Twenty one year old Momoyo, from Japan, knows she hasn’t been so healthy since moving to Adelaide for study. She eats hamburgers rather than her mother’s noodles, and she suspects she smokes and drinks too much.

Momoyo is having fun. However, she doesn’t realise that her diet and lifestyle might harm not just her long-term health but the health of her children and grandchildren.

Scientists in the field of epigenetics say that if we damage our health, at any time of life, we’re likely to change the way our genes perform, increasing our risk of diseases such as diabetes, cancer and obesity. And worse, these epigenetic alterations can be passed to our progeny through the protein molecules in our chromosomes.

It seems that we have more DNA instruction than we need, and not all genes are equally ‘active’. For example, liver cells have the same DNA molecule as hair cells, but in liver cells, hair-growing capacity is blocked. This happens when certain molecules attach to genes to nullify one or more of the gene’s capabilities, a process known as methylation.

As we age, our genes tend to become more methylated. They might also become methylated when our bodies are abused- for example, when we smoke, eat badly, or are exposed to dangerous toxins.

Methylation is not necessarily bad, but, when capabilities of parts of genes essential to health are nullified, risk of disease increases.

The long-term impact of gene methylation was demonstrated in a protracted study of a famine in Holland in World War Two. During a time known as the Hungry Winter, children in western Holland tended to be born underweight. Scientists found that, as adults, they were more likely to experience obesity, diabetes and cancer. Intriguingly, their children and grandchildren also tended to have low birth weights and be vulnerable as adults to these afflictions.

In another experiment, fruit flies were exposed to a dangerous toxin that caused a strange growth around their eyes, and their offspring had the same condition for at least 13 generations.

This suggests that humans’ health is at least partly determined by the lifestyles and experiences of their parents and grandparents. Indeed, some scientists believe lifestyle-related diseases such as diabetes, heart disease and obesity are soaring in Australia because successive generations have literally enjoyed the ‘the fat of the land’.

So what should you do if you want to give your descendents the best genetic start in life?

Eat sensibly

Too much high fat food not only results in weight gain but also increases risk of cancer and other illnesses. Breast cancer, for instance, is six times higher in the United States than Japan, and when Japanese migrate to the US, their children’s risk of this disease doubles. A Taiwanese study found that pregnant female mice fed a high fat diet had offspring with twice the risk of breast cancer, even if the youngsters ate a healthy diet itself. But offspring that grew up eating the same high fat diet as their mothers were three times more likely to develop cancers.

Similarly, an Australian lab study found that animals fed a high fat and low nutrition diet while pregnant had offspring prone to diabetes and high blood pressure.

However, it might not be just the quality of food that is important, but also the quantity. Pregnant women may be urged to ‘eat for two’. Yet a study was made of boys in a 19^th Century Swedish village conceived during times when food was abundant. The study found the grandchildren of these boys died, on average, several years younger than boys conceived in so-called normal times.

Adelaide researchers are finding that intensive diet advice, and exercise, during pregnancy, can help women with gestational diabetes to control glucose levels and moderate the weight of their babies, thus benefiting the children long-term.

Meanwhile, a major national project has started to monitor the health of the children of overweight mothers that have successfully restricted weight gain during pregnancy.

However, Professor Julie Owens, from the Research Centre for Reproductive Health, says that there is still not enough evidence to prescribe precisely what, and how much, pregnant women should or shouldn’t eat. Nonetheless, she advises overweight women intending to get pregnant to lose weight and get fit, which at least will improve fertility and make delivery easier.

Don’t smoke

Smoking when young, at a time when the body experiences more epigenetic change, might harm future generations. A 2006 study of 14,000 men in the UK found that fathers who had began smoking before the age of nine had sons with higher body mass index, making them more prone to diabetes and obesity in later life.

A study in Los Angeles has found that children whose grandparents smoked, but whose parents didn’t, had twice the risk of asthma. Children whose grandmothers and mothers had both smoked during their pregnancies had three times this risk. The head of the study concluded that the toxins might methylate genes in the immune system.

Eat more greens and vitamins

There is much debate about how methylated genes might be reactivated, but research suggests getting enough vegetables and vitamins could provide the answer.

For instance, a tumour-suppressor gene known as P16 can be methylated in lung cells through nicotine exposure, increasing their risk of lung cancer. But an American researcher, Steve Belinsky, has found that that consuming green leafy plants, vegetables, folates, folic acids and vitamins A and E could reduce this methylation, and even reactivate P16. Indeed, he concluded that just 12 servings of leafy vegetables a month could reduce DNA methylation in these genes by 20%. And taking multivitamins could reduce the methylation by half.

Similar findings have been made in regard to heart disease.

There is evidence that soy beans and green vegetables such as broccoli have chemicals essential in healthy methylation, that is, positive methylation.

What’s more, in 2003, scientists gave multivitamins and folic acid to pregnant mice that had a gene making them fat, yellow and diabetic. As a result of the treatment, the offspring were born slim, brown and healthy.

No easy solutions

Adelaide cancer researcher Tina Bianco-Miotto says that Australia is facing an obesity epidemic. However, she says that, rather than relying on a pill to solve the problem, people should be encouraged to follow a healthy diet and lifestyle.

The message from the epigenetic scientists is unequivocal. Food, lifestyle and the environment can all modify genes for good or bad.

Be aware of this and heed the scientists’ message and you will unquestionably benefit, as will your offspring, and their offspring. Ignore it and there might, sadly, be a price to be paid.

David is an ESL (English as a Second Language) teacher in Adelaide. His wife is pregnant with their third child, and they researched how their lifestyle and diet influences their children’s health. This article began as a research project for a Professional Writing Advanced Diploma.

References list for epigenetics article


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2. Leak, J 2008 ‘How your behaviour can change your children’s DNA’, Sunday Times, 20 July www.timesonline.co.uk

3. Lo, CY et al. 2009, ‘A maternal high-fat diet during pregnancy results in a greater risk of carcinogen-induced mammary tumors in the female offspring than exposure to a high-fat diet in postnatal life’ International Journal of Cancer, 125(4), pp.767-773

4. Pray, LA 2004, ‘Epigenetics: genome, meet your environment’, The Scientist, 5 July, www.thescientist.com

5. ScienceDaily 2005, ‘Epigenetics means what we eat, how we live and live, alters how our genes behave’, 27 Oct. http://www.sciencedaily

6. Stone, J 2010 ‘Why your DNA isn’t your destiny’, Time, 6 Jan, www.time.com

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8. Walker, BE, et al. 1997, ‘Multigenerational effects of dietary fat carcinogens in mice’, Cancer Research 57, Oct 1, pp.4162-4165