While basic nutritional needs are, by and large, similar among men and women, there is a range of unique considerations that researchers, ingredient suppliers, and the nutraceuticals industry should keep in mind when it comes to the health needs of women across various life stages.

With this in mind, at this year’s Science in Session event held by the Council for Responsible Nutrition in Laguna Niguel, CA, nutrition research experts discussed their perspectives and experiences in the open frontier of women’s health.
 
Across Life’s Stages
Integrative physician Tieraona Low Dog, MD, emphasized that products positioned for women’s health must account for the differences in health issues that women experience, and public health recommendations should not treat women as one homogenous group.
 
“Public health recommendations are not so straightforward, with so many different dietary restrictions people have in their lives. Beyond that, while many women are athletes, or engaging in intense work and exercise, a large swath of women currently have insulin resistance and metabolic syndrome. As we age, our ability to absorb certain nutrients changes, and medications and illnesses seen more commonly later in life can interfere with micronutrients, and vice-versa, because they use the same metabolic pathways.”
 
With rates of deficiency in several micronutrients prevalent among women in the U.S., Low Dog said that one of her top priorities in improving public health for women is more rigor and availability of testing for both micronutrients and inflammatory markers.
 
“It’s thought that some nutrient deficiencies may actually be redistributions of those nutrients to tissues where they’re needed. For example, ferritin levels rise when iron gets low, but bacteria use iron for fuel […] we also think that zinc deficiency, for example, could be the body not making zinc available for bacterial use in some cases. Supplementing certain nutrients such as these in large amounts might or might not be smart, and we need to develop ways to better figure out where the true deficiencies lie,” she said.
 
Citing data from the National Health and Nutrition Examination Survey (NHANES), Low Dog pointed to key areas of concern. Iron remains the most common deficiency in female teens. Even among an adolescent population which included those taking dietary supplements, 30% of girls between the ages of 14 and 18 are at risk for inadequate intake of vitamins C, D, calcium, and magnesium. Iron deficiency in particular, however, is highly prevalent for much longer, with very high rates across an age span of 12-49.
 
The Reproductive Cycle
Low Dog said many nutrients that are vital during the prenatal stage are becoming more scarce in women’s diets due to increasing rates of restrictive eating habits that limit animal food sources.
 
Another under-examined concern for women that requires greater recognition is the interference that oral contraceptives may have with certain nutrients. For instance, they may interfere with the activity of vitamin B6. Meanwhile, there is little mainstream discussion among the majority of women who take these medications about the potential need for supplementation.
 
“Doctors will tell women to ‘just eat right,’ but what about one of these medications which interferes with a person’s absorption or metabolism?” Low Dog said, pointing to emerging research which shows potential promising benefits for B6 supplementation in ameliorating PMS symptoms.
 
Low Dog also mentioned a lack of distinction between folate and folic acid, leading to confusion among clinicians and consumers. With a recommendation to consume 400-800 mcg of folic acid daily for pregnant women, few people understand the daily folate equivalent (DFE). With the emergence of L-methylfolate supplements, the industry still needs to lay the groundwork for establishing its equivalency.
 
Insufficiency rates of both choline and iodine are growing among women of reproductive age and pregnant women in particular, Low Dog said, which is significant because these nutrients are important to maternal health and the health of children.
 
Elders
As women in the U.S. reach their golden years, they become woefully deficient in magnesium, zinc, and vitamin D, Low Dog said. Despite the fact that proton-pump inhibitors (PPIs) are commonly used in older people, little action is being taken to ensure that magnesium absorption remains stable. One in nine women are magnesium deficient, and these deficiencies are linked to insulin resistance, greater disease progression in people with diabetes, and heart disease risk. Zinc insufficiencies occur in 35-45% of the female population over the age of 60, and 29% of nursing home patients are still zinc deficient even one year after taking a multivitamin containing zinc, she noted.
 
Active Women
Abbie Smith-Ryan, PhD, associate professor at the Department of Exercise and Sport Science at the University of North Carolina-Chapel Hill, discussed important factors relating to research on female athletes.
 
Research still needs to clarify a number of key questions in women’s sports nutrition, Smith-Ryan noted, such as the effect that the menstrual cycle has on inflammatory markers, energy expenditure, and protein turnover rates. “There is a huge area of opportunity for research to uncover how both menstruation and contraception can influence nutrition. While these factors don’t change baseline physiological needs, they can provide perturbations, especially when combined with heavy levels of exercise seen in athletes.”
 
Also, in active women, protein kinetics differ, Smith-Ryan said, especially in the luteal phase of ovulation, and anabolic resistance tends to set on with age more quickly. Perimenopause, the 10-12 year hormonal shift which precedes menopause, can cause whole-body protein metabolism changes as well, Smith-Ryan said. She also noted that women are especially sensitive to improvements in carbohydrate-protein ratios for muscle alterations, especially given the role that estrogen plays in promoting insulin sensitivity.
 
“Carbohydrate recommendations need to be made more accurate to the intensity and duration of activity in active women,” she said. “We could debate on what a moderate-carbohydrate diet is, but it really depends on how much exercise you’re doing.”
 
She added that research is revealing clear differences in exercise-induced oxidation between men and women. Exercise in a fasting state, which blunts fat oxidation, may make it even more difficult for women than men to burn fat. She pointed to clinical research suggesting that even a low-calorie protein supplement, rather than fasting, could have a profound benefit to energy expenditure and fat oxidation. “Women are the largest consumers of dietary supplements, and are the most educated, and still want more knowledge. Yet, few supplements are made specifically for women, even when we know that they have key physiological differences […] the time is now to think about active women who don’t know how to prioritize their health and nutrition.”
 
Energy Metabolism
Sai Krupa Das, PhD, a scientist and associate professor at the Jean-Mayer USDA Human Nutrition Research Center on Aging at Tufts University, offered insight on the differences between men and women when it comes to energy metabolism. She also broke down the research and development of the iDiet, a weight management strategy shown to alter responses to healthier food items in scans of the reward center of the brain.
 
Fundamental differences in adiposity, she noted, are important to understanding metabolic and cardiovascular health differences. Men, throughout their lives, tend to have more visceral fat than women, however, during menopause, women begin accruing more fat in their visceral stores despite previously favoring subcutaneous storage, leading to a potential increase in cardiovascular risk around the age of menopause. Differences in energy needs are also critical to investigations of weight management/loss, Das said, noting that by age nine, boys and girls have a 200 kcal difference in energy expenditure, a gap which can become amplified to nearly 1,000 kcals by adulthood.
 
Das noted that controlling weight gain during pregnancy, and the impact that this can have on future outcomes of mothers and children is an area still relatively neglected in the field of women’s nutrition. “Weight gain needs to be optimal because of the multigenerational impact that obesity can have, but most women gain above the recommended weight during pregnancy,” Das said. “Moving away from a mentality of ‘eating for two’ is an important thing to focus on. Health statuses before pregnancy, weight gained during pregnancy, and a mother being in charge of her child’s nutrition leaves mothers with a tri-factorial impact on the health of their children […] obesity begets obesity without intervention.”
 
Further, post-menopause can be a more critical life stage in lifelong weight management than some clinical studies have suggested, Das added. Hormonal changes cause women to begin accruing visceral fat, and these same hormonal changes cause a decrease in energy expenditure and a slowdown of fat oxidation.
 
In the development of the iDiet, a strategy centered around its ease of adherence through long-term craving reductions, Das noted that significant differences in the degrees of cravings experienced made clear that will power is a factor for everyone, but even more so for women. Studies on food cravings also reveal that women are more likely to experience guilt over indulgences, making dietary strategies which reduce this cycle of high importance. “It’s easy to under-expend calories,” Das said. “Between sedentary jobs, automation, and the food environment we live in, along with a lack of knowledge and insufficiencies in willpower, it becomes humbling to understand what it takes to lose weight.”

Click Here to Read Part 2 of Women’s Health and Nutrition Research …