[DrQuietus]

Got it. It was a simple if statement with .first like so:

{section name=product loop=$products}
{if $smarty.section.product.first}
{foreach from=$products[product].extra_fields item=extra_field name=field}

{if $extra_field.value ne ''}
<th>{$extra_field.field}</th>
{/if}

{/foreach}
{/if}
{/section}