protein reduced cholesterol. Taken as whole, soy consumption reduced total serum cholesterol by 9%, low-density lipoprotein by 13%, and triglycerides by 11% (Anderson, Johnstone, & Cook-Newell, 1995). In another study of 75,000 Chinese women, researchers found an inverse dose-response relationship between soy consumption and risk of coronary heart disease (Zhang et al., 2003). However, such positive findings are contradicted by studies that report soy intake has no effect on cholesterol and cardiovascular disease risk (Hodgson, Puddey, Beilin, Mori, & Croft, 1998). Therefore, soy protein may lower cholesterol levels, but more evidence is required.

Similarly, the research on the effect of soy on other diseases, such as osteoporosis, atherosclerosis, prostate cancer, and so on, is also controversial (Willet, 2001). The conflicting findings in the literature may be related to a variety of factors, such as the dose and duration of soy consumption, the type of soy food studied (eg. fermented versus non-fermented), the way the diseases are measured, and so on (Copeland, 1999). Since the research on the health effects of soy is inconclusive, it is difficult to predict how modern consumption patterns of doufu affect the health of the Chinese population. Consequently, doufu should only be consumed in moderation until more conclusive evidence is developed (Willet, 2001). However, it is important to note that the nutritional value of doufu depends on how it is cooked. For example, fried doufu is likely to contain more fat (due to the frying oil) than fresh or boiled doufu (Willet, 2001). Nonetheless, despite the controversy over the health effects of doufu, doufu is a healthier source of protein than animal protein, as it is lower in calories, has less saturated fat, and no cholesterol. Therefore, doufu may be a healthier alternative to meat (Willet, 2001).

Overall, doufu is a type of soy food theorized to have been discovered in China around 164BC by Lui An. Since the discovery of doufu, the consumption patterns have increased as a result of Buddhism, Chinese scholars and celebrities, the expansion of soy production, media hype over the health benefits of soy, innovations to extend the shelf-life of doufu, and the addition of doufu to Western dishes. Although doufu is frequently consumed among the Chinese, the health effects on the population are unclear as the literature on the health effects of soy is inconsistent, which is the principal ingredient in doufu. Consequently, doufu should only be consumed in moderation until more conclusive evidence is developed.

References

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