"So in the same way that you invest in machines and technology and other goods that create your wealth, you certainly have to invest in the people that you have as your staff".
Invest now in improved health in the developing world, and you will reap massive returns later.
"If you invest in health, you increase economic growth and economic development," Dr Brundtland said.
And this, she argued, is true both for companies motivated by profits and for struggling nations trying to escape poverty.
"Enlightened self interest compels both industrialised country governments and private corporations to do what it takes to drastically reduce the current burden of disease in the developing world," Dr Brundtland said.
Healthy workers are efficient workers
"The people that you have as your staff in your company are of course an investment. You train them, you need them. If they are healthy, they will be at work and they will be more productive," Dr Brundtland reasoned.
"So in the same way that you invest in machines and technology and other goods that create your wealth, you certainly have to invest in the people that you have as your staff".
Personnel managers in the political West, which comprises the rich countries in the world, have known this for a long time.
Now, says Dr Brundtland, the message is beginning to reach companies in Africa, South America and Asia as well.
Many European and US companies operating in these regions are beginning to invest in their staff, in their staff's families, and in the communities in which they work, she said.
New markets
"A healthy environment and more healthy staff is an asset for the company. Not only for their image, but even in more complete terms in the way they are able to make profits," Dr Brundtland said.
So investing in health is not about squeezing more work out of labourers in poor countries.
"When poor people continue to be poor, they don't contribute to the market. So its not only a direct investment in healthier people who are more productive. You also create a market which, globally, is important."
Sick Africa
One such massive market could have been created in Africa by tackling malaria as soon as medication and pesticides made this easier. The failure to do so in the 1970s was a lost opportunity, Dr Brundtland argued.
"One can calculate that the GDP of Africa could have been $100bn higher than it is today because the drain on the African economies from malaria alone is immense," Dr Brundtland said.
Compare that to the estimated $1bn per year that the WHO estimates is required to tackle malaria, and the economic benefits become obvious.
These days, the additional drain of HIV and Aids are burdening the African economies.
The consequent loss of young, sometimes educated, people is an economic as well as a human loss.
Pharmaceutical industry
Dr Brundtland would like to see the global drugs industry play an important role.
She accepts that they need to retain their intellectual property rights and patents to fund new research.
Therefore, she wants the WHO to work with the World Trade Organisation (WTO) to develop an international framework where patents are protected in countries where drugs could be sold at a profit.
But these same drugs should be provided for free or at cost to poor countries.
"You still could keep the incentives for the pharmaceutical companies, because those incentives come from the richer markets where people have the ability to pay," she said.
Reaching the poor
However, even when drugs are free or very cheap, they often fail to reach the poor people who need them.
The cost of distributing the drugs must be borne by the international community.
And the cash may be on its way:
Both the European Commission and the leaders of the world's richest countries have now agreed to targets relating to the reduction in disease.
"I would be surprised if we will not see commitments of substantial amounts of funds by the time the G8 leaders meet again in Genoa in July," Dr Brundtland said.