Pharmacists can reassure patients that nuts can form a healthy - and tasty - part of a balanced diet, says Rod Tucker
It has become enshrined in our minds that it is relatively easy to lose weight; you either eat less or exercise more.
Weight gain becomes a problem as we age, as illustrated by one study which observed that among US adults, the mean weight gain was 0.5 to 1 kg per year from early to middle adulthood.
When trying to lose weight, it’s important to avoid foods that are high in calories and two examples that spring to mind are chocolate and nuts. For instance, even a 100g bar of Cadbury’s dairy milk chocolate contains 534 calories and an equivalent amount of walnuts 616 calories. So, ditching both foods would be a great start in the fight against obesity. Or would it?
Emerging evidence points to the fact that eating more nuts might actually help minimise weight gain. Nuts are packed with nutrients including antioxidants. However, due to the presence of a high level of unsaturated fatty acids, which boosts their calorie content, many people avoid eating nuts, being fearful that they must be fattening.
But it seems that the opposite is true. A review of 33 clinical trials in 2013 found that diets enriched with nuts did not increase body weight. As an example, in one study, participants were asked to consume a 345 calorie portion of almonds every day for 10 weeks in addition to their normal diet. The results showed that consuming these extra calories caused no change in body weight.
The impact of eating nuts was again in the news after a study in the September issue of the BMJ Nutrition, Prevention & Health. Researchers looked at data collected from three longitudinal cohort studies including 21,322 people over a four-year period. The results showed that increasing nut consumption by 0.5 serving/day was associated with a 3% lower risk of becoming obese.
To put this into perspective, the average participant gained 0.32kg per year, whereas for those increasing their nut consumption to a 0.5 serving/day, the average weight gain was 0.19 kg. In the study, a serving was defined as 28g, though in practice this clearly varies depending on the particular nuts.
Exactly how increasing nut consumption does not increase weight, despite the obvious higher calorie intake, may be due to several reasons. Firstly, the high fibre content of nuts might provide a feeling of fulness and there is strong evidence that dietary fibre intake prevents obesity. Secondly, it is possible that the high fatty acid content leads to greater fat burning from body stores.
A further positive effect of increased nut consumption is the potential to lower this risk of developing cardiovascular disease. A review of prospective studies with a 32-year follow-up found that consuming nuts five or more times a week led to a 14% lower risk of cardiovascular disease, irrespective of the type of nut eaten.
It is certainly my experience that patients wishing to lose weight are fearful that eating nuts will make them fat and hence avoid them. It is therefore important that pharmacists reassure patients that despite the high calorie content, nuts can be incorporated into the diet as a healthy snack and that this might even reduce an individual’s risk of cardiovascular disease.