SIEM REAP —Ros Mom wears socks even on hot days. No one is supposed to see her feet while she is sitting on the bed in her Quonset hut in a small village near Siem Reap, in northwestern Cambodia. Ros Mom lives not far from the ruins of Angkor Wat. But the money brought by 2 million tourists every year has little impact on the economy in the surrounding jungle. The streets around the temple are paved. But the path leading up to Ros Mom's hut is just dirt and sand.

A couple of months ago the mother of four developed an open sore on her left foot because she didn't have enough money to buy insulin to treat her Type-2 diabetes. The monthly prescription of the vital drug costs $25, Ros Mom explains as a squeaky old ventilator churns up the hot air under the corrugated iron of her hut. Only when the ulcer developed did she return to the clinic of the Cambodian Diabetes Society (CDA) to visit her doctor, Lim Keuky.

The clinic is situated on a muddy alleyway of Siem Reap, the capital of Siem Reap province. From here the 80-year-old endocrinologist leads his fight against obesity, diabetes, and the burden of the past.

The Khmer Rouge regime was short, but long enough to cause damage across generations

Approximately 6% of Cambodia's 16.6 million people suffer from diabetes, according to the World Health Organization (WHO). Of those, the vast majority (90%) have the Type-2 variety. More troubling still is that the numbers are rising, particularly among young patients. Compared to other countries, the overall diabetes rate isn't all that high in Cambodia. But it's rising, particularly among young people, says Lim Keuky.

Elsewhere in the world, the typical Type-2 diabetic is old, obese, and is not active enough. But at the CDA clinic on the edge of Siem Reap, Lim Keuky has had to treat more and more patients in their 30s and 40s, many of whom, he notes, who were born when the Khmer Rouge ruled Cambodia and starved, tortured, and massacred millions. A lot of these patients are of normal weight but are unable, nevertheless, to regulate their blood sugar levels.

"The Khmer Rouge regime was short but long enough to cause damage across generations," the doctor says.

Genetic scars

Lim Keuky isn't the only person who connects the horrible experiences under the Pol Pot regime to the suffering his patients experience all these years later. Biochemists in the new field of epigenetics have considered how the environment can influence a person's molecular biology. Hunger, stress, and violence appear to alter how cells interpret a gene's DNA code and thus leave traces behind in the genotype.

The Munich-based doctor and neuroscientist Elisabeth Binder, today the director of the Max Planck Institute for Psychiatry, was able to show several years ago that people who experienced trauma in early childhood also carry this trauma later in life. The damage caused can be like a scars on the genome in the victim, she demonstrated. Not only that, but these epigenetic alterations are also likely to pass on to the next generation.

In Siem Reap, Lim Keuky usually greets people with a handshake rather than putting his palms together in front of his torso as is customary here. It's one of the western mannerisms he picked up while studying in United States and France. After discussing the daily schedule with his coworkers, he sits down, gazes in the distance and says, "I'm here to save lives."

He and his two colleagues handle 1,200 diabetic patients at the clinic they founded in Siem Reap in 2010. That's the most they can do. Their workspace consists of a big room, where the office and the treatment areas are separated by shelves and curtains. Only the bathroom and the cold storage room containing the medication have a door.

Right now it's 9 a.m., and the first 20 patients are already back on their way to work. Most of patients come with relatives, and the room fills up quickly. Everyone stands shoulder-to-shoulder.

Death camps

Cambodia has still not recovered from the atrocities committed by the Khmer Rouge, the guerilla movement that seized power on April 17, 1975, when it captured the capital city, Phnom Penh. The movement wanted to bring communism to Cambodia.

Two days later, its soldiers began to deport urban residents to the countryside, where they were forced to grow rice. The capital was nearly emptied in 24 hours. Many were arrested without a reason. For the soldiers, the orderly arrest of a person sufficed as proof of guilt. For "brother number 1" — Pol Pot — the willpower of the people alone sufficed.

Stress and hunger very often influence the disease risk, as they influence how the cells read the DNA code of the genes.

Lim Keuky had the chance to leave his country before the mass murders began. When he returned, 42 members of his family were dead. The Pol Pot regime raged for just three years, eight months and 20 days. And yet, in that relatively short time, between 1.4 and 2.2 million Cambodians died. There are no exact numbers, despite the fact that the Khmer Rouge held registers of the people exterminated in their death camps. The people who died in the fields or starved remain uncounted.

After a glance at the patient's past, Lim Keuky creates a file for each of them. He wants to know how their grandparents lived, what their parents had to endure during the Khmer regime, if they starved, if they were tortured. The fate of the patient's ancestors tells the doctor about his risks of being diabetic. Stress and hunger very often influence the disease risk, as they influence how the cells read the DNA code of the genes. Embryos and fetuses are particularly sensitive to these signals, which they experience in the womb.

To grow from a single cell to a being constituted of multiple organs, a human being's chemical labels on the DNA activate or deactivate the necessary genes, depending on the organs that are formed. The cells don't actually use all the genes stored in their genome. A nerve cell develops differently from a skin cell. The same mechanism also allows biochemical communication between different generations. Parents, through their own life experiences, can therefore influence the health of their children via molecular biology.

Impoverished patients

A lot of Lim Keuky's patients had never heard of type-2 diabetes before they were diagnosed. And the public health system is not yet focused on this "sugar disease." In recent decades, the government successfully decreased the overall mortality rate among children and has fought infectious diseases like HIV. But diabetes was largely overlooked until 2007, when a WHO study revealed the magnitude of the problem.

Distrust in governmental institutions is commonplace in Cambodia, another legacy of the Khmer regime.

It was at that time that Ros Mom discovered her condition. She didn't trust the public health centers, so she drove 300 kilometers to Phnom Penh to have the diagnosis confirmed by another clinic. Distrust in governmental institutions is commonplace in Cambodia, another legacy, perhaps, of the Khmer regime.

Ros Mom couldn't afford regular appointments at a private clinic, and so an acquaintance recommended she contact Lim Keuky. At the diabetes center in Siem Reap, patients pay what they can. "When they can't afford to give us anything, that's OK," Lim Keuky says. But the patients do still have to pay for their medication.

In public institutions, Cambodians with a card specially issued for the poor can access the medication free of charge. But there are still more patients coming to the center than the endocrinologist and his colleagues can handle. So far, Lim Keuky hasn't been able to convince other doctors to come work in Siem Reap. "Working here is a sacrifice. You barely have a private life," he says.

Short lives

Given all her pains and problems, Ros Mom's medical story is a actually success, though one that could change course if she can't afford medication anymore. According to the Cambodian NGO Mopotsyo, most diabetics in Cambodia live short lives. Out of a group of 500 polled diabetic individuals, the average life expectancy after the illness had been diagnosed was of only four years. Only one in 10 survives more than 10 years.

The high death rate also comes from the fact that for many, the illness goes undiagnosed. Either that, or it's discovered too late. Lim Keuky says that patients usually ignore the first symptoms: thirst, hunger, tiredness or a numbing in their hands and feet. "Without the right treatment at the right time, they die," he explains mater of factly.

Even if the epigenetic program from at least one generation of Cambodians has been mixed up, most diseases can be prevented. The most vulnerable individuals just need to be careful, as Lim Keuky always explains to his patients. Once of the tools he uses is a school textbook in which medial recommendations are presented as comic strips. He has several thousand copies.

"Exercise more, eat less. Listen to the doctor," the last piece of advice reads. Sometimes, it's that easy.