Q&A with Prof. Jennie Brand-Miller
Professor Jennie Brand-Miller holds a Personal Chair in Human Nutrition in the School of Molecular Bioscience.
Her research focuses on all aspects of carbohydrates - diet and diabetes, the glycemic index of foods, insulin resistance, lactose intolerance and oligosaccharides in infant nutrition.
She holds a special interest in evolutionary nutrition and the diet of Australian Aborigines. Her books about the glycemic index and its relationship to diabetes and weight loss have gained her international acclaim, having sold over two million copies since 1996.
She is currently researching a new and exciting theory called the "Carnivore Connection", which she hopes will displace the "Thrifty Genotype Hypothesis" as the standard explanation of why obesity and diabetes have become so common.
Do you remember when the idea first crystallized that you would become an academic?
I never had a firm view about what I would do after my PhD. When I was close to the end I decided I should start applying for jobs. The very first Saturday I started looking I saw an advertisement for a Lecturer in Nutrition. I had no expectation of ever receiving an offer, but thought it would be good for the practice. I still had six months left on my PhD in any case. Professor Stewart Truswell was the person conducting the interview and a few days later he offered me the job. He even said I could finish my PhD while I lectured.
Who do you think has been your most influential mentor during your scientific career?
I never really had a mentor as such. Certainly Professor Truswell has been a significant influence. Professor Stephen Colaguiri, an endocronologist who worked with my husband, also played a large role. We both shared an interest in diabetes and nutrition. I’ve also been very fortunate to have developed a wide range of contacts outside this School. Mostly, however, I have been driven by my own intellectual curiosity.
Is there a discovery related to your research for which you would you most like to be awarded the Nobel Prize?
We call it the ‘Carnivore Connection’, a rival to the ‘Thrifty Genotype Hypothesis’. Our hypothesis proposes that insulin resistance was an evolutionary advantage that helped us survive and reproduce when carbohydrates were scarce and meat was the basis of our diet. Studies are now being conducted to try to test its validity. A research group at the Museum of Natural History in Paris is working with hunter/gatherer communities in Central Asia to test the Carnivore Connection and already finding some support.
My hope is that the ‘Carnivore Connection’ might one day displace the view that currently dominates much of the thinking on why obesity and diabetes are so common (ie the thrifty gene hypothesis). According to that hypothesis, food was often scarce in the past and it was an evolutionary advantage to be able to lay down fat stores very efficiently when food was plentiful. I think this view is wrong.
What do you think is the most pressing and exciting question in your field?
In recent research, we have shown that high-GI carbohydrates compromise insulin sensitivity and the rate of weight loss, while low GI foods help people lose weight faster as well as maintain the weight loss. This is very exciting because a lot of people are doing research to try to prove us wrong. A few papers will be coming out soon that are very supportive of our view.
What are the most exciting things happening in your lab at the moment?
We are conducting several projects in pregnancy. In a pilot study, we found that a low GI diet helps improve pregnancy outcomes in terms of the baby’s body fat composition. We know that babies over 4 kg often go on to be overweight children who type 2 diabetes as adults. We are also learning about the connections between the blood sugar levels in pregnancy and other undesirable outcomes like caesarean rates and shoulder distocia.
We are also working on an insulin index of foods in collaboration with researchers at Harvard School of Public Health. The aim is to provide a measure that goes beyond the glycemic index and covers all foods, no matter what their nutrient composition. We already have the top 120 foods contributing to energy intake in western diets in the database.
Our collaborators at Harvard and at the Child Nutrition Research Institute in Dortmund, Germany are applying this work to nutritional epidemiology. They are testing to see whether a diet with very high insulin demand is associated with greater levels of body fat, type 2 diabetes and cancer.
Another exciting aspect of our research is that the index might be relevant to the management of type 1 diabetes. At the moment, these individuals adjust their insulin dose on the basis of their intake of carbohydrates. Perhaps, it would be better if they used a dose comparable to normal insulin demand in a healthy person. I currently have a PhD student that is testing that hypothesis and the results to date are very exciting.
We are also beginning new research in an area called ‘nutrigenomics’. The FTO gene has been found to be commonly associated with obesity in western civilisations (40% of individuals have one copy, 16% have two copies). We will use a mouse model of diet in pregnancy to see whether diet composition (including low GI/high GI diets) affects the expression of the FTO gene in the fetus, placenta and offspring.
We are conducting separate studies on another gene related to the starch digestion, the AMY gene which codes for the enzyme, amylase. We alredy know that different people have different numbers of copies of the AMY gene. The question is: do people with more copies digest starch more quickly than people with fewer copies and therefore produce a higher glycemic response?
What do you enjoy most about being in academia?
I enjoy the intellectual stimulation and the recognition and I love reading the journals in my field. My job gives me the ability to mix with students and get to know young adults (other than my kids!). It’s great to have the kind of flexibility and autonomy that allows me to organise my work in a way that suits me best.
What would you do differently if you had your time over?
I would spend more time with my children while they were young. We didn’t have the same allowance for maternity leave that women enjoy today (I had to come back to work full time when they were only 12 weeks old). I’m so pleased that the university has since adopted some of the most progressive policies for maternity leave in the world. I have no other regrets.
What are you most passionate about outside the laboratory?
Frankly, I’m a very lucky person and I just love being alive. I went gradually deaf (which is soul-destroying) but I now have two cochlear implants or bionic ears which allow me to lead a normal life. I also think we are so lucky to live in a country like Australia with a beautiful climate and lifestyle.
I love reading popular science books, particularly about evolution as well as staying up to date with the latest medical breakthroughs. I love travelling and combining holidays with physically active things like skiing and bushwalking.
What achievement outside science are you most proud of?
A happy marriage and two healthy offspring. I’m really proud that my children have grown up into caring, happy and hard-working individuals.