A personal observation. If I eat of lot of some types of nuts - such as almonds, hazelnuts or walnuts - and the same probably applies to seed mixtures e.g.pumpkin, sesame, sunflower) then it makes me feel generally rather 'off' - a bit queasy and down-spirited.
But this does not seem to apply to brazil nuts, nor to peanuts (which are technically not true 'nuts', but more like a bean).
I speculate that the difference might be related to whether the nuts have a bitter taste; and this may be causal, because bitterness is often the taste of plant toxins - leaves and seeds are often made toxic by plants to deter animals from eating them.
Nuts are seeds and would therefore be expected to be toxic; but they are sometimes edible when they are protected by a shell, because the shell makes a toxin unnecessary.
However, it would not be surprising if some nuts were somewhat toxic- enough to have a subtle deleterious effect when a lot are consumed quickly - which is so easy to do nowadays, when nuts can be bought ready prepared for instant consumption.
Has anyone else had a similar experience?