Discussing vegetarian diets can be a lot like discussing politics, I’ve found. There are definitely two camps: those who are ardent supporters of staying away from animal foods as much as possible, and those who insist that humans aren’t meant to subsist on plant foods and that eating animal protein is the way to go. Both sides have valid arguments. Personally, I tend to lean more towards the vegetarian side, in part because I prefer to eat more plant foods and also because there’s research to back up the health claims of vegetarian diets. But, as in most cases, there’s a middle ground.
Last week, I mentioned two studies that supported the merits of a vegetarian diet. There are two additional studies that I wanted to focus on this week.
Low-Carbohydrate Diet and All-Cause and Cause-Specific Mortality
This past September, a study was published in the journal Annals of Internal Medicine. It looked at the link between a low-carbohydrate diet and mortality (death) during 26 years of follow-up with roughly 85,000 women and 20 years in approximately 45,000 men. This was no small-scale study. The subjects were asked to fill out food frequency questionnaires and from these, it was determined whether folks were eating a low-carbohydrate diet and whether it was vegetable based or animal based. I should mention, too, that at baseline, none of the subjects had diabetes, heart disease, or cancer.
Results: The researchers found that the people who ate a low-carbohydrate, animal-based diet were slightly (but statistically significantly) more likely to die from cancer and heart disease; in fact, they were 23% more likely to die during the study. Those people who ate a low-carbohydrate, plant-based diet were 20% less likely to die during the study. So, in other words, those on a low-carbohydrate diet fared pretty well… as long as the protein source came mostly from plants, not animals. Walter Willett, one of the study’s authors and the chair of the Department of Nutrition at the Harvard School of Public Health was quoted as saying, “This comes as no big surprise.” Animal-based diets tend to be high in saturated fat and cholesterol, while plant-based diets contain more of the healthful fats that can lower the risk of heart disease.
Another interesting finding from the study: The researchers don’t believe that low-carbohydrate diets are necessarily “bad.” However, they point out that it’s what you replace those carbs with. Ditching the potatoes, bread, and pasta for beef, lamb, and cheese, for example, isn’t exactly the way to go. They feel that the “Eco-Atkins” diet that I mentioned last week, which emphasizes plant protein foods such as soy and nuts, for example, can be quite healthy. Will it help you live longer? That’s yet to be determined.
Vegetarian Diets and Renal Disease
Switching gears a little bit, a study published in December in the Clinical Journal of the American Society Nephrology had some good news for people with renal (kidney) disease. People with kidney disease often have difficulty clearing the mineral phosphorous from the body. Phosphorous is essential, but as with many nutrients, too much can be harmful. It’s needed to help build strong bones, to carry oxygen to tissues, and for energy. Healthy kidneys help to regulate how much phosphorous is in the body, but when they’re not working so well, levels of this mineral start to build up. This can lead to serious health problems, including bone pain and broken bones and heart problems. People with kidney disease are often put on a low-phosphorous diet (which can be hard to follow) as well as medicines called phosphate binders.
The study mentioned above was small — only nine patients with kidney disease were involved. The patients followed a vegetarian diet or a meat-based diet for one week, and then switched diets 2 to 4 weeks later. Blood and urine tests were done at the end of each diet. Both diets, by the way, had the same amount of protein and phosphorous.
Results: The patients on the vegetarian diet had lower blood phosphorous levels and lost less phosphorous in their urine compared to those on the meat-based diet. The reason may be that the vegetarian diet that they followed included grains. Grains contain a substance called phytate, which is a source of phosphorous but isn’t well absorbed by humans.
This was obviously a very small study, which means a larger one would probably need to be done make concrete recommendations. But the good news is that people with kidney disease who need to limit their phosphorous intake may benefit from more of a plant-based diet. Of course, if you have kidney disease or any other type of medical condition and you’re interested in changing your eating plan, always check with your health-care provider first before doing so, and while you’re at it, meet with a dietitian to make sure that you’re getting the right amount of nutrients.
Not sure if you want to become a vegetarian? That’s OK. But it probably wouldn’t hurt to have a couple of meatless meals during the week. How does black bean soup sound?