Sunday October 28, 2012
Too much dairy, carbs Beans a Boon for people might harm men’s sperm with diabetes, Study Finds (HealthDay News) — Diet can have a notable impact on reproductive health, a group of new studies suggests. One set of findings: The more carbohydrates or diary a man eats, the poorer the quality of his sperm. Similarly, two other studies focused on in vitro fertilization (IVF), and found that women who lowered their carb intake while upping their protein consumption stood better chances of becoming pregnant. While the studies showed an association between diet and fertility, they did not prove any cause-and-effect links. The research was scheduled for presentation this week at the American Society for Reproductive Medicine annual meeting, in San Diego. The pair of IVF studies was led by J. B. Russell, of the division of reproductive endocrinology and infertility at Christiana Care Health Systems in Newark, Del. The two sperm studies were led, respectively, by Dr. Jorge Chavarro, an assistant professor of nutrition and epidemiology, and research fellow Myriam Afeiche, both with the Harvard School of Public Health. “[Recent] studies have found that there appears to be a downward trend in sperm counts throughout the world that spanned the entire 20th century, and more recent studies suggest that it may have continued into the early 21st century,” Chavarro said. “While this is still highly controversial, if a downward trend in sperm counts is indeed taking place, the determinants of these decline are not clear at all.” “One of the proposed hypotheses,” he said, “is that exposure to environmental
factors, particularly environmental estrogens, [namely] ‘female’ hormones, may be the culprit. In addition, this downward trend has also coincided with a large number of changes in the population, some of which are known to affect sperm counts, most notably obesity.” The Harvard team launched two investigations exploring the impact of nutrition on sperm quality. One focused on dairy intake and the other on carb consumption. The carb study involved just under 200 “highly physical active” healthy men between the ages of 18 and 22, most of whom were white. A dietary analysis revealed that carbs accounted for roughly half of all calories consumed among the participants. The team found that carb intake did not appear to have any impact on sperm mobility or shape. However, it did find that the more carbs consumed, the lower the man’s overall sperm count. On the dairy front, the Harvard group found that sperm shape was less likely to be “normal” as men’s dairy intake went up. This connection was particularly strong when full-fat dairy products — such as whole milk, cheese and cream — were consumed. Neither sperm count nor sperm movement seemed to be affected by this relationship. Chavarro said that the results of both studies held up even after accounting for a number of possibly influencing factors, such as body weight, smoking history, and alcohol and caffeine consumption habits. Two other studies focused on women
undergoing in vitro fertilization. In the first instance, 120 women filled out a three-day dietary diary before ever having IVF. The team found that those with a high protein/ low carb intake had a better chance of having their fertilized eggs survive to the so-called blastocyst stage of development and becoming pregnant. A smaller study involved 12 women who had already tried IVF and failed to become pregnant. A similar food diary analysis was conducted before a second round of IVF. The women were counseled to up their protein intake and lower their carb consumption. The result: Successful blastocyst formation jumped from just 19 percent on the first try at IVF to 45 percent following dietary counseling. What’s more, pregnancy rates similarly shot up, from 17 percent to 83 percent. Lona Sandon, an assistant professor of clinical nutrition at the University of Texas Southwestern Dallas, said the findings “make a lot of sense.” “First of all, you would of course expect that something produced by the body would be affected by the quality of nutrition put into it,” Sandon said. “For one thing, we’ve known for years, from the female perspective, that the quality of nutrition that a woman takes in at the time of conception or even before conception has an influence on that child’s health long-term in all sorts of ways. So, it shouldn’t be surprising that nutrition would have an impact on men and the quality of their sperm, which is basically made by protein, or on in vitro pregnancy rates.”
(HealthDay News) People suffering from type 2 diabetes can see an improvement in both their blood sugar levels and blood pressure if they add beans and other legumes to their diet, Canadian researchers report. Chickpeas, lentils and beans are rich in protein and fiber, and these may improve heart health. Because they are low on the glycemic index, a measure of sugar in foods, they may also help control diabetes, the researchers explained. “Legumes, which we always thought were good for the heart, actually are good for the heart in ways we didn’t expect,” said lead researcher Dr. David Jenkins, the Canada Research Chair in Nutrition and Metabolism at the University of Toronto. Among diabetics, “not only did their glucose control become better, but — and this surprised us — it had a significant effect on blood pressure,” he said. Exactly why legumes have this effect on blood sugar and blood pressure isn’t known, Jenkins said. The effect is most likely due to the protein, fiber and minerals they include, he noted. Jenkins recommends adding more legumes to the diet. “They will do well for you,” he said. “They will help you keep your blood pressure down and your blood glucose under control, and help you keep your cholesterol down.” The report was published online Oct. 22 in the Archives of Internal Medicine. For the study, Jenkins’s team randomly assigned 121 patients with type 2 diabetes to eat one cup of legumes a day or whole-wheat products. Over three months, the researchers found that those
eating legumes saw an improvement in their blood sugar of 0.5 compared with 0.3 for those eating whole-wheat products. In addition, those eating legumes saw a reduction in blood pressure of 4.5 mm Hg, compared with a reduction of 2.1 mm Hg among those eating wholewheat products, they found. These improvements in blood pressure and blood sugar add up to better diabetes control and a reduced risk of cardiovascular disease, the researchers said. The study was funded in part by the Saskatchewan Pulse Growers, a nonprofit organization representing pulse-crop farmers in Saskatchewan. Pulse crops include chickpeas, lentils, fava beans and soybeans. Marion Franz, from Nutrition Concepts by Franz Inc., in Minneapolis, and author of an accompanying journal editorial, said “the study clearly shows that legumes are part of a healthy eating pattern.” Franz noted that patients were able to control blood sugar as well with whole wheat as they did with beans, and it may be easier for people to eat three servings of whole wheat a day rather than a cup of beans a day. “What’s really important for people with type 2 diabetes is not really what they eat, but how much they eat,” Franz said. “You can overeat on healthy foods too.” Samantha Heller, an exercise physiologist and clinical nutrition coordinator at the Center for Cancer Care at Griffin Hospital in Derby, Conn., agreed. “For people with type 2 diabetes, beans as part of an overall healthy diet are a great addition,” Heller said. “Not
only do legumes have a relatively low glycemic index, they are loaded with fiber, antioxidants, protein, vitamins and minerals.” Beans provide a hearthealthy, nutritious and affordable alternative to less healthy red and processed meats, Heller said. Several studies suggest a link between eating legumes and lower incidence of type 2 diabetes, cardiovascular disease and cancers, along with better weight management, she said. “While people may not eat a full cup of beans daily, as they did in this small study, including beans in a healthy diet will still provide many health benefits,” Heller said. “Beans are great to use in dips, pasta sauce, salads, burritos, soups, stews and even brownies.” Another expert, who does believe in a low glycemic diet, said patients still need individualized eating plans. “There is no standard recommendation with a low glycemic diet,” said Dr. Minisha Sood, an endocrinologist at Lenox Hill Hospital in New York City. “It is more beneficial to my patients to tailor diet recommendations.” Sood said she looks for specific problem areas, such as portion control or snacking. No single diet or food fits all patients. “ D i e t a r y recommendations should be based on a patient’s lifestyle, food likes and dislikes,” she noted. “It really requires in-depth nutritional counseling.” Although the study found an association between eating legumes and decreased blood sugar and blood pressure, it did not prove a cause-and-effect relationship.