Today we started the scientific sessions of the sixth International Congress on Vegetarian Nutrition with an interesting keynote speaker, David Jacobs, Ph.D., the Mayo Professor of Public Health at the University of Minnesota. He decried the tendency of science to be reductionist and in particular regarding nutrition. Food, not nutrients, is the fundamental unit and diet patterns are more important than lists of nutrient targets because nutrients act synergistically, not in isolation. Food synergy is concerted action—multiple constituents in each food and multiple foods in a dietary pattern act together on health. Therefore, nutrition fosters health through diet and is very different from treating disease. He pointed out that drugs work through pathway interruptions. The actions of food are more complex than drugs, but are investigated as if they were simple, stating that "even a single morsel of food has thousands of compounds." He ended by amending Michael Pollan’s famous dietary recommendations to “eat real foods, mostly plants, not too much, in colorful variety, maximizing nutrients per bite.”
Probably the greatest emphasis in foods today was on research about nuts. Barbara Shukitt-Hale, Ph.D., from Tufts University, presented on the impact of both walnuts and blueberries on the brain in lab rats. Since the brain uses about 20% of the body’s oxygen, it has been assumed that the beneficial results found in many rat studies have been due to the antioxidant and anti-inflammation properties of nuts. She presented a study that suggests that in addition to those indirect actions there are also direct effects on brain signaling, neurogenesis, branching of dendrites and recycling of cell debris (autophagy). The sweet spot in walnut consumption was equivalent in humans to an ounce a day—that amount had better outcomes than either more or fewer nuts. I was very interested to learn that they are starting a blueberry intervention study in humans between 60 and 75 years of age. It’s time that rats stop getting all the benefits.
Jondi Salas-Salvado from Spain pointed out that nuts eaten more than 7 times a week were correlated with an 18% reduction in hypertension. He presented that nuts reduce inflammation, oxidative stress, endothelial function, lower glycemic response, lower cholesterol, lower insulin resistance, waist circumference, and body mass index (BMI). The data on some of these effects was stronger than others, but I opened a package of walnuts—given out by the California Walnut Commission at the conference—and ate them. It was encouraging to hear from several presenters that there is no association with weight gain in the nut studies, instead several of the studies show modest reductions in weight compared to the control group.
Richard Mattes, M.P.H., Ph.D., R.D., of Purdue University, pointed out that probably about 65% of the increase in nut calories are offset by effects on appetite suppression and a compensatory reduction in the intake of other foods. Inefficient absorption of nuts, particularly if not thoroughly masticated can account for another 30% or so.
Sharing from the Harvard Nurses Study, Frank Hu, M.D., Ph.D., M.P.H., stated that their data showed the highest weight gain over a 20-year period was associated with the intake of potato products, sugar sweetened beverages, meats, and processed meats. The lowest weight change was associated with vegetables, whole grains, nuts, fruit and yogurt. Diet quality, he said, is likely to influence diet quantity, so the recommendation should be not just to eat less, but to eat better. His additional comment about nuts was that a handful a day is beneficial for prevention of obesity and type 2 diabetes.
Loma Linda University's Gary Fraser, MBChB, Ph.D., the principle investigator of Adventist Health Study—2 gave his update. They are still collecting data on cancer and he thinks that in one more year they will have a large enough sample size to give some strength to the data. He says it is looking like a vegan diet may reduce the risk of all cancers, but most specifically female organ cancers. All the vegetarians in concert are showing about a 12% reduction in cancer compared to non-vegetarians. He also pointed out that it is not adequate to base a diet pattern only on the presence or absence of meat, eggs, and dairy products. Other food groups have powerful effects on health. Pramil Singh, Dr.P.H., Director of the Center for Health Research at LLU, has been studying vegetarians in India and is now starting to recruit subjects of Asian descent in addition to the 250 that he found in the AHS-2 cohort. It appears that in order to avoid the non-communicable disease epidemic, South Asians need a lower BMI than those of European descent. The World Health Organization has suggested a BMI cut-off point of 23 instead of the more typical 25.
During our break for lunch today, we were able to attend a food demonstration by chefs Cory Gheen and Betty Crocker (yes, it is her real name) and eat lunches based on what they made. My favorite was the sandwich spread made with walnuts, roasted red bell peppers and pomegranate syrup—very Middle Eastern. We had it on crunchy rolls with roasted vegetables—quite delicious. Wendy Bazilian, one of the LLU graduates that I knew from her field project days at St. Helena Health Center presided over the session and I got to speak with her afterwards. She has written a book and been a presence on TV several times recently. I actually saw several former students today who are doing rewarding, challenging, and meaningful work. It is one of the pleasures of an event like this.
We did have a small flurry of excitement in the middle of the academic proceedings. A fire started in LLU's Drayson Center and all 750 of us had to evacuate while Frank Hu from Harvard was in mid-presentation. It turned out that someone had left their jacket in the sauna and it caught fire. Somewhat less exciting, but still pleasurable was the reception which brought the day to an end. Time to regroup for Monday's session.
—Vicki Saunders, M.S., is an instructor of nutrition at Pacific Union College and is the past-president of the Seventh-day Adventist Dietetic Association.
This is a companion discussion topic for the original entry at http://spectrummagazine.org/node/5110