# Diet, Polyphenols, and Human Evolution
## 8 Discussion  
Over the millennia, human beings changed their diet several times and in doing so they increased their potential. With the discovery of fire, the greater extraction of energy from food provided a higher quality diet; the brain increased in size and required even more energy. Humans began to carry out more complex activities, became more organized and managed to move geographically, adapting to each new habitat. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Class of Food**} & \multirow{2}{*}{**Food**} & \multicolumn{2}{c}{**Total Polyphenol**} & \multirow{2}{*}{\begin{tabular}{c} **Serving** \\ **(g or mL)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Total Polyphenol** \\ **Content** \\ **(mg per Serving)** \\ \end{tabular} } & \multicolumn{2}{c}{**Total Antioxidant**} \\  & & & **(g or mL)** & & **(mg per Serving)** & **Activity per Serving \({}^{*}\)** \\ \hline \multirow{8}{*}{Berries} & Blackberry & 260 & 144 & 374 & 821 \\  & Black grape & 169 & 54 & 91 & 92 \\  & Green grape & 15 & 54 & 48 & 66 \\  & Red raspberry & 215 & 144 & 310 & 213 \\  & Strawberry & 235 & 166 & 390 & 480 \\  & Sweet cherry & 274 & 145 & 394 & 249 \\  & Mean & & & 268 & 320 \\ \hline \multirow{2}{*}{Nuts} & Chestnut & 1215 & 19 & 230 & 524 \\  & Hazelnut & 495 & 28 & 138 & 192 \\  & Mean & & & 184 & 358 \\ \hline \multirow{4}{*}{Other fruits} & Apple & 136 & 110 & 149 & 221 \\  & Peach & 59 & 99 & 59 & 105 \\  & Pear & 17 & 138 & 23 & 149 \\  & Mean & & & 77 & 158 \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Permeted \\ beverages \\ \end{tabular} } & Beer & 3.8 & 574 & 22 & 160 \\  & Red wine & 101 & 125 & 126 & 269 \\  & White wine & 10 & 125 & 13 & 40 \\  & Mean & & & 53.7 & 156 \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Olive and \\ derivatives \\ \end{tabular} } & Black olive & 569 & 15 & 85 & 17 \\  & Green olive & 346 & 15 & 52 & 24 \\  & Olive oil & 62 & 16 & 10 & 8.8 \\  & Mean & & & 49 & 16.6 \\ \hline \multirow{4}{*}{Other vegetables} & Asparagus & 29 & 75 & 22 & 56 \\  & Red onion & 168 & 30 & 50 & 31 \\  & White bean & 51 & 35 & 44 & 121 \\  & Mean & & 38.7 & 69.3 \\ \hline \multirow{4}{*}{Roots and tubers} & Carrot & 14 & 54 & 7.6 & 31 \\  & Potato & 28 & 128 & 36 & 69 \\  & Mean & & & 21.8 & 50 \\ \hline \multirow{4}{*}{Cereals} & Whole rye flour & 143 & 20 & 29 & 14 \\  & Whole wheat flour & 71 & 20 & 14 & 18 \\ \cline{1-1}  & Mean & & & 21.5 & 16 \\ \hline \hline \end{tabular} \({}^{*}\)Folin Assay.  
\end{table} 
Table 3: Total polyphenol content in some foods (Modified from [74]). Unsaturated fatty acids, including DHA, are important components of brain structures, but are also a possible preferential target of ROS. These two contrasting aspects of polyunsaturated fatty acids have been identified both during the perinatal period and in old age. The Mediterranean diet seems to be the most suitable to protect polyunsaturated fatty acids given its powerful antioxidant activity. In fact, the Mediterranean diet predominantly includes fruit and vegetables, seeds, and olives, as well as fish. Some vegetable derivatives, such as olive oil and wine, also play a positive role as they are sources of mono- and polyunsaturated fatty acids (olive oil) and polyphenols (derivatives of grapes and olives). Oleic acid is the main fatty acid of olive oil, which however also contributes significantly of polyunsaturated fatty acids in areas where this oil is the most consumed. This was certainly the situation in old times when other vegetables containing polyunsaturated acids (corn, peanut and soy) had not yet been imported in regions with Mediterranean-like diets (1500-1800 AD). The introduction in the Mediterranean diet of foods rich in fatty acids of the omega-3 series and in particular in DHA may have been key to the evolution of the nervous system. The Mediterranean-type diet was the most widespread in the period in which the most advanced civilizations appeared (Table 2).