What Harvard Studies Found
A huge study (from Harvard, no less) is telling us that throwing down a handful, or more, of nuts may be one of the healthiest things you can do.
Dr. Ying Bao, of Harvard, said “There’s a general perception that if you eat more nuts you’re going to get fat. Our results show the opposite.” So what’s the deal?
Lower Heart Disease Risk
The study, published in the prestigious New England Journal of Medicine, involved more than 119,000 healthy volunteers. It found that those who regularly consumed at least a one-ounce daily serving of walnuts, almonds, cashews and other tree nuts were 25% less likely to die from heart disease!
Although they took into account factors such as participant’s dietary habits, smoking status, and physical activity level – the study couldn’t entirely rule out all other factors. This study’s findings are also backed by a long line of previous, smaller, studies that also suggest eating nuts confers health benefits. In fact, the FDA had already determined that there was enough evidence to say that eating 1.5 ounces of nuts each day “may reduce the risk of heart disease.”
Lower Mortality Rate
In fact, they had a 20% lower risk of dying from any cause (including cancer, heart disease, respiratory and even type 2 diabetes) during the three-decade-long study compared to those who did not eat nuts. (Results improved as more nuts were consumed, up to 7+ times a week.) The study found that nut eaters enjoyed longer lifespans – even if they did not exercise, avoided fruits and vegetables, and were overweight.1
Senior study author, Dr. Charles S. Fuchs, said, “The reduction in mortality was substantial. I think eating nuts is comparable to other potentially beneficial lifestyle measures like exercise and avoiding obesity and trans fats.”
It appears that nuts, which contain a lot of fiber – have an appetite-suppressing effect. And when your appetite is suppressed, that obviously makes it easier to stick to a diet. Therefore, snacking on nuts usually results in eating less at meal times.2 Adding nuts to the diet also reduces the feelings of deprivation that can accompany long-term dieting. Thanks to their high fiber, fat and protein content, nuts make you feel full and provide you with sustained energy levels.
Evidence links regular nut consumption with greater resting energy expenditure, which is a fancy way of saying, “nuts increase your metabolism”.
Nuts have been found to be quite thermogenic (anything that increases the calories the Basal Metabolic Rate uses), owing at least in part to their high levels of protein and unsaturated fats.
One study analyzed by Mattes and his researchers showed that daily consumption of a moderate amount of nuts over a 19-week period increased BMR by a whopping 11%.3 Eating nuts would burn an extra 166 calories each day – and you would get to enjoy eating a daily dose of nuts.
Inefficient energy absorption
Although nuts are energy-dense (high in calories), they have poor bioaccessibility, meaning that not all of their calories are absorbed. This is especially the case when eating whole nuts as compared to nut butters, implying that some of it has to do with how thoroughly the nuts are chewed. When whole nuts are consumed, much of their caloric value is not absorbed.
In fact, new research shows that 55-75% of the calories in nuts are not fully absorbed by the digestive tract. Nut calories are mostly excreted by your body and this is one of the reasons why nuts have been proven to help with weight loss and maintenance.4
This also applies, specifically, to the lipid fat content in nuts. Research reveals that up to 15% of the lipid content of whole nuts may be lost in your stool.5,6
Dr. Ying Bao, of Harvard, who led the study, said, “I’m fairly confident in our results. We have long known that nuts are nutritious foods filled with folate, potassium, fiber, good monounsaturated fats, and antioxidants.” (And most of us are aware that nut’s unsaturated fatty acids, minerals, and other nutrients lower cholesterol and inflammation. This, alone, will help reduce many potential irritants to the body.)
This is HUGE in Nutritional News!
Nuts have long been known to be healthy but until recently, there were not any studies of this size and quality to provide hard-core evidence to prove it. Research on food (and diets in particular) is especially hard because it is difficult to single out the effectiveness of any one food.
In addition to the Harvard study we just looked at, researchers at Purdue University conducted a review, published in the 2010 Journal of Clinical Nutrition, examining 43 studies, trials and surveys, covering over two hundred thousand human test subjects. They also concluded that nuts are not fattening and have an array of health benefits.
So, in a nutshell… nuts can be added to your diet without the fear of additional weight gain. A small handful eaten as a snack or sprinkled on a salad will boost your resting metabolism, lower your BMI and help you adhere to your diet. Roasted nuts are deep-fried in fattening, unhealthy oils, so instead choose raw, unsalted nuts for the healthiest option (or dry roasted nuts as the next best option). When eaten in moderation, nuts can be an important component of a successful weight loss program.