Aging expert Dr. Stephen Austad of the University of Texas Health Science Center kicked off our research conference’s plenary session on diet, activity, aging and cancer this morning with an overview of the history of the study of calorie restriction (generally defined as a 30 to 40 percent fewer calories without nutrient deficiency).
The fact that calorie restriction has been linked to longevity and cancer prevention in particular has been established for decades in animal models. Dr. Austad began by reviewing that literature, and highlighting more recent work which suggests that the protective effect of calorie restriction on lifespan in these animal models seems to be growing less clear-cut: work with wild mice strongly suggests that genetics play a role in determining whether calorie restriction increases or decreases longevity.
Interestingly, however, the effect of calorie restriction on cancer prevention seems just as strong in wild mice as it is in lab mice, suggesting that diet’s protective role against cancer doesn’t strongly depend on genetics.
But in addition to calorie restriction’s long-term effects, Dr. Austad presented some data on a surprising short-term effect his team has uncovered — and posited an intriguing theory.
He’s found that short-term (1-2 day) fasting of mice seems to increase their ability to defend against some common toxins, including some chemical carcinogens. He offered an evolutionary thesis: “When you’re starving, you become less choosy about what you eat,” he said. “If you’re a mouse, and you can’t get seeds, you might turn to plants that contain toxins, or spoiled and bacteria-laden foods. Nature may have installed a mechanism to bolster the body’s defenses in times of extreme fasting.”
It’s preliminary research, and it’s certainly no reason to starve yourself before travelling to a malaria zone or anything, but it’s a fascinating theory, and one that Dr. Austad hopes to pursue in the future.
AICR’s “It’s Never Too Late” campaign kicked off today, and it was launched in parallel with presentations at our Annual Research Conference on the latest findings in the field of lifestyle links with aging and cancer. The topic is the opening session of the conference and Trygve Tollefsbol, PhD, of the University of Alabama, just presented on how dietary intake – or restriction –influence genes related to both aging and cancer.
Dr. Tollefsbol’s lab is looking at how plant compounds influence cells and for over a decade he has focused on cell’s epigenetic changes, the turning “on” and “off” of genes. Epigenetic is not about what we inherit, but about how what a person eats and other life choices can affect our genes and thereby, affect aging and diseases such as cancer.
Here, Tollefsbol presented his research showing that sulforaphane, a compound in cruciferous vegetables, leads to epigenetic changes that lead to reductions in the amount of telomerase, a protein that produces telomeres. Most cancer cells need telomerase to multiply. Most healthy cells don’t have telomerase. (Telomerase produces telomeres, strips of DNA on the tips of our cells that shorten as we age.)
The amount of sulforaphane Dr. Tollefsbol used in the studies equaled about one cup of broccoli sprouts.
There will be more on his research and cruciferous vegetable research later in the conference. Stay tuned.
Although you can’t control aging – which is the number one risk factor for cancer – the good news is you can make small, everyday changes to prevent or delay cancer at any age. On our Never Too Late web section, folks age 50 and over will find many ideas, strategies and tips designed specifically to help them take important, but achievable, steps toward a healthier lifestyle.
You will probably begin to feel better as you begin to make diet and physical activity changes, too. Many people report having more energy, sleeping better and managing stress more effectively – a win-win situation as you lower your risk for cancer and other chronic diseases.
But maintaining these changes can be challenging. Support and new ideas are crucial in maintaining your good work or for getting back on track.
This is where you can share your successes and challenges, offer encouragement and connect to others working toward the same goal. Use the comment section below to let us know what you’re doing, how you’re progressing, what the challenges are and how you’re overcoming those obstacles.
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